14 CFR Part 91: General Aviation
Friday, August 03, 2018
Brantly B-2, registration:
Injuries: 2 Minor.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
On August 3, 2018, about 1605 eastern daylight time, a skid-equipped Brantly B-2A helicopter, N5901X, sustained an in-flight tail rotor blade separation and impacted terrain during an emergency landing at the Jack Barstow Airport (IKW), Midland, Michigan. The left seat air transport helicopter pilot and the right seat airplane pilot-rated passenger sustained minor injuries. The helicopter sustained substantial damage. The helicopter was registered to Beating Air Into Submission, LLC, Wilmington, Delaware, and was operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a visual flight rules orientation flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated from IKW about 1600.
In a conversation with the National Transportation Safety Board (NTSB) investigator-in-charge on August 9, the pilot reported that the purpose of the local area flight was to orient the passenger on the helicopter and demonstrate how it performs in flight. After departing from IKW, the pilot was in a level flight profile about 2,000 above ground level, located about ¼ mile south of the airport. The pilot reported that the wind condition was "light" and was originating from the west. Proceeding about 60 knots and heading about 270 degrees, the pilot felt a "flutter" emit from the helicopter and heard a subsequent "bang" noise emit from the rear of the helicopter. The helicopter immediately turned 180 degrees to the right, the pilot reduced collective, and he was able to maintain control of the helicopter. The pilot increased the airspeed and maneuvered the helicopter for an emergency landing at the airport.
The pilot was originally intending to execute a running landing to the runway, but due to his higher altitude at the time, he decided to execute a running landing to a dry, level grass field at the airport instead. During the landing sequence, the helicopter slid forward about 50 yards on the grass while heading about 220 degrees. The pilot reported as the helicopter slowed down, the left skid got "caught" on the grass. The left skid separated from the airframe, a dynamic rollover sequence occurred, and the helicopter came to rest on its left side. The three main rotor blades impacted the grass and separated about mid-span. The pilot executed an emergency shutdown and the occupants egressed from the helicopter without further incident.
The accident site was located on airport property and airport personnel arrived shortly after the accident. First responders were dispatched to the accident site at 1612. The helicopter was not equipped with an emergency locator transmitter, nor was it required to be.
The helicopter sustained substantial damage to the main rotor system, the fuselage, the tailboom, and the tail rotor system. The pilot reported that there were no preexisting mechanical malfunctions or failures with the airframe and engine that would have precluded normal operation. The pilot further reported that during the preflight process, he conducted a detailed inspection of the helicopter and observed no cracks, no corrosion, and no other abnormalities with the tail rotor system.
An aviation safety inspector (ASI) from the Federal Aviation Administration Grand Rapids Flights Standards District Office, Grand Rapids, Michigan, traveled to the accident site on August 3. The ASI examined the airframe and noted that one of the tail rotor blades (a two-blade system) fractured and separated at the spar. The tail rotor gearbox was also found separated from the tailboom. The separated tail rotor blade, along with the right side horizontal stabilizer were not recovered. All other components of the helicopter were accounted for at the accident site. The ASI was able to establish drive train continuity up to the point of separation of the tail rotor gear box. The tail rotor gear box, along with the attached tail rotor blade, were secured and transported to the NTSB Materials Laboratory in Washington, District of Columbia, for examination.
The two-seat capacity helicopter, serial number 36, was built in 1960. The helicopter was powered by a Lycoming IVO-360-A1A reciprocating engine.