Aviation Accident Summaries

Aviation Accident Summary SEA98LA082

SANDPOINT, ID, USA

Aircraft #1

N1479Q

Cessna 150L

Analysis

The flight took off with approximately a 30-minute to 1-hour fuel supply. After takeoff, the pilot/flight instructor and dual student (on her first instructional flight) practiced airwork for approximately 15 minutes, then returned to the airport for touch-and-go landings. The flight instructor, who held an FAA medical certificate valid for third-class privileges at the time, reported that on the third touch-and-go pattern, while downwind, he lost consciousness. The dual student stated that while the instructor (her father) was piloting and speaking to her, the aircraft suddenly started heading for trees, and that she then shouted, 'What are you doing?!', but that the instructor did not respond. A witness reported that the airplane's engine sputtered and stalled as the airplane went into a steep left bank, and that it then crashed into the trees. FAA on-scene investigators found a very small quantity of fuel on board the aircraft, and the aircraft's propeller exhibited no evidence of significant engine power at impact. Records of the pilot's treatment at a local hospital following the accident contained discharge diagnoses of 'syncope prior to accident (probably related to atrial fibrillation)' and 'atrial fibrillation/junctional tachycardia.' The pilot/instructor reported that no mechanical failure or malfunction was involved in the accident.

Factual Information

On May 24, 1998, approximately 1445 Pacific daylight time, a Cessna 150L, N1479Q, was substantially damaged when it struck trees at the north end of Dave Wall Field, Sandpoint, Idaho. An airline transport pilot and flight instructor, who was acting as pilot-in-command, sustained serious injuries. A student on her first dual instructional flight, who was also the pilot-in-command/flight instructor's daughter, sustained minor injuries. The 14 CFR 91 local instructional flight, which originated at Sandpoint, was operating in visual meteorological conditions at the time of the accident and no flight plan had been filed. The flight instructor's daughter reported: "We had made two touch and go's at the airport and were circling around for a third. My father was piloting and speaking to me. All of a sudden we started heading for the trees and I shouted, 'What are you doing?!' My father did not respond. The airplane then crashed through the trees." A witness reported that the airplane's engine sputtered and stalled as the airplane went into a steep left bank, and that it then crashed into the trees. The flight instructor reported that he and his daughter flew airwork for 15 minutes and then went to the airport for touch-and-go landings. The instructor reported that while downwind on the third touch-and-go, he lost consciousness. The instructor indicated on his NTSB accident report that no mechanical malfunction or failure was involved in the accident. The 69-year-old flight instructor held an FAA second-class medical certificate with a date of issue of August 5, 1996. The instructor reported no significant medical history or use of medication on his application for an FAA medical certificate at that time, except for admission to hospital in 1994 with cracked ribs and vertebrae following an auto accident, and a February 1995 visit to a physician for a hiatal hernia. At the instructor's August 5, 1996, FAA medical examination, the examiner noted no abnormal findings. The examiner recorded the instructor's sitting blood pressure as 100/80, his pulse as 64, his height as 71 inches and his weight as 153 pounds. Following the accident, the flight instructor was taken to Bonner General Hospital in Sandpoint for treatment. Copies of the instructor's treatment records from Bonner General were obtained by the NTSB. The instructor's discharge summary included discharge diagnoses of "syncope prior to accident (probably related to atrial fibrillation)" and "atrial fibrillation/junctional tachycardia." The instructor reported on his NTSB accident report that the flight departed with 7 gallons of fuel aboard (the type's total fuel capacity with standard fuel tanks is 26 gallons, with 3.5 gallons unusable.) FAA investigators who responded to the accident scene reported they found less than full fuel in the aircraft's gascolator. Photos taken by FAA investigators depicted approximately 2 tablespoons of fuel found in the aircraft's carburetor float bowl, with the carburetor floats intact. One of the aircraft's propeller blades was shown in FAA investigator photos to be bent back approximately 10 degrees just outboard of midspan, with the other blade bent back approximately 25 degrees just outboard of the hub. Neither propeller blade exhibited any significant chordwise scratching or leading edge damage. The aircraft owner's manual gives fuel burn rates at an altitude of 2,500 feet ranging from 3.5 gallons per hour at 2,100 RPM to 7.2 gallons per hour at 2,750 RPM. At 5,000 feet, fuel burn rates range from 3.4 gallons per hour at 2,100 RPM to 6.6 gallons per hour at 2,750 RPM. Dave Wall Field is 2,127 feet above sea level.

Probable Cause and Findings

Loss of consciousness by the pilot-in-command/flight instructor, resulting in loss of aircraft control and subsequent collision with terrain.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports