MD Helicopters Explorer Models 900 and 902 are the subject of an FAA Emergency Airworthiness Directive (2008-22-53) following several recent reports of loss of yaw control in the no-tail rotor (Notar) helicopters. The latest incidents occurred in October, both apparently caused by the separation of the vertical control rod from the actuator.
Eurocopter AS 350B2, Hiram, Ga., May 21, 2008–The NTSB attributed the buckling of the AS 350’s tail boom to failure of the starflex arm during engine run-up due to inadequate maintenance inspection. After the pilot started the engine at Caffery Heliport and advanced the power to flight rpm, the helicopter shook violently.
Bell 206B JetRanger, Longview, Wash., Oct. 10, 2008–The Northwest Helicopters JetRanger lost power while hauling tree limbs. The pilot attempted a power-out forced landing at the bottom of a steep ravine covered with 30-foot conifer trees. The pilot was seriously injured and the helicopter was substantially damaged.
Biggin Hill, UK-based helicopter charter operator Sky Charter has been designated the UK dealer for PZL Swidnik rotorcraft. The company has ordered three SW4 light singles and is expecting deliveries next spring.
Bell 206L LongRanger, Nikolai, Alaska, March 4, 2008–The pilot of the LongRanger was maneuvering while his passenger was filming a dogsled race when, he said, a gust of wind caused a loss of tail-rotor effectiveness. The helicopter started to turn to the right, and the pilot reduced collective pitch and followed the turn to regain control. He was losing altitude and approaching the ground.
Summer means fire season, and Columbia Helicopters’ tandem-rotor Chinooks and Vertols have already been dispatched to their bases, primarily throughout the Western U.S., under contracts with the U.S. Forest Service.
A proposed airworthiness directive for the Sikorsky S-76 would require inspections of the tail rotor vertical stabilizer aft spar assembly every 50 hours after an assembly has 1,000 hours time-in-service. It would also require track and balance of the tail rotor within 30 days and every 200 hours thereafter. The AD would affect an estimated 216 S-76A/B/Cs on the U.S. registry.
Tail-rotor cracking has prompted the FAA to issue an Airworthiness Directive for Bell helicopters. The AD affects approximately 400 Bells, including the 204B, 205A, 205A-1, 205B, 210, 212, 412, 412CF and 412EP. More than 380 of these machines are listed on the U.S. registry. The AD prescribes shortened inspection and maintenance intervals for the tail rotors on these helicopters.
In aviation, like most other industries, success breeds regulation. The bigger an industry becomes, the more the government perceives the need to regulate it, often citing reasons such as safety, unfair competition and environmental protection. Yet, in typical Darwinian fashion, most industries adapt–or die. In aviation, hush kits quiet noisier jet engines, airplanes are made RVSM compatible and helicopters are flown neighborly.
Helicopter manufacturers are exploring a number of technologies to reduce noise, both that perceived from the ground and inside the cabin. European manufacturers are working on several demonstration programs to reduce noise by changing the helicopter’s airframe dynamics.