In-Flight Fires Wreak Havoc With Systems Reliability

Air Safety Week, Sept 22, 2003

'Checking for hot spots'

Case: B757 diverts after a strong odor of sulfur fumes follows a muffled 'bang' in the aft cargo compartment.

Details: "In flight odor resembling sulfur was smelled. The flight attendants were concerned and we asked pax if anyone had lit a match. The smell got worse, following the meal service and now we began searching overhead bins and seat areas ... Unable to find it. We notified the cockpit. FO came out and also smelled odor ... FO returned to cockpit and we went to last coach row. As we sat down, there was a loud bang and rumbling sound from the area of aft cargo. Following the sound, the entire cabin filled with a very strong burning sulfur smell. The fumes ... were so strong that the cockpit crew had to go on oxygen, including the FA that was there ... The cockpit crew had the cabin crew turn off all of the cabin electrical items, with the cabin crew then checking for hot spots on the floor."

Issues:

* Suspected improvised explosive device placed on board by a suspicious passenger who had "a handheld device resembling a TV remote control which he said was his remote for his computer that was in his checked baggage."

* Difficulty isolating source.

* Anxiety level among FA's, all other pax save this one 'cool' pax.

'No indication'

Case: B767-200 crew had #1 engine failure.

Details: "Climbing through FL [flight level] 300, crew heard a loud bang. Aircraft yawed to the left. Almost instantaneous burning smell and some smoke in the cockpit ... captain accomplished engine surge checklist and directed FO to declare an emergency and begin a descent. Engine stabilized at idle. Donned oxygen mask. There were no EICAS messages and no indication of fire.

"We landed with flaps 20 degrees and auto brakes #2. Still no indication of fire. "

Issues:

* Nil instrument readings.

* Rapid pace of events.

'Detectors did not alert'

Case: MD-11 smoke in cruise.

Details: "A slight haze/smoke was noticed in the cockpit. A visual inspection of main cabin revealed moderate smoke. An immediate diversion ... was initiated. Landing was uneventful. Note: smoke detectors did not alert crew to smoke.

"Once the decision was made to divert, it was approximately 30 minutes to landing. The cabin was depressurized at FL 250. 350 KIAS [knots indicated air speed] was maintained until 15 NM on final. Speed was maintained above 250 knots below 10,000 feet because of the unknown source of the smoke and fumes.

"High speed approaches had been previously trained for in simulator sessions."

Issues:

* Difficulty isolating/locating source of smoke.

* Reliability of smoke detectors.

* Virtue of simulator training in high speed approaches.

* Note crew dispensed with 250-kt. speed limit below 10,000 feet.

'Smoke pouring out'

Case: B737-300 had heavy smoke entering the aircraft following takeoff, after being de-iced.

Details: "Got de-iced, Taxied to runway. On takeoff after gear retraction, saw thick white smoke pouring out above and behind the FO - so thick we could not see the instrument panel.