# NTSB ERA13LA434: Timothy J Cowper Pitts Special S-1E, N85AT, Edinburg, NY, September 29, 2013

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: September 29, 2013, 15:55 local (19:55 UTC)
- Place: Edinburg, NY
- Coordinates: 43.217777, -74.116111 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.2178&lon=-74.1161&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report March 26, 2015
- Report: Approved by Office Director
- NTSB office: Eastern Region Aviation
- NTSB case key (mKey): 88154
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA13LA434
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88154/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88154
- Page: https://openairdocs.org/ntsb/ERA13LA434

## Probable cause

The pilot’s failure to maintain adequate airspeed during low-altitude maneuvering, which resulted in the airplane exceeding its critical angle-of-attack and experiencing an aerodynamic stall.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Timothy J Cowper PITTS SPECIAL S-1E, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=05631WZ), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Timothy J Cowper PITTS SPECIAL S-1E, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05631WZ), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Timothy J Cowper PITTS SPECIAL S-1E, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=05631WZ), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Timothy J Cowper PITTS SPECIAL S-1E, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=05631WZ), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Timothy J Cowper PITTS SPECIAL S-1E, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05631WZ), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

Witnesses reported that they observed the airplane maneuvering at low altitude after it departed from the airport. One witness recalled hearing normal engine noise followed by an increase in engine speed. When he looked in the direction of the airplane, he observed it in a nose-down bank. The airplane then disappeared behind a tree line and crashed. The wreckage was found in a wooded area about 1/2 mile south-southwest of the airport. The wreckage was confined to one area with no discernible linear wreckage path noted, which was consistent with an aerodynamic stall and loss of control. Most of the wreckage was consumed in a postcrash fire. Flight control continuity was established from the flight control surfaces to the cockpit. Examination of the airframe and engine revealed no anomalies that would have precluded normal operation.

## Factual narrative

The accident aircraft was a single-seat, experimental, amateur-built, bi-wing design airplane, equipped with a single Lycoming O-360-A4A engine, rated at 180 horsepower. According to registration and airworthiness documents on file with the FAA, the airplane was built in 2012 and a Special Airworthiness Certificate was issued on November 8, 2012. The aircraft and engine maintenance logbooks were not recovered after the accident. On September 29, 2013, about 1555 eastern daylight time, an experimental, amateur-built Cowper Pitts Special S-1E, N85AT, was destroyed following a collision with terrain after an in-flight loss of control near Edinburg, New York. The private pilot was fatally injured. The airplane was operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated at Plateau Sky Ranch Airport (1F2) about 1550. One witness was at 1F2 when the accident occurred. He stated that the accident pilot was airborne for about five minutes prior to the crash. Initially, he did not pay attention to the airplane attitude because "all sounded normal." He noticed that there was an increase in RPMs, so he turned toward the airplane and saw it "banked and nose down towards the ground." He observed the airplane disappear below the tree line and all went quiet. He ran around a hangar and observed smoke coming from the accident site. Another witness was on a nearby road and observed the accident airplane "flying upside down." The airplane was "teetering" back and forth as if trying to right itself. After about 15 seconds, it went down into the trees. Another witness reported that he observed the airplane descend "really fast" toward a tree line and suddenly come back up. The airplane then circled east again and "went straight down" into a tree line. A postmortem examination of the pilot was performed at the Albany Medical Center, Albany, New York, on September 30, 2013. The autopsy report noted the cause of death as "Multiple severe traumatic blunt force injuries" and the manner of death was "Accident." Forensic toxicology testing was performed on specimens of the pilot by the Federal Aviation Administration (FAA) Bioaeronautical Sciences Research Laboratory (CAMI), Oklahoma City, Oklahoma. The CAMI toxicology report indicated no carbon monoxide, ethanol, or drugs present. Testing for cyanide was not performed. The 1553 surface weather observation for Floyd Bennett Memorial Airport (GFL), Glens Fall, New York, located about 23 nautical miles east of the accident site, included sky clear, visibility 10 statute miles or greater, surface wind from 210 degrees at 7 knots, temperature 22 degrees C, dew point 11 degrees C, and altimeter setting 30.09 inches of mercury. The pilot, age 55, held a private pilot certificate with airplane, single engine land privileges. His personal pilot logbook was not located after theaccident. He reported a total flight time of 460 hours on his latest FAA third class medical certificate application of November, 2012. He also possessed an experimental aircraft builder certificate and was the registered builder of the accident aircraft. An inspector with the Federal Aviation Administration responded to the accident site and examined the wreckage. The main wreckage was located in a wooded area about one half nautical mile south-southwest of 1F2. The wreckage was confined to one area with no discernible linear wreckage path noted. A majority of the wreckage was consumed by a post-crash fire. The wreckage was examined by the NTSB investigator-in-charge, assisted by an FAA inspector, on November 13, 2013, at a private storage facility. Most of the fuselage's fabric skin was burned away, leaving the steel tube structure visible. The rudder and elevator remained attached to the empennage by their hinges. The rudder was connected to the cockpit controls by cables. The left rudder cable remained attached to the rudder horn. Continuity was confirmed to left rudder pedal, which was broken free of the fuselage frame. The right rudder cable also remained attached to the rudder horn. The right rudder cable was separated about 2 feet aft of the connection on the right rudder pedal and exhibited signatures of overload. The right rudder pedal remained attached to firewall and frame. The elevator remained attached to empennage by its hinges. The steel push/pull tube led to the control stick in cockpit. There was a compression kink in the push/pull tube about midway to the cockpit. The rod was broken at the threaded end with signatures of bending overload. The upper portion of the cockpit control stick was broken off near its base and was not located. The lower end of the stick was attached to the airframe and exhibited overload signatures. The elevator trim tab was observed to be about 15 degrees tab down. The wings were of wooden construction with fabric skin. A majority of the wing skin and wooden wing structure were consumed in the post-crash fire. The aileron push/pull tubes, hinges, and attachment hardware were examined; all fractures were consistent with overload. The ailerons were consumed by fire. An external examination of the engine revealed impact and heat damage. The pressure carburetor was broken off from engine oil sump. A manual fuel primer pump and strainer remained in cockpit. The fuel strainer was disassembled and the bowl was found clear of debris. The fuel filter element showed heat distress (black and hard, crumbled when held in hand). Some brown-colored water remained inside the filter bowl. Top spark plugs were removed and photographed. The electrodes were normal in color with minimal wear observed. The plugs were tested on Champion test bench and all operated normally. The ignition harness wires appeared to be undamaged. The interior of the cylinders and the piston heads were examined with a lighted borescope; noanomalies were noted. The propeller could be moved about 10 degrees due to propeller flange impact damage and deformation of the propeller blades. One blade was bent forward about 20 degrees. The opposite blade was bent aft about 60 degrees, with blade tip curl, blade twist, chord wise scratching, and surface polishing noted. The propeller spinner showed indications of twisting deformation around the propeller hub.

## Aircraft

- Registration: [N85AT](https://openairdocs.org/deregistered/N85AT-2018-02-21), registration cancelled 2018-02-21, S/N 8-0073, built 2012 (OpenAirDocs)
- Reported make and model: TIMOTHY J COWPER PITTS SPECIAL S-1E
- Registry model: [Timothy J Cowper PITTS SPECIAL S-1E](https://openairdocs.org/model/timothy-j-cowper-pitts-special-s-1e) (registry code 05631WZ) (OpenAirDocs)
- Registry engine: [Lycoming O-360-A4A](https://openairdocs.org/engine/lycoming-o-360-a4a) (registry code 42270, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 8-0073
- Year built: 2012
- Engines: Lycoming O-360-A4A 180 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Cowper Timothy J
- Registered owner: Cowper Timothy J
- Airworthiness certificate: Special, Experimental (Special)
- Departed: 1F2, Edinburg, NY
- Destination: 1F2, Edinburg, NY
- Airport: 1F2, Plateau Sky Ranch Airport, runway 24, 2,400 × 100 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 55; injuries: fatal; private; airplane ratings: single-engine land; medical: class 3; seat: single; restraint: 5-point; toxicology performed; flight hours: 460 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 52 °F
- Altimeter: 30.09 inHg
- Observed at: GFL, 23 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 20130929020759A](https://openairdocs.org/incident/20130929020759A), Sep 29, 2013: Timothy J Cowper PITTS SPECIAL S-1E, Edinburg, NY, Destroyed, 1 fatal. The aircraft departed Edinburg airport to the west, turned left, flew around the airport, and during climb and leaving the area to the west, the aircraft…

## Docket (18 files)

The files NTSB released with the investigation on March 3, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88154. 39.7 MB in all.

- Witness Statements Obtained by New York State Police (item 1, .PDF, 695 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407929&FileExtension=.PDF&FileName=Witness%20Statements%20Obtained%20by%20New%20York%20State%20Police-Redacted.PDF
- Toxicology - Cowper (item 2, .PDF, 113 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407938&FileExtension=.PDF&FileName=Toxicology%20-%20Cowper-Master.PDF
- Photo 1: Main Wreckage, Empennage on Left Side of Photo and Engine on Right Side of Photo (FAA On-scene Photo) (item 3, .PDF, 6.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407940&FileExtension=.PDF&FileName=Photo%201%3A%20Main%20Wreckage,%20Empennage%20on%20Left%20Side%20of%20Photo%20and%20Engine%20on%20Right%20Side%20of%20Photo%20(FAA%20On-scene%20Photo)-Master.PDF
- Photo 2: Main Wreckage, Forward Fuselage in Foreground and Empennage in Background (FAA On-scene Photo) (item 4, .PDF, 6.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407942&FileExtension=.PDF&FileName=Photo%202%3A%20Main%20Wreckage,%20Forward%20Fuselage%20in%20Foreground%20and%20Empennage%20in%20Background%20(FAA%20On-scene%20Photo)-Master.PDF
- Photo 3: Center Fuselage, Engine Firewall on Left Side of Photo (FAA On-scene Photo) (item 5, .PDF, 5.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407943&FileExtension=.PDF&FileName=Photo%203%3A%20Center%20Fuselage,%20Engine%20Firewall%20on%20Left%20Side%20of%20Photo%20(FAA%20On-scene%20Photo)-Master.PDF
- Photo 4: Empennage (FAA On-scene Photo) (item 6, .PDF, 6.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407944&FileExtension=.PDF&FileName=Photo%204%3A%20Empennage%20(FAA%20On-scene%20Photo)-Master.PDF
- Photo 5: Engine and Propeller (FAA On-scene Photo) (item 7, .PDF, 5.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407945&FileExtension=.PDF&FileName=Photo%205%3A%20Engine%20and%20Propeller%20(FAA%20On-scene%20Photo)-Master.PDF
- Photo 6: Empennage (NTSB Digital Photo) (item 8, .PDF, 977 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407947&FileExtension=.PDF&FileName=Photo%206%3A%20Empennage%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 7: Base of Control Stick (NTSB Digital Photo) (item 9, .PDF, 978 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407948&FileExtension=.PDF&FileName=Photo%207%3A%20Base%20of%20Control%20Stick%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 8: Aileron Control Linkages, After Reconstruction (NTSB Digital Photo) (item 10, .PDF, 816 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407949&FileExtension=.PDF&FileName=Photo%208%3A%20Aileron%20Control%20Linkages,%20After%20Reconstruction%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 9: Aileron Control Linkages, After Reconstruction (NTSB Digital Photo) (item 11, .PDF, 689 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407950&FileExtension=.PDF&FileName=Photo%209%3A%20Aileron%20Control%20Linkages,%20After%20Reconstruction%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 10: Aileron Control Linkages, After Reconstruction (NTSB Digital Photo) (item 12, .PDF, 811 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407951&FileExtension=.PDF&FileName=Photo%2010%3A%20Aileron%20Control%20Linkages,%20After%20Reconstruction%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 11: 5-Point Seat Restraint Buckle, As Found in Wreckage (NTSB Digital Photo) (item 13, .PDF, 989 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407952&FileExtension=.PDF&FileName=Photo%2011%3A%205-Point%20Seat%20Restraint%20Buckle,%20As%20Found%20in%20Wreckage%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 12: Propeller Blade, Exhibiting Chordwise Scratching, Surface Polishing, and Blade Twisting (NTSB Digital Photo) (item 14, .PDF, 808 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407958&FileExtension=.PDF&FileName=Photo%2012%3A%20Propeller%20Blade,%20Exhibiting%20Chordwise%20Scratching,%20Surface%20Polishing,%20and%20Blade%20Twisting%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 13: Propeller Blade, Exhibiting Blade Twisting (NTSB Digital Photo) (item 15, .PDF, 927 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407959&FileExtension=.PDF&FileName=Photo%2013%3A%20Propeller%20Blade,%20Exhibiting%20Blade%20Twisting%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 14: Propeller Blade, Exhibiting Forward Bending (NTSB Digital Photo) (item 16, .PDF, 917 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407956&FileExtension=.PDF&FileName=Photo%2014%3A%20Propeller%20Blade,%20Exhibiting%20Forward%20Bending%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 15: Propeller Spinner, Conformed Around Propeller Hub (NTSB Digital Photo) (item 17, .PDF, 996 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407960&FileExtension=.PDF&FileName=Photo%2015%3A%20Propeller%20Spinner,%20Conformed%20Around%20Propeller%20Hub%20(NTSB%20Digital%20Photo)-Master.PDF
- Photo 16: Engine Top Spark Plugs, Removed (NTSB Digital Photo) (item 18, .PDF, 875 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407961&FileExtension=.PDF&FileName=Photo%2016%3A%20Engine%20Top%20Spark%20Plugs,%20Removed%20(NTSB%20Digital%20Photo)-Master.PDF

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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