AVIATION OCCURRENCE REPORT LOSS OF ENGINE POWER / STALL CESSNA 177 RG CARDINAL C-GWNW

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AVIATION OCCURRENCE REPORT LOSS OF ENGINE POWER / STALL CESSNA 177 RG CARDINAL C-GWNW AIRDRIE, ALBERTA 12 MARCH 1996 REPORT NUMBER A96W0055 The Transportation Safety Board of Canada (TSB) investigated this occurrence for the purpose of advancing transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability. AVIATION OCCURRENCE REPORT LOSS OF ENGINE POWER/STALL CESSNA 177RG CARDINAL C-GWNW AIRDRIE, ALBERTA 12 MARCH 1996 REPORT NUMBER A96W0055 Summary The pilot departed from runway 34, Calgary International Airport, on a visual flight rules (VFR) flight to Villeneuve Airport, Alberta, at about 1100 mountain standard time (MST). He climbed to 4,500 feet above sea level (asl) to clear the zone, and initiated a climb to his cruise altitude of 8,500 feet asl. As the pilot reached about 5,000 feet asl, the engine rpm smoothly dropped to idle. Attempts to regain normal power by movement of engine and fuel system controls were unsuccessful. The pilot declared an emergency, extended the landing gear, and established a 65 mph glide. Air Traffic Control (ATC) advised the pilot that Airdrie, behind him, was the closest airport to his location. The pilot made a left turn back toward Airdrie, but was unable to make it to the airport. The pilot selected a secondary road, running east-west toward Airdrie, for an emergency landing. While banking to the west to align with the road, he noticed a set of power lines and planned to clear them; however, he then noticed a second set of power lines and checked back on the elevator controls. While manoeuvring, the pilot heard the stall horn beeping and noticed that the aircraft was drifting south of his intended landing area. The left wing then dropped and the flight controls were initially unresponsive before the aircraft began a steep descent. The pilot attempted to flare during the dive. The aircraft struck the ground hard in a nose-low attitude, bounced twice, the right main wheel broke off, and the nose gear collapsed. The aircraft left the road and came to rest in the ditch against a barbed wire fence. The pilot sustained serious injuries. He turned off the master switch and called 911 from his cell phone. Police and ambulance personnel arrived shortly thereafter, and the pilot was evacuated to a Calgary hospital. Ce rapport est également disponible en français. - 2 - A96W0055 Other Factual Information The aircraft fuselage was heavily damaged during the impact, with indications of high vertical loads evidenced by the collapse of the cockpit floor under the pilot's seat. The flaps were found in the retracted position. The pilot was not wearing the shoulder harness installed in the aircraft. There was evidence of rotation on the propeller blades, prior to one blade becoming jammed into the lower cowl. At the request of the injured pilot, the emergency locator transmitter (ELT) had been selected to the manual ON position by a passer-by. The aircraft was reported to have been leaking fuel after the occurrence. Examination of the aircraft showed that the impulse spring (part no. 10-51324) in the magneto (Teledyne Continental Motors (TCM)/Bendix model D4LN-2021) had broken. The engine (Textron Lycoming IO-360A1B6D) in this aircraft is equipped with a single-drive, dual magneto. The impulse coupling is a spring-loaded device that mechanically retards the spark advance to assist starting. Failure of this spring would allow the common drive of the dual magneto to move in the direction that would retard the spark. This would affect both ignition systems and could cause a significant power loss if the resulting spark timing was near top dead centre (TDC). A search of the Service Difficulty Report (SDR) data base determined there had been 58 other reports of the failure of this spring, five in this model dual magneto, with similar power losses reported. A detailed examination of the broken spring by the TSB Engineering Branch found evidence of an inter-granular pre-crack region, indicating an environmentally assisted fracture. Examination determined that the magneto breaker points were pitted and gapped incorrectly, resulting in weak spark output when the magneto was bench tested, although this is not believed to be a causal factor in the occurrence. Airworthiness Directive (AD) 78-09-07 R3, pertaining to this aircraft, requires inspection of the impulse coupling for excessive wear at 500-hour intervals. A survey of the aircraft logs and records determined that this AD had never been complied with. The engine log indicated that the engine had accumulated 758.1 hours since overhaul in 1983. The AD requires compliance with Bendix Service Bulletin (SB) 599B, which has been superseded by TCM mandatory SB (MSB) 645. This MSB adds requirements for inspection of riveted impulse couplings at 100-hour intervals, and replacement of the impulse spring if the impulse coupling is disassembled for inspection; inspection is possible without disassembly. The aircraft was being maintained by a freelance aircraft maintenance engineer (AME), who was a close acquaintance of the pilot. The AME had last certified the aircraft on 03 February 1996, at 2,290.3 airframe hours. The AME indicated that he had obtained a listing of the ADs required for this aircraft from an American aircraft sales publication called The Aircraft Bluebook. The book was examined and AD 78-09-07 R3 was not included in the list of ADs for the Cessna 177RG. A disclaimer printed in the lower margin of the AD notes - 3 - A96W0055 section of this book reads: "NOTE - this AD note listing is intended as a guide only and should not be relied upon as conclusive evidence of AD applicability on any particular aircraft." The pilot has held a private pilot licence since 1986 and has flown a total of about 600 hours, 468 hours of which were on type. He had obtained a night endorsement in 1989. The pilot had not performed