Cessna 172RG incident near West Chicago, Illinois, April 2, 1991
On April 2, 1991 at about 9:00 pm local time, a Cessna 172RG, registered N9592B, suffered minor damage in an incident near West Chicago, Illinois (Dupage airport). It was an instructional 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
FAILURE OF THE SPLINED SHAFT ON THE RIGHT MAIN LANDING GEAR PIVOT ASSEMBLY. A FACTOR RELATED TO THE INCIDENT WAS INADEQUATE DESIGN OF THE LANDING GEAR PIVOT ASSEMBLY.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 2, 1991 · about 9:00 pm local time
- Place
- West Chicago, Illinois · Dupage · map
- Type
- Incident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172RG · all 172RGs on the register
- Registration
- N9592B · no longer on the register · serial 172RG0905
- Damage
- Minor damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
AFTER REPEATED ATTEMPTS TO LOWER THE LANDING GEAR, ONLY THE LEFT MAIN AND NOSE GEAR WOULD EXTEND. THE PILOTS ELECTED TO MAKE A WHEELS-UP LANDING. DURING THE LANDING, THE LOWER FUSELAGE AND PROPELLER TIPS RECEIVED MINOR DAMAGE. AN INVESTIGATION REVEALED THE RIGHT MAIN LANDING GEAR PIVOT ASSEMBLY (PN 2441100-1) HAD FAILED. A METALLURGICAL EXAMINATION DISCLOSED THE SPLINED SHAFT ON THE PIVOT ASSEMBLY HAD FRACTURED IN TORSIONAL OVERLOAD. AS A RESULT, MECHANICAL EXTENSION OF THE RIGHT MAIN LANDING GEAR WAS NOT POSSIBLE.
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
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 1,531 hours in all; 280 in this make and model; 25 in the last 90 days; 15 in the last 30 days; 1,430 as pilot in command; 1,195 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 4,567 hours
- Last inspection: 100-hour inspection, March 20, 1991; 45 hours since
- Maximum gross weight: 2,650 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming O-360-F1A6 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 15, 3,400 ft by 100 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 140° at 10 knots
- Visibility: 15 statute miles
- Sky: scat at 2,500 ft
- Temperature: 54°F (12°C), dew point 45°F (7°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.