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Overall statistics for Accidents and Serious Incidents show that non revenue flights have a much higher risk of producing an accident or serious incident than the revenue flying which most professional flight crew routinely undertake. A similar, though statistically unproven conclusion may be drawn in respect of revenue flights which are planned to depart from, and return to, the same aerodrome when operated by an airline which predominantly carries out flights from one location to another. A further, also statistically unproven but highly likely, claim is often advanced that airworthiness function flights carried out by flight crew who are not trained and experienced as professional test pilots are also more likely to result in an accident or serious incident. A causal factor can be that the procedures documented within the Operations Manual and procedures implemented by an Aircraft Operator for such flights are inadequate.

Non-Standard Flights are those that are outside their normal operating experience for the operating flight crew and/or their Company.

Potential hazard

Two issues that have usually been associated with this increased risk, either singly or together, both relate to the substantially different nature of such flights from a flight crew perspective compared to the routine of normal operations:

An unfamiliar environment with a significantly modified context for standard operating procedures, in particular the possibility in many cases of an absence of the usual en route period of relative inactivity.

The apparent willingness of a minority of flight crew making non-standard flights to apply less than their usual rigor to the use of prevailing standard operating procedures. A well-knit flight test team, including the right spirit and motivation, is much more important for operational safety than a well-trained pilot on their own.

Corroborating sources and comments


While any definition of what is non-standard must be made by reference to what is standard for any particular operator, a number of generalized cases can be identified:

Any flight that deviates from laid down Rules and Regulations.

Positioning or ferry flights (both fully and conditionally released to service)

Pleasure, sightseeing or other ‘air experience’ flights

Display or ‘exhibition’ flying for the benefit of persons on the ground

Air-to-air photography

Airworthiness function or check flights after maintenance input or in association with aircraft acceptance or hand back

Flights to develop operator-specific visual approach/departure procedures

Flights undertaken specifically and solely for crew training or familiarisation purposes

An exceptional freight-only flight made by an operator which does not normally undertake such flights

Airworthiness certification flights (unless flown by trained test pilots following their main occupation)

Formation flying where it is not part of Standard Operating Procedures.

Loss of Control

CRJ2, en-route, Jefferson City USA, 2004 (HF LOC AGC FIRE): On October 14, 2004, a Bombardier CL-600 belonging to Pinnacle Airlines and on a positioning flight crashed into a residential area in the vicinity of Jefferson City Memorial Airport, Missouri.

B737, en-route, west of Norwich UK 2009 (LOC HF AW): On 12 January 2009, a B737 operated by easyJet, overhead Norwich UK, experienced a loss of control during functional checks of the flying controls. A successful recovery was achieved following significant loss of height.

A320, vicinity Perpignan France, 2008 (LOC HF AW): On 27 November 2008, an A320 operated by XL Airways Germany, crashed into the sea at Canet Plage, France, following loss of control, without recovery, during a low speed handling test attempted at low altitude as part of a function flight.

DC86, en-route, Narrows VA USA, 1996 (LOC AW HF): On 22 December 1996, a Douglas DC-8-63 operated by Airborne Express, crashed in mountainous terrain near Narrows, Virginia, USA, following loss of control attributed to mishandling during a post maintenance function flght.


Air New Zealand DC10 crash Mount Erebus 1979

Loss of Separation

SH36 / SH36, en-route, Watertown WI USA, 2006 (LOS LOC RE HF): On 5 February 2006, two Shorts SD-360-300 aircraft collided in mid air while in formation near Watertown, WI, USA; both aircraft suffered damage. One aircraft experienced loss of control and impacted terrain while the other made an emergency landing, overunning the runway, at a nearby airport.

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