View source for Alliance Air Flight 7412

{{short description|Aviation accident}}
{{Use dmy dates|date=September 2019}}
{{Use Indian English|date=August 2017}}
{{Infobox aircraft occurrence
| image = VT-EGJ Boeing B.737 Alliance Air (8539297299).jpg
| alt = 
| caption = An Alliance Air Boeing 737-2A8 similar to the one involved in the crash
| occurrence_type = Accident
| date = {{start date|2000|07|17|df=y}}
| summary = [[Pilot error]] due to violating approach procedure which leads to loss of control
| site = near [[Jay Prakash Narayan Airport|Lok Nayak Jayaprakash Airport]], [[Patna]], [[Bihar]], [[India]]
| coordinates = {{Coord|25|35|24|N|85|06|18|E|type:event|display=inline,title}}
| total_fatalities = 60
| total_injuries = 8
| aircraft_type = [[Boeing 737|Boeing 737-2A8]]
| aircraft_name = 
| operator = [[Alliance Air (India)|Alliance Air]]
| IATA = 9I7412
| ICAO = LLR7412
| callsign = ALLIED 7412
| tail_number = VT-EGD
| origin = [[Netaji Subhas Chandra Bose International Airport]], [[Kolkata]], India
| stopover = 
| stopover0 = [[Jay Prakash Narayan Airport|Lok Nayak Jayaprakash Airport]], [[Patna]], India
| last_stopover = [[Chaudhary Charan Singh Airport]], [[Lucknow]], India
| destination = [[Indira Gandhi International Airport]], [[Delhi]], India
| passengers = 52
| crew = 6
| fatalities = 55
| injuries = 3
| missing = 
| survivors = 3 (initially 7)
| ground_fatalities = 5
| ground_injuries = 5
| occupants = 58
}}

'''Alliance Air Flight 7412''' was a scheduled domestic passenger flight operated by [[Alliance Air (India)|Alliance Air]], a subsidiary of the airline [[Indian (airline)|Indian]], from Kolkata's [[Netaji Subhas Chandra Bose International Airport]] to [[Indira Gandhi International Airport]] in Delhi. On 17 July 2000, while on approach to its first stopover in [[Patna]], the [[Boeing 737-200|Boeing 737-2A8]] operating the route nose-dived and crashed into a residential area in [[Patna]], killing 60 people including 5 on the ground.

The final report, investigated by the Indian [[Directorate General of Civil Aviation (India)|Directorate General of Civil Aviation]], concluded that the cause of the crash was due to pilot error.<ref name="DGAC">{{Cite web|title=REPORT ON ACCIDENT TO ALLIANCE AIR BOEING 737-200 AIRCRAFT VT-EGD ON 17TH JULY, 2000 AT PATNA|url=https://dgca.gov.in/digigov-portal/Upload?flag=iframeAttachView&attachId=130617556&mainAccidentReports|date=31 March 2001|website=dgca.gov.in|publisher=[[Directorate General of Civil Aviation (India)|Directorate General of Civil Aviation]]|access-date=2019-03-10}}</ref> 

== Accident ==
Flight 7412 departed Calcutta ([[Kolkata]]) at 06:51 on 17 July 2000, for a flight to [[Delhi]], with stops at [[Patna]] and [[Lucknow]]. Patna ATC asked the aircraft at 07:17 to report for descent and also to check descent traffic with Kolkata Area Control.  The aircraft soon responded that Kolkata had reported negative traffic.  Flight 7412 was then cleared for descent to [[Flight level|FL75]] and asked to report 25 NM and the same was reported by the aircraft at 07:26. Flight 7412 was cleared to descend to 4000&nbsp;ft. and was asked to report for approach runway 25.<ref name="DGAC" />

At 07:28, Flight 7412 reported commencing the turn and at 07:31 reported crossing the airport area and coming up on the localiser.  Flight 7412 was then asked to descend to 1700&nbsp;ft. The crew had been cleared to land at runway 25 at [[Jay Prakash Narayan Airport|Lok Nayak Jayaprakash Airport]] at [[Patna]] when the pilots requested a 360-degree [[Airfield traffic pattern#orbit|orbit]] due to the flight being high on the approach. Permission was granted and a left turn was initiated. During the left turn, the aircraft [[stall (flight)|stalled]]. The plane then grazed a few single-storied houses in a government residential housing estate and crashed in a government residential colony behind Gardani Bagh Girls School at Anishabad, which is located about 2&nbsp;km southwest of the Patna Airport.<ref name=ASN>{{ASN accident|id=20000717-0}}</ref> The aircraft broke into four pieces.<ref name="ASN" />

When the aircraft struck the residential quarters and the ground, the impact was severe.  The intensity of post impact fire was also severe.  Initially, seven passengers were extricated alive.  Of them, six were seriously injured.  Miraculously, one of the passengers walked out of the wreckage without much injury even though he had a minor concussion and was treated later.  Of the six injured passengers, four died subsequently. Two passengers recovered completely after treatment.<ref name="DGAC" />

The airport ambulance had proceeded to the crash site along with the CFTs.  Two injured passengers were transported to the PMCH in the first instance.  Subsequently, the second ambulance from the airport was also pressed into service to transport the remaining injured passengers for medical aid.  Shortly after the arrival of the airport ambulance, ambulances from other assisting agencies also arrived and helped in removing all the injured for medical aid.<ref name="DGAC" />

===Failures in Rescue Services===
The accident site was 5–6&nbsp;km from the airport. The fire personnel reached the site in 5 to 6 minutes (local residents stated that the tenders reached only after 15–20 minutes). The first Crash Fire Tender (CFT) laid two hoses and began to fight the fire; however, it failed in 3 minutes. After failing in their efforts to rectify the fault, the CFT crew had to call a mechanic from the airport and the CFT was put back into operation after an hour. However, after a few minutes of operation, it went back to the airport to refill water. On the way it broke down twice.<ref name="Human factor">{{Cite journal|last=Gomez|first=Wg Cdr G|date=2002|title=Human factor analysis of Alliance air crash flight CD-7412|url=http://medind.nic.in/iab/t02/i1/iabt02i1p66o.pdf|url-status=live|journal=Indian Journal of Aerospace Medicine|pages=66–74|archive-url=https://www.webcitation.org/6O63f9E7c?url=http://medind.nic.in/iab/t02/i1/iabt02i1p66o.pdf|archive-date=2014-03-15}}</ref>

The second CFT after a few minutes of operation had to return to the airport to refill water. The crowd that collected within a short time was unmanageable and definitely hampered the rescue operations. According to witnesses, crowd tempers ran high and there was a general tendency to target anybody in uniform or position of authority with verbal abuse and physical violence. At times there were hundreds of people trying to climb on to the rescue vehicles to get a better view. It was only after the arrival of the Bihar military police jawans and the army contingent that some semblance of crowd control was achieved.<ref name="Human factor" />

==Aircraft==
The aircraft involved in the accident was a Boeing 737-200. Boeing 737-200 is a twin-engine jet transport airplane manufactured by Boeing Commercial Airplane Company, USA.  It is designed to operate over short to medium ranges at cruise speeds of approximately 950 kilometres per hour (km/h).  Two P&W JT8D/17A engines power the aircraft, each developing approximately 16,000 pounds (lbf) of thrust at sea level.<ref name="DGAC" />

The aircraft involved in the accident was registered in India as VT-EGD with a serial number of MSN22280. The aircraft was manufactured in 1980 and sold to Indian Airlines. It was subsequently leased to Alliance Air in 1999.<ref name="DGAC" />

==Investigation==
The aircraft in question, VT-EGD, had been involved in an earlier accident. On 15 January 1986, the pilot of flight 529 attempted to land at Tiruchirapalli in conditions below weather minima (reported Wx was exactly the minima). During a go-around (wave-off, just before touch down) the wing contacted the runway due to an excessive bank angle (the delay in spool-up times for both engines were more than 5 seconds apart with the right engine slow). The HIALS was not switched on at the time 529 was approaching and the ATC anemometer was unserviceable. The wing was substantially damaged, but there were no injuries among the 6 crew and 122 passengers. The pilot displayed great skill in manually flying the B737 at FL100 and diverted to Chennai and landed safely with flight controls in "manual reversion" on runway 07<ref name="ASN" /><ref name="ASN2">{{ASN accident|id=19860115-1|title=Flight 529}}</ref> The aircraft was to be phased out by the end of the year per Indian government guidelines which do not allow aircraft over 20 years old to operate in Indian airspace.<ref name="rediff1">{{Cite web|title=Alliance Air Boeing 737 crashes near Patna|url=https://www.rediff.com/news/2000/jul/17air20.htm|website=www.rediff.com|access-date=2019-03-10}}</ref>

Investigators ruled out terrorism as the cause of the accident. They didn't find any signs of explosion nor a fire had occurred in flight. Both pilots were not intoxicated and fully aware at the time of the crash.<ref name="DGAC" />

The flight crew consisted of Captain Manjit Singh Sohanpal and co-pilot Arvind Singh Bagga. A criminal case, filed against them based on the statement of a surviving passenger, was later withdrawn.<ref name="rediff1" /><ref name="rediff2">{{Cite web|url=https://www.rediff.com/news/2000/jul/21crash.htm|title=FIR against Alliance Air pilot, co-pilot withdrawn|website=www.rediff.com|access-date=2019-03-10}}</ref> Both Captain Sohanpal and co-pilot Bagga died in the accident.<ref name="rediff1" />
[[File:Boeing 737-3K2 AN0769754.jpg|thumbnail|A [[TAESA]] Boeing 737 with the rudder (yellow) visible.]]
Investigators later conducted an observation with its Rudder Power Control Unit (PCU). The Main Power Control Unit (MPCU) of the rudder has been a [[Boeing 737 rudder issues|subject of intense debate and discussions]] and has undergone mandatory modifications as a result of some previous accident investigations. The PCU has responsible for several high-profile crashes, such as [[United Airlines Flight 585]], [[USAir Flight 427]], and [[Eastwind Airlines Flight 517]]. Flight 7412 nose-dived before the crash, as well as two previous crashes, Flight 585 and Flight 427. The rudder locked up in a particular direction, and reversal of rudder to that of the commanded position (anomalous rudder movements such as un-commanded movements). These have been attributed to the secondary slide jamming with the primary slide due to contamination or adverse buildup of tolerances during manufacture. However, investigators later dismissed it and ruled out the failure of the PCU as the cause, and concluded that it was serviceable and was in good condition.<ref name="DGAC" />

As both black boxes were found by search and rescue teams, investigators tore into both black boxes and analyzed their contents. The results showed that the engines were at idle thrust throughout the descent profile and the speed was continuously reducing. It was not clear why the engines were kept at idle thrust even after selecting Flaps 40.   It was perhaps because the aircraft was higher than normal on approach.  If the intention was to regain the correct glide path then classic flying technique would have required the Pilot to maintain speed by reducing the angle of attack by pushing the control column forward while allowing the aircraft to regain the correct glide path with an increased rate of descent.<ref name="DGAC" />

When it was realized that the aircraft was too high to effect a landing, a 360° orbit was requested. The [[V speeds#VREF|landing reference speed or threshold crossing speed]]{{clarify|date=August 2019}} at this time was 119 knots, the landing speed. The procedure to carry out a 360° turn was not an authorised procedure as per the Alliance Air Operations Manual and could have caused confusion in the mind of First Officer Arvind.  It was clear from the FDR recording that the aircraft was not following the ILS procedure but Patna ATC was being given the impression that the aircraft was doing so.
 
At any busy airport, this would have been unthinkable and would have created a conflict.  However, there was no other traffic for miles around Patna and ATC gave the permission after confirming that the crew had the airfield in sight. Captain Manjit tried to resolve this issue without any discussion with First Officer Arvind. The atmosphere in the cockpit was relaxed and tension free till 15 seconds before the crash. The first sign of anxiety became apparent only when Arvind called for raising the landing gear.<ref name="DGAC" />

Investigators conducted a simulation of the crash and found that at 16 seconds before the crash, the spooling up of the engine had reduced the rate of descent.  However, eight seconds later when the Flap Lever was moved to 15, the rate of descent increased as seen by the steepening of the slope of the curve.  This was caused by loss of lift due to the reduction in wing area as the flaps moved up from 40 to 15. Six seconds after the flap Lever was moved to 15, the rate of descent increased even further indicating that the flaps were close to 15 position and the wing no longer generated enough lift to support the aircraft. This high rate of descent together with the high Nose Up pitch attitude held by the pilot resulted in the aircraft attaining a very high [[angle of attack]] of the order of 26<sup>o</sup>.  The aircraft had completely stalled by this time and even though thrust had been increased to the maximum possible on both engines, recovery was not possible.<ref name="DGAC" />

The final investigation noted pilot error as the cause of the plane crash.<ref name="rediff3">{{Cite web|title=Patna crash blamed on pilot error|url=https://www.rediff.com/news/2001/mar/31crash.htm|website=www.rediff.com|access-date=2019-07-03}}</ref> According to the panel, the crew had not followed the correct approach procedure, which resulted in the aircraft being high on approach. The engines had been kept at idle thrust, which allowed the airspeed to decline below the allowed minimum for approach and caused the aircraft to stall. The inquiry also pointed out that the airport had "several operational constraints, resulting in erosion of safety margins for the operation of Airbus 320s and Boeing 737s."

==Controversy==

There were a number of aspersions cast on the maintenance of flights by [[Air India Regional|Alliance Air]], with the then civil aviation minister [[Sharad Yadav]] reportedly unhappy with the maintenance of the aircraft<ref name="rediff4">{{Cite web|title=Minister unhappy with Alliance Air maintenance|url=https://www.rediff.com/news/2000/jul/21crash2.htm|website=www.rediff.com|access-date=2019-03-10}}</ref> and asking for replacement of a number of additional aircraft.<ref name="rediff4" /> Some reports even claimed that one of the engines was on fire before the crash.<ref name="rediff1" /> However, the investigation clearly said the aircraft was fully airworthy and properly maintained.<ref name="rediff1" />

Initially, the [[Bihar]] Air Traffic Controller was blamed as the cause of the accident. Even after the official final report was published, most residents who lived near the crash site, along with the relatives of those who perished on the flight, believed that ATC error was the cause of the accident.<ref>{{cite news|author=Swaroop|first=Vijay|date=19 July 2001|title=Memories of plane crash still haunt Patnaites|work=Times of India|url=http://timesofindia.indiatimes.com/city/patna/Memories-of-plane-crash-still-haunt-Patnaites/articleshow/976004966.cms|access-date=3 April 2016}}</ref>

==See also==

* [[Air India Express Flight 812]]
* [[List of accidents and incidents involving commercial aircraft]]
* [[Vidya Malvade]] (Indian film actress), wife of Capt. Arvind Singh Bagga

==References==
{{Reflist}}

==External links==
*{{ASN accident|id=20000717-0}}
*[https://dgca.gov.in/digigov-portal/?dynamicPage=dynamicPdf/130617556&mainAccidentReports/500005/0/viewApplicationDtlsReq Final Accident Report] - REPORT ON ACCIDENT TO ALLIANCE AIR BOEING 737-200 AIRCRAFT VT-EGD ON 17TH JULY, 2000 AT PATNA BY THE COURT OF INQUIRY AIR MARSHAL P. RAJ KUMAR, PVSM, AVSM, VM PROGRAMME DIRECTOR (FLIGHT TEST) AERONAUTICAL DEVELOPMENT AGENCY, BANGLORE - Posted on the website of the [[Ministry of Civil Aviation (India)|India Ministry of Civil Aviation]] ([http://civilaviation.nic.in/coi-fin/contents.htm Text format], [https://dgca.gov.in/digigov-portal/Upload?flag=iframeAttachView&attachId=130617556&mainAccidentReports PDF format]) ([https://web.archive.org/web/20020802095528/http://civilaviation.nic.in/coi-fin/contents.htm Archive in text format], [https://web.archive.org/web/20200526013738if_/https://dgca.gov.in/digigov-portal/Upload?flag=iframeAttachView&attachId=130617556&mainAccidentReports archive in PDF format])
* [http://www.tailstrike.com/170700.htm Cockpit Voice Recorder transcript and accident summary]
* Wg Cdr G Gomez. "[http://medind.nic.in/iab/t02/i1/iabt02i1p66o.pdf Case Report: Human factor analysis of Alliance air crash flight CD-7412]" ([https://www.webcitation.org/6O63f9E7c?url=http://medind.nic.in/iab/t02/i1/iabt02i1p66o.pdf Archive]). ''[[Indian Journal of Aerospace Medicine]]'' (Ind J Aerospace Med) 46(1), 2002. p.&nbsp;66-74.

<br />
{{Air India}}
{{Aviation incidents and accidents in 2000}}
{{Aviation accidents and incidents in India}}

[[Category:Aviation accidents and incidents in 2000]]
[[Category:Aviation accidents and incidents in India]]
[[Category:Airliner accidents and incidents caused by pilot error]]
[[Category:2000 in India]]
[[Category:History of Patna]]
[[Category:July 2000 events in Asia]]
[[Category:Accidents and incidents involving the Boeing 737 Original]]