NYC03FA067

The Boeing 717 was on final approach when the display units (DUs) in the cockpit blanked, and the cockpit darkened. In addition smoke was smelled in the cockpit, and cabin. In the cabin, the emergency light illuminated for a few minutes, and then all lights extinguished and the cabin was dark. The landing gear was lowered. When the wing flaps were positioned to 40 degrees, a landing gear aural warning commenced and continued until power was removed after landing. The captain reported when the event initiated, he directed his vision outside the cockpit where it remained until after landing. The co-pilot reported that he also directed his vision outside of the cockpit in the final 20 seconds of approach. Neither pilot made use of the standby instruments or used a flashlight to check instruments. The captain commanded an emergency evacuation after he cleared the runway and stopped. When interviewed, the flight attendants reported that during the emergency evacuation, they did not check conditions outside of their doors prior to opening them. In addition, cabin emergency lighting was not turned on by the flight attendants, and the flight attendant at the tail cone station was unable to deploy her slide. Examination of the airplane revealed the left power control distribution unit (PCDU) had failed. The left DC bus was also lost and the ability to power the left DC bus from other sources was also lost. The failure of the PCDU was not instantaneous and it tried to recycle several times. Each time the PCDU recycled, it also reset the display of new data on the remaining DUs. This caused an extended blank display followed by eventual reset of data. The pre-programmed response to the loss of the left DC bus was the loss of two DUs, one on each side of the cockpit.

History of flight

On March 26, 2003, about 2239 eastern standard time, a Boeing 717-200, N957AT, operated by AirTran Airways as flight 356, received minor damage when the left side power control distribution power unit (PCDU) failed while on approach to land at LaGuardia Airport (LGA), Flushing, New York. During a subsequent emergency evacuation, 1 passenger was seriously injured, and 22 passengers received minor injuries. There were no injuries to the 2 pilots, 3 flight attendants, and 55 passengers. Night visual meteorological conditions prevailed for the scheduled passenger flight. An instrument flight rules (IFR) flight plan had been filed for the flight that departed from The William B Hartsfield Atlanta International Airport (ATL), Atlanta, Georgia, and was conducted under 14 CFR Part 121.

According to flightcrew interviews and documents from Air Tran airways, the en route part of the flight was without incident. Upon arrival in the New York area, the flight was radar vectored for the ILS runway 04 approach. The in-range checklist was completed and the landing weight was determined to be 97,000 pounds. The Vmin speed on approach was 135 knots, and the Vref with 40 degrees of flaps was 130 knots.

The flight was cleared for the ILS runway 4 approach, and instructed to contact LaGuardia control tower. After establishing contact with the control tower, the pilots were told that they were number 3 for the runway, following a Boeing 757, and that the braking action was reported as good by a preceding MD-80.

At 2239:16, the CVR recorded two thumps and two clicks on all channels.

The co-pilot called out the left generator was off, followed by the captain who reported they were, "...losing everything." The APU was started and the crew commented that they had lost all of their busses also. The cockpit area microphone (CAM), recorded the crew alerting and warning system (CAWS) stabilizer alert, "stabilizer motion" which repeated seven times. The co-pilot called, "select FADEC alternate" and advised the captain that he had manual throttles.

At 2239:42, the captain stated, "kill that light out of my face." The co-pilot acknowledged the captain's request, and then asked, "are you moving the stabilizer?" The captain replied that he was, "...not doing anything. I've lost everything." The co-pilot then stated, "generator left off." followed by the captain stating, "kill, kill this light...." to which, the co-pilot replied, "alright."

At 2240:00 the CAM recorded the CAWS stabilizer alert again. The co-pilot then tried to reset the generator, and the captain called, "there's the runway. I'm landing the airplane," followed by a request for landing gear down, and the landing checklist. The co-pilot reported that the auxiliary hydraulic pump had failed, followed by the captain who asked for the landing gear to be lowered. This was followed by the sound of a click and increased air noise similar to landing gear being operated.

At 2240:26, the captain questioned his Vref speed of 140 knots, and the co-pilot replied, "roger that." The captain then stated, "we don't have any idea if the gear's down, do we?", to which the co-pilot replied, "not yet, no. Weird huh."

At 2240:37, the flight was cleared to land by the control tower and told that the winds were from 010 degrees at 13 knots.

At 2240:45, the co-pilot said, "I smell something too, don't you."

At 2241:04, the captain said, "go to flaps forty." This was acknowledged by the co-pilot.

At 2241:08, the CAM recorded a sound similar to the CAWS landing gear alert, which started, and continued to the end of the recording. The CAM also recorded a mechanical voice, which stated, "one thousand [feet]."

At 2241:10, the captain stated, "you smell something burning? I think we have a fire." The co-pilot replied, "I smell something weird...no way to tell if landing gear down. A few seconds later the co-pilot stated, "we lost everything, that's for sure. Your speed's pretty damn high.", to which the captain replied, "that's all right...."

At 2241:34, the captain stated, "tell him we're declaring an emergency. We have an electrical problem." The co-pilot told the control tower that they had an electrical emergency. The captain further stated, "tell him to send the equipment", and the co-pilot transmitted to the control tower,"...we might have a possible fire...we're landing on runway four."

At 2241:58, the captain stated, "all right, we'll stay at this altitude." The co-pilot replied, "roger that. I wouldn't go any lower." At 2242:02, the CAM recorded a mechanical voice, which stated, "minimums." At 2242:04, the captain stated, "...we may have to evacuate the airplane." This was acknowledged by the co-pilot.

At 2242:09, the co-pilot stated, "I wouldn't get any lower." and the captain replied, "...we're all right...". At 2242:12, the co-pilot stated, "okay, your looking good. You're definitely fast. Don't go any faster." The captain replied, "I know, I know that." At the same time as the captain's reply, the CAM recorded a mechanical voice, which stated, "one hundred."

Between 2242:19 and 2242:25, the CAM recorded a mechanical voice calling out "fifty", "forty", "thirty", "twenty", "ten", and "five."

At 2242:25, the CAM recorded a sound similar to the airplane touching down on the runway, and at 2242:28, the CAM recorded a "thump" similar to nose landing gear contact with the runway. At 2242:36, the co-pilot called ,"reverse," and one second later he called, "eighty knots."

At 2242:50, the captain stated, "tell him we need the fire trucks out here. I think we may have a fi, some kind of fire." At 2242:52, the co-pilot transmitted to the control tower, "...tower, Citrus three fifty six, uh, please run the fire trucks out here. We are smelling electrical smoke." The local controller asked the pilots to pull all the way onto taxiway BRAVO, and acknowledged their request for fire trucks.

At 2243:04, the captain stated, "get, get the door, get the door unlocked." The local controller asked the pilots to hold short of taxiway FOXTROT, and this was acknowledged. The local controller then instructed the pilot to contact ground control, and the co-pilot replied, "sir, I can't..." The captain then transmitted, "We, we don't have time for that sir. I may have to evacuate. You're gonna have to just get some people out here. The local controller replied, "Okay, you can stop right there if you need to and do what you have to do."

At 2243:37, the captain stated, "we got some kind of fire guys. Get ready to get out of here. A flight attendant stated, "we have no lights", and the captain said, "just, just um all right just hold still, all right, just hold still, hold still."

At 2243:43, an announcement was made on the public address system which stated, "Ladies and gentlemen, we need everybody in their seats please...."

At 2243:44, the captain asked, "do you have any emergency lights?", and the co-pilot replied, "nothing." At 2243:47, the captain stated, "alright, evacuate the airplane. Tell 'em we've gotta evacuate the airplane." At 2243:48, the CAM reported a flight attendant stating, "evacuate, evacuate."

At 2243:50, the captain stated, "All right do your, lets do the checklist." The co-pilot replied, "okay."

The transcript ended at 2243:52

The captain reported that after he stopped the airplane, he exited his seat and opened the cockpit door to assess the situation. The cabin was dark. There was a stronger burning smell in the cabin than they had experienced in the cockpit. The captain then ordered an emergency evacuation of the airplane. The first officer reported that he completed the emergency evacuation checklist, which included resetting the wing flaps to 25 degrees.

The flight attendants reported that on approach, the cabin lights extinguished, and the emergency lights illuminated. Then a