A nearly empty fuel tank was a factor in an April forced landing of an ultralight aircraft on a Kauai dirt road, according to a report by the National Transportation Safety Board.

The engine died in the Evolution Trike, a powered, hang glider-like aircraft, in the April 19 incident in Eleele, as the Birds in Paradise aircraft was ready to land.

The pilot instructor reported that the engine quit during the student pilot’s first dual instruction flight. Neither person was seriously injured in the landing, said the report, filed Tuesday.

Investigators found 1.2 gallons of fuel remained in the tank, which is less than the level of usable fuel, according to the manufacturer.

The NTSB investigation led the manufacturer to correct its aircraft flight manual to indicate that 1.4 gallons is the unusable fuel level.

In another investigation, the NTSB reported that pilot error was the apparent cause of an accident at Kaunakakai Airport on July 25. The pilot received minor injuries and the single-engine Aerostar was substantially damaged when he made a night landing after turning off the plane’s landing lights and experiencing a brief, partial loss of night vision.

The pilot told investigators he had made numerous night landings at his home airport and that there were no mechanical problems with the craft at the time of the accident. He said that night he did not cross-check the altimeter during his approach and had not properly configured the plane for landing.

The airplane was owned by John Hutton Corp.