Lightning strike, near Darwin, Northern Territory, VH-FWI, Fokker F28 Mk 100

At approximately 1620 CST¹ on 17 December 2005, a Fokker 100 series aircraft, registered VH-FWI, with 14 passengers and a crew of 5 was returning to Darwin on a charter flight from the Indonesian port of Kupang.

On approach to Darwin, the crew were instructed by air traffic control to hold approximately 50 NM to the south of Darwin due to thunderstorms at the airport. The crew reported that, while holding in instrument meteorological conditions at approximately 16,000 ft above ground level, and between 6 and 8 NM from any storm cells, the aircraft was stuck by lightning.

While the aircraft was still holding, approximately 20 minutes after the lighting strike, the number 2 hydraulic system low quantity warning light illuminated and the number 1 hydraulic system quantity was observed to be reducing. The aircraft was then immediately tracked for a landing on runway 29 at Darwin.

The number 1 hydraulic system low quantity warning light illuminated when the crew selected the landing gear and flap, early on final approach to land. The landing was continued, and the aircraft was able to be taxied to the gate.

An engineering examination found that two of the hydraulic return lines to the elevator boost unit and a hydraulic union and attaching line were damaged, due to electrical arcing as a result of the lightning strike. The examination also found at least two strike holes to the forward and mid-section of the aircraft fuselage. There were approximately 90 other strike related damage zones along the underside of the fuselage, landing gear doors and on the trailing edges of the wings and tailplane.

During subsequent scheduled maintenance, further melting damage was found to the elevator flight control cables.

The aircraft operator reported that the aircraft was repaired and returned to service.

1. The 24-hour clock is used in this report to describe the local time of day, Central Standard Time, when particular events occurred. Central Standard Time is Coordinated Universal Time (UTC) + 9.5 hours.