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Accidents · NTSB CEN23LA403 · Final report

Israel Aircraft Industries 1125 WESTWIND ASTRA accident near Wheeling, Illinois, August 21, 2023

On August 21, 2023 at about 6:15 pm local time, a 1991 Israel Aircraft Industries 1125 WESTWIND ASTRA, registered N39TT, was substantially damaged in an accident during landing (landing roll) near Wheeling, Illinois (Chicago Exec airport). It was a positioning flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

A loss of braking effectiveness during landing for reasons that could not be determined, which resulted in a runway excursion.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
August 21, 2023 · about 6:15 pm local time
Place
Wheeling, Illinois · Chicago Exec · map
Type
Accident
Injuries
No one was hurt; 2 people were on board or involved.
Weather
visual conditions (good weather)
Aircraft
Israel Aircraft Industries 1125 WESTWIND ASTRA, built 1991 · all 1125 WESTWIND ASTRAs on the register
Registration
N39TT · registry record · serial 053
Damage
Substantial damage
Flight
Positioning flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

According to the flight crew, the airplane touched down within the touchdown zone. The pilot reported that he applied the brakes and deployed the thrust reversers (TRs), but the brakes “were not grabbing.” The pilot released and reapplied brake pressure with no effect and advised the co-pilot he had no brakes. The co-pilot applied his brakes with no effect. The pilot selected the emergency brake handle and applied emergency braking. The emergency braking produced some slowing, and with the airplane’s nose wheel tiller, the pilot attempted a left turn to exit the runway onto a 45° taxiway, which he thought provided additional stopping distance; however, the airplane slid off the taxiway and into the adjacent grass. The right main landing gear collapsed, and the airplane came to rest upright, resulting in substantial damage to the right wing spar. Examination and testing of the airplane systems did not reveal any evidence of preimpact mechanical malfunctions with the wheel brakes or any other systems. Video evidence and recorded airplane data revealed the TRs were not deployed during the landing sequence. The cockpit voice recorder was overwritten during postaccident maintenance actions, and the accident flight communications were not available. Landing simulations based on available data were consistent with reduced deceleration during the landing roll; however, the simulations could not determine if the airbrakes were stowed or extended during the landing, and the airplane was not equipped with a flight data recorder, which could have captured airbrake deployment and position. Landing performance calculations showed that, without ground airbrakes, the landing ground roll distance exceeded the runway available from the airplane’s touchdown point. Tire skid marks indicated that heavy wheel braking occurred on the runway and taxiway surfaces. Based on the available information, the reason for the flight crew’s reported loss of braking effectiveness during landing could not be determined.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

What happened, in order

  1. Runway excursion during landing (landing roll) defining event
  2. Unknown or undetermined during landing (landing roll)

The NTSB's findings

  • Aircraft › Aircraft systems › Landing gear system › Brake › Unknown/Not determined
  • Not determined › Not determined › (general) › (general) › Unknown/Not determined

Pilot

  • Certificate: airline transport pilot, commercial pilot, private
  • Ratings: multi-engine land; instrument: airplane
  • Flight time: 7,500 hours in all; 2,000 in this make and model; 18 in the last 90 days; 10 in the last 30 days; 6,500 as pilot in command
  • Last flight review: June 1, 2023
  • Medical certificate: Class 1 (with waivers/limitations)
  • Seat: left
  • Injury: no injuries

Co-pilot

  • Certificate: airline transport pilot, flight instructor, commercial pilot, private
  • Ratings: multi-engine land; single-engine land; instructor: instrument airplane; instrument: airplane
  • Flight time: 8,500 hours in all; 2,300 in this make and model; 22 in the last 90 days; 14 in the last 30 days; 1,700 as pilot in command; 949 on instruments
  • Last flight review: April 1, 2023
  • Medical certificate: Class 1 (with waivers/limitations)
  • Seat: rgt
  • Injury: no injuries

The aircraft

  • Airframe total time: 8,307 hours
  • Last inspection: approved inspection programme, August 16, 2023
  • Maximum gross weight: 20,700 lb
  • Seats: 9
  • Landing gear: retractable
  • Engine 1: Honeywell TFE731-3C-200 (turbofan); 8,138 hours total
  • Engine 3: Honeywell TFE731-3C-200 (turbofan); 8,165 hours total
  • Operator: Astra053 LLC

The flight

  • Departed from: MDW Chicago IL at 6:00 pm
  • Flight plan: IFR
  • Runway 16, 5,001 ft by 150 ft
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Wind: from 080° at 7 knots
  • Visibility: 10 statute miles
  • Sky: clear
  • Temperature: 81°F (27°C), dew point 66°F (19°C)
  • Altimeter: 30.24 inHg
  • Observation at 1:25 pm from PWK

Injuries

FatalSeriousMinorNone
Flight crew2

Documents from the investigation the NTSB's docket: the evidence folder behind the report

24 documents, released by the NTSB on March 5, 2025. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.

#DocumentWhat it is
1 Aircraft Performance Memorandum - Performance Plots During Landing PDF, 10 pages View Download
2 FAA ADS-B Data data file Download
3 ADS-B Exchange Data map file Download
4 Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 PDF, 8 pages View Download
5 Flight Crew Record of Conversation (FAA) PDF, 2 pages View Download
6 Company Trip Report PDF, 17 pages View Download
7 Surveillance Video 1 - Landing video View Download
8 Surveillance Video 2 - Landing AVI file Download
9 Email - Pilot PDF, 1 page View Download
10 Email - Gulfstream Landing Distance Calculation PDF, 1 page View Download
11 Airplane Company Checklist PDF, 2 pages View Download
12 Email - Company Director of Maintenance PDF, 1 page View Download
13 Email - Company Recovery Notes PDF, 1 page View Download
14 Component Examination Summary PDF, 3 pages View Download
15 Power Brake Valve Test Results PDF, 10 pages View Download
16 Email - Weight on Wheel Test Results PDF, 1 page View Download
17 Honeywell Deec Summary PDF, 3 pages View Download
18 Excerpt of Airplane Maintenance Manual - Airbrakes System PDF, 14 pages View Download
19 Statement of Party Representatives to NTSB Investigation - Operator PDF, 1 page View Download
20 Statement of Party Representatives to NTSB Investigation - Gulfstream PDF, 1 page View Download
21 Statement of Party Representatives to NTSB Investigation - Honeywell PDF, 1 page View Download
22 Release of Aircraft Wreckage, NTSB Form 6120.15 PDF, 1 page View Download
23 Investigation Photographs - Company PDF, 8 pages View Download
24 ICAO Accredited Representative Draft Report Comments PDF, 2 pages View Download

The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.