IAD99FA005 · Cessna R172K
Cessna R172K · Accident: in flight encounter with weather en route
From Montgomery County Airpark (GAI) to Freeway Airport (W00)
Event
- NTSB case
- IAD99FA005
- 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
- 1 · 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
- Instrument Meteorological Cond
Cessna R172K
- Aircraft type
- Cessna 172
- 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
- N736KL
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Montgomery County Airpark (GAI), Gaithersburg, MDTo Freeway Airport (W00), MD
- 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
- In flight encounter with weather
- 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
- Visual flight rules (VFR) flight into instrument meteorological conditions (IMC); 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, inadequate
- Pilot in command › In-flight planning/decision, poor
- Pilot in command › Stall, inadvertent
- Pilot in command › VFR flight into imc, continued
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was scheduled to fly the early morning traffic watch with a traffic reporter, for about 3 hours, to provide coverage in the Washington/Virginia area. The reporter said they departed about 6:00 a.m. and that he was unable to provide his first traffic update due to the ground fog. A witness about a 1/4 mile from the accident site, said he heard an airplane circle overhead, but he was unable to see it through the dense fog. Shortly thereafter, through the broken clouds, he saw a blue and white airplane, followed by an engine surge, and then he heard an impact. The airplane struck the patio of a residence. The airplane and the rear section of the residence was destroyed as a result of the collision and post-crash fire. A helicopter pilot who was also reporting traffic said that the ceiling was about 300 feet and there was no forward visibility. The traffic reporter in the accident airplane said that they were about 400 feet, and they tried to land, but the pilot added power with 40 degree of flaps. He said the airplane stalled and he heard the pilot say, 'Oh no.' Examination of the engine and airframe did not disclose any evidence of mechanical malfunction.
Probable cause
The pilot's failure to maintain adequate airspeed which resulted in an inadvertent stall. Also causal was the pilot's poor in-flight planning/decision, and his continued VFR flight into instrument meteorological conditions. A related factor was the fog.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record IAD99FA005
- Event ID
- 20001211X11268
- Case number
- IAD99FA005
- 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: 9ea22bea5e69bca90db574d676fd3cfec8e442c06426b480932381220a0c5fa4; retrieved 2026-09-20T22:21:09.099Z.