Anthony J. Mireles wrote:This is my view on the B-17E take-off accident that killed Major Kenneth McCullar on April 12, 1943, at Jackson Airdrome, Port Moresby, PNG--the famous "Wallaby" accident. I first purchased this accident report in 2003 and a few years later wrote the following summary concerning this unusual accident. It was the first accident I studied while doing the preliminary research for a project I plan on publishing soon. I tweaked this summary here and there but it is essentially what I originally wrote several years ago.
The airplane suffered two unrelated failures during the take-off, leading to a third failure related to one of the original failures. But there was some human error. Neither the failure of the starboard expander tube or the failure of the left tire would cause the airplane to enter a steep climb to the point of stalling. What is surprising about this accident is the fact that the landing gear locking pins were still in place when the airplane took off. This is according to the Boeing reps who conducted a separate investigation. And these findings bear out the testimony of a witness who states that the landing gear did not retract during the take-off, contradicting the findings of the engineering department. If the locking pins were indeed still in place then perhaps the pre-flight errors did not end there. Maybe the elevator lock was still in place and also missed on the pre-flight. This is what caused the crash of the first B-17, Model 299. It certainly is an interesting fact.
And then there is the Wallaby. Could the small wallaby cause a catastrophic failure when struck by an aircraft as large as and as tough as a Boeing B-17? Since no zoo in the Chicago area had a wallaby, I drove a couple hundred miles to the Miller Park Zoo at Bloomington, Illinois, to see one for myself. Zoologist Carol Pagluica gave me a special presentation on the New Guinean Forest Wallaby. And I was allowed to go into their living space. They are very small creatures. About 35 pounds, and smaller than my smallest Pitt Bull Missy (a 47-pounder). Man it's a stretch to think that this little creature could cook out a B-17 landing gear plumbing. I guess it could be possible if it hit just right with a great velocity, but probably very unlikely. I don't think it is likely that striking a wallaby would cause the left tire to fling off or suddenly go flat.
And almost seventy years later the accident is still a mystery somewhat. We'll never really know what happened to McCullar's airplane on the take off roll that dark night and what caused the steep climb that led to a fatal stall. I am of the opinion that the left tire struck the elevators and caused them to jam. The following summary is based on the original Army Air Forces Form Number 14 Aircraft Accident Report; Microfilm Call # 46189, 12 April 1943, Accident # 502. There are eight photos with the accident report.
4-12-43A. Jackson Airdrome, Port Moresby, New Guinea. At 0148 (local time), a Boeing B-17E (41-9209) crashed while attempting a take-off from Jackson Airdrome, Port Moresby, Papua, New Guinea, killing the crew of eleven. Killed in the crash were: Major Kenneth D. McCullar, 27, Courtland, Mississippi, pilot; 2Lt. Byron G. Andrews, co-pilot; 2Lt. Blaine McCord Jr., navigator; 2Lt. John W. Schultz Jr., bombardier; TSgt. Elmer R. Hansen, engineer; Sgt. Phillip A. Zumwalt, radio operator; Sgt. Bert F. Bredemeier, gunner; Pvt. David W. Stuckey, gunner; Cpl. George A. Mowad, gunner, SSgt. Pierre R. O’Grady, Ft. Kent, Maine, gunner; SSgt. Michael J. Paz, Bridgeport, New Jersey, gunner.
The airplane was the lead airplane of a flight that was taking off on a raid against Japanese airfields at Rabaul, New Britain. A B-17 acting as a weather and observation ship took off for Rabaul at 0130 local time. Weather at Jackson Airdrome was reported as “High thin overcast with scattered cumulus at 3,000 feet. Surface wind calm with visibility twelve miles. Thin patches of ground fog beginning to form.” The subject airplane began its take-off roll and at a point when it was almost halfway down the runway flames were observed trailing the number-three nacelle on the underside of the starboard wing. The B-17 became airborne and climbed steeply to about 400 feet agl. The airplane fell off on the port wing into about a 60-degree bank and then entered a steep dive to the left. The airplane struck the ground at a steep angle on the port wing and nose, exploding violently into flames upon impact and killing the crew instantly. The bomb load detonated in the resultant fire.
Investigation revealed that the starboard main landing gear brake system expander tube had failed, allowing hydraulic fluid to flow out and be ignited by the hot ducting of the number-three turbo-supercharger. Investigators found that the starboard main wheel hub had cracked in the center. Witnesses observed that the starboard main tire was on fire while still attached to the starboard landing gear during the take-off roll and immediately after take-off. Further investigation revealed that the port main tire had been thrown from the port main wheel assembly and landing gear soon after the airplane left the ground.
The Aircraft Accident Classification Committee stated, “The findings of the committee rest at 100% undetermined. There are possibilities that fire resulted from the hydraulic fluid being ignited from the heat of the supercharger, blinding the pilot during take-off, which necessarily would have been on instruments inasmuch as there was not even starlight. Also, the tire [that] came off might have damaged the elevator and/or stabilizer either by bouncing off the runway or by direct contact accounting for the aircraft stalling before crashing. Major McCullar was a superior pilot, thoroughly experienced, and it is not believed that any pilot error as involved.”
Engineering officers stated on 12 April 1943, “B-17E Aircraft # 41-9209, piloted by Maj. Kenneth D. McCullar, caught fire and crashed at 0148 on April 12, 1943, approximately 1,000 yards off the southeast end of Seven-Mile Airdrome. Investigation of the wreckage and interrogation of witnesses on the scene indicate that two unrelated failures occurred during the take-off. A hydraulic brake line on the right hand strut failed, oil trailing back under the wing ignited from the Turbo-Supercharger, and when the wheel and strut retracted into the number-three nacelle it ignited either the main fuel line running along the left hand side of the wheel housing or the fuel tanks directly to the rear of this nacelle. The fire then spread throughout the right hand wing causing the pilot to lose control a few hundred feet in the air and either stalled or slipped into the ground. During the take-off the right hand wheel cracked in a plane thru the tire, pinched the inner tube, allowed the locking ring, dust cover, movable flange and tire to tear off the wheel about the time the aircraft was airborne and the wheels braked prior to retraction. A dead wallaby was found on the runway about 200 yards from the initial take-off point. It had been struck by an aircraft and may or may not have been struck by this airplane and caused a hydraulic line failure by impact. …Midway down the runway on the take-off when abreast of the control tower flames were observed low towards the ground on the right hand side. This small fire seemed to burn for about seven or eight seconds, die down for four or five seconds and then mount in intensity and gradually spread over the bottom of the right wing until 20 to 25 seconds later the plane crashed. On the take-off the engines seemed to function normally, the plane executed a normal unswerving take-off, then suddenly pulled up in a steep climb and seemed to slip into the ground on the left wing. No explosion occurred in the air. Several competent witnesses located the fire in the vicinity of the number-three nacelle spreading rapidly. The plane was observed to climb rapidly, stall and fall in on the left wing. The stall could have been caused by the tire [that] was thrown off, hitting the elevators causing them to stick in the up position causing the aircraft to exceed a safe rate of climb. Examination of the right hand wheel showed it to be cracked as described, the remaining flange was unmarked by being run on, but the entire hydraulic installation was burned completely away and the steel strut perforated by bomb splinters. The lock ring and movable flange recovered alongside the runway were in good condition. The attached photographs show the general wreck, the destroyed left hand strut and wheel assembly, the remains of the right hand strut, intact tire, lock ring and movable wheel flange, the damaged inner tube and the outer tire. Study of the photographs will indicate the difficulty of forming an exact, accurate conclusion as to the failure. …It is assured fatigue failure of the metal lines or breakage by impact of the wallaby occurred.”
A classified U.S. Army Air Forces “Unsatisfactory Report” written by 43BG engineering officers on 19 April 1943 stated, “The present hydraulic fluid (type 3580C) being used on B-17 type aircraft of this group has presented us with a serious problem due to its inflammable nature. On a night take-off here, one ship used excessive brake, and consequently broke the expander tube. The fluid liberated flowed on hot brake bands and broke into flames. The wheel was retracted in flight and a resultant airplane fire started which ended in the crash and death of all occupants. …Several fires have been extinguished on the ground due to excessive braking with resultant failure of expander tube and liberation of hydraulic fluid on ‘over hot’ brakes.”
After further examination investigators stated, “Mr. David Weaver and Mr. Richard L. Stith, Boeing Factory Representatives, at present attached to this group, conducted a more thorough and detailed investigation of the accident. It is their opinion that the tire which was found 60 yards to the left and about two-thirds of the distance of the runway in the direction of travel of the airplane was off the left wheel rather than the right (Bearing out MSgt. Charles P. Raynor’s testimony [that the right main tire was attached to the wheel and landing gear while the airplane was airborne and that the right hand tire was seen rotating slowly while on fire]). This is based on a thorough examination of the inside of the hub found in the tire. Scratches and their direction of travel on the hub indicate this. In addition, in their opinion, if the right hand tire had been off the wheel, the rim would have been dented from impact against the ground. However, the rim is smooth. The crash could very easily have caused the right rim to crack through the center, even with the tire still on it. Further investigation by them disclosed the fact that the landing gear was never retracted, inasmuch as the lock pins were in the struts in the lock down position.”
An AAF officer who witnessed the accident, Capt. Marshall E. Nelson, stated, “Major McCullar made a normal take-off. I was unable to observe the right wing of ship # 41-9209 during its run on the ground but just as it left the ground, I observed a spreading fire on both the upper and lower surfaces of the right wing which quickly enveloped number-three engine and nacelle, as the fire spread the aircraft pulled up into a stall, fell off on its left wing and crashed 400 yards from the Southeast end of the runway.”
Major David W. Hassemer, an AAF officer who was present in the Jackson Airdrome control tower at the time of the accident, stated, “At the time of take-off, I was in the tower located approximately the center of the runway, about 60 yards east of the runway. As the plane came to a point about 200 yards short of the center [midpoint] of the runway, a loud metallic crack was heard by the occupants of the tower. At a point opposite the tower a long streak of bluish-white sparking flame appeared below the number-three engine nacelle and in the right wheel assembly. This flame lasted for five or six seconds and then went out momentarily. The plane appeared to have been pulled off the ground sharply. At that time the flames appeared again and turned into a dullish red-orange color. The plane climbed steeply a few seconds after take-off and appeared to reach an altitude of about 300 or 400 feet. It then fell off on the left wing and apparently dove straight into the ground. All of the engines appeared to be functioning normally during the take-off run and immediately after take-off.”
Whether the dead wallaby found on the runway figured in the failure of the starboard main landing gear hydraulic brake line/expander tube could not be determined with any certainty. It is uncertain whether a collision with the wallaby on the take-off roll could cause the left tire to fail. It was later speculated that the airplane had probably suffered a partially flat or rapidly deflating left main tire/tube during the take-off roll. The pilot, attempting to keep the airplane straight on the runway heading during the instrument take-off, used excessive right brake to over come the failing left tire. The excessive right braking against take-off power caused the right expander tube to fail. Liberated hydraulic fluid was ignited, setting the starboard landing gear and wing on fire. The extremely overheated condition of the right wheel and brakes during the take-off roll may have caused the right rim to crack and fail. The failing left tire apparently was flung from the wheel and rim just as the airplane lifted off. The failed left tire may or may not have struck the tail surfaces after it was flung free, perhaps causing the elevator to be jammed in the climb position.
Whatever the case may be, the airplane then entered a steep climb to 400 feet agl before stalling and falling off on the port wing and smashing to the ground at a steep angle on the port wing and nose. The airplane exploded violently into flames and the wreckage was extremely fragmented because of the detonating bomb load. It was later speculated that since investigation revealed that the landing gear lock pins were inadvertently left in place on the take-off, perhaps the elevator control lock could have been inadvertently left in place as well. It should be noted that there was no mention of the position of the flight control locks in the accident report. (64BS/43BG) (502). Copyright 2007 Anthony J. Mireles.
This summary was properly spaced and set up before I pasted it. When I pasted it on this thread, the spacing and such disappeared. The spacing should make it easier to read.