ERA21LA196 · Cessna 402C
Hyannis Air Service Cessna 402C · Accident: loss of engine power (partial) on approach
Event
- NTSB case
- ERA21LA196
- 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
- Event fatalities
- Unknown
- Ground fatalities
- Unknown
- 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
Cessna 402C
- Aircraft type
- Cessna 402
- 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
- N2714B
- Operator
- Hyannis Air Service
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- Aircraft age
- About 42 years (built 1979)
- 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
- Approach · VFR go-around
- Defining eventThe 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 (partial)
- 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
- Personnel issues › Psychological
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
A flight instructor and a new-hire trainee pilot were practicing instrument approach procedures in the multi-engine airplane. The first approach was a circle-to-land that terminated with a go-around/rejected landing. On climb out, the flight instructor reduced power on the left engine to simulate an engine failure on takeoff. The pilot then ran the memory items for an engine failure, which included turning the left engine auxiliary fuel boost pump to high. Air traffic control then vectored the airplane for another instrument approach. The approach terminated with the pilot making visual contact with the runway and preparing to land. When the airplane was about 50 ft above the runway, the flight instructor called for a two-engine go-around. The pilot brought both throttles to full power and retracted the flaps and gear. The flight instructor said the airplane yawed left, and the airspeed was about 80 knots, well under the airplane’s best single engine rate of climb speed of 95 knots. The flight instructor took control of the airplane and called for the gear to be extended. He told the pilot that he was going to land on the grass. The airplane landed hard and rolled before the nose and left main landing gear collapsed, resulting in substantial damage to the left engine and wing. Prior to exiting the airplane, the pilot said he turned the left engine auxiliary boost pump from the high position to the off position. The flight instructor said that turning the boost pump to high while the engine was still operating could flood the engine with excess fuel and cause it to lose power. He said that he normally reminds pilots not to turn the pump to high during a simulated engine failure in flight, but neither he nor the pilot recalled it being mentioned during the accident flight. Postaccident examination of the left engine revealed no mechanical discrepancies that would have precluded normal operation. As a result, its most likely that when the boost pump was turned to high, it flooded the engine with excess fuel, resulting in loss of engine power while attempting to go around. The flight instructor and the pilot were not prepared for the loss of engine power and the airspeed dropped well below the airplane’s best single engine rate of climb speed of 95 knots. Due to the low airspeed and altitude, the flight instructor took control of the airplane and landed on the grass adjacent to the runway. The pilot said that he had practiced simulated engine out procedures in the simulator, but never in the airplane. In the simulator, he was taught to physically move the auxiliary boost pump to the high position when practicing a simulated engine failure. He was not aware that turning the auxiliary fuel boost pump to high could result in a loss of engine power.
Probable cause
The flight instructor’s failure to confirm the position of the left engine’s auxiliary fuel boost pump switch during a simulated engine out procedure, which resulted in an excess amount of fuel in the engine and subsequent partial loss of power during a go-around/rejected landing. Contributing to the accident was the flight instructor’s failure to maintain control of the airplane, which resulted in a hard landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA21LA196
- Event ID
- 20210430103000
- Case number
- ERA21LA196
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, coordinates, cause areas. 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: 025d3167f8a4b3f99d36977e102e0963e24fca680c6105f3be450384abc02c02; retrieved 2026-09-16T13:59:44.111Z.