ATL88LA232 · Hiller UH-12A
Hiller UH-12A · Accident: total loss of engine power (mechanical failure) en route
From KY29 to NEW BURNSIDE, IL
Event
- NTSB case
- ATL88LA232
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Hiller UH-12A
- Aircraft type
- Hiller UH-12
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N4828E
- Operator
- James F.Allen
- Onboard fatalities
- Unknown
- Route
- From KY29To NEW BURNSIDE, IL
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · climb to cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Total loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Accessory drive assembly, drive gear › Disconnected
- Ignition system, magneto › Failure, total
- Other maintenance personnel › Maintenance, overhaul, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AFTER DEPARTURE THE ENG QUIT & PIC MADE AN AUTOROTATIVE LANDING IN A WOODED AREA. INITIAL EXAM OF ENG REVEALED WATER IN THE CARB FLOAT BOWL. INVESTIGATION SHOWED HELO HAD 100 HR INSPECTION RECORDED IN THE LOG, BUT MAY HAVE BEEN RETURNED TO SERVICE BY MECHANIC WITHOUT INSPECTION AUTHORIZATION AS AN ANNUAL INSPECTION. HELO RECORDS WERE OBTAINED BY ONE OF THE MECHANICS FROM THE SAME REPAIR STATION, BUT NOT GIVEN TO FAA INSPECTOR & LATER LOST. LATER EXAM OF THE ENG SHOWED HOLES IN ACCESSORY CASE. PARTIAL TEARDOWN SHOWED THAT THE LEFT MAG DRIVE COUPLING NUT COTTER KEY WAS MISSING. IT IS BELIEVED THE COTTER KEY WAS NOT INSTALLED OR WAS DAMAGED DURING INSTALLATION & BACKED OUT OF THE NUT ALLOWING THE NUT TO BACK OFF & THE DRIVE COUPLING TO DISCONNECT. THE PLT DID NOT FILE AN ACC REPORT. THE PLTS LOG BOOKS HAVE NOT BEEN LOCATED. THE ACFT ROLLED OVER AFTER LNDG.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record ATL88LA232
- Event ID
- 20001213X26448
- Case number
- ATL88LA232
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 7bee6f572352c6518c68bb5aa5ea496d84934cd3817d6fafad5cd5f0029ae909; retrieved 2026-09-21T16:05:14.242Z.