Boeing Model 299
Accident Case Study
It seems hard to believe these days, but there was a time when pilots simply memorized everything and hopped in the airplane and flew. There are records of written instructions as early as 1918 (for the Curtis NH-4 Jenny) but no widespread "do list" that gave pilots step-by-step procedures on how to do their jobs. The crash of Boeing Model 299 changed all that.
Before we get started, however, a word about the pilots of this particular mishap. They were the best of the Army Air Corps and if forgetting a gust lock seems to be an overgiveable oversight, it was understandable back then. It isn't today because we have checklists. If you want to read about an unforgiveable gust lock incident, see: Gulfstream IV N121JM. The pilots of Boeing Model 299 didn't have that luxury.
Photo: Boeing Model 299 Crash, 30 Oct 1935, USAF Photo
- Date: 30 October 1935
- Time: 0930
- Type: Boeing Model 299
- Operator: U.S. Army Air Corps
- Fatalities: 2 of 7 crew, 0 of 0 passengers
- Aircraft Fate: Destroyed
- Phase: Takeoff
- Departure Airport: Wright Field, Ohio
- Destination Airport: Wright Field, Ohio
[Boyne, p. 53]
- The Model 299 was manned by a very experienced crew, including Maj. Ployer P. Hill, Wright Field’s Flying Branch chief, and his copilot, 1st Lt. Donald L. Putt. Also on board were John B. Cutting, a flight-test observer; Mark H. Koogler, also from the Flying Branch; and [Boeing chief test pilot Leslie R.] Tower. Hill was an experienced test pilot, having flown the earliest versions of the Martin B-10. It was his first flight in the Model 299. Tower was positioned behind the two pilots, ready to give advice.
- Observers described the initial run of the Model 299’s takeoff as normal, even though it broke ground at about 74 mph in a “tail low” attitude. As its speed increased, the bomber’s nose went up much higher than normal. Two men, 1st Lt. Robert K. Giovannoli and 1st Lt. Leonard F. Harman, sensed it was in trouble and ran forward as the airplane reached an altitude of about 300 feet.
- The Model 299 stalled, turned 180 degrees, and fell back onto a field. It landed on its left wing, cushioning the impact, which probably saved the lives of several crew. Lying flat on the field, the bomber burst into flames. Amazingly, four crew members were able to crawl from the blazing wreckage.
- Putt and Tower emerged from the cockpit area, while Cutting and Koogler got out from the rear. Giovannoli rushed into the fire to find Hill jammed behind the controls. Harman crawled in and cut Hill’s shoe off, freeing him from the rudder pedal. Giovannoli handed Hill out of the cockpit into the arms of Barney Miller, an employee of the Martin Co., but Hill died later from his injuries.
[Mellinger, p. 81]
- Tower, who had been standing behind the pilots as an observer, blamed himself for the accident. Though he did not seem to be seriously injured, he died not long afterward.
- Investigators determined that the Fortress had crashed because the elevator and rudder controls were locked—the pilot could not lower the nose, so the aircraft quickly stalled. Ironically, the elevator locks had only been recently installed as a safety feature, to protect the control surfaces from moving about on the ground and being damaged during high winds.
- The locking mechanism was controlled from inside the cockpit, but no one remembered to disengage it before takeoff. Tower apparently noticed that the control lock was still engaged as the aircraft moved up to stall, but was unable to get to it in time to prevent a crash. More familiar with the 299 than anyone else, this oversight on his part is why he blamed himself for the disaster.
[Boyne, p. 54]
- A board of officers convened at Wright Field to investigate the crash. The board determined the accident was “not caused by”: structural failure; malfunction of flight controls, engines, or propellers; the automatic pilot; or any faulty structural or aerodynamic design. Instead, it ascribed the direct cause to the elevator control being locked.
- This is, by implication, a “pilot error” verdict—but the board did not say that directly. The board’s determination was based on a detailed analysis of the flight-control mechanism and the testimony of Tower and Putt on how the aircraft behaved in the air. This assessment was corroborated by eyewitnesses on the ground, many of whom were experienced airmen who watched the flight from takeoff to impact.
- The tail section of the aircraft was virtually all that survived the fire, but it contained the cause of the accident: an internal control lock that controlled both the elevator and rudder. There were three positions for the elevator on this lock. Two of these were “up”; one was “down.” The board concluded that the elevator control could not have been in the extreme up position, because at that position the control yokes would have been inclined back at an angle of 12.5 degrees, and the pilots would not have been able to climb into their seats without releasing the controls. They also deduced that it could not have been in the down position because the aircraft would not have been able to take off.
- Further, the Pratt & Whitney representative, Henry Igo, had conducted the engine run-up with the controls locked in the first up position. This meant the pilots could have initiated takeoff without realizing the controls were locked. The flight would have seemed normal until they increased the speed, which would have affected the locked control surface, forcing the aircraft’s nose up into a stall.
[Boyne, p. 54] The board stated that—due to the size of the airplane and the inherent design of the control system—it was improbable that any pilot, taking off under the same conditions, would discover the locked controls until it was too late to prevent a crash. Ordinarily, pilots make checks of their movement as a precaution, but apparently this did not occur.
[Boyne, pp. 54-55]
- In the aftermath of the Boeing Model 299’s crash, the Air Corps declared Douglas Aircraft Co. to be the winner of the multiengine bomber competition. Douglas’ DB-1 was redesignated the B-18 and later given the name Bolo. Some 350 were built, and they gave excellent service—but not in the long-range bomber role.
- The Air Corps still wanted B-17s, and Boeing received a consolation prize, a contract for 13 aircraft designated Y1B-17. Still, the Air Corps faced arguments that the aircraft was too big to handle.
- The Air Corps, however, properly recognized that the limiting factor here was human memory, not the aircraft’s size or complexity. To avoid another accident, Air Corps personnel developed checklists the crew would follow for takeoff, flight, before landing, and after landing.
- The idea was so simple, and so effective, that the checklist was to become the future norm for aircraft operations. The basic concept had already been around for decades, and was in scattered use in aviation worldwide, but it took the Model 299 crash to institutionalize its use.
[Mellinger, p. 81]
- Boeing was in dire straits, and it seemed perilously close to folding. Fortunately, a legal loophole allowed the Air Corps to buy a small number of test aircraft—13 to be precise— which was enough to equip one squadron. These airplanes, soon designated YB-17s, were to prove of enormous importance.
- Over the next few years, Air Corps pilots would log more than 9,200 flying hours on their YB-17s with- out experiencing even a single major accident.
- When World War II broke out in Europe in September 1939, the Army Air Corps had barely two dozen of the new B-17s.
12,730 B-17s were to be produced.
Boyne, Walter J., "The Checklist," Air Force Magazine, August 2013, pp. 52 - 56.
Mellinger, Phillip S., "When the Fortress Went Down," Air Force Magazine, October 2004, pp. 78 - 82.