Sunday, 9th of January, 2011

– Iran

Iran Air Flight 277, a domestic scheduled passenger flight from Tehran-Mehrabad Airport (THR/OIII), Iran, to Urmia (Orumiyeh) Airport (OMH/OITR), Iran, operated with a Boeing 727-286, registration EP-IRP, impacted the ground while on approach to Urmia (Orumiyeh) Airport (OMH/OITR), Iran.

The airplane was destroyed. Eight crew members and 70 passengers perished. The remaining crew member and 26 passengers survived. (78 fatalities, 27 survivors)

The crash of Flight 277 is the 26th deadliest crash involving the Boeing 727. It is also the twelveth deadliest aviation accident on Iranian soil.

– Details:

The aircraft departed Tehran-Mehrabad Airport at 1815LT with a delay of more than two hours due to poor weather conditions at destination. While descending to Orūmīyeh Airport by night, the crew encountered poor weather conditions with snow falls, visibility 800 metres and three ceilings at 1,500, 2,000 and 6,000 feet. After the crew was unable to intercept the ILS, the decision to initiate a go-around procedure was taken. Approaching the stall speed, the stick shaker activated and the aircraft probably encountered icing conditions. In a left bank angle estimated between 26 and 40°, the engine n°3 and 1 failed. At an altitude of 600 feet and at a speed of 96 knots, the flaps were retracted, causing the aircraft to stall and to impact the ground.

– Cause:

“Contributing factors were:

– the old technology of aircraft systems

– absence of a suitable simulator for adverse weather conditions

– failure to correctly follow the operating manual by the flight crew

– inadequate cockpit management (CRM)

1- the crew could not align the aircraft in ILS inbound course due to setting wrong understanding of lead Radial for approach.

2- the pilot decided to Miss Approach and getting back to IAF but while 25 Deg banking with flap 5, they encountered Stick shaker which means near to stall.

3- the weather was in icy condition. The pilot should use enough power to supply hot air from engines for Anti-icing. This action was not observed by them. This error caused accumulation of Ice (snow) on wing surface and Engine nacelle.

4- they decided to increase power of the engines with rapid acceleration after stick shaker to get high velocity to prevent stall.

5- the crew tried to restart the Engine #1 but it was too late and aircraft impacted with ground.

6- due to Ice accumulation ON WING SURFACE, there was turbulence airflow in the engine intakes . so engine #1 and 3 were flame out and EPR decreased.

The causes of the accident are stated as:

1- severe icing condition for the flight and lack of enough preparation for cockpit crew to face this weather phenomenon.”