ANC05LA088

The Title 14, CFR Part 121 cargo flight was about 32 miles north of the destination airport, descending for landing in instrument meteorological conditions, when it was struck by lightning. The radar and several electrical systems were knocked off-line by the strike. Most of the systems were restored, and the airplane landed without incident. The pilot reported that after takeoff, they deviated around a thunderstorm, and that there were numerous thunderstorms in the area. The pilot said after clearing the thunderstorm, they were flying in clear air. He said along the route, most of the observed thunderstorms were behind them, and that they entered instrument meteorological conditions in a large area of cloud cover. As they started a normal descent for the destination airport in smooth air, he indicated that he and the first officer simultaneously noticed that the radio magnetic indicator needles "spun around in different directions," and that an "instant later" they were struck by lightning. He did not indicate what was observed on the radar screen. The pilot did not report any mechanical anomalies prior to the lightning strike. Portions of the left aileron's lightning strike protection were de-bonded by the strike, and the aileron was replaced.

On June 15, 2005, about 2345 Alaska daylight time, an Aerospatiale ATR-42-300 airplane, N42NC, sustained substantial damage resulting from a lightning strike during a normal descent, about 32 miles north of Anchorage, Alaska. The airplane was being operated as Flight Yukon 24, by Northern Air Cargo Inc., of Anchorage, as an instrument flight rules (IFR) non-scheduled cargo flight under Title 14, CFR Part 121, when the accident occurred. The two flight crew members and a company maintenance person were not injured. Instrument meteorological conditions prevailed, and an instrument flight plan was filed. The flight originated at Fairbanks International Airport, Fairbanks, Alaska, about 2241.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on June 16, the Director of Safety for the operator said the flight was in meteorological conditions (IMC) and descending normally into the Ted Stevens Anchorage International Airport, Anchorage, when it was struck by lightning. He said the airplane was equipped with functioning radar, which was knocked off-line along with several other electrical systems, but most of the systems were restored in-flight. He said the airplane landed without incident, but sustained structural damage to the left aileron, requiring replacement of the aileron.

In a written statement to the NTSB dated June 17, the pilot wrote that after takeoff, they deviated to the southwest around a thunderstorm, and that there were numerous thunderstorms north of the Alaska Range, and in the Fairbanks area. The pilot wrote that after clearing the thunderstorm he was cleared to Talkeetna, Alaska, and that most of the observed thunderstorms were behind them. He stated that after flying through clear air, they entered instrument meteorological conditions, and after receiving clearance from Anchorage Center, started a normal descent for the destination airport in smooth air. He wrote that he and the first officer simultaneously noticed that the radio magnetic indicator needles "spun around in different directions." He did not indicate what was observed on the radar screen. He continued, " an instant later, we were struck by lightning."