Non Revenue Flights
Non Revenue Flights
Definition
Flights which are conducted for non revenue purposes such as:
- Ferry and positioning
- Flying Displays
- Airworthiness Function / Check flights
- Flight crew base trainimg
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 22 April 2019, a Eurocopter-Kawasaki BK-117C-1 helicopter was being positioned for the aeromedical evacuation the following day of a sick crewman on a fishing vessel when it was unintentionally flown into the sea at night. The three crew members were able to evacuate from the partially submerged aircraft before it sank. The accident was attributed to the single pilot’s loss of situational awareness due to loss of visual depth perception when using night vision goggles. The relevant aircraft operator procedures and the applicable regulatory requirements were both found be inadequate relative to the operational risk which the flight involved.
On 24 October 2021, a Shorts SD360 intending to land at the international airport serving Ndola did so at the recently closed old international airport after visually navigating there in hazy conditions whilst unknowingly in contact with ATC at the very recently opened new airport which had taken the same name and radio frequencies as the old one. The Investigation found multiple aspects of the airport changeover and re-designation had been mismanaged, particularly but not only failure to publish new flight procedures for both airports and ensure that NOTAM communication of the changes internationally had been effective.
On 14 September 2021 the crew of a Saab S340B being used for type conversion training purposes were unable to cross start the left engine after it had been temporarily shut down to demonstrate single engine handling performance because the right starter-generator failed. A MAYDAY was declared and after prompt electrical load shedding, sufficient battery power remained to complete a successful diversion. The starter-generator failure was suspected to be attributable to its use whilst in service with a previous operator to support multiple starts at intervals which were insufficient to allow the unit to cool.
On 28 April 2018, a Dassault Falcon F900B came into close proximity with a Beech B36T Bonanza at the uncontrolled VFR-only aerodrome at Bremgarten during its tailwind approach to runway 23 made without contacting the designated Flight Information frequency as the other aircraft was on approach to runway-in-use 05 and in contact with Flight Information. The Beech pilot took avoiding action by turning north and climbing in order to avoid a collision. The Falcon 900 crew had not prepared for the approach which was then unstabilised with late gear extension and multiple EGPWS ‘SINK RATE’ warnings annunciated.
On 3 December 2020, a Dassault Falcon 900 lost directional control and any braking action after touchdown on the 60 metre wide runway at Kangerlussuaq, but as the speed reduced the crew were able to keep the aircraft on the runway. Once stopped, an external inspection found that three of the four mainwheel tyres had deflated with corresponding resultant wheel and hydraulic system damage. Investigation found that a number of brake disks on the three affected wheels had been frozen preventing wheel rotation and attributed this to the crew failure to follow the recommended use of the brake heating system.
On 1 December 2021, a lightly loaded Boeing 737-800 became airborne near the end of the runway at Kuusamo with only engine run-up thrust set with only the abnormally low climb rate alerting the crew to their error. Serial failure by both pilots to follow relevant normal takeoff procedures followed after the type-experienced First Officer had been surprised when the aircraft began to move because his inexperience in brake use resulted in insufficient brake pressure being applied during the engine run-up. The Captain’s failure to notice the error was associated with allowing himself to be distracted by a non-urgent radio call.
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.
Related Articles
- No Technical Objection (NTO)
- Loss of Control
- Mitigating Risk for Non Standard Flights
- Maintenance Check Flight