NYC06LA112 · Bulmer Lancair IV-P
Bulmer Lancair IV-P · Accident: partial loss of engine power (non-mechanical) during takeoff
From Somerset County Airport (2G9) to an unrecorded destination
Event
- NTSB case
- NYC06LA112
- 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
- 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
Bulmer Lancair IV-P
- Aircraft type
- Bulmer LANCAIR IV-P
- 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
- N5473
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Somerset County Airport (2G9), Somerset, PATo 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
- Takeoff · roll/run
- 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 (non-mechanical)
- 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
- Stall
- 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
- Pilot in command › Airspeed(vs), not maintained
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The experimental airplane had accrued 27 hours of total flight time, and had just completed its 25-hour Phase I flight testing period. Witnesses related that they saw the airplane engine start, and that the crew appeared to go through an extensive series of checks for approximately 10 minutes prior to takeoff. The engine idled smoothly, and was accelerated several times prior to taxi, once to full power. At takeoff, with a tailwind, the airplane accelerated smoothly, and rotated at a point along the runway that the witnesses thought was later than usual. The airplane pitched nose-up about 20 to 30 degrees in the climb, and the landing gear retracted. When the airplane reached treetop height, black smoke trailed from the engine exhaust system, and the engine "sputtered." The airplane entered a smooth roll to the left, yawed left, and then "plunged" to the ground, in a near vertical attitude. Witnesses said the turn after the loss of engine power was performed at a very high deck angle. Examination of data extracted from the airplane's electronic flight instrumentation system revealed that during the takeoff roll, the fuel flow was more than 20 percent above maximum, and the propeller was over-speeding. The engine rpm, fuel flow, and "Engine" warnings on the multi-function displays should have been visible to the crew. Examination of flight data revealed that the airplane continued to pitch-up as high as 22 degrees, as altitude decreased and airspeed decayed. Examination of the cockpit schematic revealed that the auxiliary fuel pump "high boost/low boost" switch was positioned next to the "Nav" lighting switch. In the airplane's "Before Takeoff" checklist, the "Lights-as required" task was to be performed four tasks prior to the "Takeoff" checklist.
Probable cause
The pilot's failure to maintain sufficient airspeed after takeoff to preclude a stall, which resulted in a loss of control and an inadvertent stall. Factors associated with the accident are the inadvertent stall, the loss of engine power due to the pilot's inadvertent activation of the high pressure auxiliary fuel pump, and the pilot's failure to abort the takeoff after receiving abnormal engine and fuel flow warnings on the primary flight display.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC06LA112
- Event ID
- 20060522X00601
- Case number
- NYC06LA112
- 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, coordinates. 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: 30cc8603fc8a1c3a052739bd47ff875cae853e0878fff21383c88614d3cc169a; retrieved 2026-09-20T17:21:27.223Z.