On 4 June 2010, a Boeing 737-800 being operated by Ryanair and departing on a scheduled passenger flight from Eindhoven to Faro, Portugal carried out a daytime rejected take off on runway 04 from above V1 in normal visibility because the handling pilot perceived that the aircraft status was abnormal. The aircraft was stopped 500m before the end of the 3000m runway, none of the occupants were injured and the aircraft suffered only hot brakes.
An Investigation was carried out by the Dutch TSB. The Flight Data Recorder (FDR) recording was available for the investigation but the Cockpit Voice Recorder (CVR) was not. The latter situation prevented the Investigation from fully exploring the effectiveness of co-ordination between the aircraft commander, who was PM, and the First Officer who was PF, for the take off.
No evidence was found of any airworthiness fault in the aircraft prior to or during the take off roll and extensive work also failed to identify or even suggest an origin for any external atmospheric effects which might have helped to convey to the PF an impression that an abnormal circumstance prevailed.
It was noted that the standard 80 knot cross check had been carried out normally and it was reported that there had been no remarks about an abnormality prior to the action by PF to reject the take off. It was also noted that any rejected take off decision made above 80 KIAS is the sole prerogative of the aircraft commander.
When interviewed for the Investigation, the First Officer is reported to have said that “he had the feeling that the aircraft was unsafe to fly and (therefore) pulled back the thrust levers.” This action automatically activated the auto brakes and the speed brakes and initiated a rejected takeoff. After the thrust levers had been retarded, the aircraft commander was stated to have taken control and deployed the thrust reversers to assist deceleration.
The aircraft had then been taxied back to the gate where smoke was seen coming from the overheated brake units and the aircraft commander decided to disembark the passengers.
FDR and A/T solid state memory data indicated that the rejected takeoff actions had been commenced at 152 KCAS with the nose wheels just off the ground and a maximum airspeed of 160 KCAS then reached before deceleration took effect. The applicable V1 of 140 KIAS was found to have been correctly calculated and it appeared that a positive rotation had not been commenced by the PF at the Rotation Speed (Vr) call.
The Investigation noted that a high speed rejected take off is usually made because of clear evidence that the aircraft is “unsafe or unable to fly”. Since these or equivalent terms were not defined in the Operations Manual, it was noted that there is “room for interpretation”. The Investigation asked the aircraft manufacturer to define “unsafe” and “unable to fly“ and were provided with the following:
- Unsafe to fly - the circumstance whereby rejecting the takeoff carries significantly lessrisk than flying the aircraft.'
- Unable to fly - the circumstance where there is a reasonable probability of not being able to control the aircraft if the takeoff is continued and the aircraft becomes airborne.
It was observed that the definitions provided did not alter the need for pilot judgment.
Conclusions of the Investigation included the following:
- To reject a takeoff above V1, especially when the nose wheel is off the ground, is in principle considered to be improper and unsafe. There is no specific guidance from the operator or manufacturer on dealing with control issues at the time of rotating the aircraft.
- Review of past statistics and studies show that pilot training and requirements focus on rejected takeoffs due to an engine failure. Studies and statistical information show that this accounts for less than 25% of the reasons for rejected takeoffs. Thus 75% of the reasons for the rejection of a takeoff are not trained for.
The Final Report of the Investigation: Rejected takeoff after the takeoff decision speed 'V1', B737-800, at Eindhoven Airport, 4 June 2010 was published on 23 June 2011. No Safety Recommendations were made.