MIA99LA186 · Robert R. Callahan EXEC 90
Robert R. Callahan EXEC 90 · Accident: loss of engine power en route
From X39 to an unrecorded destination
Event
- NTSB case
- MIA99LA186
- 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
Robert R. Callahan EXEC 90
- Aircraft type
- Robert R Callahan EXEC 90
- 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
- N4359N
- Operator
- David Mcclamma
- Onboard fatalities
- Unknown
- Route
- From X39To 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
- En route · descent
- 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
- 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
- Unqualified person › Cyclic, excessive
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The non-certificated pilot preflighted the helicopter and after engine start, one of the magnetos was intermittent. Manipulation of the magneto switch corrected the problem; the flight then departed and flew about 5 miles away. While returning, the non-rotorcraft rated passenger began flying the helicopter and while descending over the airport about 300 feet, the engine quit. The passenger lowered full collective, maintained 60 mph, then when the helicopter was 20 feet agl, he flared using a 45 degree flare angle. The tailboom contacted the ground first, followed by the main rotor blades contacting the tailboom. The helicopter then landed hard. The passenger stated after takeoff, the pilot performed 3 or 4 simulated loss of engine power with power recoveries and while performing another, the engine quit at 100-150 feet. He took the controls from the pilot and with the main rotor tachometer indicating 0, performed an autorotative landing but the helicopter landed hard. The engine was started postaccident and found to operate normally. Examination of the engine systems revealed no evidence of preimpact failure or malfunction. The pilot stated that he found corrosion at the wiring connections at each ignition pack. Preflight examination of the ignitions packs is required.
Probable cause
The excessive cyclic input by the non-qualified passenger during the autorotative landing following a reported loss of engine power. A factor in the accident was the inadequate preflight of the helicopter by the unqualified pilot for his failure to detect corrosion at each ignition pack during the helicopter preflight, resulting in the loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA99LA186
- Event ID
- 20001212X19073
- Case number
- MIA99LA186
- 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: 440dc97a1ef222118cee8f64a5f3c3a5229bf6d3825036965d6e2dc6ebdc59a2; retrieved 2026-09-21T10:58:56.273Z.