A giant phallic shape mapped flight path websites had plane spotters amused - but it turns out, it's actually completely normal.

The penis-like route was flown between 10:30 and 11pm on Wednesday by two light aircraft, both belonging to the Canterbury Areo Club.

It was noticed by internet users and several screenshots, taken from flight-tracking websites, were sent to Newshub.

But while entertaining, it's nothing new. Newshub rang the club who explained it was an "entry hold" manoeuvre which was being practised.

It's a "regular flying pattern", a spokesperson confirmed.

Airways, a navigation service provider, went back and checked and told Newshub it's been done many times before in the Selwyn training ground.

Newshub.