NYC97FA011 · Yakovlev YAK-18T
Yakovlev YAK-18T · Accident: loss of engine power while maneuvering
From 19N to an unrecorded destination
Event
- NTSB case
- NYC97FA011
- 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
- 2 · 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
Yakovlev YAK-18T
- Aircraft type
- Yakovlev YAK-18
- 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
- N9418
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 19NTo not recorded
- 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
- Maneuvering
- 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
- Loss of engine power
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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
- Engine assembly, connecting rod › Bent
- Engine assembly, piston › Failure
- Engine assembly, piston › Movement restricted
- Flightcrew › Aircraft control, not maintained
- Flightcrew › Clearance, not maintained
- Unknown › Aircraft preflight, inadequate
Approximate · Estimated position: the centre of Berlin, NJ, the place the record names. Not the accident site.
NTSB narrative
The airplane was on a demonstration flight with a prospective buyer in the left front seat & the co-owners in the right front & a rear seat. A witness said the airplane was above the airport when a puff of white smoke came from the exhaust, & the engine lost power. The gear was extended, & the pilot(s) entered a left turn to circle & descend for a forced landing at the airport. The left seat pilot said the right seat pilot abandoned the controls, saying 'You have it.' He also said that before entering an uncontrolled descent, the right seat pilot yelled, 'We're not going to make it,' then he grabbed the controls, yanked back, and the airplane half snap rolled & dove into trees. However, a ground witness said the airplane descended until it impacted a tree, while still in a left spiral. Exam of the engine revealed 3 broken connecting rods & a shattered #5 piston. The piston had failed in compression & showed polished edges & distress associated with hydraulic lock. Operating instructions required that spark plugs & drain plugs be removed from the #4, #5, & #6 cylinders before turning the propeller to prevent hydraulic lock (if parked more than 3 days). A witness said the owners started the radial engine every couple of weeks without removing anything from the engine. A factory trained engine technician said there was evidence '...the engine was started without the operator having first checked for the presence of oil in the lower cylinders as is described in the aircraft operating instructions.'
Probable cause
an inadequate preflight by unknown person(s), sometime before the flight, by failing to avoid a hydraulic lock (from oil seepage) in the #5 cylinder, which resulted in a bent connecting rod, subsequent failure of the #5 piston, and loss of engine power. Also causal was: the flight crew's failure to maintain adequate control of the aircraft and/or clearance from a tree, while maneuvering for an emergency landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC97FA011
- Event ID
- 20001208X06957
- Case number
- NYC97FA011
- 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: 9939687acfd0670ca3f8e8296fc00fcce74051f1600ebd3cd54185ba4a3274c2; retrieved 2026-09-20T23:09:39.994Z.