January 13, 1982 brought one of the worst blizzards in history to Washington, D.C. Businesses closed early, schools closed their doors, and even Congress recessed early. Washington's National Airport had been closed all morning, but re-opened by 12:00 pm. Sitting at gate B12 was Boeing 737-222B, in command of the aircraft, were Capt. Larry Wheaton and First Officer Roger Pettit, both relatively young pilots enjoying their new jobs at Air Florida. The flight was scheduled to depart at 2:15, but both men knew that time would come and go.
Just before 1:40 pm, the airport was closed so that crews could plow the field's one instrument runway, 18/36. It was scheduled to re-open at 2:30. Despite the delay, Air Florida elected to begin the boarding process, and all passengers were on board by 2:30. Meanwhile, Capt. Wheaton had ordered de-icing to begin. The tower told him to expect a further delay, and he requested that de-icing be halted. 'Palm 90' was number 11 for departure when the airport reopened.
At 3:00, Wheaton instructed de-icing to continue, and the job was done by 3:10. Ground personnel reported only a "light dusting" of snow on the wings. At 3:23 pm, 'Palm 90' was cleared to push from the gate and the towing equipment was attached. Due to the deep accumulations of snow, however, the TUG was unsuccesful in its attempts to push the aircraft, and contrary to company policy, Wheaton elected to use the reverse thrust to back the airplane out of the gate. The reversers were engaged for a minute and a half, but only succeeded in sucking large amounts of storm debris into the engines. Finally, cooler heads prevailed, and a TUG with chains attached was called in. The aircraft was successfully pushed back.
'Palm 90' then proceeded to taxi into position behind a New York Air DC-9, the last of sixteen aircraft in line for takeoff. With a light snow still falling, Wheaton decided to use the hot exhaust from the preceeding DC-9's engines to melt the snow off the wings, which in the end only had the effect of pushing it to the trailing portion of the wing to refreeze. The aircraft's anti-ice system was unable to de-ice this portion of the wing, not that it made any difference.
While running through the takeoff checklist, the following conversation took place:
CAM-2: Air conditioning and pressurization?
CAM-2: Engine anti-ice?
When the Cockpit Voice Recorder tape was played back after recovery, there was much disagreement about Capt. Wheaton's response to "anti-ice." Many of the investigators could not accept the fact that, despite the freezing 20 degree temperatures and 25+ inches of snow on the ground, Wheaton said "off." The tapes were taken to the FBI Labs in Washington for analasys, and it was concluded that the word was, in fact, "off." Apparently, despite the weather, the crew had forgotten to activate the anti-ice systems.
At 3:59 pm, 'Palm 90' was cleared for takeoff with the remark "no delay on departure, if you will, traffic's two and a half out for the runway," added a few seconds later by ATC. Pettit advanced the throttles, and quickly responded "real cold, real cold," implying that the engines reached the takeoff EPR of 2.04 before the throttles had been fully advanced. Throughout the entire takeoff roll, the First Officer tried to inform the Captain that something wasn't right, but it was in vain. Wheaton was sure everything was in order:
15:59:51 CAM-1 It's spooled. Real cold, real cold.
15:59:58 CAM-2 God, look at that thing. That don't seem right, does it? Uh, that's not right.
16:00:09 CAM-1 Yes it is, there's eighty.
16:00:10 CAM-2 Naw, I don't think that's right. Ah, maybe it is.
16:00:21 CAM-1 Hundred and twenty.
16:00:23 CAM-2 I don't know.
16:00:31 CAM-1 Vee-one. Easy, vee-two.
At rotation speed, the aircraft pitched up sharply, causing Wheaton to reply "easy." It was a known fact that ice buildup on the wings of a 737 can cause a tendancy to pitch up. Pettit's correction of the nose-up attitude, however, failed to resolve the problem and the stickshaker immediately began to sound. Wheaton called "Forward, forward, easy. We only want 500," refering to the altitude at which the airplane had to be to make the 40 degree turn to the left around the Washington Monument and the restricted airspace over the Capitol.
"Come on. Forward, forward. Just barely climb," exclaimed Wheaton as the aircraft continued to stall. Moments later the aircraft was no longer climbing, but falling back to earth.
"Stalling, we're falling."
"Larry, we're going down Larry."
"I know it."
These are the last words spoken from the cockpit of 'Palm 90.' The aircraft came down directly on top of the 14th Street Bridge, which spans the Potomac River and is a major route from the Virginia suburbs into the city. Four automobiles were crushed, resulting in five deaths on the ground. The aircraft then impacted the icy water and quickly sank to the bottom. In the hours after the crash, only four passengers and a Flight Attendant would be pulled alive from the icy water.
The investigation of the crash concluded that the combination of the crew's use of thrust reverse on the ground, and their failure to active the engine anti-ice system, caused the crash. By failing to activate the engine anti-ice, the large amouts of snow and ice that were sucked into the engines during reverse thrust use was allowed to remain there, unchallenged. The ice buildup on the compressor inlet pressure probe, the probe which measures engine power, can cause false readings, as was the case here. The indications in the cockpit showed an Engine Pressure Ratio of 2.04, while the power plants were in reality only producing 1.70 EPR, or about 70% of available power. The combination of the ice covered wings and low power caused an immediate stall on takeoff that resulted in 74 lives lost.