Non Revenue Flights

Non Revenue Flights

Definition

Flights which are conducted for non revenue purposes such as:

Description

Non Revenue Flights have often been identified as attracting a greater risk of an accident or serious incident than the revenue flights which form the main business of any operator of commercial aircraft. In many respects, the causes of increased risk for this type of flight are similar to those which have been associated with a slightly wider sub group of flights - Non Standard Flights.

 

Accident & Incident Reports

A selection of accidents and events which have occurred on non-revenue flights:

On 14 March 2017, control of a Sikorsky S92A positioning in very poor visibility at 200 feet over the sea in accordance with an obstacle-marked FMS ground track in order to refuel at a coastally-located helipad was lost after it collided with late-sighted terrain ahead before crashing into the sea killing all on board. The Investigation attributed the accident to the lack of crew terrain awareness but found a context of inadequate safety management at the operator, the comprehensively ineffective regulatory oversight of the operation and confusion as to responsibility for State oversight of its contract with the operator.

On 30 August 2018, a Boeing 747-400F making a crosswind landing at Hong Kong which was well within limits veered and rolled abnormally immediately after touchdown and runway impact damaged the two right side engines. The Investigation found that the flight was an experienced Captain’s line check handling sector and concluded that a succession of inappropriate control inputs made at and immediately after touchdown which caused the damage may have been a consequence of the Check Captain’s indication just before touchdown that he was expecting a landing using an alternative technique to the one he was familiar with.

On 17 September 2020, a Bombardier Global 6000 which had completed a circling approach to land at Biggin Hill in day VMC touched down with an inappropriate pitch and roll attitude which caused the right wingtip to contact the runway surface. The Investigation found that the landing technique just before touchdown was not in accordance with the manufacturer’s crosswind landing technique although the roll rate achieved could not be accounted for by the roll control input alone and was probably increased by localised wind velocity variations despite the absence of any such variations being reported by ATC.

On 7 November 2018, a Boeing 747-400F overran wet landing runway 14 at Halifax at night and was sufficiently damaged as a result of exceeding the available RESA to render it a hull loss. The Investigation attributed the overrun to a combination of factors including use of un-factored landing distance, momentary mishandling of the thrust levers just after touchdown, a pilot-caused lateral deviation diverting attention from deceleration, inadequate braking and late recognition of an approach tailwind component. Poor NOTAM presentation of runway availability also led the crew to believe that the longer and more suitable runway 25 was not available.

On 12 September 2018, a Gulfstream G-IV overran the runway at Abuja after the air/ground status system failed to transition to ground on touchdown and the crew were slow to recognise that as a result neither spoilers nor thrust reversers had deployed. In the absence of recorded flight data, it was not possible to establish why the air/ground sensing system did not transition normally but no fault was found. The aircraft operator’s procedures in the event of such circumstances were found to be inadequate and regulatory oversight of the operator to have been comprehensively deficient over an extended period.

On 26 February 2020, after a difficult Airbus A321 left engine first flight of the day start, the same happened on the third sector with en-route engine abnormalities then affecting both engines. With no fault found during post flight maintenance inspections and despite similar engine starting problems, both engines then malfunctioned after takeoff from Gatwick. A MAYDAY return followed. Investigation found that the cause was fuel system contamination by addition of approximately 38 times the correct quantity of biocide during earlier scheduled maintenance and that the release of the aircraft to service for the flight had followed inadequate troubleshooting action.

On 24 April 2019, the engine of a Beech B200 en-route from Winnipeg to Churchill at FL 250 failed due to fuel exhaustion and the crew realised that they had forgotten to refuel before departure. An emergency was declared and a diversion to the nearest available airport was commenced but the right engine later failed for the same reason leaving them with no option but to land on a frozen lake surface. The Investigation concluded that confusion as to relative responsibility between the trainee Captain and the supervising pilot-in-command were central to the failure to refuel prior to departure as intended.

On 11 November 2018, an Embraer 190-100LR just airborne on a post maintenance non revenue positioning flight became extremely difficult to control as it entered cloud despite the complete absence of any flight control warnings. After reversion to Direct Law, partial normal control was regained and, once visual, the flight was guided to an eventually successful landing. The Investigation found that the aircraft had been released from heavy maintenance with the aileron system incorrectly configured and attributed this primarily to the comprehensively dysfunctional working processes at the maintenance facility involved. Extensive airframe deformation meant the aircraft was a hull loss.

On 7 January 2019, a Saab 340B made a late touchdown during light snowfall at night close to the edge of the runway at Savonlinna before veering off and eventually stopping. The Investigation attributed the excursion to flight crew misjudgements when landing but also noted the aircraft operator had a long history of similar investigated events in Scandinavia and had failed to follow its own documented Safety Management System. The Investigation also concluded that there was a significant risk that EU competition rules could indirectly compromise publicly-funded air service contract tendering by discounting the operational safety assessment of tendering organisations.

On 11 January 2017, control of a Cessna Citation 560 departing Oslo on a short positioning flight was lost control during flap retraction when a violent nose-down manoeuvre occurred. The First Officer took control when the Captain did not react and recovered with a 6 g pullout which left only 170 feet of ground clearance. A MAYDAY - subsequently cancelled when control was regained - was declared and the intended flight was then completed without further event. The Investigation concluded that tailplane stall after the aircraft was not de-iced prior to departure was the probable cause of the upset.

On 9 May 2019, a Cessna 550 level at FL 350 experienced an unexplained left engine rundown to idle and the crew began descent and a diversion to Savannah. When the right engine also began to run down passing 8000 feet, an emergency was declared and the already-planned straight-in approach was successfully accomplished without any engine thrust. The ongoing Investigation has already established that the likely cause was fuel contamination resulting from the inadvertent mixing of a required fuel additive with an unapproved substance known to form deposits which impede fuel flow when they accumulate on critical fuel system components.

On 2 November 2017, a Fairchild SA 227-AC Metro III landing at Thompson after a ferry-permit flight issued to facilitate a hydraulic fluid leak rectification left the runway when reverse pitch was selected and sustained substantial damage. The Investigation found that the flight had been continued without shutting down the left engine when its oil pressure dropped below the level requiring this in the QRH. The oil loss was found to be attributable to the same cause as a similar loss identified two days previously for which rectification had supposedly been achieved. The hydraulic leak did not affect the flight.

On 16 November 2017, a Boeing 737-700 departing Singapore Seletar was observed by ATC to only become airborne very near the end of the runway and to then climb only very slowly. Ten approach lights were subsequently found to have been impact-damaged by contact with the aircraft. The Investigation found that after the crew had failed to follow procedures requiring them to validate the FMC recalculation of modified takeoff performance data against independent calculations made on their EFBs, takeoff was made with reduced thrust instead of the full thrust required. The modification made was also found not to have been required.

On 23 August 2018, a low experience Sikorsky S92 First Officer undergoing line training made a visual transit between two North Sea offshore platforms but completed an approach to the wrong one. The platform radio operator alerted the crew to their error and the helicopter then flew to the correct platform. The Investigation attributed the error primarily to the inadequate performance of both pilots on what should have been a straightforward short visual flight but particularly highlighted the apparent failure of the Training Captain to fully recognise the challenges of the flight involved when training and acting as Pilot Monitoring.

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