Alliance Air Flight 7412

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Alliance Air Flight 7412
VT-EGJ Boeing 737 Alliance Air (8539297299) .jpg

An identical Boeing 737-2A8 Adv. From Alliance Air
Accident summary
Accident type Loss of control
place Anishabad , Bihar , IndiaIndiaIndia 
date July 17, 2000
Fatalities 55
Survivors 3
Injured 3
Fatalities on the ground 5
Injured on the ground 5
Aircraft
Aircraft type United StatesUnited States Boeing 737-2A8 Adv.
operator IndiaIndia Alliance Air
Mark IndiaIndia VT-EGD
Departure airport Calcutta Airport , West Bengal , IndiaIndiaIndia 
1. Stopover Patna Airport , Bihar , IndiaIndiaIndia 
2. Stopover Lucknow Airport , Uttar Pradesh , IndiaIndiaIndia 
Destination airport Delhi Airport , IndiaIndiaIndia 
Passengers 52
crew 6th
Lists of aviation accidents

The Alliance Air flight 7412 (flight number IATA : 9I7412 , ICAO : LLR7412 , call sign: ALLIED 7412 ) was a line domestic flight of the airline Alliance Air from the airport Calcutta to Delhi airport with scheduled stops at the airport Patna and Lucknow airport . On July 17, 2000, a Boeing 737-2A8 Adv. With the registration number VT-EGD had an accident on this flight near Patna Airport after losing control. 60 people were killed in the accident.

plane

The aircraft involved in the accident was a Boeing 737-2A8 Adv., Which was 20 years and two months old at the time of the accident. The machine was assembled at the Boeing plant in Renton , Washington , and made its maiden flight on May 29, 1980, before being delivered to Indian Airlines on June 18, 1980 of the same year . The aircraft had the factory number 22280, it was the 671st Boeing 737 from ongoing production. The machine was approved with the aircraft registration VT-EGD .

The machine was involved in an accident on January 15, 1986 when the captain on Indian Airlines Flight 529 attempted to land the machine at Tiruchirapalli Airport in sub-weather conditions . During the go- around shortly before touchdown, the wing touched the runway due to a roll angle that was too large and was significantly damaged in the process. There were no injuries among the 122 passengers and six crew members.

Alliance Air, a newly founded subsidiary of Indian Airlines at the time, took over the aircraft on January 2, 1997. The twin - engine narrow -body aircraft was equipped with two Pratt & Whitney JT8D-17A engines. At the time of the accident, the machine had completed 44,087 operating hours and 51,278 take-offs and landings. The machine was due to be decommissioned in late 2000, according to Government of India regulations prohibiting the operation of aircraft more than 20 years old.

Crew and passengers

There was a crew of six on board, consisting of a captain, first officer and four flight attendants. For the flight of the first flight segment to Patna, 52 passengers were seated on board the machine. The 35-year-old captain Manjit Singh Sohanpal had 4,072 hours of flight experience, 1,489 hours of which in the Boeing 737. The 32-year-old First Officer Arvind Singh Bagga had 3,536 hours of flight experience, 2,844 of which he had worked in the cockpit of the Boeing 737.

the accident

On the day of the accident, the plane took off from Calcutta at 6:51 a.m. local time. At 07:17 am, air traffic control in Patna asked the pilots to report for the approach and to inquire about possible aircraft in the vicinity at Calcutta air traffic control. A short time later, the crew replied that the air traffic controllers in Calcutta had reported that there were no other machines along the planned approach route. The aircraft was finally cleared to descend to 7,500 feet and the pilots were instructed to report to the airport at a distance of 25 nautical miles , which the crew did at 0726. This was followed by clearance to descend to 4,000 feet, followed by instructions to report for the approach on runway 25.

At 0728, the crew reported that they were entering the last curve for the final approach and at 0731 that they were now entering the control area of ​​the airport. At this point the machine appeared on the radar. The pilots were then instructed to descend to 1,700 feet. The crew received clearance to land on runway 25 when the pilots requested clearance to fly a 360-degree turn, as the aircraft was too high for a safe approach at the critical moment. Permission was granted and the pilots initiated a left turn. There was a stall when flying the curve . The machine struck several one-story houses in a state housing estate and crashed about two kilometers southwest of the airport into a state housing estate behind the Gardani Bagh girls' school in Anishabad. The machine broke into four parts in the crash and caught fire. The impact and the ensuing fire were enormous.

Rescue operation

The airport fire brigade's ambulance arrived at the crash site together with the fire engines and initially transported two injured people to the local hospital. Then the second ambulance from the airport fire department arrived and transported more injured passengers to the hospital. Shortly afterwards, ambulances from other aid organizations also arrived and helped evacuate all the injured.

The crash site was five to six kilometers from the airport. According to the accident report, the airport fire brigade arrived five to six minutes later, with residents saying that 15 to 20 minutes had passed before the emergency services arrived. The first fire engine laid two hoses and began fighting the fire, with the device failing after three minutes. After the emergency services could not fix the defect on the fire engine, a mechanic had to be called from the airport and the vehicle could be put back into operation after an hour. However, after a few minutes of operation, the truck had to drive back to the airport to refill water. On the way he stopped twice because of mishaps.

The second fire engine also had to return to the airport a few minutes after the start of the fire fighting operation to refill water. Within a short period of time, an unmanageably large number of onlookers gathered around the crash site and hindered the rescue operation. According to witnesses, the mood was charged and some in attendance showed a willingness to verbally or physically attack persons in uniform or positions of authority. Sometimes hundreds of people tried to climb onto the ambulance to get a better view. Only after the arrival of the military police from Bihar and an army contingent did the masses calm down to some extent.

Victims and survivors

Seven passengers were rescued from the plane alive, six of whom were seriously injured. The seventh passenger had not suffered any major injuries apart from a slight concussion. Of the six seriously injured, four later died. Thus 55 passengers were killed in the accident while only three survived. Five dead and five were injured in the housing estate into which the machine crashed.

Accident investigation

After the accident, a rudder control unit failure such as on United Airlines Flight 585 or USAir Flight 427 was considered. The investigators later rejected this thesis and stated that the control unit was operational and in good condition.

The flight recorder analysis showed that the engines had been idling during the entire descent profile and that the speed was continuously decreasing. The investigators could not understand why the engines were left idling after the lift aids were extended to 40 degrees. It was suspected that this was due to the excessively high approach. If the intention was to find the glideslope, the pilot would have had to maintain the speed with the classic flight technique by reducing the angle of attack by moving the control column forward so that the machine could find its way back onto the glide slope at an increased rate of descent. When the application to fly the 360-degree turn was requested, the speed of the machine was 119 knots, which was the normal landing speed. Flying a 360-degree turn was not an authorized practice under the Alliance Air manual, so it may have confused First Officer Arvind. From the recordings of the flight data recorder it emerged that the aircraft was not flown according to the ILS procedure during the approach , although the air traffic control was given the impression that this was the case.

The atmosphere in the cockpit was relaxed until 15 seconds before the crash. The first signs of fear only became apparent when Captain Arvind asked for the landing gear to be retracted. The investigators recreated the crash in the simulator and came to the conclusion that increasing the engine thrust 16 seconds before the crash had reduced the rate of descent. However, eight seconds later when the buoyancy aid lever was set to 15 degrees, the rate of descent increased again. This was caused by a loss of lift due to the reduction in the wing attack area when the lift aids moved from 40 to 15 degrees. Six seconds after the flap lever was moved 15 degrees, the rate of descent increased even further. The alignment of the lift aids and the wings no longer produced enough lift to keep the machine in the air. The machine developed a very high angle of attack of 26 degrees, after which it came to a stall from which the machine could no longer be supported.

context

Just one month later there was an accident on Gulf Air flight 072 with 143 deaths. In this case, too, the accident occurred while flying a 360-degree turn that did not comply with the standard procedures.

swell

Coordinates: 25 ° 35 ′ 24 ″  N , 85 ° 6 ′ 18 ″  E