Air New Zealand is mystified at why the Airbus A320 that crashed off the coast of France last year was attempting a low-speed flight check at too low an altitude.
French authorities have released an interim report into the crash, which the airline says offers only a small insight into the crash.
Air New Zealand chief executive Rob Fyfe says it would be quite clear to a trained pilot at what altitude such checks should be carried out.
This would allow pilots plenty of time to recover in the event of a problem.
Mr Fyfe says the report also shows low-altitude sensors on the plane were not working properly.
The aircraft, which was on a test flight, went down into the sea as it was coming in to land at Perpignan at 4.46pm on 27 November.
All seven people on board - the two Germans pilots and five New Zealanders - were killed.
The French report says the Air New Zealand aircraft got into trouble attempting a low-speed flight check as it approached Perpignan.
An alarm sounded telling crew the aircraft was stalling and the German pilots tried to rectify the situation. However, the plane was flying too slowly and at too low an altitude to recover and plunged into the sea.
On the approach to the airport, air traffic control twice advised the pilots to reduce the aircraft's speed.
The Transport Accident Investigation Commission says it is not normal for an aircraft to stall while attempting a low-speed flight check.
The commission says the investigation is a quarter of the way through and the next phase is to produce a draft final report.
The French report says the impact was violent and not survivable.
It also says the crew had not received any specific training for this type of test flight, although one of the passengers, an Air New Zealand pilot, had carried out two simulator training sessions.
Mr Fyfe said the report did not outline why the crash occurred, adding that it was too early to draw conclusions.
The New Zealand Airline Pilot's Association agreed with his comments.
The report recommends more rules about how to conduct flights without paying passengers on board.