# NTSB MKC83FU003: Airmass Sunburst, Pittsburg, KS, June 8, 1983

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: June 7, 1983, 20:15 local (Jun 8, 1983, 01:15 UTC)
- Place: Pittsburg, KS
- Coordinates: 37.410587, -94.689491 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.4106&lon=-94.6895&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 33359
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC83FU003
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/33359/pdf
- Page: https://openairdocs.org/ntsb/MKC83FU003

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff - initial climb
  - touch-and-go - performed, pilot in command (contributing factor)
  - go-around - initiated, pilot in command (contributing factor)
  - flt control syst,elevator control - other (cause)
  - maintenance,installation - improper, pilot in command (cause)
  - condition(s)/step(s) insufficiently defined, manufacturer (contributing factor)
  - maintenance,service bulletin/letter - issued, manufacturer (contributing factor)
  - maintenance,service bulletin/letter - not received, pilot in command (contributing factor)
  - information, manufacturer (contributing factor)
  - flt control syst,elevator control - disconnected (cause)
- Loss of control - in flight, takeoff
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT HAD COMPLETED A PRIVATE PLT GROUND SCHOOL COURSE & HAD FLOWN APRX 4.6 HRS IN A CESSNA 172 BEFORE FLYING HIS HOME BUILT ULTRALIGHT VEHICLE. DURING A TEST FLT, HE WAS MAKING A GO-AROUND FROM A TOUCH-AND-GO LANDING WHEN THE VEHICLE CRASHED. A WITNESS STATED THAT THE ULTRALIGHT PITCHED NOSE DOWN TO ABOUT A 45 DEG ANGLE & THE NOISE OF THE ENG INCREASED AS IT PITCHED DOWN. AN EXAM OF THE WRECKAGE REVEALED THAT THE SHORT ELEVATOR PUSH-PULL ROD HAD SEPARATED FROM THE ELEVATOR CLEVIS FORK. REPORTEDLY, THE HALF NYLOCK LOCKNUT WAS INSTALLED ON THE CONNECTING BOLT IN A REVERSE DIRECTION. THE MANUFACTURER'S ASSEMBLY INSTRUCTIONS DID NOT PROVIDE DETAILS ON THE JAM LOCKING OF THE NUT. ON 10/12/82, THE MANUFACTURER HAD ISSUED SPECIFIC INSTRUCTIONS FOR INSTALLATION OF LOCK NUTS, BUT REPORTEDLY, THESE PROCEDURES WERE NOT APPLIED TO THIS VEHICLE. HOWEVER, THE FAA A&P MECHANICS HANDBOOK (AC65-9A) DISCUSSED PROCEDURES FOR SECURING PUSH-PULL TUBE LINKAGES/FITTINGS/JAMNUTS. MAINT INSTRUCTIONS DO NOT ALWAYS DISCUSS SPECIFIC SAFETY METHODS.

## Aircraft

- Registration: UNREG (not matched to a registry record)
- Reported make and model: AIRMASS SUNBURST
- Category: Ultralight, amateur-built
- Airframe hours: 1
- Engines: CUYUNA 430CC 30 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 103
- Registered owner: Michael Montgomery
- Airport: PTS, Atkinson Muni, runway 34, 3,660 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 23; airplane ratings: single-engine land; medical: unknown; seat: center; toxicology performed; flight hours: 5 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 260° at 5 knots
- Visibility: 15 statute miles
- Lowest ceiling: 25,000 ft overcast
- Temperature: 73 °F, dew point 52 °F
- Altimeter: 29.00 inHg
- Observed at: JLN, 22 nm away

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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