NYC98LA152 · Piper PA-28-151
Piper PA-28-151 · Accident: partial loss of engine power (mechanical failure) en route
From Laurence G Hanscom Field (BED) to Patrick Leahy Burlington International Airport (BTV)
Event
- NTSB case
- NYC98LA152
- 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
Piper PA-28-151
- Aircraft type
- Piper PA-28
- Category
- Airplane
- 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
- N44438
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Laurence G Hanscom Field (BED), Bedford, MATo Patrick Leahy Burlington International Airport (BTV), Burlington, VT
- 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 · 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
- Partial 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
- Destroyed
Cause areas
- Other maintenance personnel › Maintenance, overhaul, improper
- Throttle/power lever › Seized
Approximate · Estimated position: the centre of Newport, NH, the place the record names. Not the accident site.
NTSB narrative
After departing and climbing to a cruise altitude of 6,500 feet above mean sea level, the pilot made a power reduction to descend below a cloud layer. After reducing power the throttle became stuck. Unable to move the throttle, the pilot diverted to an alternate airport. With the engine still running the airplane touchdown on the runway, but the pilot was unable to stop the airplane. The airplane exited the departure end of the runway, traveled 75 feet, and came to rest on top of a hill. While landing, the pilot thought the throttle was in the idle position. After the accident he realized it was slightly open. Examination of the carburetor, which had 12 hours since overhaul, revealed that the throttle shaft could not be rotated by hand, and a punch and hammer was required to remove the shaft. The shaft was galled where it rested on the bushings. Both ends of the original shaft (part number CF 13-1521) measured .3105 of an inch in diameter. A new shaft supplied by the overhaul facility measured .3104 of an inch in diameter at both ends. Under the supervision of the NTSB Investigator, the original throttle bushings were re reamed with the original router. Then, the new throttle shaft was inserted, and it rotated freely. The old shaft was then inserted, but was difficult to rotate. After removing the old throttle shaft, the bushings were re reamed, using a new router the company had bought after the accident. Again, the old shaft was inserted, but this time it rotated freely. The butterfly valve was then installed, and the throttle shaft continued to rotate without difficulty
Probable cause
The seizure of the throttle shaft, due to the overhaul facilities' failure to insure all metal fragments had been removed from the carburetor before inserting the throttle shaft after reaming the throttle shaft bushings.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC98LA152
- Event ID
- 20001211X10686
- Case number
- NYC98LA152
- 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: 8176c011c7a51662ba263e3b7f786c327e0bb57f4d7295d387292e6073b5c053; retrieved 2026-09-21T20:45:04.079Z.