Amateur-built GLASTAR accident near Chicago, Illinois, July 22, 2012
On July 22, 2012 at about 6:30 pm local time, a amateur-built GLASTAR, registered N4970Y, was substantially damaged in an accident during enroute (cruise) near Chicago, Illinois (None airport). It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Failure of the automotive engine's reduction gearbox while in cruise flight.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 22, 2012 · about 6:30 pm local time
- Place
- Chicago, Illinois · None · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built GLASTAR
- Registration
- N4970Y · registry record · serial 5377
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot was on a cross-country flight in an experimental airplane when the engine began to “race.” The pilot tried to reduce power by adjusting the throttle, but the engine and propeller were unresponsive. He then made a forced landing to a soft field, and the airplane nosed over. Examination of the automotive engine revealed that the spline-shaft and adapter gears in the reduction gearbox were worn, which resulted in the gearbox's failure. According to the pilot, the gearbox was not a regularly inspected item for this particular engine/gearbox combination. At the time it failed, the gearbox had accrued 247 total hours since new.
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
- Powerplant sys/comp malf/fail during enroute (cruise) defining event
- Off-field or emergency landing during emergency descent
- Nose over/nose down during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Accessory gear › boxes › (general) › Failure
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,515 hours in all; 1,424 in this make and model; 47 in the last 90 days; 25 in the last 30 days
- Last flight review: May 29, 2010
- Medical certificate: Class 3
- Seat: left
- Injury: minor injuries
The aircraft
- Airframe total time: 1,424 hours
- Last inspection: condition inspection, October 25, 2011; 87 hours since
- Maximum gross weight: 1,970 lb
- Seats: 2
- Landing gear: fixed
- Engine: Subaru Boxer 2.5L (piston); 0 hours total
The flight
- Departed from: OSH Osh Kosh WI at 5:00 pm
- Destination: BEH Benton Harbor MI
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on October 23, 2012. 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.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Record of Conversation - Pilot | PDF, 1 page | View Download |
| 3 | Record of Conversation -faa Inspector | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N4970Y the same tail number, which may have belonged to a different aircraft at the time
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.