A plane which crashed just metres from Whangarei Airport this year - the pilot miraculously walking away after the incident - had a broken heat shroud, meaning the carburettor would not have been working effectively.
The Civil Aviation Authority has issued a note to pilots after the July 2 crash left
Ballistic Blondes Skydiving pilot Sarah Collinson, 24, shaken with only a facial cut.
The authority said a pilot should always identify recurrent mechanical issues, however subtle (such as a tendency to suffer carburettor icing), in the aircraft's technical log.
Ms Collinson had to choose whether to head for the sea or try to land after the Cessna 172's engine cut out while returning to Whangarei Airport after dropping off four skydivers about 10.55am.
She managed to land just short of the Onerahi airport, the aircraft straddling the road and its nose in a bank.
In its report, the authority said it was not unusual for the Cessna's engine to run rough, as it did before the accident, because it had a history of the carburretor icing.
However, that had always cleared before it became an issue, and when it started icing up before the accident, Ms Collinson expected it to clear quickly.
Examination of the aircraft showed the carburettor heat shroud, which collected warm air from around the engine exhaust, was broken and not in place. The carburettor would not have worked effectively, making it prone to icing.
Ms Collinson told the authority that four or five times during a steep descent the plane would get a bit of carb icing which would then clear. She said when carb icing started before the accident she was not initially alarmed.
"I kept expecting it to clear, and I'd got quite a bit lower by the time I realised that it wasn't going to come right," Ms Collinson told the CAA magazine, Vector.
"Everyone I spoke to said this plane seemed to be more prone to carb icing than others, but it always cleared, so I got used to it. I think now, no matter how often a fault repeats, you should always treat it as an emergency."
