- Date
- November 4, 1989, 09:15 local (16:15 UTC)
- Place
- Mesa, AZ
- Injuries
- 2 uninjured
- Damage
- Destroyed
- Phase of flight
- Maneuvering
- Aircraft
- N138USBell UH-1E
- Weather
- Visual (VMC) · Day
- Status
- Completed · report June 30, 1992
- Report
- Approved by Office Director
- FAA report
- 19891104044199A
- Case key
- 26544
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The inflight separation of the tail rotor due to improper maintenance procedures and the installation of incorrect attachment hardware on the tail rotor blade pitch change linkages.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
Investigation disclosed that the tail rotor separated from the helicopter in flight. The tail rotor assembly was sent to the manufacturer for analysis. On tail rotor blade 'a' the bolt, nut and associated hardware that attached the pitch change link to the blade grip were missing. The bolt bushing was worn beyond the service limits that mandated replacement. On blade 'b' the attaching bolt, nut and hardware were determined to be the wrong size. In addition, the wrong spacer was attached to the bolt. Four more washers than allowed were under the trailing edge blade retaining bolt nut. According to the preflight inspection requirements, the discrepancies on the blade 'a' bushing and the incorrect hardware on the blade 'b' pitch change link should have been detected during the daily inspection event.
Aircraft
- Registration
- N138US
- Reported as
- Bell UH-1E
- Category
- Helicopter
- Serial number
- 154944
- Airframe hours
- 6,866
- Engine
- Lycoming T5311, 1,100 horsepower, turbo shaft
- Damage
- Destroyed
- Flight
- Aerial application · Part 137
- Operator
- Gilman D. Christopher, doing business as Chris'S Aviation
- Registered owner
- Phillip D. Barnes
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- Annual · May 30, 1989 · 300 hours before
- Departed
- NONE · Queen Creek, AZ
- Destination
- NONE
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 46
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Right
- Flight hours
- 21,020 total · 580 in this make and model · 20,820 as pilot in command · 300 in the last 90 days · 100 in the last 30 days · 6 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Lowest ceiling
- None
- Altimeter
- 29.00 inHg
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.