# NTSB DEN93LA079: Piper PA-11, N4834M, Burkburnett, TX, July 15, 1993 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 15, 1993, 17:45 local (22:45 UTC) - Place: Burkburnett, TX - Coordinates: 34.069961, -98.560569 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.0700&lon=-98.5606&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report June 22, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 11094 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN93LA079 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/11094/pdf - Page: https://openairdocs.org/ntsb/DEN93LA079 ## Probable cause THE DISCONNECTION OF THE UP ELEVATOR CABLE FROM THE CONTROL HORN. A FACTOR WAS THE INCORRECT INSTALLATION OF THE BOLT AND CASTLE NUT BY UNKNOWN MAINTENANCE PERSONNEL. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - flt control syst,elevator control cable/rod - disconnected (cause) - maintenance,installation - improper, other maintenance personnel (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - sand bar ## Analysis AFTER SIGHTSEEING FOR ABOUT 30 MINUTES, THE PILOT INITIATED A RIGHT BANK TO RETURN TO THE AIRPORT. THE AIRPLANE BEGAN DESCENDING AND FULL BACK PRESSURE WOULD NOT ARREST THE DESCENT. THE PILOT LEVELED THE WINGS AND APPLIED FULL POWER. THE AIRPLANE IMPACTED A RIVER SAND BAR. POST-ACCIDENT EXAMINATION DISCLOSED THE UP ELEVATOR CABLE WAS DISCONNECTED FROM THE CONTROL HORN. A BOLT, SEVERAL CASTLE NUTS, WASHERS, SHEET METAL SCREWS, A SPACER AND A REMNANT OF A COTTER PIN WERE VACUUMED FROM THE FLOOR OF THE AIRPLANE BENEATH THE ELEVATOR CONTROL HORN. THE AIRPLANE HAD ACCUMULATED 142 HOURS SINCE THE LAST ANNUAL INSPECTION 10 MONTHS BEFORE THE ACCIDENT. ## Factual narrative On July 15, 1993, at approximately 1745 central daylight time, a Piper PA-11, N4834M, was substantially damaged when it collided with terrain near Burkburnett, Texas. The pilot sustained minor injuries and the passenger was not injured. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local personal flight. The pilot of N4834M was also an Air Force pilot stationed at Sheppard Air Force Base, Wichita Falls, Texas. The following is based on a verbal statement he gave to a Federal Aviation Administration (FAA) inspector and a written statement he submitted along with his accident report. The pilot and his passenger had been flying along the Red River at about 300 feet AGL. They decided to return to their home airport at Wichita Falls, Texas. The pilot said he made a 30 to 40 degree right bank at an indicated airspeed between 55 and 60 MPH. The airplane began descending and he applied back pressure to arrest the descent. Instead, the rate of descent increased. The pilot applied left rudder, leveled the wings, and applied full aft elevator and full throttle. The descent continued until ground impact. The passenger, an Air Force maintenance officer also assigned to Sheppard AFB submitted a written statement that read (in part): "...the pilot...made a steep diving turn. After approximately 360 degrees of turn, an immediate loss of lift was felt and the aircraft entered a nose low attitude. The wings were immediately leveled, however, altitude was not sufficient to recover from the ensuing dive. The aircraft impacted the ground in full throttle, stick aft, and nose level attitude. The aircraft seemed to be operating normally throughout the entire flight." The FAA inspector examined the airplane after it had been taken back to the airport. The inspector reported that the bolt and castle nut that attaches the up elevator cable to the control horn was missing. A bolt, several castle nuts, washers, sheet metal screws, a spacer, and a remnant of a cotter pin were vacuumed from the floor of the airplane beneath the elevator control horn. The airplane's maintenance records indicated the last annual inspection was performed ten months before the accident, on September 21, 1992. At the time of the accident, 142 hours had elapsed since the annual inspection. ## Aircraft - Registration: [N4834M](https://openairdocs.org/aircraft/N4834M), registered now, S/N 11-345, built 1947 (OpenAirDocs) - Reported make and model: PIPER PA-11 - Registry model: [Piper PA-11](https://openairdocs.org/model/piper-pa-11) (registry code 7101102) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 11-345 - Airframe hours: 1217 - Engines: CONTINENTAL A-65-8F 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Renton, Paul N. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 21, 1992, 142 hours before - Departed: SPS, WICHITA FALLS, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 24; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 283 total, 6 in this make and model, 245 as pilot in command, 29 in the last 90 days, 11 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 95 °F ## 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 19930715023779A](https://openairdocs.org/incident/19930715023779A), Jul 15, 1993: Piper PA11, Burkburnett, TX, Substantial damage. Sightseeing began turn to airport. No elevator control. Impacted on sandbar. Elevator cable came off control horn. 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.