Mandala Airlines Flight 091

Mandala Airlines Flight 091 (RI091/MDL091) was a scheduled domestic passenger flight from Medan to Jakarta, operated by Mandala Airlines with a Boeing 737-200. On 5 September 2005 at 10:15 a.m. WIB (UTC+7), the aircraft stalled and crashed into a heavily populated residential area seconds after taking off from Polonia International Airport. Of the 117 passengers and crew on board, only 17 survived. An additional 49 civilians on the ground were killed, making a total of 149 fatalities.

The crash of Flight 091 was a shock to North Sumatrans as the leader of North Sumatra province, Governor Rizal Nurdin, and his predecessor, Raja Inal Siregar, were among the passengers and both were killed in the crash.

The Indonesian National Transportation Safety Committee (NTSC) concluded that the crash was caused by the actions of the flight crew, in that they did not configure the aircraft properly for take-off. The retracted flaps and slats resulted in the aircraft being unable to fly due to insufficient lift. The aircraft take-off warning was not heard and investigators stated that it was possible the pilots did not receive a warning about the improper configuration, and were therefore unaware of their erroneous actions.

Flight

Flight 091 was a scheduled domestic passenger flight from Polonia International Airport (now Soewondo Air Force Base) in Medan, the largest city in Sumatra, to Soekarno-Hatta International Airport in the Indonesian capital Jakarta. Flight 091 was the second trip of the day for the aircraft, which had earlier flown from Jakarta to Medan with the same flight crew. The aircraft was pushed back at 09:52 a.m. and start-up clearance was given immediately after. It then taxied out onto Runway 23 and was cleared to take off at 10:03 a.m. with an altitude of 1,500 ft.

Accident

Flight crews then added thrust and the aircraft began rolling on the runway. As it was rolling, some passengers noted that the aircraft took longer than usual to take off from the airport, even though the aircraft was already in a nose up position. The aircraft briefly took off, then veered to the left and to the right, stalled and then the tail impacted the runway. As the tail struck the runway, it left marks on Runway 23.

The aircraft then struck several approach lights located at the end of the runway before traveling across grass, crossing a small river and finally crashing onto the crowded Djamin Ginting road. Onlookers and motorists on the road panicked as the aircraft came towards them. The left wing struck a building and the aircraft exploded into flames. It broke into three parts. Passengers on the aft fuselage stated that the front part of the aircraft was obliterated as the aircraft exploded. It continued to slide onto the road, hitting multiple cars, bikes, powerlines and streetlamps and destroying several shops and houses. Several unaware drivers got their vehicles flipped by the sliding aircraft and subsequently burst into flames. The aft fuselage then came to rest in the middle of the road.