Narrative:
Air India Express flight 611, a Boeing 737-800, impacted the localizer antenna and an airport wall on takeoff from Tiruchirappalli International Airport, India.
The aircraft was operating a regular flight to Dubai. It was cleared for takeoff from runway 27 at 01:18 local time. As the aircraft accelerated through a speed of 117 knots, the captain's seat recliner mechanism failed. As the captain became unsettled, the throttle levers and control column were moved back inadvertently. He handed over control to the co-pilot for five seconds.
After adjusting his seat the captain took control back from the co-pilot and the take off was continued.
Both crew members failed to notice drop in engine thrust from 98% to 77%. And since the Auto Throttle was in Throttle Hold mode above 84 kts, the thrust remained at 77%.
At 144 knots, some 2000 feet short of the runway end, the captain raised the nose of the aircraft for rotation. he noticed a slower rotation rate and that a higher control column force was required than normal. He increased the control column force aft in order to get airborne. This caused a higher rotation rate and a pitch angle of 10.7 degrees which lead to tail strike on the undulated soft surface past the end of the runway for 17 meters followed by the aft fuselage contacting the localizer antenna and boundary wall. Both main landing gears also impacted the brick boundary wall, causing two holes.
The aircraft climbed to FL360 and proceeded towards Dubai because all systems were normal. While en route the operations department insisted upon a diversion to Mumbai. At that time the flight was well over the Arabian Sea. The aircraft landed safely at Mumbai at 05:38 local time.
PROBABLE CAUSE OF THE ACCIDENT: Delayed take-off due to reduction of take-off thrust N1 from 98 % to 77 % before reaching V1, inability of both the crew members to monitor the thrust parameters and to take timely corrective action. This resulted in tail strike and subsequent hitting of the localizer Antenna and boundary wall of the airport.
Contributory factors:
- PIC seatback recliner mechanism failure during take-off roll.
- Breakdown of Crew coordination during switching between PF, PM and back.
- Loss of situational awareness
Runway excursion (overrun)
VOTR 111930Z 00000KT 5000 BR FEW018 SCT100 27/24 Q1008 NOSIG
20:00 UTC / 01:30 local time:
VOTR 112000Z 00000KT 5000 BR FEW018 SCT100 27/24 Q1007 NOSIG
departure track
flight track
accident date: 12-10-2018
type: Boeing 737-8HG (WL)
registration: VT-AYD
| Status: | Accident investigation report completed and information captured |
| Date: | Friday 12 October 2018 |
| Time: | 01:18 |
| Type: |  Boeing 737-8HG (WL) |
| Operator: | Air India Express |
| Registration: | VT-AYD |
| MSN: | 36340/3122 |
| First flight: | 2009-12-02 (8 years 11 months) |
| Total airframe hrs: | 29719 |
| Cycles: | 10023 |
| Engines: | 2 CFMI CFM56-7B27 |
| Crew: | Fatalities: 0 / Occupants: 6 |
| Passengers: | Fatalities: 0 / Occupants: 130 |
| Total: | Fatalities: 0 / Occupants: 136 |
| Aircraft damage: | Substantial |
| Aircraft fate: | Repaired |
| Location: | Tiruchirappalli-Civil Airport (TRZ) ( India)
|
| Phase: | Takeoff (TOF) |
| Nature: | International Scheduled Passenger |
| Departure airport: | Tiruchirappalli-Civil Airport (TRZ/VOTR), India |
| Dubai Airport (DXB/OMDB), United Arab Emirates | |
| Flightnumber: | IX611 |
Air India Express flight 611, a Boeing 737-800, impacted the localizer antenna and an airport wall on takeoff from Tiruchirappalli International Airport, India.
The aircraft was operating a regular flight to Dubai. It was cleared for takeoff from runway 27 at 01:18 local time. As the aircraft accelerated through a speed of 117 knots, the captain's seat recliner mechanism failed. As the captain became unsettled, the throttle levers and control column were moved back inadvertently. He handed over control to the co-pilot for five seconds.
After adjusting his seat the captain took control back from the co-pilot and the take off was continued.
Both crew members failed to notice drop in engine thrust from 98% to 77%. And since the Auto Throttle was in Throttle Hold mode above 84 kts, the thrust remained at 77%.
At 144 knots, some 2000 feet short of the runway end, the captain raised the nose of the aircraft for rotation. he noticed a slower rotation rate and that a higher control column force was required than normal. He increased the control column force aft in order to get airborne. This caused a higher rotation rate and a pitch angle of 10.7 degrees which lead to tail strike on the undulated soft surface past the end of the runway for 17 meters followed by the aft fuselage contacting the localizer antenna and boundary wall. Both main landing gears also impacted the brick boundary wall, causing two holes.
The aircraft climbed to FL360 and proceeded towards Dubai because all systems were normal. While en route the operations department insisted upon a diversion to Mumbai. At that time the flight was well over the Arabian Sea. The aircraft landed safely at Mumbai at 05:38 local time.
Probable Cause:
PROBABLE CAUSE OF THE ACCIDENT: Delayed take-off due to reduction of take-off thrust N1 from 98 % to 77 % before reaching V1, inability of both the crew members to monitor the thrust parameters and to take timely corrective action. This resulted in tail strike and subsequent hitting of the localizer Antenna and boundary wall of the airport.
Contributory factors:
- PIC seatback recliner mechanism failure during take-off roll.
- Breakdown of Crew coordination during switching between PF, PM and back.
- Loss of situational awareness
Accident investigation:
 |
|
Classification:
Collision with approach or runway lightsRunway excursion (overrun)
METAR Weather report:
19:30 UTC / 01:00 local time:VOTR 111930Z 00000KT 5000 BR FEW018 SCT100 27/24 Q1008 NOSIG
20:00 UTC / 01:30 local time:
VOTR 112000Z 00000KT 5000 BR FEW018 SCT100 27/24 Q1007 NOSIG
Follow-up / safety actions
Photos
departure track
flight track
accident date: 12-10-2018
type: Boeing 737-8HG (WL)
registration: VT-AYD
Video, social media
Air India Trichy pics coming in. Severe Boeing 737 damage pic.twitter.com/SJVGLiEQvx
Tarun Shukla (@shukla_tarun) October 12, 2018
Obstacle chart for Tiruchirappalli Airport (TRZ/VOTR). Antenna array and brick wall are 7 and 5 feet above the elevation of the runway end. pic.twitter.com/oXu7KNJXyZ
— Aviation Safety Net (@AviationSafety) October 12, 2018
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Tiruchirappalli-Civil Airport to Dubai Airport as the crow flies is 2924 km (1827 miles).
Accident location: Exact; deduced from official accident report.
Distance from Tiruchirappalli-Civil Airport to Dubai Airport as the crow flies is 2924 km (1827 miles).
Accident location: Exact; deduced from official accident report.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2023 Flight Safety Foundation