Hiller UH 12A accident near Griffith, Indiana, September 11, 2017
On September 11, 2017 at about 4:00 pm local time, a 1950 Hiller UH 12A (helicopter), registered N2686, was substantially damaged in an accident during maneuvering near Griffith, Indiana (Griffith-Merriville Airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The loss of tail rotor thrust due to a failed tail rotor driveshaft, which resulted in a loss of tail rotor control and a hard landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 11, 2017 · about 4:00 pm local time
- Place
- Griffith, Indiana · Griffith-Merriville Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Hiller UH 12A NO SERIES, built 1950 · all UH 12As on the register
- Registration
- N2686 · no longer on the register · serial 168
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The flight instructor was providing dual flight instruction to a student pilot in the helicopter. About 10 minutes into the flight, while in a 3-5 ft hover, the student began to lose helicopter control and the helicopter began to spin to the right. Because the student could not regain control, the instructor took the controls, but the helicopter did not respond to cyclic inputs and left pedal input. At this point, the instructor assumed there was a loss of thrust from the tail rotor. He rolled the throttle off, and the helicopter settled to the ground and landed hard. After the landing, the instructor observed that the tail rotor and tail rotor driveshaft were not spinning and heard a grinding noise near the connection of the transmission output shaft and the tail rotor driveshaft. The instructor found that the tail rotor guard had broken off the helicopter and was about 20 ft away. The instructor could not recall if or when the tail rotor guard struck the ground. Examination of the helicopter revealed that the tail rotor driveshaft had failed near the output shaft of the tail rotor drive assembly. Substantial damage was incurred to the tail rotor and tailboom. Maintenance records were not available. Because neither the student nor the instructor could regain helicopter control, it is likely that the tail rotor driveshaft failed in flight, which led to the loss of tail rotor thrust and subsequent loss of tail rotor control.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Flight control sys malf/fail during maneuvering defining event
- Loss of control in flight during maneuvering
- Collision with terrain or object (not controlled flight into terrain) during maneuvering
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Tail rotor drive system › Tail rotor drive shaft › Failure
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,261 hours in all; 95 in this make and model; 43 in the last 90 days; 9 in the last 30 days; 1,161 as pilot in command; 348 on instruments
- Last flight review: February 19, 2017
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Dual student
- Certificate: private
- Ratings: single-engine land
- Flight time: 250 hours in all; 10 in this make and model
- Medical certificate: Unknown
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 2,653.8 hours
- Last inspection: annual inspection, September 1, 2017; 49 hours since
- Maximum gross weight: 2,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Franklin 6V350 (piston); 0 hours total
The flight
- Departed from: 05C Griffith IN
- Destination: 05C Griffith IN
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 210° at 6 knots, gusting 14
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 30°F (-1°C), dew point 19°F (-7°C)
- Altimeter: 30.00 inHg
- Observation at 5:15 pm from GYY, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on April 11, 2019. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Memorandum for the Record - FAA Inspector Phone Conversation | PDF, 1 page | View Download |
| 3 | Schematic Diagrams of Tail Rotor Drive Components | PDF, 2 pages | View Download |
| 4 | Photo Array | PDF, 2 pages | View Download |
| 5 | Ihst Helicopter Accident/incident Supplemental Checklist | PDF, 5 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.