Air Wanganui, which operates medical and charter flights from its Wanganui base, is unsure when one of its two planes will be back in service.
The company's Piper Mojave was forced to make an emergency landing at Paraparaumu last Tuesday when its left engine developed a fault.
As well as the pilot, there was a flight nurse and patient on board the flight from Wanganui to Wellington.
This week Air Wanganui chief executive Charlie Anderson said the twin-engined Mojave was still out of service and he was not sure when it would return.
The company's other plane, a King Air C90 turboprop, was being serviced last week, which was why the Mojave was making the flight. The King Air was back in service on Monday.