ANC08LA018

The certificated flight instructor (CFI) was providing flight instruction to a student pilot. While on a northerly approach to the runway, during dark night conditions, the CFI said he inadvertently allowed the student pilot to descend too steeply, and with a high airspeed. His verbal command for the student to stop the excessive descent and slow the airspeed was initially followed, but the student pilot again allowed the airplane to attain a rapid descent rate and high airspeed as the approach continued. The CFI took control of the airplane, added full engine power, and initiated a go-around. During the attempted go-around, the CFI said he encountered severe windshear. He wrote, in part: "I felt the aircraft had gotten into a severe vertical windshear, and no amount of power we had available was stopping the rate of descent, and we hit the ground." The airplane collided with a stand of trees and came to rest inverted, about 300 yards short of the approach end of the runway, sustaining substantial damage to the wings, fuselage, and empennage. At the time of the accident wind conditions were reported to be 350 degrees (true) at 9 knots. An FAA airworthiness inspector reported that during his postaccident inspection of the airplane, no preaccident mechanical anomalies with the airplane were discovered. Due to the absence of any mechanical problems with the airplane, the dark night conditions, and the relatively light winds reported at the time of the accident, it is probable that the accident could have been prevented if the CFI had provided better supervision of the student and initiated a go-around sooner.

On November 9, 2007, about 1823 Alaska standard time, a Cessna 150 airplane, N11764, sustained substantial damage when it collided with trees and grass-covered terrain while on approach to runway 34, at the Palmer Municipal Airport, Palmer, Alaska. The airplane was being operated by Pegasus Aviation, Palmer, as a visual flight rules (VFR) instructional flight under Title 14, CFR Part 91, when the accident occurred. The certificated flight instructor (CFI) and the student pilot received serious injuries. Dark night visual meteorological conditions prevailed, and no flight plan was filed. The airplane departed the Wolf Lake Airport, Palmer, Alaska, about 1815.

A Federal Aviation Administration (FAA) airworthiness inspector from the Anchorage Flight Standards District Office responded to the accident scene shortly after the accident, and examined the airplane prior to recovery efforts. The FAA inspector reported that rescue personnel told him they talked to the student pilot shortly after the accident, and before he was transported to the hospital. They said the student pilot told them that the airplane struck a stand of trees at the approach end of runway 34, while he was receiving dual instruction during dark night conditions. The airplane came to rest inverted, about 300 yards short of the approach end of runway 34. It sustained substantial damage to the wings, fuselage, and empennage. The FAA airworthiness inspector reported that during his postaccident inspection of the airplane, no preaccident mechanical anomalies with the airplane were discovered.

The CFI did not complete an NTSB Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1). In a written statement to the FAA, dated January 24, the CFI reported that while on final approach to runway 34, he inadvertently allowed the student pilot to descend too steeply, and with higher than normal airspeed. He said his verbal command for the student to arrest the descent and slow the airplane's airspeed was initially followed, but the student pilot again allowed the airplane to attain a rapid descent rate and high airspeed as the approach continued. The CFI said that he then took control of the airplane, added full engine power, and initiated a go-around. During the attempted go-around, the CFI said he encountered a severe windshear. He wrote, in part: "I felt the aircraft had gotten into a severe vertical wind shear, and no amount of power we had available was stopping the rate of descent, and we hit the ground."

The closest weather observation station is the Palmer Municipal Airport. On November 9, at 1753, an Aviation Routine Weather Report (METAR) was reporting in part: Sky conditions and ceiling, 8,500 feet broken; visibility, 10 statute miles; wind, 350 degrees (true) at 9 knots.