Critical Air Medicine Cessna 421C accident
Cessna 421C · Accident: in flight encounter with weather during initial climb
From 5T9 to San Antonio International Airport (SAT)
Event
- NTSB case
- FTW99LA012
- 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
- Charter & commuter
- 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 421C
- Aircraft type
- Cessna 421
- 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
- N19MH
- Operator
- Critical Air Medicine
- Onboard fatalities
- Unknown
- Route
- From 5T9To San Antonio International Airport (SAT), San Antonio, TX
- 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 135: Air Taxi & Commuter
- 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
- Initial climb
- 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
- 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
- Aircraft performance, climb capability › Exceeded
- Weather condition › Downdraft
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During takeoff climb, the twin-engine airplane encountered a strong downdraft and impacted trees and terrain. The pilot reported that while taxiing to the runway, he scanned the sky with the monochrome weather radar, which was set at the 40-mile range. 'No weather was shown behind the runway and a cell was shown 15 miles from the runway.' The takeoff roll was 'uneventful,' and the airplane was rotated at 95 knots. Climb out was accomplished at 110 knots, the engines were at maximum power, the propellers at maximum RPM, and the manifold pressure was indicating maximum. A 10-degree turn towards the Cotulla VOR was being made when at 1,500 feet msl, a sharp descent was felt with the VSI indicating an 800 ft/min rate of descent. The wings were leveled and the airspeed was slowed to 85 knots. 'The rate of descent slowed to 400 ft/min and then finally to 300 ft/min until impact...' The airplane was destroyed by fire that erupted on impact. A review of doppler weather radar images showed thunderstorms in the vicinity of the airport.
Probable cause
A downdraft, which exceeded the aircraft's climb performance. A factor was the thunderstorms in the vicinity of the airport.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW99LA012
- Event ID
- 20001211X11262
- Case number
- FTW99LA012
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- 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: 71c1a92d247ebfb7bec239a0eda56b4218fa34a52aad5383c99d8c858aa1d2c2; retrieved 2026-09-18T17:03:41.985Z.
- The NTSB's operator name is blank for N19MH; the operator shown is the name the NTSB records it doing business as.