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CHI91MA224 · Learjet 23

22 Jul 1991 · Detroit, MI, United States

Jetstream International Learjet 23 · Accident: loss of control in flight during takeoff

From Coleman A. Young Municipal Airport (DET) to Chicago Midway International Airport (MDW)

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Event

NTSB case
CHI91MA224
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
3 · 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
N959SC
Onboard fatalities
Unknown
Route
From Coleman A. Young Municipal Airport (DET)To Chicago Midway International Airport (MDW), Chicago, IL
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
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
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/mush; 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

  • Pilot in command › Aborted takeoff, not performed
  • Pilot in command › Aircraft preflight, inadequate
  • Pilot in command › Lift-off, premature

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

A LINEMAN NOTED PARKING BRAKE (P/B) WAS SET BFR FLT. PLTS BGN TKOF ON 5147' RWY WITH 10 KT X-WND. A WITNESS SAID ACFT ROTATED FOR TKOF ABT 4500' DWN RWY & LIFTED OFF ABT 50' LTR. RPRTDLY, IT RMND LOW & SLOW (20-60 FT AGL) AFTER LIFT-OFF, THEN BANKED (ROCKED) LEFT & RIGHT IN NOSE HI ATTITUDE, SETTLED, HIT TREES & CRASHED ABT 200' BYD RWY. ONE PERSON SAID ACFT WENT OUT OF CTL BFR IMPACT; ANOTHER SAID IT WAS 'IN OR ON THE EDGE OF STALLED FLIGHT.' EXAM SHOWED ROTATIONAL DMG OCCURRED IN BOTH ENGS DRG IMPACT. THE BRAKING SYS HAD EVIDENCE THAT P/B CTL VLV WAS PARTIALLY ON; BRAKE TORQUE TUBE CONTAINED HEAT BLUEING. ON THIS EARLY MODEL (LEARJET 23/SN: 23-45A), P/B HAD TO BE RLSD BY DEPRESSING BRAKE PEDALS 1ST; PLT HANDBOOK DID NOT ADDRESS THIS. ON LTR MODELS (SN: 23-050 & UP), P/B NEEDED ONLY TO BE MOVED 'OFF.' INV SHOWED LEFT SEAT PLT HAD TRNG IN LATER MODELS (LEARJET 24/25); BUT ONLY A BIENNIAL FLT REVIEW WAS NOTED IN THE MODEL 23. COMPANY DISPATCHER SAID NO TRNG WOULD HAVE BEEN PERFORMED ON ACDNT FLT (WITH PSGR ABOARD). ACFT WAS ABT 430 LBS OVR MAX WT LMT.

Probable cause

IMPROPER PREFLIGHT BY THE PILOT, HIS FAILURE TO ABORT THE TAKEOFF WHILE THERE WAS SUFFICIENT RUNWAY REMAINING, AND HIS FAILURE TO ASSURE THAT THE AIRCRAFT ATTAINED SUFFICIENT AIRSPEED FOR LIFT-OFF AND CLIMB. FACTORS RELATED TO THE ACCIDENT WERE: THE PILOT'S FAILURE TO ASSURE THE AIRCRAFT WAS WITHIN ITS MAXIMUM WEIGHT LIMITATION, HIS IMPROPER USE OF THE PARKING BRAKE, AND INSUFFICIENT INFORMATION IN THE PILOT OPERATING HANDBOOK CONCERNING THE AIRCRAFT PARKING BRAKE.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record CHI91MA224
Event ID
20001212X17518
Case number
CHI91MA224
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: local date, investigation status. Values present in the bulk record are kept.
  • The date is the local date; the NTSB stores the UTC date 1991-07-23.
  • API snapshot SHA-256: b3b385dd8e4fb677c6326ad62f8ba020fa0b430bce144b33c9e4eec5398c4ffa; retrieved 2026-09-21T01:41:28.785Z.