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On 18 May 2018 at 16:08Z, 737-200, XA-UHZ, (21816/592), FF 15/4/1979, lost control and crashed approximately 10 seconds after take off from Runway 06 at Havana, Cuba. The aircraft was owned and operated by Mexican airline Damojh Aerolíneas, operating as Global Air, on behalf of Cubana as flight CU972.

The IACC analysed that there were multiple large errors in the weight and balance of the aircraft that were not corrected by the crew, nor were LMCs taken into consideration. The report says that the number of passengers in the forward cabin was given as 62 when it had only had a capacity for 54, and the weight in the cargo compartments was "incorrect". The fuel weight at take-off exceeded that calculated by some 5,000lb. The load sheet presented to the crew put the take-off weight at about 99,900lb (45.3t) but recalculation by investigators produced a figure of just over 104,000lb, while the ZFW was wrong because the weight of luggage was lower than planned. More significantly, the centre-of-gravity was listed as 17.4% of MAC but the recalculation put it much higher at 28.5%. The inquiry says this put it "very close" to the permissible operating limit of 29%, while the stabiliser trim setting was more than two units in error. Although the weight and CofG were technically within the aircraft's capabilities, the inquiry states that the balance miscalculation and the position of the trim "undoubtedly caused unstable behaviour" from the aircraft and made piloting the jet "difficult".

The aircraft rolled to the right 33.5 degrees immediately after lift off. The pitch angle also increased despite forward control column input. Bank angle and stick shaker warnings sounded. The captain took control of the aircraft and tried to correct the roll back to wings level but the aircraft rolled back to the right several times. Oscillation of the aircraft became more rapid, with the captain's attempts to counteract the bank resulting in a 17°/s roll manoeuvre which swung the aircraft into a 39° left bank, before it quickly rolled back, at nearly 28°/s, into a right bank of more than 72°.

The crew called Mayday just before impacting the ground onto a house, trees and railway line and just outside the airport perimeter and was destroyed by impact and fire and there were only 2 survivors from the 107 passengers and 6 crew.

The CEIAA released their final report in Spanish (available here). They concluded that the probable causes of the crash were:

"The most likely cause of the accident was the fall of the aircraft as result of its entry into abnormal positions immediately after takeoff, that led to a loss of control due to a chain of errors with a preponderance of human factors."

Contributing factors were:

  • inconsistencies in crew training
  • errors in weight and balance calculations
  • low operational standards set out in flight

On 22 May 2018 Damojh Aerolíneas was grounded UFN by the Mexican civil aviation authorities whilst they conducted a special inspection. It is the third such action in eight years against the carrier.

On 16 July 2018, Damojh Aerolíneas said in a statement that "the crew took off at a very steep angle creating a lack of lift which caused the aircraft to plunge". Mexican pilots' union ASPA said Damojh's statement, which was released before the official investigation has concluded, was "irresponsible".

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*** Updated 18 Apr 2019 ***

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The fin and rudder visible at the accident site (Photo AFP)

FDR traces for XA-UHZ

FDR traces for XA-UHZ

The FDR shows that the aircraft began to roll right immediately after the main gear left the ground reaching a roll rate of 5.6 degrees/s until reaching a maximum of 33.5 degrees, then a left rudder input occurred reaching a displacement of 12.6 degrees. At that point, 85 feet AGL, the pitch had risen to 27.2 degrees nose up and the IAS was 139 knots. There is no indication on the FDR of any inadequate movements of the rudder (including yaw damper), slats and flaps remained in their position and also did not produce any asymmetry. The elevators were working properly. The crew attempted to counter the right roll by turning the control wheel to the left and applying left rudder, this rolled the aircraft back to wings level briefly and even reached -13.6 degrees of bank (to the left), the rudder deflection is reduced to 1.53 degrees. For a brief time the flight conditions are in an acceptable range to continue flying with the pitch angle at 16.5 degrees nose up. However, the aircraft rolled right again at 12 degrees/s reaching 28 degrees, the rudder is deflected again to 12.4 degrees left, the airspeed reduced to 124 KIAS at 20.5 degrees nose up. The wings came not level again due to the loss of effectivity of spoilers due to the reduced airspeed and remained at 9.31 degrees right bank. The aircraft rolled again to the right, IAS reduced to less than 122 knots, the pitch increased to 25.1 degrees, the aircraft entered stall. The ailerons were fully deflected to the left, the rudder moved to the left, and aircraft rolled left at 17.2 degrees/s and reached -39.09 degrees, ailerons and rudder were deflected to the right now, the aircraft rolled right at 27 degrees/s and reached 72.6 degrees right bank, the airspeed reduced further to 116 KIAS, the aircraft lost height and impacted ground.

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