Pilots of an Air Nelson Bombardier Q300 ignored warnings that the nose landing gear was not locked in place, leading to the aircraft skidding upon landing.
The aircraft (ZK-NEB) was on a domestic New Zealand flight from Wellington to Nelson on 30 September 2010 when it diverted to Blenheim because of poor weather.
Upon landing, the nose landing gear was pushed into the wheel well and this caused the aircraft to skid on its landing-gear doors. None of the 45 passengers and crew was injured and the aircraft sustained minimal damage.
However, New Zealand's Transport Accident Investigation Commission found the Air New Zealand subsidiary's pilots had ignored a warning that the nose-gear was not properly locked, after a secondary system indicated that all three landing-gear legs were extended and locked.
They also ignored an aural warning, which was triggered when the aircraft's flaps were deployed.
"The commission found that the pilots ought to have heeded the aural warnings, which sounded on the final approach, and should have abandoned that landing attempt until the actual position of the nose landing gear had been determined," says the report.
It notes that the secondary system indication was in line with procedures in the aircraft's quick reference handbook, but that there was no requirement in the handbook for verification of the landing gear status, such as a flypast for ground observation.
The inquiry recommends that the director of civil aviation liaise with Transport Canada to note instances of false landing-gear verification and require Bombardier to take action to "improve the reliability and dependability of the down-lock verification system".
It states that Bombardier has implemented service bulletins to verify the integrity of the down-lock indication system and has made changes to the aircraft flight manual and quick-reference handbook to implement alternate methods of validating gear status.