# Accident 20180803014899A: Brantly B-2, Midland, MI, August 3, 2018 - Type: FAA accident report (Accident/Incident Data System), as reported - Date: August 3, 2018, 16:05 local time - Place: Midland, MI - Damage: Substantial damage - Phase of flight: Cruise/Level Flight - Operating rules: General operating rules (Part 91) - Location: 43.6631° N, 84.2622° W: From the FAA - Nearby events: https://openairdocs.org/map.md?lat=43.6631&lon=-84.2622&mi=10 - Aircraft: N5901X, a cancelled registration (https://openairdocs.org/deregistered/N5901X-2020-04-03) (OpenAirDocs) - Registry model: Brantly B-2 (registry code 1440502, https://openairdocs.org/model/brantly-b-2) (OpenAirDocs) - Reported make and model: BRANTLY B-2 - People aboard: 2 - Fatal injuries: 0 - Other injuries: 1 - Pilot certificates: Airline transport, flight instructor - Pilot flight hours: 35,000 total, 300 in this make and model, 2 in the last 90 days - NTSB investigation: [NTSB CEN18LA313](https://openairdocs.org/ntsb/CEN18LA313) (OpenAirDocs) - FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/) - Page: https://openairdocs.org/incident/20180803014899A ## Narrative As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^. ON AUGUST 3, 2018 AT 4:05 PM EASTERN DAYLIGHT TIME, A BRANTLY B2A HELICOPTER, N5901X, REGISTERED TO AND OPERATED BY AN AIRLINE TRANSPORT PILOT RECEIVED SUBSTANTIAL DAMAGE DURING AN AUTOROTATION AT THE MIDLAND BARSTOW AIRPORT (IKW), MIDLAND, MICHIGAN. VISUAL METEOROLOGICAL CONDITIONS AND LIGHT WINDS WERE REPORTED AT THE TIME OF THE ACCIDENT. THE FLIGHT WAS BEING CONDUCTED UNDER THE PROVISIONS OF TITLE 14 CODE OF FEDERAL REGULATIONS (CFR) PART 91 WITHOUT A FLIGHT PLAN. THE PILOT SUSTAINED MINOR INJURIES AND THE SOLE PASSENGER WAS NOT INJURED. THE LOCAL FLIGHT ORIGINATED FROM THE MIDLAND BARSTOW AIRPORT APPROXIMATELY 15 MINUTES PRIOR TO THE ACCIDENT. ACCORDING TO THE PILOT, HE WAS GIVING AN INTRODUCTORY FLIGHT TO THE PASSENGER AND REMAINED IN THE AIRPORT TRAFFIC AREA. AT AN ALTITUDE OF 2000 FEET MSL (APPROXIMATELY 1400 FEET AGL), WITH A FORWARD SPEED AROUND 80 MPH, IN LEVEL FLIGHT, THE HELICOPTER DEVELOPED A SUDDEN VIBRATION IN THE TAIL AND THE SOUND OF A LOUD BANG WITHIN 1 SECOND OF ONSET. FOLLOWING THE NOISE, THE HELICOPTER LOST ALL TAIL ROTOR DIRECTIONAL CONTROL AND PITCHED NOSE DOWN. THE PILOT IMMEDIATELY INITIATED AN AUTOROTATION TO THE AIRPORT SURFACE AREA. THE HELICOPTER TOUCHED-DOWN IN THE GRASS, JUST NORTHWEST OF THE RUNWAY 06/36 INTERSECTION IN A FORWARD SKID. PRIOR TO THE AIRCRAFT COMING TO A COMPLETE STOP THE LEFT LANDING SKID CAUGHT IN THE SOFT GRASS AND THE HELICOPTER ROLLED ONTO ITS LEFT SIDE COMING TO REST ON A HEADING OF 040 DEGREES. THE PILOT AND PASSENGER WERE ABLE TO EGRESS FROM THE AIRCRAFT THROUGH THE BROKEN CANOPY. THERE WAS NO POST-CRASH FIRE. LOCAL LAW ENFORCEMENT AND RESCUE PERSONNEL ARRIVED SHORTLY AND SECURED THE ACCIDENT SCENE. INVESTIGATION REVEALED THE TAIL ROTOR AND UPPER TAIL ROTOR GEARBOX ASSEMBLY TO BE MISSING FROM THE PRIMARY ACCIDENT SITE AND WAS LOCATED APPROXIMATELY ONE-HALF MILE AWAY BY THE AIRCRAFT OWNER. THE GEARBOX DRIVE SHAFT WAS SHEARED AND REMAINED WITH THE HELICOPTER DURING THE ACCIDENT SEQUENCE. THE RECOVERED GEARBOX HAD MULTIPLE LOCATIONS OF IMPACT DAMAGE WITH ONLY ONE OF TWO BLADES STILL ATTACHED TO THE YOKE. IT APPEARS THE MISSING BLADE WAS SHED DURING FLIGHT CAUSING THE VIBRATION AND SUBSEQUENT LOSS OF THE REMAINING BLADE AND GEARBOX. THE MISSING BLADE HAS NOT BEEN RECOVERED AS OF THIS DATE. CLOSE EXAMINATION OF THE TAIL ROTOR YOKE SHOWED SIGNS OF DAMAGE/CRACKING PRIOR TO FAILURE. THE YOKE BREAK POINT SHOWS BEACH MARKING AND SURFACE SMOOTHING THROUGH ¾ DIAMETER OF THE SHAFT WITH A 45-DEGREE SHEER LIP AT THE FINAL FAILURE AREA. THE PILOT^PRIVACY DATA OMITTED^ REPORTED NO KNOWN DAMAGE HISTORY TO THE TAIL ROTOR AND THAT THE HELICOPTER WAS WITHIN ANNUAL INSPECTION WHERE NO ANOMALIES WERE NOTED. THE REMAINING BLADE AND TAIL ROTOR GEARBOX WERE SECURED FOR FURTHER DETAILED TESTING AND EXAMINATION. WEATHER AT KIKW AIRPORT: 1955 UTC, WIND 250 DEGREES AT 4 KNOTS, VISIBILITY 10 STATUTE MILES SCATTERED AT 4300?, TEMP. 27 C, DEW POINT 16 C, ALTIMETER 30.04. ## The NTSB's investigation of this event (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB CEN18LA313](https://openairdocs.org/ntsb/CEN18LA313), Aug 3, 2018: Brantly B-2 (N5901X), Midland, MI, substantial damage. Probable cause: The in-flight separation of the tail rotor blade due to fatigue, which resulted in the subsequent emergency landing and dynamic rollover. From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.