Caspian Airlines Flight 6936

On 27 January 2020, Caspian Airlines Flight 6936 overran the runway on landing at Mahshahr Airport, Iran, on a domestic flight from Tehran. All 144 people on board survived, with two injured.

Accident
Flight 6936 departed from Tehran at 06:35 local time (02:05 UTC) and landed at Mahshahr Airport at 07:50.

The flight was normal until the approach. The descent/approach checklist was carried out, however, only partially. The landing checklist was missed by the crew.

The transcript quoted in the report shows eight "sink rate" ground proximity warning system (GPWS) callouts between 1000 feet AGL and 500 feet AGL (automated GPWS callouts), following the automated 400 feet AGL GPWS call out the GPWS sounded "Sink rate!", "Pull up!", "Pull up!", "Pull up!", "Sink rate!", "Sink rate!", "Sink rate!", "Forty", "Sink rate!", "Twenty", "Ten".

Radar data showed the aircraft at 2700 feet above MSL (aerodrome elevation 18 feet) at 249 knots over ground about 3 nautical miles from the runway threshold.

The aircraft touched down nose gear first at 171 KIAS (Vapp 135 KIAS, Vref 131 KIAS) 1695 meters past the runway threshold (LDA 2695 meters) at about +1.22G after having descended through the last 1000 feet AGL in 38 seconds (average rate of descent about 1580 feet per minute). The gear proximity switch went into ground mode, briefly into airborne mode before returning to ground mode, a bounce thus was likely.

The aircraft overran the runway on landing, ending up on the Mahshahr-Sarbandar Expressway, 170 m past the end of the runway

All 144 people on board, including 135 passengers, survived. The aircraft's landing gear collapsed during the overrun.

No injuries occurred, the aircraft however received such substantial damage that the Accident Investigation Board assessed the aircraft as destroyed.

A witness said that the aircraft's undercarriage did not appear to be fully down as it came in to land. The head of Khuzestan Province's aviation authority stated that the aircraft landed long on the runway, causing the overrun.

Aircraft and crew


The accident aircraft was a McDonnell Douglas MD-83, registration EP-CPZ, msn 53464. It first flew in 1994, then served with several airlines before being transferred to Caspian in 2012.

The captain was a 64-year-old man, who had joined Caspian in 2019, having previously flown for Kish Air and the Iranian Navy. He had 18,430 flight hours, including 7,840 hours on the MD-80. The first officer was a 28-year-old man, who had logged 300 flight hours, with 124 of them on the MD-80.

Investigation
The accident was investigated by Iran Civil Aviation Organization. On the final report released on September, 1 2020, it was established that the accident was caused by an unstabilized approach that lead to a runway overrun, all of which occurred due to crew errors which are poor decision making about the risk of high-speed landings, poor crew resource management (CRM) and incorrect judgement in not making an appropriate Go-around while perform the unstabilized approach. Three more contributory factors are also discovered by the report which are the decision to load five extra tons of fuel which increased the required landing distance, the decision by the pilots to make the landing on runway 13 despite the tailwind and the inability of the copilot (Pilot Monitoring) to take control of the aircraft and make proper action to execute the Go-around.

Aftermath
After the results of the investigation were released, the Aircraft Accident Investigation Board of Iran issued some recommendations, three to the Iran Civil Aviation Organization which are intended to provide guidance and mandate additional training for pilots and dispatchers of all operators regarding various internal aspects and to improve the situation of certain airports, four to Caspian Airlines that are focused to improve some systems to assist pilots and one each to Mahshahr Airport where it says to follow the CAO. IRI aerodrome requirements for air navigation services (ANS), check if there are any obstacles in the airport infrastructures and review their instrument approach procedures and the other one recommendation to the Iran Airports and Air Navigation Company (IAC) to provide training guidelines for air traffic service (ATS) personnel about the agreed coordination between ATS units that are involved.