Beschrijving:A Cessna 525 Citation CJ1+ corporate jet plane, registered HB-VOV, sustained substantial damage in a take-off accident at Grenchen Airport, Switzerland. The airplane operated on a flight from Grenchen Airport. Destination of the ferry flight was Newquay-Cornwall Airport (NQY) in England.
|Datum:||woensdag 16 februari 2011|
|Type:||Cessna 525 Citation CJ1+|
|Luchtvaartmaatschappij:||Swiss Private Aviation|
|Motoren:|| 2 Williams International FJ44-1AP|
|Bemanning:||slachtoffers: 0 / inzittenden: 2|
|Passagiers:||slachtoffers: 0 / inzittenden: 0|
|Totaal:||slachtoffers: 0 / inzittenden: 2 |
|Plaats:||Grenchen Airport (ZHI) (Zwitserland)
|Fase:|| Start (TOF)|
|Vliegveld van vertrek:||Grenchen Airport (ZHI/LSZG), Zwitserland|
|Vliegveld van aankomst:||Newquay-Cornwall Airport (NQY/EGHQ), Verenigd Koninkrijk|
The co-pilot was pilot flying (PF) and the commander was pilot not flying (PNF).
HB-VOV left stand "white alpha" at 08:48 LT. The crew had previously received the necessary clearance to take off from runway 07 after a request to Grenchen aerodrome control (tower). The de-icing system was switched on from the outset in view of the prevailing conditions. The taxi checklist was completed on the short route to the runway 07 holding position via taxiway WHISKEY. This included, among other things, testing the functionality of the brakes, which was carried out by both crew members. No anomalies were found.
At approximately the same time, the Grenchen aerodrome control air traffic control officer (ATCO) arranged for a runway inspection, as visibility did not allow a view from the tower to the end of runway 07.
After receiving clearance at 08:51 LT, the commander steered the aircraft onto runway 07 and initially turned west, in order to have the maximum runway length available for the subsequent take-off (backtrack). After a further 180 degree clockwise turn, HB-VOV was positioned just north of the runway centerline, pointing to the east. To take advantage of the available runway length, the commander, according to his own statements, did not manoeuvre the aircraft precisely onto the runway centerline. Runway 07 has a take-off run available (TORA) of 3281 ft (1000 m).
The ATCO observed HB-VOV taxiing onto the runway and instructed the crew to hold on the runway, as a runway inspection was still in progress. In view of the expected delay, the commander then set the parking brake.
At 08:53:43 LT, the crew of HB-VOV received take-off clearance: "Hotel Oscar Victor, wind zero six zero degrees six knots, runway zero seven, cleared for takeoff".
The commander then switched on the pitot heater and landing lights, pushed the thrust levers forward and handed control over to the copilot. He instructed the copilot, in view of the reduced visibility, to carry out a so-called standing take-off.
At a power setting with a low-pressure compressor speed N1 of approximately 90% of the rated speed the copilot took his feet off the brake pedals, set take-off thrust and steered the aircraft on the runway centerline. The set take-off thrust was checked by both crew members.
The ATCO watched the HB-VOV take-off roll and noticed slower acceleration than usual.
After checking the take-off thrust and the speed indications at the beginning of the take-off roll, the commander had the impression that the aircraft's acceleration was lower than usual. HB-VOV attained a speed of 80 kt before taxiway ECHO 1, i.e. rather late, but still within a framework which seemed acceptable to the commander. On reaching rotation speed (VR), in the co-pilot's estimation approximately 250 m before the end of the runway, the commander called out "rotate", whereupon the copilot pulled on the control column. Both crew members immediately noticed that the nose of the aircraft was not lifting. After a repeated callout by the commander, he too pulled on the control column. On overshooting the end of the runway, the right main landing gear of HB-VOV struck a "end-of-runway" light, which was perceived by the crew as a distinctly noticeable impact. On the transition from the runway to the grass, the copilot, according to his statement, had the feeling that it was no longer possible to continue the take-off and briefly reduced power. But at approximately the same time, the copilot noted that HB-VOV had already lifted off and applied full power again.
At the same time, he asked the commander whether the take-off process should continue. The latter answered the copilot's question in the affirmative, with the consideration that they would perhaps still have a chance to get the aircraft into the air. The events from overshooting the end of the runway to lift-off of HB-VOV, after a roll of more than 100 metres in the adjacent meadow, occurred within a few seconds. In the process the aircraft crossed a small stream bed running perpendicular to the runway.
Once the aircraft had attained the normal attitude for a climb at the appropriate take-off safety speed V2, the commander reduced power to maximum continuous thrust (MCT) and retracted the flaps. Then the crew realised that the parking brake was still set. The commander retracted the landing gear and detected that the red warning light did not go out. He instructed the copilot to keep the speed low and extended the gear again. All three landing gear indicators indicated green. At an altitude of approximately 3500 ft AMSL, HB-VOV was transferred to Berne arrival air traffic control. As part of the climb check, the de-icing system was switched off again.
The crew subsequently decided to make an alternate landing at Zurich airport.
The crew did not declare an emergency and did not apply for landing priority. According to the landing gear indicators in the cockpit, the crew assumed that the landing gear was extended and locked. For this reason they did not make a low pass at Zurich airport for an external visual check of the landing gear.
After the approach and landing, HB-VOV exited runway 14 at the end via taxiway HOTEL 3. The crew then waived a visual check and taxied the aircraft directly to the stand on the apron near the General Aviation Centre (GAC).
As a result of the collision of the right main landing gear of HB-VOV with the endof-runway light and the subsequent crossing of the stream bed, structural damage was found in the area of the nose gear and main gear, as well as to both rear wing spars. Also, a certain asymmetry was ascertained in the dimensions of the aircraft.
The two pilots were uninjured in the accident.
The accident is attributable to a collision with obstacles beyond the end of the runway, because the aircraft did not achieve the expected acceleration during the take-off roll and because the take-off roll was nevertheless continued.
The following causal factors were identified:
- reduced acceleration of the aircraft during take-off because of the set parking brake.
- the missing decision of the crew to respond to the reduced acceleration by aborting the take-off.
The fact that the aircraft had no warning device to indicate a set parking brake when the take-off roll is initiated contributed to the accident.
Official accident investigation report
Deze kaart geeft het vliegveld van vetrek weer en de geplande bestemming van de vlucht. De lijn tussen de vliegvelden geeft niet
de exacte vliegroute weer.
De afstand tussen Grenchen Airport en Newquay-Cornwall Airport bedraagt 970 km (606 miles).