Wichita State University Martin 404 Accident Report
The following are Ron's hand-typed cepy from the NTSB accident report investigation supplied by Randy Holder of Parker, CO. Some abbreviation and omissions and lots of typing mistakes are made.
1.1 History of the Flight
On Oct. 2, 1970, two Martin 404 aircraft, N470M and N464M, were to be used to transport the Wichita State University football team and associated personnel to Logan, Utah. Both aircraft were owned by the Jack Richards Aircraft Company, Inc., of Oklahoma City, Oklahoma. The flghtcrews for each aircraft were provided by Golden Eagle Aviation, Inc., also with headquarters in Oklahoma City, Oklahoma. The first officer for N464M, Mr. Ronald G. Skipper, was the president of Golden Eagle Aviation, Inc.. The Captain for N464M, Danny E. Crocker, had been hired by Golden Eagle Aviation, Inc., as a mechanic, and was used only occasionally as a pilot on an "individual contractor" basis, according to Mr. Skipper.
Flight planning for the trip was accomplished by Mr. Ralph Hill, first officer for N470M, and approved by Captain Leland Everett. Weather conditions over the entire route were not considered to be a factor. The flight plan provided for a direct heading between Oklahoma City, Oklahoma, and Wichita, Kansas, and from Wichita to Denver, CO., under Visual Flight Rules (VFR).
From Denver to Logan, Utah, the proposed route of the flight was via Airway Victor 4 to Laramie, Wyo., and thence to Logan by way of Rock Springs, Wyo. This routing would provide an initial flight path parallel to the mountain ranges, allowing ample time for the aircraft to reach a safe en route altitude prior to turning westward over the mountains. A copy of this flight plan was given to First Officer Skipper for the use of the crew on N464M.
On the morning of Oct. 2, 1970, the aircraft were ferried to Wichita, Kansas, arriving at approximately 0750 MDT. Neither aircraft was serviced with fuel or ADI (Anti-detonation injection) fluid there. However, 5 gallons of oil were placed in each engine supply tank on N464M. Catering supplies and football gear were placed on each aircraft, and the passengers boarded.
On departure from Wichita at 0908, there were 36 passengers, a regular crew of three, and a friend of the crew who was to serve as an additional assistant stewardess on N464M. There were 35 passengers and a crew of three on N470M.
Both aircraft proceeded toward Denver, CO., for a planned refueling stop. En route to Denver, the first officer of N464M, while visiting with passengers in the cabin, advised some of them that the flight would take the "scenic route" from Denver to Logan and that he would point out the ski resorts and significant points of interest.
On arrival at Stapleton International Airport, Denver, CO., at appx. 1119, both aircraft were serviced with fuel and oil. Neither alcohol nor ADI fluid was added at this stop. N464M received 12 gallons of oil for each engine and 721 gallons of 100 octane gasoline, which filled the tanks and brought the total fuel load to 1,340 gallons.
Minor maintenance involving the servicing of the main landing gear shock struts on N464M with air and oil was performed. During this time, First Officer Skipper purchased aeronautical sectional charts for the contemplated scenic route. He made the decision to purchase these charts after departure from Wichita. According to FO Skipper, the decision to proceed via the scenic route was made without benefit of any discussion with Capt. Crocker. Capt. Crocker, however, was aware of the intention to depart from the previously prepared flight plan and to proceed on a southwesterly course from Denver. While on the ground at Denver, he had advised Capt. Everett and one of the passengers that they were planning a scenic flight via Loveland Pass.
On departure from Denver, N470M proceeded northbound according to the original flight plan and subsequently landed safely at Logan, Utah.
N464M, with FO Skipper at the control and occupying the left side pilot seat, departed from Rwy 35 at Stapleton at 1229.
When N464M was appx 1/4 to 1/2 mi beyond the departure end of Rwy 35, the ATC Specialist who cleared the flight for takeoff observed that it appeared to be at a fairly low altitude and that an unusual amount of black smoke was coming from the right engine. He advised N464M of his observation and asked if there was a problem. The reply was "No, we're just running a little rich, is all." This was the last communications contact with N464M. The aircraft was last observed by the ATC specialist appx 4 miles north of the departure end of Rwy 35, still on a northerly heading.
With respect to the flightpath after departure from Stapleton, Mr. Skipper testified that there was no specific conversation with Capt. Crocker concerning the route, and that there was no flight planning as to routing other than the intention "to go to Logan direct, or as direct as possible." He stated that after takeoff, the flight proceeded north until they intercepted the airway between Denver and Kremmling, CO, at which point they made a turn to the west on the airway. Thereafter he was given heading directions by Capt. Crocker. He did not recall the exact route, but recalled that the aircraft was turned slightly south, off the airway, to go through a pass in order to follow a valley. He believed that the flight proceeded past Nevadaville and intercepted the valley in the vicinity of Idaho Springs, CO. This flightpath was confirmed by eyewitnesses on the ground who observed the aircraft at various stages in the flight. FO Skipper stated that the flaps were retracted after takeoff and that a climb had been maintained continuously at about 165 MBEP (equates to appx 1400 HP. 404 manual lists 2400 rpm as en route climb setting) power setting on each engine and an indicated airspeed of appx 140 kts. He did not recall the rate of climb.
After intercepting Clear Creek Valley, the flight proceeded along US Hwy 5, slightly south of it, past Georgetown and Silver Plume, toward Loveland Pass. The elevation at Georgetown is 8512 MSL and at Silver Plume is 9118 MSL. Thereafter, the valley floor continues to rise, reaching an elevation of 11,900 feet MSL at Loveland Pass. In the area west of Georgetown, the mountains on either side of Clear Creek valley range from 12,477 MSL to over 13,000 MSL.
Across the end of the valley at the Loveland ski resort area, the ground rises rapidly from the valley floor at 10,600 MSL to 12,700 MSL at the Continental Divide, directly ahead on a westward flight path.
Pilots of an aircraft proceeding westward along Clear Creek Valley at an altitude of 11,000' or less would not have a view of the end of the valley until in the vicinity of Dry Gulch, since it would be cut off by Mt. Sniktau (elev. 13,234').
Mr. Skipper testified that in the vicinity of Dry Gulch, "We were in the valley. It began to look to me as if we were not going to climb so as to have clearance, sufficient clearance, over what I now know to be the Continental Divide ahead of us. I said something to the effect to Capt. Crocker that maybe we should reverse course and gain some altitude. I initiated a turn to the right. We were to the left side slightly of the valley." In continuing testimony, Mr. Skipper said: "I initiated a turn of appx 45 change in heading, a medium bank turn which in my mind is somewhere between 20 and 30 degrees, and as I was rolling out of this turn, Capt. Crocker said 'I've got the airplane.' He initiated a left turn, the aircraft began vibrating, he put the nose down, and shortly thereafter we crashed." He also testified that to his knowledge the aircraft was operating properly up until the moment the vibration occurred.
The aircraft first struck trees at the 10.800' level on Mt. Trelease (elev. 12,477MSL), and came to rest on the ground some 425' beyond the point of initial impact at an elev. of 10,750 ' MSL. Ten person and FO Skipper survived the impact and fire, and were subsequently transported to hospitals in Denver, CO. The time of the crash was appx 1300 according to eyewitnesses and one of the surviving passengers.
Twenty-six eyewitnesses who saw the aircraft at various places along the flightpath provided statements concerning their observations. Most describe the altitude as low or very low. Many were concerned that the aircraft was in danger because of the low altitude over the mountainous terrain. All who observed the aircraft along the last 10 miles of flight in Clear Creek Valley stated that the aircraft was below the mountaintops at all times. A pilot employed by a major airline as a flight engineer observed the aircraft as it passed over Georgetown, CO. He estimated that the aircraft altitude was between 1,000 and 1,500' above Georgetown, and that it appeared to be climbing at a slow airspeed. The engines appeared to be operating normally.
An engineer for the Martin Marietta Corp. also observed the aircraft as it passed over Georgetown, CO. He stated: "I had been a military pilot of multi-engine aircraft during WWII and was awed by the aspect of such a large aircraft cruising up the valley at appx 500 to 1,000' above the terrain. The engines sounded as though they were throttled back and not at high rpm, a condition not in keeping with what would be expected if the aircraft was attempting to clear the Continental Divide. When the plan made a turn to the right, I noticed a mushiness to its flight characteristics. Both engines appeared to be running normally, no smoke, fire or sounds of missing or backfiring." He also stated: "After studying the power curves of this aircraft in the Martin 404 Airplane Flight manual dated Sept. 10. 1951, it appears the plane was well above the critical engine altitude, and it didn't appear to be much above the minimum control speed of 110 mph."
Another witness, a pilot familiar with the Loveland Pass area, observed the aircraft as he was driving eastward on US Hwy 6 about 2 miles east of Dry Gulch. He stated, "Thinking it must be in trouble, I stopped the car to get out and look and listen. My initial and firm feeling was that the plane was in serious trouble as it was below the level of the mountains on either side that form the valley, and I didn't see how it could possibly turn around. Also, it was in nose high attitude and flying at a low rate of speed, obviously straining to gain altitude, but barely keeping up with the rise of terrain. I have driven over this route countless times and know that the steepness of the slope increases radically in only 3 or 4 miles from where he was and that the plane could never make it." He also said that both engines sounded good as the aircraft passed over him, and he did not observe any sign of smoke from either engine.
A witness, located on US Hwy 6 west of the crash site, first observed the aircraft at Dry Gulch. The distance from his location to Dry Gulch was appx 5,000'. A sight line bearing from his point of observation (elev. 10,650'MSL) to where he saw the aircraft measured 4.5degrees upward.
Two witnesses at the 11,900' altitude level on the east side of Loveland Pass were looking down at the aircraft when they observed it make a right turn across the highway just east of Dry Gulch, and a left turn while over the timber on the northwest side of the highway, before crashing into the mountain. A sight line bearing taken from their point of observation tot he point of the turn near Dry Gulch measured 4.25degrees downward. One of these witnesses believed that the propellers stopped revolving immediately prior to contact with the trees. The other believed both props were turning slowly.
Two other witnesses, who were on US Hwy 6 almost directly opposite the subsequent crash site, estimated that the aircraft was only about 100' above the highway as it was coming toward them, and seemed to be losing altitude. The aircraft made a steep turn in front of them, with a bank angle that permitted them to see the tops of the plane's wings an the top of the fuselage. Seconds later, this couple observed the aircraft strike the trees. According to them, there was no smoke coming from the engines. The props were turning slowly.
Two witnesses, one in Georgetown and one located appx 1 and 1/2 miles east of the crash site, reported hearing the engine(s) make a sound similar to backfiring. One of these witnesses testified that when he was halfway between the Bethel and Silver Plume campgrounds, he first saw the aircraft as it passed over the highway. He stopped his car and observed the aircraft through a pair of binoculars. He stated that he read two of the numbers on the aircraft as "4" and "M" when the aircraft was 3/4 to 1 mile past his position, and that these numbers were on the side of the aircraft, on the fuselage, directly forward of the tail section. He testified that he called the FAA FSS in Denver to inform the FAA of his observation. However the telephone logs in the FAA FSS do not reflect that such a call was received.
Eight of the surviving passengers were interviewed. All confirm that the aircraft was continuously below the mountaintops while flying up Clear Creek Valley. None recalled any indications that the engines were not running normally. Several recalled that the aircraft was banked sharply just before impact. The banks upset a stewardess who was serving refreshments to the passengers. Three described the aircraft as shaking or vibrating coincident with, or immediately following, the initiation of the rapid banks. One survivor, who had been standing in the doorway to the pilot's compartment and immediately behind the two pilots, stated that the vibration felt like "a boat slapping water." While he was standing in the doorway, he overheard the pilots discussing the elevation of the mountain peak ahead, and about that time the quick right turn and left turn were made. He did not recall any conversation between the two pilots other than this. The engines sounded normal to him and, until the right turn was initiated, it did not seem to him that the pilots were overly concerned about the flight.
1.2 Injuries to Persons
Post-mortem examination of the captain did not reveal any evidence of pre-existing disease or physical impairment that would have adversely affected the performance of his duties.
1.3 Damage to Aircraft
The aircraft was destroyed by impact with trees and the ground, and the fire which occurred after impact.
1.4 Other Damage
A number of trees up to 2 feet in diameter were destroyed.
1.5 Crew Information
The crewmembers were properly certificated to conduct this flight.
(Ref to appendix B - not in my possession)
1.6 Aircraft Information
N464M, serial No. 14151, was one of 14 Martin 404 aircraft purchased in "as is" condition by the Jack Richards Aircraft Co. on Feb. 16, 1968, pursuant to a purchase agreement with the Fairchild Hiller Corp. Prior to the acquisition by F.H. Cop, N464M had been owned and operated in airline service by Ozark Air Lines, Inc. According to Ozark Air Lines records, N464M was last operated in airline service on a flight terminating in St. Louis, MO, on June7, 1967. Total airframe time then was 38,593:26 hrs; time since overhaul was 13,586:14. The time since overhaul on the left engine was 1011:05 hrs and on the right engine 1747:14 hrs.
N464M subsequently was ferried to Las Vegas, Nevada, where it was to be maintained in operational, or fly-away status. This fly-away storage procedure consisted of regular inspections and engine runups at appx 2-week intervals. The aircraft remained in storage status in Las Vegas until Aug. 30, 1970, at which time an "annual" inspection was partially completed by Mr. Donald R. Sizemore, who held an Inspection Authorization issued by the FAA. Mr. Sizemore signed the aircraft logbooks on Sept 8, 1970, indicating completion of the annual inspection. However, at that time, a required X-ray inspection of the engine mounts had not been completed. Because of this, he held the logbooks in his possession until the X-ray exam could be accomplished. Accordingly, on Sept 14, 1970, the aircraft was flown, pursuant to a ferry permit, from Las Vegas, Nev. to the Jack Richards Aircraft Co. facilities in OKC.
The captain who flew N464M on this ferry trip testified that in his opinion, "... this airplane appeared to be as good as the ones I have been flying every day for an air carrier. It was in good condition."
On Sept. 15,1970, the X-ray inspection was accomplished and the X-rays submitted to Mr. Sizemore for examination. He testified that following his exam, he made appropriate entries in the logbooks. On Sept 201 1970, he released the logbooks to the Jack Richards Aircraft Co. He testified that at that time, he considered the aircraft airworthy and duly licensed for passenger travel.
Since the seat location of all passengers and the location of all baggage could not be determined, the precise center of gravity of the aircraft at impact could not be computed. The gross weight computations are contained in Appendix C (not in my possession).
1.7 Meteorological Information
The weather was clear in the vicinity of the crash site. There was no evidence of turbulence or up-or downdraft activity. Witness estimates of the outdoor temps in the vicinity of the crash site ranged from 55F to 65F. The wind condition at the crash site was estimated to be 10 kts from 350 true. Weather conditions are not considered to be a factor in this accident.
1.8 Aids to Navigation
Not applicable. This flight was under VFR and no plan was filed.
There were no communications with the flight after its departure from the vicinity of Stapleton.
1.10 Aerodrome and Ground Facilities
1.11 Flight Recorders.
Neither a flight recorder nor a cockpit voice recorder was installed on N464M, nor were these required by FAA regulations.
The crash occurred in a heavily wooded area. The trees were up to 2 feet in dia. Many were more than 50 feet high.
The first tree truck by the aircraft was at an elev. of appx 10,800' MSL. Continuing along a magnetic heading of 215, trees were cut off on a descending slope of 4 to 4.5degrees. The swath path indicated a left bank angle of appx 31 degrees. The dist. between the first tree strike and the tail of the wrecked aircraft was 425 feet. First evidence of fire was discovered on the ground at appx 185 feet from the first tree contact. The area of tree wreckage and burnout was appx 350 ft in width at the widest point and 525 feet in length from the first tree strike. The slope of the terrain was 29 to 31 degrees.
Many pieces of the aircraft were torn off as it descended through the trees. The wings were broken off at their attach points. They were torn apart and pieces were found along the tree swath path.
The fuselage was entirely burned down to molten aluminum and twisted longerons and stringers. It lay on its left side. The empennage was severed from the fuselage, 2 feet forward of the aft pressure bulkhead. the vertical stabilizer leaned downhill at an angle of appx 25 degrees. The rudder frame remained, burned out. Portions of the elevator remained with the empennage. Elevator trim and spring tabs were found attached to the remaining elevator. The elevator tab was positioned 3 degrees up.
Control cables lay along the span of the wrecked fuselage. No breaks were discovered.
A portion of the horizontal stabilizer remained with the empennage. The measurement of the horizontal stabilizer jackscrew was 1 - 1/2 inches or equivalent to 3 degrees leading edge up. The horizontal stabilizer adjustment is a function of the selection of takeoff or 12.5degrees of flaps. The interacting mechanism, which causes the stabilizer to move up when 12.5degrees of flaps are selected, was totally destroyed by fire.
A flap actuator was found, minus all connecting hydraulic hoses. It was fully compressed. A second flap actuator minus all hoses was found, measuring 3-3/4" extension. The flaps selector was in the takeoff position. The landing gear handle was in neutral (up)position. The throttle quadrant lay burned out in the wreckage. No control cables remained attached to it. The right mixture control was in auto rich. The left mixture control was free to move to any setting.
Ground fire was of such duration and intensity that virtually no meaningful information could be obtained from the aircraft systems.
Except for a burned out altimeter, and a few battered instruments found separately away from the main wreckage area, no instruments, panels, or any other components were recovered with any pertinent information. The barometric setting on the altimeter was 30.27 inches Hg.
1. On-Site Investigation.
The propellers and engines were found on the side of a mountain and were resting on an incline in excess of 30 degrees.
The left and right engines were found separated from their respective props. The front section cases of both engines were attached to the props. The engine/prop separations occurred at the front accessory support plate and case.
(a) Left Propeller
Two of the three blades remained attached to the prop assembly. These blades were subsequently identified as Nos 1 and 3 blades. the other blade, which was subsequently identified as No. 2 blade, was broken away from the propeller assembly, 18 inches out from the hub. The blade was found about 50 feet below and in line with the separated propeller blade assembly. The blade separations were typical of impact fractures. All blades were accounted for.
The blade tips of the attached blades were broken. All of the blades were twisted and bent rearward. The separated blade was intact. The prop assembly was not damaged by the ground fire. The two attached prop blades were cut off by hand, and the prop/reduction gear assembly was removed from the accident site.
(b) Right Propeller
Two blades remained attached to the separated prop/reduction gear assembly. These blades were subsequently identified as Nos 1 and 2 blades. The No. 3 blade was separated at the blade shank. A section of the separated blade was found about 150 feet to the rear of, and in line with, the separated right prop assembly. One attached prop blade was intact; the second prop blade had a section near the tip broken away. All three blade assemblies were bent rearward and twisted to varying degrees.
All blades were accounted for, and the blade separations were all indicative of impact-type fractures.
The prop and separated reduction-drive gear housing bore some evidence of heat damage in the vicinity of the barrel halves.
The two attached blades were cut by hacksaw from the prop hub, and the propeller assembly was removed from the accident site.
(d) Left Engine
The power and accessory sections were intact. The accessories mounted on the rear accessory case were all intact and did not appear to be damaged by impact forces. The only apparent component damage occurred to the carburetor and generator. The mixture control housing was broken away from the carburetor, and the rear of the generator housing was heavily burned.
The power and accessory sections of this engine evidenced indications of ground fire and heat damage, primarily in the area of the reduction gear area of the power section. The rear accessory case and attached components evidenced indications of heat damage to a generally lesser degree than the power section.
The cowling for this engine was separated and extensively broken up and fragmented. A few cowl flap actuators attached to small sections of cowl flap were found and were retracted or in the cowl closed position.
The engine was identified through a partially attached section of a supercharger which comprises the pressurization system that is mounted on the right engine accessory pad of this model aircraft. The power section was basically intact except for some separated cylinder heads. The accessory section was almost totally destroyed by ground fire. The impeller drive shaft remained attached to the power section and was extensively damaged by ground fire. Several burned components were found adjacent to the right engine accessory area. these accessories included several rear accessory drive gears and a separated main oil screen. The housing of this screen was burned away. A separated generator was also found. The generator was completely burned and would not rotate. A blower clutch drive, starter clutch, three valves with the valve springs attached, and a section of cylinder head were found in the area adjacent to the engine. The engine cowlings were separated and were almost totally destroyed. Some small sections of cowl flap, with the flap actuators still attached, were found. These actuators were in the retracted position.
Only one valve related to either the fuel or engine hydraulic system was found. The valve serial number was C-41-9788, part number was 4-1846-2. The valve was removed from a 3-4 inch line and was found closed.
2. INVESTIGATION OF ENGINES AND PROPELLORS AT THE MAINTENANCE BASE AT FRONTIER AIRLINES
The engines were removed from the accident site on Oct. 4, 1970, and were transported to Denver on Oct. 5, 1970, for disassembly and examination. The props were also disassembled and examined.
(a) Left Prop S/N A4929
The reduction gear assembly rotated freely when turned at the prop shaft. The visible portion of the blade bushings were all intact and did not display any evidence of damage. The bushing attaching screws and locating dowels were broken, which allowed the bushing assembly of each prop to be displaced beyond its normal position. The degree of displacement was not determined. The blade shank radius of the three blades displayed circumferential gouges from contacting the blade chafing ring at impact.
The three blade spider shim plates were removed from the prop assembly. The No. 1 blade shim plate was broken into two pieces and was cracked at the dowel pin hole. The fracture was parallel to the prop spider shoulder. The No. 2 blade shim plate was intact except for a crack which was parallel to the prop spider shoulder. The No. 3 blade shim plate was cracked into three pieces and bore an impact mark that was parallel to the prop spider shoulder. These impact marks and/or fractures were determined to correspond to a prop blade angle of appx 32deg. The dome angle was also measured and computed to be 32.9d. The scavenge pump was removed. The pump was intact and contained an extensive amount of dirt and small parts of tree limbs. No foreign metal was found within the pump cavity area.
(b) Right Prop S/N A3696
The condition noted for the right prop was similar to that for the left prop. The oil scavenge pump was removed and evidenced impact damage. The pump vanes were exposed and the drive shaft was broken. No evidence of foreign metal was observed. An extensive amount of mud and debris was found in the pump cavity area.
The blade spider shim plates were removed from the prop. The No. 1 and No. 2 blade shim plates were broken into two pieces. The fracture was parallel to the prop spider shoulder. the No. 3 spider shim plate was broken into four pieces, and an impact mark was visible which was parallel to the prop spider shoulder. The fractures and/or impact marks corresponded to a prop blade angle of appx 32 de. The dome angle was also measured and computed to be 32.9d.
(c) Right Prop Governor, Woodward Part No. 5U1849P2, S/N WH51213 and/or 0ZA5
The governor was disassembled to determine the selected speed of the engine. The distance from the head mounting surface to the rack spring seat measured 0.925 inch. this distance corresponds to a governor speed of 2,400 rpm.
(d) Engine Examination
Both engines were disassembled by conventional means, with the exception that a cutting torch was used in order to expedite the removal of the impact-damaged exhaust collector rings of both engines. A number of other non-engine structural parts, such as cowl rings and sections of the firewall, were also removed by this method.
The cylinder barrels of both engines were securely attached to their respective crank cases. All of the intact cylinders from both engines were borescoped after spark plug removal. There was no visible evidence of any internal damage or pre-existing distress noted to the cylinder barrel walls, piston heads, valves, etc.
After removal of a representative number of cylinders, the internal components of the power section of both engines were examined visually. This exam revealed that the link rods, master rods, and piston skirts were not damaged by the impact, nor did these components display any evidence of pre-existing distress. The left engine master and link rods all moved freely, with no evidence of binding noted. The master rod cylinder for the right engine was crushed and damaged by the ground fire, thus seizing the engine. However, the link rods could be rotated on their respective link pins.
Nine cylinders were removed from each engine. The walls of all these cylinders bore piston skirt and ring markings characteristic of storage in a stationary position for an extended period of time. The piston rings were not "feathered" as in a normal engine; rather, the rings were rounded and displayed both polished and dull finished areas, characteristic of rings that have not seated properly during engine operation after an extended storage period.
Many of the spark plugs were fouled with oil and heavy carbon deposits. The intake and exhaust ports and pipes on the right engine had a heavy coating of oil, distributed uniformly throughout the port cavities and pipes. The blower section on the left engine displayed a uniformly distributed, heavy coating of oil.
There was no evidence in either engine to indicate that the engines were not capable of producing power up to the point of impact.
In order to assess to what extent, if any, the oil deposits found in the engines (and an oil consumption of appx 6 gallons per hour per engine) might indicate a potential power loss, questions were asked of Pratt & Whitney CB-3 engine specialists. Testimony concerning the oil consumption was that there is no maximum specified or permissible amount per hour if the engine is otherwise operating normally, nor is high oil consumption an indication of potential or existing power loss. High oil consumption and the oil coating found in the intake and exhaust ports and the blower section could result from seized piston rings, causing blow-by, and from leakage around the impeller seals. In turn, these conditions could exist as the result of inadequate, long-term storage practices. One indication of potential high oil consumption is piston ring markings on the cylinder walls. One expert testified, "... I would certainly be inclined, in fact I'd be strongly urged to remove a couple of the jugs and have a look, because I would suspect possibly that this is there, that this particular ring is making this mark, may possibly be seized where it wouldn't function properly when it (the engine) did start operation."
Mr. Skipper testified that on takeoff at Denver, the manifold pressure on the engines of N464M was about 1 inch below the maximum allowable, or about 58.5 inches. With respect to this statement, a P&W performance engineer testified that the 58.5" of manifold pressure would be normal at Stapleton elevation, and from that he would conclude that the engines were developing normal takeoff power. He further stated that at a power setting of 165 BMEP and 2400 rpm, the engines would be at, or very near, full throttle at 12,000'MSL on a standard day. If the temperature were higher than that for a standard day, fuss throttle would be reached at some altitude below 12,000'. (Note- The altitude at which full throttle is reached, or the supercharger is no longer capable of supplying more air than is necessary to achieve a give brake horsepower is known as the engine's "critical altitude.")
In normal climb, additional power can be achieved after full throttle is reached by increasing engine rpm from 2400 to 2600.
Fire occurred after ground impact. First evidence of fire was discovered on the ground appx 185' from the first tree contact. The burned out area measured 350' wide and 525' long. The aircraft fuselage was reduced to molten aluminum from the aft pressure bulkhead forward, except for a small section of the nose cone.
1.14 Survival Aspects
N464M was configured as a single-class service aircraft. The passenger compartment seated 40 passengers in 10 rows of two double seats each. The seats in row one were aft facing; the other seats faced forward.
Ten passengers and one pilot survived the initial impact and fire. One of the passengers had been seated in Row 4; two in Row 7; two in Row 8; and three in Row 9. One survivor was standing in the doorway to the cockpit and jumped into the forward baggage compartment when he recognized that a crash was imminent. The surviving first officer was occupying the left pilot seat at the time of impact.
All but one of the surviving passengers had their seatbelts unfastened. They were thrown forward and to the left at impact. Escape from the aircraft was through a hole in the left side of the fuselage and a hole in the right side of the cockpit.
Rescuers first arriving at the scene stated that the fuselage was relatively intact, with a small hole on the right side and a large hole on the left. One rescuer related that he observed fire in the forward baggage compartment area. He was about to step inside the fuselage to assist any survivors when an explosion occurred, and flames traveled aft into the cabin.
It is believed that many of the persons fatally injured initially survived the impact conditions. This is based on statements from the seriously injured copilot who saw and talked to passengers lying in the forward baggage compartment through the partially opened cockpit door, albeit the opening in the door was too small to reach them. One of the first rescuers on the scene of the accident related also that he saw passengers on the floor in the forward section of the cabin. They were moving but making no effort to extricate themselves. This rescuer noted that the seats in the aircraft resembled "broken furniture" and that many seats were pushed together in the forward section of the cabin. One of the survivors mentioned having to free himself from a seat which was on top of him in order to make his escape.
1.15 Tests and Research
Studies of the performance charts in the Martin 404 airplane flight manual (AFM) were made to determine the operating capabilities of the aircraft at a gross weight of 48,165 lb on departure from Denver at a field elevation of 5,300'MSL, and at a gross weight of 47,565 lb (calculated based on fuel burnoff) at an indicated altitude of 11,000'MSL with a free air temp of 50F. Since these charts do not present information for weights in excess of the 44,900 max. certificated gross takeoff weight of the aircraft, extrapolations from the climb performance data were necessary. The studies were accomplished by an FAA aeronautical engineer who had been responsible for determining that the Martin 404 performance satisfied certification requirements at the time of original certification of the aircraft for use in airline passenger-carrying activities.
Concerning the climb performance capability, the AFM notes that best climb is obtained with METO (Max except takeoff)power at 130kts and the flaps retracted.
Stall buffet on the Martin 404 begins at appx 6 kts above stall speed. Testimony adduced during the public hearing held in connection with this accident was that the buffet can "take the form of anything from a noticeable shake in the steering column, which, generally speaking, is not audible or noticeable to passengers, to a very pronounced shaking of the airplane which almost anyone would observe. My recollection of the Martin 202-404 series is, that in its certification configuration, it had a very pronounced stall buffet. There was no mistaking it when you got into the stall."
1.16 Other Information
Aircraft of US registry, having a maximum certificated takeoff weight of 12,500 lb or more, may be operated in passenger-carrying activities in the US under more than one part of the FAR's. The determining factors generally relate to the intended use of the aircraft, the responsibility for its operation, and whether the flights are for compensation or hire. It became apparent in the early stages of this investigation that there was a disagreement among the three interested parties concerning the designation of "operator." In the course of the public hearing, an FAA witness testified that the FAA considered Golden Eagle Aviation, Inc. , to be the operator, and as such did not have the proper authority for the operation of Martin 404 aircraft. Both the Jack Richards Aircraft Company and Golden Eagle Aviation, Inc., contended that the Wichita State Univ. was the operator. It was the position of Wichita State Univ. officials that they had chartered the aircraft and Wichita State Univ. was not the operator. The testimony of the three parties concerning the contractual relationships may be summarized as follows:
a. Jack Richards Aircraft Company, Inc.
Mr. Joseph H. Richards testified that he was the president and sole stockholder of the Jack Richards Aircraft Company, Inc. The company's business involved aircraft sales and both long- and short-term leases (about 5 percent of the total company business), and it was necessary for such potential customers to come to Mr. Richards, rather than the company seeking such customers. He testified "I'm really not looking for their business, but while my aircraft are sitting there, I will lease them out at times...." With respect to the manner in which the short-term leases were accomplished, he stated "Usually, whoever they send to pick up the aircraft, I have them sign it if they are an officer, or, you know, an agent of the lessee. If they are not, I usually send the lease along (with the pilots) with my signature on them and with a return envelope, stamped, that when they people arrive, they can have them sign it, drop it in the mail, and return it to me." A sample of a lease (involving a Martin 404 aircraft, N461M) to Wichita State Univ. (WSU) for a trip from Wichita, Kansas, to College Station, Texas, and return was submitted as an exhibit in the public hearing. This lease did not specify any payment for the use of the aircraft, and was undated.
All agreements as to price and availability of aircraft were accomplished verbally, and no agreements in writing concerning the basis for any charges were ever made. With respect to the leasing of Martin aircraft for the WSU 1970 football season, Mr. Richards stated, "During the summer 1970 I spoke with Mr. Bert Katzenmeyer concerning the leasing of airplanes for the coming football season. Although Mr. Katzenmeyer wanted to lease an airplane for the entire season it was agreed that if the company had planes available, we would lease to them on a single-trip basis. I explained to Mr. Katzenmeyer that this was the only way that I could do it because the company was primarily interested in selling airplanes and could not possibly tie up a plane for an entire season at the price the Univ. was willing to pay. Mr. Katzenmeyer stated that he understood and agreed to lease planes from us when available at an hourly rate of $125.00."
Mr. Richards testified that all of his contacts were by telephone, that he had never visited WSU, that no officers of the Univ. had called on him in Okla. , and that he had never met Mr. Bert Katzenmeyer (who was Athletic Director of WSU and an officer in the WSU Physical Education Corp (WSU/PEC)). All contacts by telephone were initiated by Mr. Katzenmeyer, one in Nov. 1969, and one in July 1970, at which time verbal agreements were reached for the use of Jack Richards Aircraft Company aircraft. Initially, Mr. Richards intended to supply a DC-6 aircraft. However, this aircraft was damaged in July 1970 during a windstorm. Since it was not repaired in time, two Martin 404 aircraft were substituted.
No payment was ever made by the WSU/PEC to Jack Richards Aircraft Company, nor was WSU ever billed for the use of any Jack Richards Aircraft Company aircraft. Instead, all payments to the Jack Richards Aircraft Company for use of aircraft in transportation of WSU athletic teams were made by Golden Eagle Aviation, Inc.
b. Golden Eagle Aviation, Inc.
Golden Eagle Aviation, Inc. (Golden Eagle) was incorporated on Nov. 26, 1969, by Mr. John P. Kennedy, Mr. Bruce Danielson, and Mr. Ronald G. Skipper. The company business included consulting services to potential users of large aircraft, the supplying of flight crewmembers to operators of large aircraft, and airmail operations in small aircraft pursuant to an air taxi certificate issued in accordance with Part 135 of the FARs.
In a letter dated April 3, 1970, addressed to Mr. Robert Kirkpatrick, Business Manager of WSU/PEC, Golden Eagle offered to provide services for the transportation of the WSU football team during the 1970 season. This letter stated, "The total adjusted maximum price including all standard Gold Carpet services and aircraft lease is $19.388.60."
On April 24, 1970, Mr. Bert Katzenmeyer, Athletic Director of WSU/PEC, advised Golden Eagle, "May this letter serve as acceptance of the Golden Eagle Aviation, Inc. , bid for charter service for the WSU football team travel for five games in the fall of 1970 at the price quoted of $19,388.60. Terms of this contract are based upon your bid, dated April 3, 1970, as submitted by letter to Mr. Robert Kirkpatrick, Business Manager."
Subsequently, a sixth game was added to the WSU schedule, and Golden Eagle was asked to submit a bid for the extra game. To this request, Golden Eagle responded, "Our computed price, all things included and considered, on the Sept. 12,1970, football flight to College Station, Texas, is $5,000."
On July 21,1970, an "Aviation Service Agreement" was signed by Mr. Bruce Danielson for Golden Eagle, and by Mr. Bert Katzenmeyer for WSU. Mr. Danielson testified that it was his understanding that the DC-6 mentioned in the agreement had been secured by WSU from Jack Richards Aircraft Company.
When the DC-6 was damaged in a windstorm, Golden Eagle did not consider it necessary to negotiate a new contract, but instead simply provided two crews for the replacement Martin 404 aircraft at no additional cost.
With respect to the agreement, Mr. Danielson testified that appx $5,000 of the $24,388.60 contract price was for the lease of the aircraft. By verbal agreement between him and Mr. Katzenmeyer, WSU would write one check to Golden Eagle, who in turn would forward the lease payment to Mr. Richards. According to Mr. Skipper, this arrangement was for the purpose of "simplifying the bookkeeping."
With respect to the operational control of the aircraft, Mr. Danielson testified, "But in particular, we wanted to make sure that there was no misunderstanding that WSU was the operator of the aircraft, that we were acting only as pilots, and we would advise them as best we could, because we had been knowledgeable in the aviation industry, and we were in the consulting business, and if there was any way I could find out for him or help him we would do this." In response to this advice, Mr. Kirkpatrick informed him that he was aware of the regulatory requirements and displayed a copy of the FARs.
On the trip from Wichita to Logan in N464M on Oct. 2, 1970, Mr. Skipper had a copy of the leases on N464M and N470M in his possession at the time of the crash. The leases had been signed by Mr. Richards, but had not been signed by any official of WSU or the WSU/PEC because, according to Mr. Skipper, "It had not become convenient for me to have Mr. Katzenmeyer sign them yet."
c. Wichita State University (WSU)
Since intercollegiate athletic activities were not supported by state appropriations, a separate, independent, nonprofit WSU/PEC was organized to manage WSU's intercollegiate athletic program. Mr. Bert Katzenmeyer was the athletic director. Mr. Robert Kirkpatrick was the assistant athletic director and assistant business manager of the athletic corporation. Mr. Floyd Farmer was originally employed by the corporation as ticket manager. Upon the death of Mr. Kirkpatrick in May 1970, Mr. Farmer became the assistant athletic director and assumed some of the business management responsibilities previously performed by Mr. Kirkpatrick. These were the persons in WSU/PEC who entered into the several agreements with Golden Eagle, and other organizations before them, for the transportation of WSU athletic teams. They were the only officials having direct contact with Golden Eagle officers. Mr. Katzenmeyer and Mr. Farmer were among the passengers who did not survive the crash of N464M.
According to Dr. Clark D. Ahlberg, President of WSU, the details of the contracts entered into with Golden Eagle by Mr. Kirkpatrick and Mr. Katzenmeyer were not discussed with him or other officers of WSU. He testified that his understanding of the arrangements with Golden Eagle, based upon brief discussions with Mr. Katzenmeyer, was that WSU/PEC had entered into an arrangement with an organization that provided airplanes and pilots for a fee to perform certain services, and that the organization operated and owned the aircraft. Prior to the accident, he had never heard of the Jack Richards Aircraft Company. He stated that Mr. Katzenmeyer could execute contracts for services to the WSU/PEC, but did not have any authority to sign for or bind WSU to any contract. He advised that prior to the 1969 season, when an agreement was entered into between WSU/PEC and Four Winds, Inc., that Mr. Katzenmeyer had informed him of difficulties in arranging a satisfactory contract with a scheduled air carrier for charter services. The difficulties related to commitments to cover all games, and the inability to schedule departures that would permit the team to practice prior to a game. He was not aware of any dissatisfaction with the subsequent agreements entered into with Four Winds, Inc.
Following the accident, the records of WSU/PEC were examined, and several pieces of correspondence between Messrs. Katzenmeyer, Kirkpatrick, Farmer, and Golden Eagle were found. Two copies of a lease between Jack Richards Aircraft Company and WSU for a trip to College Station, TX, were in the records. These lease agreements did not specify any payment for the use of the aircraft. There were no other lease agreements located. Dr. Ahlberg testified that following the accident he talked with personnel in the WSU/PEC offices and stated, "It is my assumption, and the assumption of others here at the Univ. that Mr. Katzenmeyer was simply agreeing to accept planes with Mr. Richards' company would furnish Golden Eagle Aviation, Inc., as they were unable to supply their own aircraft at the time." With respect to that statement, Dr. Ahlberg testified, "Well, since the accident occurred, I have talked with Mrs. Harmon and other people who made trips, and discovered that there was a good deal of displeasure on the part of Mr. Katzenmeyer and Mr. Farmer that a DC-6 which they thought they had contracted for was not available, and that the team had to travel in two planes rather than one. I had not been aware of that until after the accident. Looking at a contract which carried no provision for payments to Mr. Richards, it is hard for me to believe that Mr. Katzenmeyer was doing anything more than agreeing to accept these two Martins instead of a DC-6. I could not prove that, but that would be my assumption, knowing Mr. Katzenmeyer."
Mrs. Dorothy Harmon was the executive secretary of the WSU/PEC when bids were requested for the transportation of the WSU football team for the 1970 season. She sent identical letters to several airlines, Four Winds Travel Club, Golden Eagle, and others. On the basis of the bids received, the contract for charter services for the original five "away games" was awarded to Golden Eagle. She testified that she had never seen a copy of any FARs in the offices of WSU/PEC.
d. Additional Information
1. A search of the long-distance telephone calls from the WSU, or charged to the WSU/PEC credit card held by Mr. Katzenmeyer, did not disclose any telephone calls to the Jack Richards Aircraft Company or to Mr. Richards' home phone.
2. A search of the offices occupied by Mr. Kirkpatrick and Mr. Katzenmeyer did not locate a copy of any FARs.
3. Mr. John Kennedy and Mr. Bruce Danielson were crewmembers on the DC-6 leased to WSU/PEC by Four Winds, Inc., for the 1969 football season. In the course of this activity they became well acquainted with Mr. Katzenmeyer.
Mr. John Kennedy was put in contact with Four Winds, Inc., by Mr. Jack Richards, who recommended him as a pilot, well qualified on the DC-6.
2. ANALYSIS AND CONCLUSIONS
Examination of the wreckage disclosed no evidence of mechanical failure of the airframe or the aircraft control systems. Although ground fire destruction precluded examination of some of the aircraft components, it is noted that both pilots appeared to be satisfied with the aircraft's performance until after the right turn was executed by FO Skipper. The only concern in the cockpit, according to Mr. Skipper and to the passenger standing behind the crew until seconds before impact, was the elevation of the terrain ahead.
Most ground witnesses and the surviving passengers thought that the engines were operating normally. However, two witnesses described a backfiring sound from the aircraft. In considering their testimony, the Safety Board notes that one witness who reported the backfiring was situated in Georgetown, Five other witnesses in the same location, including the father of the witness in question, and a pilot employed as a flight engineer by a major airline, all stated that the engine sounds were normal.
The other witness, located 1-1/2 miles east of Dry Gulch, stated that the backfiring sound was so loud that passengers in the aircraft definitely should have been able to hear it. However, none of the surviving passengers recalled anything unusual about the operation of the engines. This witness also testified that as the aircraft proceeded away from his position, he observed the entire aircraft fuselage was dark green and the markings "4" and 'M" were visible on the fuselage directly forward of the tail section. Registration numbers on small aircraft are painted on the fuselage in the position described by this witness. However, they are seldom found in that location on airline aircraft. On N464M, the registration numbers were located on the vertical stabilizer, not on the fuselage, and would be nearly unreadable from behind the aircraft at the angular bearing described by the witness. So far as the fuselage is concerned, the top was painted white, there was a green stripe in the center, and the bottom was unpainted. The Board concludes, therefore, that this witness also may have been mistaken in the source of the sounds he heard, and that the backfiring may have come from large trucks or road construction machinery that was being operated in the vicinity.
While some witnesses reported a small amount of black smoke coming from the right engine, those familiar with large aircraft did not consider it excessive, and most described it as similar to a "rich" mixture but not of any great concern. The fact that a rich mixture existed on takeoff at Denver was acknowledged by the crew. However, there is no evidence that the rich mixture condition seriously affected the engine performance. Examination disclosed that on both props, the blades were off the low-pitch stops, indicating that both engines were turning and producing power at impact.
The vibration of the aircraft described by FO Skipper and the survivors occurred concurrent with the attempt to execute a 180degree reversal of course. The severest vibration occurred during the left bank, described by surviving passengers as "very, very steep" and "awful sharp." One of them stated that the bank was reduced greatly just before the aircraft struck the trees. The swath cut through the trees indicated a bank angle of 31degrees. Ground witnesses located on US Hwy 6, only a few hundred feet from where the aircraft crossed the road in front of them, stated that the entire top of both wings and aircraft fuselage was visible to them. At an altitude of 11,000' MSL, with a left turn initiated just before the aircraft starts to cross US Hwy 6, a bank in excess of 60degrees will be required for terrain avoidance at an indicated airspeed of 140 kts. If an attempt is made to maintain altitude and power is not increased, the airspeed will decrease. In a 60degree bank, with flaps extended 12.5deg., prestall buffet will be encountered at 134kts CAS, and the aircraft will be stalled at 128 kts. If flaps are not extended, the stall speed would be appx 137 kts. Accordingly, the Board believes that the vibration was the result of abrupt maneuvers and a steep bank which induced prestall buffet, and was not the result of malfunction of the aircraft, aircraft engines, or control systems. The 12.5deg flap setting found on the aircraft could have been selected by Capt. Crocker to reduce the stall speed. It is also possible that they may have been extended previously to improve maneuvering stability in the valley.
In considering the operational factors in this accident, the lack of adequate flight planning for the alternate route segment from Denver to Logan is immediately apparent. Mr. Skipper testified that at the start of the trip, he had in his possession a flight plan prepared by the FO of the other crew. This flight plan called for a northbound departure from Denver, on established airways, via Laramie, Wyo. This route parallels the mountain ranges and offers ample time to climb to a safe altitude before turning westward over the mountains. The distance over this route is virtually the same as it is over the "scenic route" flown by Mr. Skipper. The change in routing, therefore, was purely for sightseeing purposes. Mr. Skipper several times testified that Capt. Crocker was the pilot-in-command of the trip and that it was Capt. Crocker who made the decisions relating to the flight. However, with respect to the route between Denver and Logan, Mr. Skipper also testified that after the flight departed from Wichita, it was he who made the decision to purchase charts at Denver to be used in pointing out landmarks and points of scenic interest to the passengers. Accordingly, while Capt. Crocker may have been distinguished as the p-i-c by virtue of the fact that he held a type rating on the aircraft and Mr. Skipper did not, it is the Board's opinion that Mr. Skipper, in his capacity as president of Golden Eagle, was in fact the person who decided the route to be traveled.
The manner in which the route from Denver was flown is worthy of comment.
All ground witnesses describe the aircraft as being extremely low over the mountainous terrain, and many described engine sounds as being similar to cruising power rather than to climb power. From Idaho Springs to the point of crash, the aircraft was continuously below the mountaintops. Operation at such a low altitude could have been for sightseeing purposes only, since the aircraft was capable of climbing at a much greater rate than was actually accomplished. By best estimates, the total time from departure at Denver to the time of crash was 25 to 30 min.
In one-half that time, the aircraft was capable of reaching an altitude of 15,000'MSL, or more, if max continuous power had been used. In the event that the crew did not wish to use any higher setting than the regular en route
climb power that Mr. Skipper testified he was maintaining, a climb maneuver could have been executed which would have produced a safe altitude before the flight proceeded westbound toward the Continental Divide. Either procedure not only would have resulted in ample clearance over the mountain ranges along the flightpath, but would have provided the capability to reach a safe landing place in the event of an engine failure.
Mr. Skipper, by his own testimony, was aware of the "drift down" safety practice employed by airlines and most operators of large aircraft when operating over mountainous terrain. Notwithstanding, he flew the aircraft in the mountain valley below the mountaintops at an altitude higher than the aircraft was capable of maintaining in the event of an engine failure. ("Drift down" relates to the planning of a flight at an altitude sufficiently high so that in the event of engine failure, the excess altitude can be used to provide clearance over terrain ahead as the aircraft proceeds to a suitable landing area in descending flight.)
It must also be presumed that neither Mr. Skipper nor Capt. Crocker spent any time examining the charts for the route to be flown, since Mr. Skipper did not return to the aircraft after he purchased them until appx 15 minutes before takeoff and, at that time, engaged in conversation with the passengers. If the charts had been studied, the pilots could have known that the minimum altitude necessary to clear Loveland Pass at the end of Clear Creek Valley, was 2,000'MSL Mr. Skipper was flying the aircraft at reduced power at appx. 11,000'MSL when the flight reached Dry Gulch an the crew first discovered that Clear Creek Valley was ending in what has been described as a "box canyon."
The altitude of the aircraft as it passed over Georgetown was appx 9,800'MSL, based upon witness observations and measurements made therefrom. At this point, the aircraft was appx 1,200' above the valley floor. At the 140 kts IAS testified to by Mr. Skipper, the aircraft would have been capable of a climb of appx 240 feet per mile at max continuous power, or an altitude of appx 12,000' at Dry Gulch. Mr. Skipper testified, however, that lesser power was used throughout the climb, which would result in the aircraft's being at a lower altitude at Dry Gulch. In this regard, calculations using the angular bearings taken from observation points of two witnesses who observed the crash serve to establish a reasonably precise altitude, as follows: <<<<< NOT INCLUDED BY R.M>
Based upon the foregoing evidence and computations, the Board concludes that N464M was at, or very near, an altitude of 11,000'MSL when the reversal turn at Dry Gulch was attempted.
With respect to the ability of the aircraft to climb over the mountains ahead, a review of the performance data shows that if max continuous power had been applied when the aircraft was at Dry Gulch, a climb gradient of 4.57 percent could have been achieved. This translates into a climb capability of 240 feet per mile traversed. Since the distance from Dry Gulch to Loveland Pass was only 2 miles, and the distance to the other lowest point on the Continental Divide ahead was appx 3 miles, it would have been impossible for the aircraft to clear the terrain ahead.
Concerning the aircraft's ability to execute a reversal turn, ref to App. D indicates that at 140 kts IAS a 60 deg bank will produce a turn radius of 1,490'. However, in a 60deg bank, even at max continuous power, altitude would be lost at a rate of about 340 fpm.
At 130kts, the turn radius in a 60 deg bank would be 1,300'. However, this would require the aircraft to be operated constantly at only 2 kts above stall speed, and well into the stall buffet range. entry into the stall buffet boundary would result in an increase in the rate of sink because of the drag induced by flow separation.
Even if the pilot had possessed sufficient skill to operate the aircraft within such extremely small tolerances, there would not have been sufficient space available to execute the turn. At the 11,000' contour, the valley width at ground level is about 3,000' in the area immediately beyond Dry Gulch. At the 10,800' contour, the valley width at ground level is only 2,400'. Accordingly, the Board concludes that once the aircraft had reached the Dry Gulch area, it was no longer possible to have executed a course reversal. If the crew had been concerned about the aircraft's ability to clear the terrain head less than 1 minute sooner, when the aircraft was still 1-1/2 to 2 miles east of Dry Gulch,
a successful turnaround could have been executed with use of maximum continuous power and a bank angle of only 30deg. However, at that point on the flightpath, the crew would have been unable to see that the valley ended at Loveland Pass, and thus they proceeded into an area from which an escape was not possible.
At the point where FO Skipper executed the right turn toward Dry Gulch, Capt. Crocker could not be sure of Skipper's intentions since there had been no discussion in the cockpit concerning any specific procedure. The only conversation overheard by the survivor, standing immediately behind the crew, was a discussion of the height of one of the mountains. It is likely therefore that Capt. Crocker may have believed that FO Skipper's intention was to fly up Dry Gulch.
Since he had a good view of Dry Gulch out of his window, he could see that its floor extended only a few thousand feet before rising rapidly toward the Continental Divide. Also, on completion of the turn, the aircraft was proceeding toward the rising ground of Mt. Trelease. Any decision that was to be made, had to be made immediately. It is likely, therefore, that this is what induced Capt. Crocker to take over the controls. The steep left bank was then necessary to avoid the mountain. In the process, the aircraft was stalled, resulting in a loss of altitude, and contact with the trees.
Since resistance of modern aircraft structure to abrupt deceleration is generally assumed to be equal to or less than the resistance or tolerance of humans to such deceleration, the post-impact conditions of aircraft structure can therefore be applied as a practical means to establish survivability of an accident. The apparent intactness of the passenger cabin in this accident indicates such a survivable condition. However, two other criteria must be met to insure survival: (1) the occupant becomes involved in the deceleration of his environment and (2) immediate access to a means of escape.
According to rescuers, the seats in this aircraft were pushed together in the forward section of the aircraft, indicating that failure of seat tiedowns occurred at some point during the crash sequence. Depending on the failure mode at the moment of failure in the crash sequence, such seat failures may make the difference in the survival or non-survival of occupants in an otherwise totally survivable accident.
The seat, as the occupant's supporting structure, the restraint system in the form of a seatbelt and the underlying floor structure and seat anchorages are the media through which the occupant becomes involved in the deceleration of the aircraft structure. failure of any one of these will allow the occupant to accelerate in relation to his environment and strike objects or structure with a force exceeding the overall crash deceleration.
Although the peak magnitude and duration of the main crash force cannot be calculated with any degree of accuracy, the forces were considered to be fairly moderate in view of the intactness of the fuselage, the low velocity with which the aircraft struck the ground and the fact that many occupants survived the impact. Additionally, the fact that all but one of the survivors who escaped did not have their seatbelt fastened attests to the low velocity at impact as well as the fact that a lateral force vector prevented them from gaining momentum within the confines of the fuselage.
It is reasonable to assume that more occupants than just those who escaped had their seatbelts unfastened. The ones who escaped were fortunate to remain conscious while others did not or were too stunned to effect their escape. The failure of many occupants to evacuate must nevertheless be directly attributed to the seat failures as being the major injury producer. Indeed, the passengers' not being tied down may have been, in itself, a major triggering force in the seat failures, since passengers as "missiles" can induce failing loads on seats ahead of them.
This accident shows once more that passengers can receive needless injuries inside intact fuselage structure. The Board is aware that the present design "G" levels for transport aircraft seats and their testing criteria have been improved since the original design of the Martin 404. Hence, without continued concern for this problem, needless loss of life can result.
Finally, with regard to the problem in this accident concerning the identification of the operator who had the responsibility for compliance with the regulations applicable to the flight, it is obvious that there was classic disagreement among the parties involved in the flight. As previously stated in this report, it was the position of the FAA that Golden Eagle Aviation, Inc., was the operator. Both Jack Richards Aircraft Company and Golden Eagle Aviation, Inc., contend that WSU was the operator. It is the position of WSU that they were not the operator but had been merely chartering air service. This question will be fully resolved in a proceeding separate and apart from this accident inquiry and for the purpose of this report the Board does not believe it necessary to resolve this conflict. For present purposes, it is sufficient to conclude from the post accident denial of the parties that they were the operator with the responsibility for the safe conduct of this flight, that they did not acknowledge such responsibility at the time of the flight.
It is the view of the Board that the numerous deficiencies, unsafe practices, and deviations from regulations, involved in this operation, are typical of operations where none of the participants acknowledge responsibility for the safe conduct of a flight. As this Board stated in a prior accident report, "It is not unusual that such operations are characterized by safety problems such as those found to be present in this operation." (Ref- Aircraft Accident Report- Douglas DC-3, N142D New Orleans Louisiana, March 20, 1969) The Board believes that the management required for a safe operation appears to have been absent and was a significant factor in this accident.
1. There was no failure or malfunction of the aircraft, powerplants, or control systems.
2. The crew was properly certificated for the flight.
3. There was a current airworthiness certificate in the aircraft and an annual inspection had been performed.
4. The aircraft was 5,190 lb over the max. permissible takeoff weight at Denver, and 2,665 lb over the max. certificated takeoff weight at impact.
5. The original flight plan was altered to provide a "scenic route" for sightseeing purposes.
6. The aircraft was operated over Clear Creek Valley at an altitude always below the mountaintops.
7. After the flight reached the Dry Gulch area, it was no longer possible for the aircraft either to climb over the terrain ahead, or to execute a course reversal.
8. None of the participants in this flight, the owner of the aircraft, lessee, or the company providing the crew and other services acknowledged that they were the operator and accepted responsibility for the safety of such flight.
(b) Probable Cause
The Board determines that the probable cause of this accident was the intentional operation of the aircraft over a mountain valley route at an altitude from which the aircraft could neither climb over the obstructing terrain ahead, nor execute a successful course reversal. Significant factors were the overloaded condition of the aircraft, the virtual absence of flight planning for the chosen route of flight from Denver to Logan, a lack of understanding on the part of the crew of the performance capabilities and limitations of the aircraft, and the lack of operational management to monitor and appropriately control the actions of the flightcrew.
The testimony given during the public hearing held in connection with this accident indicated a widespread misunderstanding by educational institution and business concern personnel of the problems and regulations involved in the operation of large aircraft, or the responsibilities of lessees of an aircraft. Accordingly, on Nov.9, 1970, the Board issued a Safety Information release recommending that potential users of large aircraft on a short-term charter basis, question providers of such services as to the type of operations for which they have been certificated. Should there be any doubt as to the proper certification, such users should consult the nearest FAA office for advice. A copy of this release is included in this report as Appendix F (not in my possession)
As noted in this release the Safety Board is aware of the investigation into all charter operations as ordered by the Secretary of Transportation Volpe. The Board is in accord with the need for such an investigation, and is hopeful that the results will establish safe practices in all charter or leasing activities.
Last Modified: 1/1/2008