ATL90MA051 · Learjet 23
Aero Smith Leasing Learjet 23 · Accident: loss of control in flight en route
From Willow Run Airport (YIP) to Louisville Muhammad Ali International Airport (SDF)
Event
- NTSB case
- ATL90MA051
- 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
- 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
Learjet 23
- Aircraft type
- Learjet 23
- 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
- N331DP
- Operator
- Aero Smith Leasing
- Onboard fatalities
- Unknown
- Route
- From Willow Run Airport (YIP), YPLISANTA, MITo Louisville Muhammad Ali International Airport (SDF), Louisville, KY
- 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 · climb to cruise
- 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 control in flight
- 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
- Copilot/second pilot › Incapacitation
- Pilot in command › Incapacitation
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AT 0515 EST, THE FLT WAS CLRD FOR TAKEOFF ON A FLT FM YPLISANTA, MI TO LOUISVILLE, KY. ABT 17 MIN LATER, THE FLT CREW BGN TO DISPLAY INDCNS OF A DETERIORATION OF THEIR ABILITY TO CTL THE ACFT. AT 1ST, THEY DEVIATED FM INSTRNS TO HOLD WEST OF THE FINDLAY VOR AT FL220. AS THE FLT CONTD & WAS CLRD TO FL270, THE CREW DISPLAYED CONFUSION ABT MAG HDGS & BASIC INSTRNS. AT 1048 EST, THE ACFT DEVIATED FM THE EN ROUTE HDG & THE WRONG HDG WAS READ BACK AFTER A HDG CORRECTION WAS GIVEN. ALSO, THE ACFT CONTD CLIMBING (TO FL291), THEN RADAR & RADIO CTC WERE LOST AT 0551 EST. THE CTLR NOTED THE PLT'S SPEECH WAS SLURRED & SOME PORTIONS OF THE CONVERSATION WERE UNINTELLIGIBLE. SUBSEQUENTLY, THE ACFT CRASHED IN A STEEP DIVE. NO PREIMPACT PART FAILURE WAS VERIFIED, THOUGH IMPACT FORCES & POST-CRASH FIRE RESULTED IN EXTSV DMG OF THE ACFT. THE ACFT WAS EQUIPPED WITH OXYGEN & PRESSURIZATION SYS. NO AUDIBLE WARNING WAS NOTED ON ATC RECORDINGS TO INDC THE CABIN ALT HAD EXCEEDED 10,000', THOUGH THE ACFT WAS EQUIPPED WITH SUCH A DEVICE.
Probable cause
THE FLIGHT CREW BECAME INCAPACITATED FOR UNDETERMINED REASONS AND LOST CONTROL OF THE AIRPLANE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL90MA051
- Event ID
- 20001212X22374
- Case number
- ATL90MA051
- 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: 0a321bf01e0bfa1ae4d1f1edcf56fd6b175e344def7e037ba51df755f0263600; retrieved 2026-09-21T03:01:48.855Z.