Aviation Accident Summaries

Aviation Accident Summary DEN00LA124

LOGAN, UT, USA

Aircraft #1

N38903

Bell 206L-3

Analysis

Following maintenance on the helicopter, the pilot was conducting a test flight. Takeoff was made with the left passenger door unlatched. When this was pointed out to the pilot by radio, he commenced a precautionary approach/landing to close the door. During the approach, the pilot felt and heard a bang followed by a vibration and rattling noise. This subsided and the pilot analyzed a loss of tail rotor control. He conducted a forced landing and the helicopter rolled on its left side during the landing. The main rotor blades and rotor head separated and the main rotor blades and tail rotor struck the tail boom. At the time of the flight, a jacket with red and black stenciled letters on the back was lying on the passenger seat. It was not found following the accident. Examination of the helicopter following the accident revealed a torsional fracture of the number 4 tail rotor drive shaft section and a bend in the number 5 section. Also, the tail rotor blades had red paint transfer, and one had a dent in the leading edge, and was bent near the blade root. Analysis of the paint transfer revealed it did not come from the jacket lettering. Parts of the helicopter were painted red and the red part of the tail boom exhibited paint transfer and slap marks. The tail rotor blades did not exhibit rotational impact damage.

Factual Information

On July 7, 2000, at 1500 mountain daylight time, a Bell 206L-3, N38903, operated by Papillion Airways, Inc., sustained substantial damage during a forced landing approximately 6 miles west of Logan, Utah. The commercial pilot and his passenger were not injured. The flight was a local area maintenance test flight operating under Title 14 CFR Part 91 and no flight plan was filed. Visual meteorological conditions were present. A torque gauge had been changed and the pilot was conducting a test flight. Shortly after takeoff, persons on the ground noticed the left passenger door appeared to be open. The pilot was informed and was making a precautionary approach to landing to close the door when he heard and felt a bang followed by a slight vibration and rattling which subsided. When the nose of the helicopter started to drift right, the pilot said he attempted to correct it with pedal and found the pedals unresponsive and loose. He performed an autorotation with the engine power set at idle. During the flare for landing, the helicopter turned rapidly to the right and upon touchdown rolled on its left side. The pilot secured the engine and he and the passenger exited the helicopter. During the impact sequence, the helicopter shed the main rotor head and blades, which were both damaged by impact, and the tail boom was partially separated by main rotor impact about 3 feet aft of the horizontal stabilizer. The tail rotor drive shaft was intact through the boom separation area but the number 4 section was fractured and the number 5 section bent. They remained attached. When the flight originated, there were several items lying on the passenger seats. One of the items was a jacket with some red and black lettering stenciled on the back. This item was not found following the accident. Examination of the tail rotor drive shaft sections revealed a torsional fracture of the number 4 drive shaft 11.2 inches from the engine end as mounted on the aircraft. Wall thickness of the 1.26-inch diameter drive shafts was 0.0498-inch, which was within the range spelled out in the American National Standard Dimensional Tolerance for Aluminum Mill Products. Hardness of the 2024-T3 aluminum drive shaft tubes was 98 HRB, which met the 66 HRB minimums per BPS 4467 for typical 2024-T3 aluminum. Spectrographic analysis of the drive shaft tubes showed conformation to WWW-T-700/3 per the engineering drawing (reference SJL00-0361). Examination of tail rotor blade S/N CS 6266 revealed a red paint spot on the blade tip inboard side. The painted section of the blade was removed and sent to the Bell chemical laboratory for analysis. Paint transfer on the blade was analyzed and compared to the paint on a jacket like the one missing from the passenger seat. The analysis revealed that the paints were not chemically similar. Examination of tail rotor blade S/N CS 5999 reveled red paint transfer on the inboard and outboard sides of the blade's leading edge 5 inches from the blade tip. Analysis provided evidence that the paint was not chemically similar to that on the jacket. This blade also exhibited a dent on the outboard side of the blade 4.8 inches from the blade tip. In addition, this blade was bent 8.5 inches from the blade butt. Neither tail rotor blade exhibited damage consistent with rotation at impact. The helicopter color was white, yellow, red, maroon, and blue. The tail boom exhibited both main and tail rotor slap marks on the red painted portion of the boom. Paint transfer from the blades was present on the boom.

Probable Cause and Findings

in-flight collision with a jacket, which blew out of the helicopter because the left passenger door was not properly secured prior to takeoff. A contributing factor was the pilot's failure to ensure the door was properly closed prior to takeoff.

 

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