Aviation Accident Summaries

Aviation Accident Summary ANC11LA004

Sitka, AK, USA

Aircraft #1

N111AX

BEECH 1900C

Analysis

The captain, who was the non-flying pilot, reported that he altered their course to avoid thunderstorm activity. Once clear of the thunderstorms, they flew direct to the initial instrument approach fix. During the instrument approach to land, the flight crew saw a build up of static electricity, known as St. Elmo's fire, near the nose of the airplane. The first officer reported that the light from the static electricity was very bright, and he decided to keep his eyes focused on the instruments. Shortly thereafter, lightning struck the nose of the airplane and the associated flash temporarily blinded the captain. The first officer continued to fly the approach without difficulty. Once the captain regained his sight, he took the flight controls and completed the landing. During a postaccident inspection of the airplane, the flight crew discovered substantial damage to the right elevator.

Factual Information

On October 18, 2010, at 0700 Alaska daylight time, a Beech 1900C, N111AX, sustained substantial damage when it was struck by lightning about 15 nautical miles from the Sitka Rocky Gutierrez Airport (PASI), Sitka, Alaska. The captain, first officer, and an observer sitting in the jump seat were not injured. The airplane was registered to and operated by Alaska Central Express, Inc., as a 14 Code of Federal Regulations Part 135 on-demand cargo flight. Visual meteorological conditions prevailed at the time of the accident. An instrument flight plan was filed. The airplane departed the Juneau International Airport (PAJN), Juneau, Alaska, at 0608 en route to PASI. The captain, who was the non-flying pilot, reported that they altered their planned course to avoid thunderstorm activity between Juneau and Sitka. Once clear of the thunderstorms, they proceeded direct to HESOK, the initial approach fix for the RNAV (GPS) RWY 11 approach to PASI. About 2 miles from the final approach fix, lightning struck the nose of the airplane. The lightning flash blinded the captain and the observer for about 30 seconds. The first officer was looking at the instrument panel when the lightning flash occurred so he did not lose his sight. He continued to fly the approach. Once the captain regained his sight, he took control of the airplane and landed on runway 11. During the postflight inspection of the airplane, the flight crew discovered substantial damage to the right elevator. The first officer reported that prior to the lightning strike, the flight crew observed St. Elmo's fire coming off the nose of the airplane. The light was very bright so he decided to keep his eyes focused on the instruments as he continued to fly the instrument approach. He stated that a few moments later there was a "loud bang" and the "brightest light I have ever seen in my life." He reported that the airplane's flight characteristics were not adversely affected by the lightning strike. At 0653, the surface weather observation at PASI was: Wind 180 at 13 knots gusting to 21 knots; visibility 10 miles; scattered clouds 3,100 feet; broken clouds 3,800 feet; overcast 6,500 feet; temperature 9 degrees Celsius (C); dew point 4 degrees C; altimeter 29.54 inches of mercury. At 0711, the special weather observation at PASI was: Wind 200 degrees at 15 knots gusting to 30 knots; visibility 4 miles; small hail and light rain; ceiling broken at 2,800 feet; overcast at 3,800 feet; temperature 8 degrees C; dew point 4 degrees C; altimeter 29.57 inches of mercury. Remarks: peak wind from 200 degrees at 30 knots occurred at 0709; rain began at 0657; small hail began at 0711; hourly precipitation 0.04 inches since 0653. The National Transportation Safety Board's accident database included only two previous accidents associated with "lightning blindness." The previous accidents were NYC84LA289 and FTW93LA114.

Probable Cause and Findings

A lightning strike which resulted in substantial damage to the elevator.

 

Source: NTSB Aviation Accident Database

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