History of the Flight
On 13 June 2014, Jet Airways Ltd. ATR 72-212A aircraft VT-JCS, operating flight 9W-2731 from Bengaluru to Cochin, was involved in a serious incident during pushback at Bengaluru. The aircraft had previously operated two sectors without any reported abnormalities. The weather at Bengaluru at the time of startup was fine with visibility of approximately 10 km.
The aircraft was cleared for pushback, facing east on taxiway L3. All operations were normal until immediately after pushback, when the NAC OVERHEAT warning activated. The cockpit crew shut down Engine No. 2, and the warning disappeared after about 30 seconds. Engine No. 1 was started normally. The crew then started Engine No. 2 with the prop brake released, and the NAC OVERHEAT warning illuminated again, disappearing after approximately 25 seconds. Subsequently, the MODE SEL AUTO FAULT indication appeared on the anti/de-icing panel. The crew informed the ground crew and consulted about the fault.
Shortly thereafter, a burning smell was noticed in the cockpit, followed by heavy smoke. The cabin crew also reported smoke in the cabin. The cockpit crew informed ATC and the ground crew, then decided to disembark the passengers at the same position (L3) and return to the bay. ATC was asked to activate fire services. Both engines were shut down. Passengers were deplaned normally without hand baggage, and the aircraft was towed back to bay 36. There were 68 persons on board; no injuries were reported, and there was no fire.
Injuries to Persons
No injuries occurred to any of the 68 occupants (4 crew and 64 passengers).
Damage to the Aircraft
External visual inspection revealed no signs of burning or other abnormalities. The LH and RH packs, air cycle machine, and condenser were removed and checked, with no traces of oil contamination. However, oil smell was detected in the ducts and hoses surrounding the LH ACM and condenser. Boroscopic inspection of both engines showed oil stains on the LP impeller of the LH engine and oil stains and puddles on the HP impeller vanes of both engines. Two HPT blades on each engine had oil stains on the leading edge near the tip, without burn marks.
Following recommendations from Pratt & Whitney, the air switching valves on both engines were checked and found satisfactory, then replaced. Compressor washes and a high-power engine ground run were conducted, after which no oil smell or fumes were observed. An evaluation flight on 19 June 2014 confirmed no smoke or oil smell in the cockpit and cabin. Prior to this incident, the same aircraft had been involved in a serious incident at Hyderabad involving swapped inner valves of the switching valve during maintenance.
Personnel Information
The pilot-in-command held an ATPL, with 6,481 hours total flying experience and 3,706 hours on type. The co-pilot held a CPL, with 289 hours total flying experience and 13 hours on type.
Aircraft Information
The aircraft, an ATR 72-212A (MSN 920), was powered by two PW127F engines. It had a valid Certificate of Airworthiness and was maintained according to an approved schedule. The LH engine (S/N EB0321) had 14,370 hours since new and 287 hours since last HSI. The RH engine (S/N ED0089) had 14,565 hours since new and 778 hours since last overhaul.