Accident Canadair CL-600-2B16 Challenger 604 D-AMSC,

ASN Wikibase Occurrence # 319941

Date:	Saturday 7 January 2017
Time:	08:39
Type:	Canadair CL-600-2B16 Challenger 604
Owner/operator:	MHS Aviation
Registration:	D-AMSC
MSN:	5464
Year of manufacture:	2000
Total airframe hrs:	10211 hours
Cycles:	5504 flights
Engine model:	General Electric CF34-3B
Fatalities:	Fatalities: 0 / Occupants: 9
Aircraft damage:	Substantial, written off
Category:	Accident
Location:	1230 km SSE of Muscat, Oman - Indian Ocean
Phase:	En route
Nature:	Executive
Departure airport:	Malé International Airport (MLE/VRMM)
Destination airport:	Abu Dhabi-Bateen Airport (AZI/OMAD)
Investigating agency:	BFU
Confidence Rating:	Information verified through data from accident investigation authorities

Narrative:
At 11:52 hours (06:52 UTC) the Challenger 604 jet took off from runway 36 at Malé, Maldive Islands, for a flight to Al-Bateen, United Arab Emirates. Three crew members and six passengers were on board the airplane.
At 07:20 UTC the airplane reached cruise level FL340. After entering Indian airspace (Mumbai FIR) the aircraft was cleared to fly to reporting point KITAL via route L894. At approximately 08:18 UTC the co-pilot radioed reaching reporting point GOLEM.
At 06:55 UTC an Airbus A380-861 (A6-EUL) had taken off at Dubai Airport, United Arab Emirates, for flight EK412 to Sydney, Australia. The aircraft flew at FL350 with a southern heading.
At 08:38:07 UTC the A380 had passed the Challenger overhead with a vertical distance of 1,000 ft.
At 08:38:54 UTC the Challenger, with engaged autopilot, began to slightly roll right. At the same time a counter-rotating aileron deflection was recorded and fluctuation of the vertical acceleration began.
In the subsequent approximately 10 seconds the airplane had a right bank angle of 4° to 6°. At 08:39:03 UTC the right bank angle began to increase. Within one second the bank angle increased to 42° to the right. At the same time the aileron deflection to the left increased to 20° and the vertical acceleration to 1.6 g. In the following second vertical acceleration changed to -3.2 g.
At 08:39:04 UTC a lateral acceleration of 0.45 g to the right was recorded. The pitch angle changed from about 3° to about 1°, then within one second increased to 9° and decreased again in the following second to -20°. At the same time the FDR recorded a rudder deflection to the left reaching 11.2° after about two seconds whereas the bank angle changed from 42° right to 31° left.
Between 08:39:05 UTC and 08:39:10 UTC Indicated Airspeed (in knots) changed from approximately 277 KIAS to 248 KIAS. The N1 of the left engine of 95% began to decrease.
The lateral acceleration then reached 0.94 g left, the autopilot disengaged, and a master warning, lasting seven seconds, was recorded.
Both pilots had actuated the aileron to the right in order to stop the rolling motion. But the airplane had continued to roll to the left thereby completing several rotations. Subsequently both Inertial Reference Systems (IRS), the Flight Management System (FMS), and the attitude indication failed.
Between 08:39:09 UTC and 08:39:41 UTC the FDR recorded a loss of altitude of approximately 8,700 ft. Large control surface deflections and acceleration were recorded. The speed increased and at 08:39:31 UTC reached approximately 330 KIAS. At 08:39:30 UTC the spoilers extended and 13 seconds later were retracted again. The N1 of the left engine had decreased to approximately 40% when the Interstage Turbine Temperature (ITT) began to increase and nine seconds later had reached 850°. The left engine was shut off.
At about 08:56 UTC the Pilot in Command (PIC) informed the air traffic controller in Mumbai of the occurrence, declared emergency, and reported their position, altitude and their intention to fly via KITAL to Oman.
At about 09:15 UTC the crew restarted the left engine. Subsequently the airplane climbed to FL250. At about 09:56 UTC the autopilot was re-engaged.
At 11:05 UTC the Challenger landed at Muscat Airport.
The A380 continued the flight to Sydney and landed there at 19:58 UTC.

The aircraft manufacturer determined that the Challenger's airframe structure could not be restored to an airworthy state as it exceeded the airframe certification design load limits during the upset encounter.

Accident investigation: