On 9 April 2017, an ATR 72-500 crew were unable to obtain a right main landing gear locked down indication during their approach to Nelson and diverted to Palmerston North where the gear did not collapse on landing. The Investigation found the indication had been consequent on failure of both right main gear locking springs due to corrosion and that existing preventative maintenance procedures would not have detected this. It was also noted that contrary to the applicable procedures, the crew had cycled the gear several times which might, but in the event did not, have had significant effects.