# NTSB CHI83FA092: Obryon Mustang II, N77HJ, West Chicago, IL, January 26, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: January 26, 1983, 15:45 local (21:45 UTC)
- Place: West Chicago, IL
- Location: 41.9071° N, 88.2480° W: Placed by OpenAirDocs at DUPAGE (DPA), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.9071&lon=-88.2480&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 11976
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI83FA092
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/11976/pdf
- Page: https://openairdocs.org/ntsb/CHI83FA092

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - on ground/water, takeoff - roll/run
  - wing - incorrect (cause)
  - maintenance - inadequate, manufacturer (cause)
  - inadequate quality control, manufacturer (cause)
  - weather condition - crosswind (contributing factor)
  - aircraft handling - not possible, pilot in command
  - aborted takeoff - performed, pilot in command
  - directional control - not maintained, pilot in command
  - ground loop/swerve - uncontrolled, pilot in command
- On ground/water collision with object, takeoff

## Analysis

THE HOME BUILT ACFT WAS ON ITS 1ST FLT AFTER BEING CONSTRUCTED. THE TAKEOFF WAS INITIATED ON RWY 33 WITH THE WIND FROM 030 DEG AT 10 KTS. THE PLT REPORTED THAT DURING THE TAKEOFF, THE RIGHT WING LIFTED, BUT THE LEFT WING WOULD NOT COME UP. WHEN CONTROL BECAME DIFFICULT, HE ABORTED THE TAKEOFF; HOWEVER, THE ACFT VEERED OFF THE LEFT SIDE OF THE RWY. THE LEFT WING OF THE ACFT HIT POSTS & WAS DAMAGED. AN INVESTIGATION REVEALED THAT THE TRAILING EDGE OF THE RIGHT WING HAD BEEN 'WASHED DOWN' ABOUT 1 INCH DURING CONSTRUCTION. THIS PROVIDED IT WITH A CONSIDERABLY GREATER ANGLE OF ATTACK.

## Aircraft

- Registration: [N77HJ](https://openairdocs.org/deregistered/N77HJ-1992-10-30), registration cancelled 1992-10-30, S/N 928 (OpenAirDocs)
- Reported make and model: OBRYON MUSTANG II
- Registry model: [Obryon Harold MUSTANG-II](https://openairdocs.org/model/obryon-harold-mustang-ii) (registry code 1690458) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 928
- Engines: LYCOMING O-360-A3A reciprocating
- Damage: Substantial damage
- Flight: Part 91
- Registered owner: Harold G. Obryon
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Unknown, January 24, 1984, 0 hours before
- Airport: DPA, Dupage County, runway 33, 3,400 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 985 total, 9 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 30° at 10 knots
- Visibility: 12 statute miles
- Lowest ceiling: 12,000 ft overcast
- Temperature: 25 °F, dew point 10 °F
- Altimeter: 30.00 inHg
- Observed at: DPA

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19830126001359A](https://openairdocs.org/incident/19830126001359A), Jan 26, 1983: Amtrbb MUSTANG2, West Chicago, IL, Substantial damage. Right wing lifted on takeoff roll. Lost control and veered off runway. Struck posts. Wings improperly rigged.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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