# NTSB LAX83FU001: Mitchell A-10, Tulare, CA, April 7, 1983

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: April 6, 1983, 17:48 local (Apr 7, 1983, 01:48 UTC)
- Place: Tulare, CA
- Location: 36.1444° N, 119.3168° W: Placed by OpenAirDocs from NTSB’s distance and direction from MEFFORD FLD (TLR), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=36.1444&lon=-119.3168&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 23522
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX83FU001
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23522/pdf
- Page: https://openairdocs.org/ntsb/LAX83FU001

## Sequence of events

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

- Airframe/component/system failure/malfunction, approach - vfr pattern - downwind
  - fuselage,skin - failure,partial (cause)
  - aircraft handling - not possible, pilot in command (contributing factor)
  - acft/equip,inadequate design, manufacturer (cause)
  - wing,spar - bent (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE ULTRALIGHT WAS ON A DEMONSTRATION FLT. REPORTEDLY, THE PLT MADE A PASS DOWN THE RWY, THEN HAD TURNED DOWNWIND AT 400 TO 500 FT, WHEN WITNESSES HEARD A LOUD BANG OR CRACK & SAW THE WINGS OF THE VEHICLE FOLD. THE ULTRALIGHT THEN ENTERED A SPIRAL & CRASHED IN A CANAL. AN EXAM REVEALED THAT THE WING HAD FOLDED DOWNWARD. COMPRESSION BUCKLING HAD OCCURRED AT THE WING CENTER SECTION. ALSO, THE MYLAR SKIN WAS FOUND SEPARATED FROM THE TOP & BOTTOM OF THE WING CENTER SECTION AT THE BONDED ATTACH AREAS. ACCORDING TO THE MANUFACTURER, LOSS OF THE MYLAR SKIN ON THE TOP OF THE WING WOULD RESULT IN AN AFT SHIFT IN THE CENTER OF PRESSURE & CAUSE THE VEHICLE TO PITCH FORWARD. WITNESSES THOUGHT THAT THE WINGS HAD FOLDED UPWARD, BUT THE INVESTIGATION VERIFIED THAT THEY FAILED IN A NEGATIVE MODE. AFTER THIS OCCURRENCE, THE MYLAR MATERIAL ON THE MITCHELL A-10 VEHICLES WAS REPLACED WITH CECONITE COVERING & WAS RIVETED IN PLACE WITH ALUMINUM BATTENS.ALTHOUGH THE PROTOTYPE HAD BALANCE WTS, THEY HAD BEEN REMOVED FROM PRODUCTION MODELS TO ELIMINATE WT.

## Aircraft

- Registration: UNREG (not matched to a registry record)
- Reported make and model: MITCHELL A-10
- Category: Ultralight
- Serial number: 102
- Airframe hours: 10
- Engines: ZENOAH A-25-B 23 horsepower reciprocating
- Damage: Destroyed
- Flight: Part 103
- Registered owner: Leonard R. Noell
- Airport: TLR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; toxicology performed; flight hours: 12,490 total, 2 in this make and model, 12,365 as pilot in command, 102 in the last 90 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: calm
- Visibility: 15 statute miles
- Lowest ceiling: none

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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