Aviation Accident Summaries

Aviation Accident Summary LAX07CA036

Tucson, AZ, USA

Aircraft #1

N4115M

Burkhart Grob Flugzeugbau G103 Twin Astir

Analysis

The glider pilot reported he was attempting to land the glider further down the runway than usual. He stated he added 1/2 spoilers and flared about 10 feet above the runway. He retracted the spoilers, and added them again when he was further down, and about 5 feet above the runway. At the second spoiler application, the glider immediately fell to the runway, hitting hard and bouncing. The glider bounced another two or three times, coming to rest after the tail section separated. The pilot stated that there were no pre accident mechanical or flight control problems with the glider.

Factual Information

On November 15, 2006, at 1437 mountain standard time, a Burkhart Grob Flugzeugbau G103 Twin Astir glider, N4115M, landed hard at El Tiro Gliderport (AZ67), Tucson, Arizona, and porpoised on runway 8R before coming to a stop. Tucson Soaring Club operated the rental glider under the provisions of 14 CFR Part 91. The private glider pilot, the sole occupant, was not injured. The tail section of the glider separated forward of the vertical stabilizer and the horizontal stabilizer sustained damage. Visual meteorological conditions prevailed for the local area flight that departed about 1430. No flight plan had been filed. According to the pilot's written statement, he had conducted two flights on the day of the accident. He noted clear sky conditions, and a slight north crosswind between 3 and 5 knots. The first flight was uneventful, except that he was only able to stay aloft for 16 minutes due to low thermal activity. He made the approach at 60 knots, and the landing was normal. On the second flight, the accident flight, he flew the pattern with the intent of landing long so that he could put the glider away for the day, as it was not scheduled for additional flights. He made the approach at 60 knots, added 1/2 spoilers, and flared about 10 feet above the ground. At that point, he closed the spoilers so that the touchdown point would be longer than normal. The glider floated about 5 feet above the runway and he applied 1/2 spoilers so that the glider would touch down. The glider immediately dropped and landed hard, which resulted in it bouncing back into the air. The pilot stated that he held the stick in a fixed position with the wings level, thinking that the glider would float down to the runway and land, with the potential of bouncing 2 or 3 more times. He stated that the glider bounced 2 or 3 more times; however, each touchdown was harder than the previous time. Upon exiting the glider, he noted that the tail section had separated from the fuselage. The pilot stated that there were no mechanical or flight control problems with the glider prior to the accident.

Probable Cause and Findings

The pilot's improper use of the spoilers during the landing flare, which resulted in a hard landing, and his inadequate bounced landing recovery technique.

 

Source: NTSB Aviation Accident Database

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