# NTSB FTW85FA259: Swearingen SA-26AT, N199TA, Rocksprings, TX, June 19, 1985

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 19, 1985, 15:10 local (20:10 UTC)
- Place: Rocksprings, TX
- Coordinates: 30.010095, -100.210556 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=30.0101&lon=-100.2106&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21557
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW85FA259
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21557/pdf
- Page: https://openairdocs.org/ntsb/FTW85FA259

## Sequence of events

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

- Decompression, climb - to cruise
  - fuselage - decompression (cause)
  - fuselage,skin - separation (cause)
  - fuselage,stringer - fatigue (cause)
  - maintenance,major repair - improper, other maintenance personnel (cause)
  - facility,inadequate design(standard/requirement), other maintenance personnel (contributing factor)
  - fuselage,stringer - previous damage (cause)
  - maintenance,inspection - not performed, other maintenance personnel (cause)
  - facility,inadequate design(standard/requirement), faa(other/organization) (contributing factor)
- Airframe/component/system failure/malfunction, descent - emergency
  - fuselage - separation (cause)
- Loss of control - in flight, descent - uncontrolled
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

AS THE ACFT WAS CLIMBING THRU 14,800' FOR 19,000', THE PLT REPORTED A RAPID DECOMPRESSION. TWO MINUTES LATER, HE REPORTED THAT HE HAS LOST THE TAIL. ACFT IMPACTED IN AN INVERTED FLAT SPIN AND THE TAIL AND A SECTION OF EMPENNAGE WERE FOUND ABOUT 3/4 MILE AWAY FROM MAIN WRECKAGE. INVESTIGATION REVEALED THAT A SKIN SEAM HAD SPLIT OPEN ALONG A 54' SPAN IN AN AREA WHERE 2 PIECES OF 'L' SHAPED CHANNEL HAD BEEN RIVETED TOGETHER TO FORM A STRINGER. NORMALLY THE STRINGER WOULD BE MADE USING A SINGLE PIECE OF 'T' SHAPED CHANNEL. THE NON-STANDARD STRINGER HAD BEEN FABRICATED DURING REPAIRS MADE ON THE ACFT FOLLOWING A GEAR UP LANDING 7 YRS PRIOR TO THIS ACCIDENT. ANALYSIS REVEALED THAT THE RIVETS HOLDING THE 'L' CHANNELS TOGETHER AND FAILED IN FATIGUE DUE TO TENSILE CYCLIC LOADING WHENEVER THE ACFT WAS PRESSURIZED. ACFT HAD A HISTORY OF PRESSURIZATION PROBLEMS FOLLOWING THE REPAIR THAT WAS NOT PROPERLY PERFORMED OR INSPECTED.

## Aircraft

- Registration: [N199TA](https://openairdocs.org/deregistered/N199TA-2013-01-31), registration cancelled 2013-01-31, S/N T26-110, built 1968 (OpenAirDocs)
- Reported make and model: SWEARINGEN SA-26AT
- Registry model: [Swearingen SA-26AT](https://openairdocs.org/model/swearingen-sa-26at) (registry code 8780112) (OpenAirDocs)
- Registry engine: [AiResearch 331SER 705HP](https://openairdocs.org/engine/airesearch-331ser-705hp) (registry code 01506, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: T26-110
- Engines: GARRETT TPE-331-1151G 665 horsepower turbo prop
- Damage: Destroyed
- Flight: Executive/Corporate, Part 91
- Registered owner: Telco Systems, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, January 16, 1985
- Departed: DRT, DEL RIO, TX
- Destination: F60, MCGREGORY, TX
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 4,843 total, 66 in this make and model, 4,624 as pilot in command, 105 in the last 90 days, 28 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 3 knots
- Visibility: 7 statute miles
- Lowest ceiling: 5,000 ft broken
- Temperature: 77 °F, dew point 66 °F
- Altimeter: 30.00 inHg
- Observed at: DLF, 35 nm away

## 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 19850619029439A](https://openairdocs.org/incident/19850619029439A), Jun 19, 1985: Swrngn SA26AT, Rock Springs, TX, Destroyed. Tail section separated during climb. Aircraft impacted inverted. Improper skin splice separated in turbulence.

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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