Greenland DH8B at Nuuk on May 30th 2019, rejected takeoff after Vr due to no rotation

Last Update: September 27, 2019 / 19:13:01 GMT/Zulu time

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Incident Facts

Date of incident
May 30, 2019

Classification
Report

Cause
Rejected takeoff

Airline
Air Greenland

Flight number
GL-548

Departure
Nuuk, Greenland

Destination
Kangerlussuaq, Greenland

Aircraft Registration
OY-GRJ

Aircraft Type
De Havilland DHC-8-200 Dash 8

ICAO Type Designator
DH8B

An Air Greenland de Havilland Dash 8-200, registration OY-GRJ performing flight GL-548 from Nuuk to Kangerlussuaq (Greenland) with 29 passengers and 3 crew, was accelerating for takeoff from Nuuk's runway 05 when the crew rejected takeoff above Vr due to the aircraft not rotating despite full back pressure on the yoke. The aircraft slowed safely and stopped about 50 meters short of the end of the runway.

The Danish Havarikommissionen (HCL) released their final report concluding the probable cause of the serious incident was:

Actual masses above standard masses on crew, passengers and carry-on hand baggage led to a CG forward of the operational aircraft CG limitations causing reduced aircraft rotation ability during the take-off roll.

The HCL summarized:

Pre-flight mass and balance calculations using standard masses on crew, passengers, and carry-on hand baggage documented a Center of Gravity (CG) within aircraft CG limitations.

Post-flight mass and balance calculations using actual masses on crew, passengers and carry-on hand baggage documented a CG forward of the operational aircraft CG limitation.

The HCL described the sequence of events:

Before the flight and in order to mitigate a forward center of gravity issue, an off duty crewmember moved from the cockpit jump seat to a passenger seat.

Nuuk Aerodrome Flight Information Service (AFIS) reported runway 05 in use, wind conditions to be 330° and 5 knots, QNH 1014, and a temperature of 10° Celsius.

Runway conditions were dry, and the visibility was more than 10 kilometers (km).

There were no remarks to the aircraft pre-flight checks.

The commander was the pilot monitoring, and the first officer was the pilot flying.

Before engine start, the first officer made a departure briefing including information on aircraft takeoff configuration (a flap setting of 15°), a V1 (decision speed) equal to VR (rotation speed) of 88 knots, and a review of the aborted take-off procedure.

After engine start, Nuuk AFIS reported no traffic on the runway and the wind conditions to be 330° and 3 knots.

The aircraft taxied to take-off position on runway 05.

The flight crew completed the before take-off checklist (including a check of aircraft flight controls) without remarks.

The first officer initiated the take-off roll.

During the take-off roll, the commander called Sixty (airspeed), and the first officer confirmed.

At approximately 80 knots, the commander called Vee-One-Rotate.

The first officer applied normal backpressure to the elevator control but experienced no positive responsive feedback (aircraft rotation) and consequentially applied full aft backpressure to the elevator control.

The first officer received no positive responsive feedback (aircraft rotation), and considered the lack of aircraft rotation to be a result of a flight control failure and aborted the take-off by retarding the power levers to DISC position and applying maximum anti-skid braking.

The aircraft came to a full stop approximately 50 meters before the end of runway 05.

The flight crew discussed different scenarios and agreed that the sequence of events did not prevent them from making a safe taxi back to the apron.

While taxiing back to the apron, the flight crew requested an external visual inspection of potential hot wheel brakes, and the commander briefed the passengers.

The HCL analysed:

Prior to the take-off roll, the flight crew experienced no precursors of the upcoming sequence of events.

During the take-off roll and at approximately 80 knots, the commander called Vee-One-Rotate leading the first officer to apply backpressure to the elevator control.

The pitot static test revealed a 3 knot higher airspeed indication than the actual airspeed (however within AMM limitations).

The 3 knot higher airspeed indication in combination with the premature commander callout most likely prolonged the first officer’s time perception of no positive responsive feedback resulting in a sooner decision on aborting the take-off roll. These findings might have been causal but were not the root cause.

Even though, the aircraft accelerated to an airspeed above VR (88 knots), and the first officer applied full backpressure to the elevator control, the control input only generated a minor increase in pitch attitude.

For that reason, the rationale behind the decision on aborting the take-off roll complied with the operating procedures and potentially prevented a more severe outcome.

Mass and Balance:

Before departure, the flight crew were aware of a forward CG issue leading to a repositioning of an off-duty crewmember from the cockpit to the cabin.

The mass and balance calculations, based on standard masses, prepared by the flight crew before the flight and subsequently by the AIB resulted in a CG within aircraft CG limitations.

The mass and balance calculation, based on actual masses (an increase of masses compared to standard masses of approximately 13% on crew, wardrobe, passengers and carry-on hand baggage), prepared by the AIB resulted in a CG 2.4 inches forward of and outside aircraft operational CG limitations.

To the AIB, actual masses above standard masses resulted in the CG being forward of and outside aircraft operational CG limitations and was the root cause to reduced aircraft rotation ability.

Operating procedures, which complied with Regulation (EU) 965/2012 on air operations, stipulated ground handling and cabin crewmembers to notify the commander when observing significant number of passengers whose masses, including carry-on hand baggage, are expected to exceed the standard passenger masses.