Aviation Accident Summaries

Aviation Accident Summary WPR10LA208

North Las Vegas, NV, USA

Aircraft #1

N68TF

Bibbee Cozy Mark IV

Analysis

The pilot, who had recently purchased the airplane, departed with the intention of determining the minimum speed of the experimental canard equipped airplane at a light weight. He accomplished two stalls (canard only) with no abnormalities encountered. During a third stall, the main wing suddenly stalled without warning. The airplane began to sink rapidly in a level to slightly nose high attitude. The pilot immediately applied full nose down elevator as recommended in the operating handbook, but the airplane did not respond. He applied full power, but the airplane remained unresponsive in pitch. He determined that only the rudders remained mildly effective, and in response, he attempted to roll the airplane in an effort to maneuver the nose down and break the stall. After two unsuccessful attempts, the airplane remained stalled with a high sink rate. As the airplane was neared the ground, the pilot leveled the wings with rudder deflection and kept the engine at full power. The airplane impacted the ground in a level attitude, and almost immediately came to a halt. During the postaccident inspection, the pilot reported that he found that the builder of the airplane did not install the canard at the proper angle of incidence, and failed to ensure the proper elevator control deflections. The builder also told the pilot that a mandatory plans change affecting the canard had been complied with, but according to the pilot it had not. The pilot’s operating handbook had also not been updated with a required change that would have highlighted these problems. The pilot reported that prior to purchase he had the airplane inspected. The purpose of the inspection was to identify discrepancies; however, the inspector did not find any. The pilot reported that he learned that all of the discrepancies had been addressed in newsletters that were sent from the kit manufacturer to builders. None of the newsletters were included with any of the material that the pilot received when he purchased the airplane, and he reported that they had been out of print for four years prior to when he bought the airplane and were no longer available in written form.

Factual Information

**This report was modified on 10/4/2011. Please see the public docket for this accident to view the revisions to the original report.** On April 16, 2010, at 0830 Pacific daylight time, an experimental Bibbee Cozy Mark (MK) IV, N68TF, collided with terrain near North Las Vegas, Nevada. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot sustained minor injuries. The airplane sustained substantial damage to the wings, fuselage, and empennage. The local personal flight departed the North Las Vegas Airport about 0818. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot had recently purchased the airplane that had been built by another individual. The airplane had a total time of 410 hours. The pilot had 64 hours as PIC in this make and model. The pilot departed with the intention of determining the minimum speed of the canard equipped airplane at a light weight. He flew to the practice area, and climbed to 7,000 feet. He determined that 67 knots indicated airspeed (KIAS) was the minimum airspeed that the airplane would maintain before the canard stalled. This was 17 knots above the published minimum speed, so the pilot felt that he was near a main wing stall. He accomplished two stalls (canard only) with no abnormalities encountered. During a third stall, the main wing suddenly stalled without warning. The airplane began to sink rapidly in a level to slightly nose high attitude. The pilot immediately applied full nose down elevator as recommended in the operating handbook, but the airplane did not respond. He applied full power, but the airplane remained unresponsive in pitch. He determined that only the rudders remained mildly effective, so he attempted to roll the airplane in order to get the nose down, and break the stall. After two unsuccessful attempts, the airplane remained stalled with a high sink rate. The airplane was nearing the ground, so the pilot leveled the wings. He left the engine at full power, and leveled the wings with the rudder. The airplane impacted the ground in a level attitude, and almost immediately came to a halt. He shut the engine down with the throttle and mixture; he shut off the ignition switches and electrical master switch prior to his egress from the airplane. He was able to walk clear of the wreckage, and call emergency services on his cell phone. During the postaccident inspection, the pilot reported that he found that the builder of the airplane did not install the canard at the proper angle of incidence, and failed to ensure the proper elevator control deflections. The builder also told the pilot that a mandatory plans change affecting the canard had been complied with, but according to the pilot it had not. The pilot’s operating handbook had also not been updated with a required change that would have highlighted these problems. The pilot reported that prior to purchase he had the airplane inspected by a company authorized by the current owner of the designer’s plan’s rights to provide builder support for this model of airplane. The purpose of the inspection was to identify discrepancies; however, the inspector did not find any. The pilot reported that he learned that all of the discrepancies had been addressed in newsletters that were sent from the kit manufacturer to builders. None of the newsletters were included with any of the material that the pilot received when he purchased the airplane, and he reported that they had been out of print for four years prior to when he bought the airplane and were no longer available in written form.

Probable Cause and Findings

The airplane's inability to recover from a stall due to the builder's failure to comply with design specifications and update the pilot’s operating handbook, which would have highlighted the discrepancies in the airplane's build-up.

 

Source: NTSB Aviation Accident Database

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