Air Florida Flight 90 was a scheduled domestic passenger flight operated from Washington National Airport (now Ronald Reagan Washington National Airport) to Fort Lauderdale–Hollywood International Airport, with an intermediate stopover at Tampa International Airport, that crashed into the 14th Street Bridge over the Potomac River just after takeoff from Washington National Airport on January 13, 1982. The Boeing 737-200 that executed the flight, registered as N62AF, struck the bridge, which carries Interstate 395 between Washington, D.C., and Arlington County, Virginia, hitting seven occupied vehicles and destroying 97 feet (30 m) of guard rail before plunging through the ice into the Potomac River.
The aircraft was carrying 74 passengers and five crew members. Only four passengers and one crew member (flight attendant Kelly Duncan) were rescued from the crash and survived. Another passenger, Arland D. Williams Jr., assisted in the rescue of the survivors, but drowned before he could be rescued. Four motorists on the bridge were killed. The survivors were rescued from the icy river by civilians and professionals. President Ronald Reagan commended these acts during his State of the Union speech 13 days later.
The National Transportation Safety Board (NTSB) determined that the cause of the accident was pilot error. The pilots failed to switch on the engines' internal ice protection systems, used reverse thrust in a snowstorm prior to takeoff, tried to use the jet exhaust of a plane in front of them to melt their ice, and failed to abandon the takeoff even after detecting a power problem while taxiing and ice and snow buildup on the wings.
Background
Aircraft
The aircraft involved, a 13-year-old Boeing 737-222, registered as N62AF, was manufactured in 1969 and previously flown by United Airlines under the registration N9050U. It was sold to Air Florida in 1980. The aircraft was powered by two Pratt & Whitney JT8D-9A turbofan engines, and had flown over 27,000 hours before the accident.
Cockpit crew
The captain, Larry M. Wheaton, aged 34, was hired by Air Florida in October 1978 as a first officer. He was promoted to captain in August 1980. At the time of the accident, he had about 8,300 total flight hours, with 2,322 hours of commercial jet experience, all logged at Air Florida. He had logged 1,752 hours on the Boeing 737, the accident aircraft type, 1,100 of those hours as captain.
Wheaton was described by fellow pilots as a quiet person, with good operational skills and knowledge, who had operated well in high-workload flying situations. His leadership style was described as similar to those of other pilots. On May 8, 1980, though, he was suspended after failing a Boeing 737 company line check and was found to be unsatisfactory in these areas: adherence to regulations, checklist usage, flight procedures such as departures and autopilot usage, and approaches and landings. He resumed his duties after passing a retest on August 27, 1980. On April 24, 1981, he received an unsatisfactory grade on a company recurrent proficiency check when he showed deficiencies in memory items, knowledge of aircraft systems, and aircraft limitations. Three days later, he satisfactorily passed a proficiency recheck.
The first officer, Roger A. Pettit, aged 31, was hired by Air Florida on October 3, 1980, as a first officer on the Boeing 737. At the time of the accident, he had around 3,353 flight hours, 992 with Air Florida, all on the 737. From October 1977 to October 1980, he had been a fighter pilot in the US Air Force, accumulating 669 hours as a flight examiner, instructor pilot, and ground instructor in an F-15 fighter unit.
The first officer was described by personal friends and pilots as a witty, bright, outgoing individual with an excellent command of physical and mental skills in aircraft piloting. Those who had flown with him during stressful flight operations said that during those times, he remained the same witty, sharp individual, "who knew his limitations." Several persons said that he was the type of pilot who would not hesitate to speak up if he knew something specific was wrong with flight operations.
Pilots normally alternate who flies each leg. One pilot is designated the pilot flying (PF) and the other the pilot monitoring (PM); however, the captain retains ultimate authority for all aircraft operations. The first officer was the pilot flying during this accident.
Cabin crew
The three cabin crew consisted of Senior Flight Attendant Donna Adams (23) with 4 years' service at Air Florida, Marilyn Nichols (25) with 3 years' service, and Kelly Duncan (23) with 3 years' service.
Weather conditions
On Wednesday, January 13, 1982, Washington National Airport (DCA) was closed following a heavy snowstorm, which produced 6.5 inches (17 cm) of snow. It reopened at noon under marginal conditions as the snowfall decreased.
That afternoon, the plane was to return to Fort Lauderdale–Hollywood International Airport, with an intermediate stop at Tampa International Airport. The scheduled departure time was delayed about 1 hour and 45 minutes because of a backlog of arrivals and departures caused by the temporary closing of Washington National Airport. As the plane was readied for departure, moderate snowfall continued with a temperature of 24 °F (−4 °C).
Improper deicing procedures
The Boeing 737 was deiced with a mixture of heated water and monopropylene glycol by American Airlines, under a ground-service agreement with Air Florida. That agreement specified that covers for the pitot tubes, static ports, and engine inlets had to be used, but the American Airlines employees failed to comply with those rules. One deicing vehicle was used by two different operators, who chose widely different mixture percentages to deice the left and right sides of the aircraft. Subsequent testing of the deicing truck showed, "the mixture dispensed differed substantially from the mixture selected" (18% actual vs. 30% selected). The inaccurate mixture was the result of the replacement of the standard nozzle, "...which is specially modified and calibrated, with a non-modified, commercially available nozzle." The operator had no means to determine if the proportioning valves were operating properly because no "mix monitor" was installed on the nozzle.
Events of crash
Flight
The plane had trouble leaving the gate when the ground-services tug could not get traction on the icy ramp. For roughly 30 to 90 seconds, the crew attempted to back away from the gate using the reverse thrust of the engines (a powerback), which proved futile. Boeing operations bulletins had warned against using reverse thrust in those kinds of conditions.
Eventually, a ground tug unit properly equipped with snow chains was used to push the aircraft back from the gate. After leaving the gate, the aircraft waited in a taxi line with many other aircraft for 49 minutes before reaching the takeoff runway. The pilot apparently decided not to return to the gate for reapplication of deicing, fearing that the flight's departure would be even further delayed. More snow and ice accumulated on the wings during that period, and the crew was aware of that fact when they decided to take off. Heavy snow was falling during their takeoff roll at 3:59 pm EST.
Though the outside temperature was well below freezing and snow was falling, the crew did not activate the engine anti-ice systems. This system uses heat from the engines to prevent sensors and the engine intake cowl from accumulating ice or snow, ensuring accurate readings.
While running through the takeoff checklist, the following conversation snippet took place (CAM-1 is the captain, CAM-2 is the first officer):
CAM-2 Pitot heat?
CAM-1 On.
CAM-2 Engine anti-ice?
CAM-1 Off.
— Transcript, Air Florida Flight 90 Cockpit Voice Recorder
As a result, this caused the engine pressure ratio (EPR) thrust indicators to provide false readings. The correct engine power setting for the temperature and airport altitude of Washington National at the time was 2.04 EPR, but analysis of the engine noise recorded on the cockpit voice recorder indicated that the actual power output corresponded with an engine pressure ratio of only 1.70.
Neither pilot had much experience flying in snowy, cold weather. The captain had made only eight takeoffs or landings in snowy conditions on the 737, and the first officer had flown in snow only twice.
Adding to the plane's troubles was the pilots' decision to maneuver closely behind a New York Air DC-9 (Callsign: Apple 4) that was taxiing just ahead of them prior to takeoff, due to their mistaken belief that the warmth from the DC-9's engines would melt the snow and ice that had accumulated on Flight 90's wings. This action, which went specifically against flight-manual recommendations for an icing situation, actually contributed to icing on the 737. The exhaust gases from the other aircraft melted the snow on the wings, but instead of falling off the plane during takeoff, this slush mixture froze on the wings' leading edges and the engine inlet nose cone.
As the takeoff roll began, the first officer noted several times to the captain that the instrument panel readings he was seeing did not seem to reflect reality (he was referring to the fact that the plane did not appear to have developed as much power as it needed for takeoff, despite the instruments indicating otherwise). The captain dismissed these concerns and let the takeoff proceed. Investigators determined that plenty of time and space on the runway remained for the captain to have abandoned the takeoff, and criticized his refusal to listen to his first officer, who was correct that the instrument panel readings were wrong. The pilot was told not to delay because another aircraft was 2.5 nautical miles (2.9 mi; 4.6 km) out on final approach to the same runway. The following is a transcript of Flight 90's cockpit voice recorder during the plane's acceleration down the runway.
15:59:32 CAM-1 Okay, your throttles.
15:59:35 [SOUND OF ENGINE SPOOLUP]
15:59:49 CAM-1 Holler if you need the wipers.
15:59:51 CAM-1 It's spooled. Really cold here, real cold.
15:59:58 CAM-2 God, look at that thing. That don't seem right, does it? Ah, 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 V1. Easy, V2.
— Transcript, Air Florida Flight 90 Cockpit Voice Recorder
As the plane became briefly airborne, the voice recorder picked up the following from the cockpit, with the sound of the stick-shaker (a device that warns that the plane is in danger of stalling) in the background:
16:00:39 [SOUND OF STICKSHAKER STARTS AND CONTINUES UNTIL IMPACT]
16:00:41 TWR Palm ninety contact departure control.
16:00:45 CAM-1 Forward, forward, easy. We only want five hundred.
16:00:48 CAM-1 Come on forward....forward, just barely climb.
16:00:59 CAM-1 Stalling, we're falling!
16:01:00 CAM-2 Larry, we're going down, Larry....
16:01:01 CAM-1 I know!
16:01:01 [SOUND OF IMPACT]
— Transcript, Air Florida Flight 90 Cockpit Voice Recorder
The aircraft traveled almost half a mile (800 m) farther down the runway than is customary before liftoff was accomplished. Survivors of the crash indicated the trip over the runway was extremely rough, with survivor Joe Stiley—a businessman and private pilot—saying that he believed that they would not get airborne and would "fall off the end of the runway". When the plane became airborne, Stiley told his co-worker (and survivor) Nikki Felch to assume the crash position, with some nearby passengers following their example.
Although the 737 did manage to become airborne, it attained a maximum altitude of just 352 feet (107 m) before it began losing altitude. Recorders later indicated that the aircraft was airborne for just 30 seconds. At 4:01 pm EST, it crashed into the 14th Street Bridge across the Potomac River, 0.75 nmi (0.9 mi; 1.4 km) from the end of the runway. The plane hit six cars and a truck on the bridge, and tore away 97 feet (30 m) of the bridge's rail and 41 feet (12 m) of the bridge's wall. The aircraft then plunged into the freezing Potomac River. It fell between two of the three spans of the bridge, between the I-395 northbound span (the Rochambeau Bridge) and the high-occupancy vehicle lane north- and southbound spans, about 200 ft (70 yd; 60 m) offshore. All but the tail section quickly became submerged.
Of the people on board the aircraft:
- Four of the crew members (including both pilots) died.
- One crew member was seriously injured.
- Seventy of the 74 passengers died.
- Nineteen occupants were believed to have survived the impact, but their injuries prevented them from escaping.
Of the motorists on the bridge involved:
- Four sustained fatal injuries
- One sustained serious injuries
- Three sustained minor injuries
Clinging to the tail section of the broken airliner in the ice-choked Potomac River were flight attendant Kelly Duncan and four passengers: Patricia "Nikki" Felch, Joe Stiley, Arland D. Williams Jr. (strapped and tangled in his seat), and Priscilla Tirado. Duncan inflated the only flotation device they could find, and passed it to the severely injured Felch. Passenger Bert Hamilton, who was floating in the water nearby, was the first to be pulled from the water.