2010-12 · NASA ASRS report 921950
L1329 flight crew experiences air conditioning smoke during climb and turns off the right side bleed switches. This corrects the hot air and smoke problem but it is noticed during troubleshooting that the left pack is not supplying any air. Flight returns to departure airport where Maintenance discovers the right ACM has seized.
Shortly after being cleared to 16;000 by Departure the air coming from the right side pack suddenly became extremely hot. I reverted the right pack temperature control to manual mode and full cold with no affect to the temperature. After being handed off to Center we were cleared to climb to FL350 and started to notice smoke coming from the windshield defrost vents. Smoke was also coming out of the cabin air vents. Stopping the climb at 16;000 FT the Captain and I donned our oxygen masks and the Captain turned off the right right side pack's bleed air supplies while I notified Center of the situation; that we needed to return back to our departure airport; and advised them of souls on board and fuel remaining. We were cleared direct to the airport. While troubleshooting the Captain noticed that left side pack was not supplying any air and that the cabin altitude was rapidly climbing. In the turn back to the airport I notified ATC that we had also lost pressurization and were descending. Center cleared us down to 10;000 FT. In less than 1 minute from turning off the affected pack the smoke had started to clear. Following the smoke in the cabin procedure the ram air vent was opened and the emergency depressurization switch was depressed to help flush the smoke out of the cockpit and cabin. The decision was made to make an overweight landing at our departure airport in order to land the aircraft as soon as possible. L-1329 maximum landing weight is 36;000 LBS and a very smooth landing was performed by the Captain at 40;000 LBS after conducting a visual approach for the runway. Once clear of the runway a normal; unassisted taxi was performed to the ramp. The aircraft is currently under inspection by our mechanic to determine the actual cause of the problem; but it is believed that the right side pack suffered a bearing failure which lead to it seizing. This resulted in the extremely hot bleed air to not be cooled before entering the cabin/cockpit ducting. This extremely hot air caused the smoke. The mechanic is currently also investigating why the left side pack was unable to maintain pressurization after the right side was shut down.
Climbing through 14;500 smelled and then saw smoke in the cockpit. Leveled at 16;000 and shut off bleed air from #3 and #4 engines while First Officer donned O2 mask and started emergency checklist for smoke and fume elimination. Smoke that was coming from the cockpit vents stopped immediately and the cabin air started to clear. Then noticed that the cabin was climbing in excess of 2;000 FPM. This aircraft has dual ACM's [Air Cycle Machines] and the #1 pack should have provided sufficient air to pressurize the cabin. Notified ATC that we needed to descend and return to our departure airport. We made a rapid descent to below 10;000 and returned. Maintenance found the ACM turbine seized and replaced the unit.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.
Loading the flight search…
Pick an aircraft model — Boeing 737, Airbus A320, A380, Boeing 787 Dreamliner and more — enter your origin airport, and FlightFinder shows every route that plane flies from there with live fares.
We support Boeing 737/747/757/767/777/787, the full Airbus A220/A319/A320/A321/A330/A340/A350/A380 family, Embraer E170/E175/E190/E195, Bombardier CRJ and Dash 8, and the ATR 42/72 turboprops.
Search and schedules are free. Pro ($4.99/month, $39/year, or $99 one-time lifetime) unlocks the enriched flight card — on-time stats, CO₂ per passenger, amenities, live gate & weather — plus My Trips with push alerts.
Live schedules come from Amadeus, AeroDataBox and Travelpayouts. Observed routes (which aircraft actually flew a given city pair) are crowdsourced from adsb.lol ADS-B data under the Open Database License.