Accident Report Narrative
|HISTORY OF THE FLIGHT
The mission was a four ship formation flight (T-1-U) authorized on Flight Orders A-75 dated 18 APR 1967, Williams Air Force Base, Arizona. Specifically, the mission was to upgrade squadron instructor pilots in full stop wing landings. Major Harry J. Peterson, as instructor pilot, was in the front cockpit, and Major Norman D. Peters, as pilot, was in the rear cockpit. They were to occupy the third aircraft in flight.
The mission was briefed by Major Oshant, the flight commander, at 1500 hours MST. Take-off was planned for 1600 hours MST with 1+20 en route. The flight was briefed to take off 30R, with the second element joining on the left wing during the turnout of traffic. The briefing was conducted in accordance with applicable directives. The briefing covered the general conduct of the mission and specific maneuvers to be accomplished prior to separating into two ship elements for full stop wing landings.
TAXIING AND TAKEOFF:
All aspects of the preflight, engine start , taxi and takeoff were normal and without incident, except that the flight became airborne 10 minutes later than planned.
JOIN UP AND CLIMB:
The element joined on the left wing as briefed and remained in this position for the remainder of the flight. While completing the join up at approximately 7500 feet MSL, the pilots heard a light "thump" or "pop" which they could not identify. There were no noticeable changes in the cabin pressurization system. All engine instruments remained within normal limits. The climb check at 16,000 feet MSL was normal. The cabin altimeter indicated an altitude of 8,000 feet. Subsequent to the climb check but prior to the level off, the pilots again heard a light "thump" or "pop" (light and soft rather than sharp). The flight leveled off at FL 270 on the 050° departure corridor. The cabin pressure was noted to be 10,500 feet during the level off check.
THE CRUISE (FLIGHT):
After completion of the level off check, the flight turned off the climb corridor to a heading of 160°. Three or four minutes later, the "thump" or "pop" occurred again (as it had in the climb). Major Peterson asked Major Peters if he had done anything to cause the noise. Major Peters replied that he had not. Very shortly thereafter, the front canopy plexi-glas separated from the aircraft. Captain Halvorson and Major Oshant, in the number four aircraft, observed the canopy to shatter explosively into small pieces. They estimated the largest of the pieces to be four to five inches in size. Major Peterson immediately leaned forward into the cock-cover. The visor which had been up, was broken into three separate pieces and fell down in front of his face. At the time of canopy failure, the speed of the aircraft was 320 KIAS, and although there was no great buffeting in the cockpit, the rushing of the air did prevent communication between the pilots. Major Peterson immediately lowered the speed brakes. Major Peters (who was flying the aircraft) turned the aircraft out of the formation and reduced speed to regain interphone communication. at 250 KIAS, Major Peters indicated the interphone communications were good, although Major Peterson stated that they had to yell, and that communications were not really satisfactory until the aircraft had slowed to 225 knots. The speed brakes were raised at this time by Major Peterson.
The descent and turn to leave formation was initiated at the time of canopy failure. Approximately 10 seconds later, Major Peters noted the left engine at 90 percent RPM and left EGT rising to 750°. The right engine was in a roll-backed condition. Major Peters attempted to recover the right engine by reducing the throttle to idle and then re-advancing it. Engine response appeared normal up to approximately 80 percent when the engine would stall and roll back. RPM fluctuated between 75 to 90 percent, EGT 500-750,° nozzles from 0-70 pounds per hour. Sometimes it was possible to stabilize the right engine at approximately 80 percent for as long as 20 to 30 seconds. It would then stall and roll back. During attempts to recover the right engine, the maximum power on the left engine was approximately 80 percent (apparently an unnoticed 10 percent roll back.). Throttle movement above 80 percent had no effect on left engine RPM. As the left throttle was advanced however, fuel flow would fluctuate from 500 to 1,000 pounds per hour, and the EGT would slowly increase from 650 to 750 degrees. Nozzle position remained at 50 percent. Major Peters indicates that there was considerably more drag on the aircraft as the result of the lost canopy. In order to maintain 225 knots, it was necessary to descend at the rate of 2,000 feet per minute. An attempt was made to level off at 12,000 feet MSL which resulted in an immediate airspeed decrease to 165 knots, thus requiring the descent to be reinitiated.
The terrain over which the pilots ejected is very mountainous. Both pilots (as advised by Major Oshant) decided to eject when they determined they could not maintain altitude, or airspeed. Major Peters made a controlled ejection at approximately 9500 feet MSL. Major Peterson made a controlled ejection at approximately 8500 feet MSL. Terrain clearance at the time of ejection is unknown due to the variances in the local topography. It could have been anywhere between 3,000 and 4,000 feet at the time of the second ejection. A range of mountains over which both pilots drifted extends up to 5500 feet in some places. Both pilots connected the zero lanyards and lowered their seats to the bottom prior to the ejection. In each instance, the ejection sequent was entirely normal. Seat separation was followed immediately by canopy deployment. Both pilots drifted approximately one mile north east of the aircraft line of flight. Major Peters (rear cockpit) ejected first. He cut only two taped risers which stabilized his chute and made it controllable. He landed on a steep hillside relatively free of large boulders. He got out of his parachute harness, spread his chute on the ground, and walked to the top of the ridge. After ejection, Major Peterson pulled the thee broken pieces of the visor loose and discarded them. He then removed his sun glasses and put them in his G-suit pocket. After considering the forward velocity of his parachute and the very rocky terrain he was crossing, he did not perform the four line cut. At touchdown, his parachute oscillation was directly into the wind, and for a moment he thought he might not fall down. Major Peterson suffered minor cuts and bruises. He is not sure but believes the bruises on the insides of his knees were caused by contract with the stick. At touchdown the canopy draped itself over a large boulder and deflated. Neither pilot reported tumbling after leaving the aircraft. Both pilots were picked up approximately 30 minutes after ejection by the local crash and rescue helicopter.
AIRCRAFT FLIGHT PATH AFTER EJECTION:
The ejection occurred approximately 35-40 miles from Williams AFB on a heading of approximately 255°. After ejection, the aircraft turned slightly to the left. The aircraft struck 5200 feet on the 070/31 mile radial of the CHD Tacan.