# NTSB FTW01FA117: Convair BT-13A, N66791, Odessa, TX, May 14, 2001 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: May 14, 2001, 13:55 local (18:55 UTC) - Place: Odessa, TX - Location: 31.8457° N, 102.3676° W: Placed by OpenAirDocs: center of Odessa, TX, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=31.8457&lon=-102.3676&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report August 26, 2002 - Report: Approved by Office Director - Parties: Federal Aviation Administartion, The Confederate Air Force - NTSB case key (mKey): 52257 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW01FA117 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/52257/pdf - Page: https://openairdocs.org/ntsb/FTW01FA117 ## Probable cause the pilot's failure to maintain the minimum required airspeed for flight, which resulted in a loss of control while performing a go-around. A contributing factor to the accident was the gusty tailwind condition. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, go-around (vfr) - weather condition - tailwind (contributing factor) - weather condition - gusts (contributing factor) - go-around - attempted, pilot in command - airspeed - not maintained, pilot in command (cause) - stall - inadvertent, pilot in command - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground - object - pole ## Analysis The commercial pilot was undergoing his 7th hour of dual familiarization training in the airplane. The airplane approached the airport from the east, over flew the south end of the airport, and then executed a left teardrop turn to runway 34. According to witnesses at the airport, the airplane was on final approach to runway 34, approximately 150 feet agl, when they heard power applied to the engine. Subsequently, the right wing dropped, the airplane impacted the ground, contacted a steel pole, and came to a stop upright. The witness accounts and ground scars are consistent with the airplane encountering a stall. One witness, who was located on the airport, reported that at the time of the accident the wind was from the south at 10 mph. Two minutes prior to the accident, two weather observation facilities that are located 7 miles northeast and 9 miles northwest of the accident site, reported wind from 200 degrees at 13 knots and gusting to 20 knots and wind from 210 degrees at 11 knots and gusting to 19 knots, respectively. The airframe and engine were examined and no pre-impact anomalies were noted that would have precluded their operation. ## Factual narrative HISTORY OF FLIGHT On May 14, 2001, at 1355 central daylight time, a 1942 vintage Convair BT-13A single-engine airplane, N66791, was destroyed when it impacted terrain during an attempted go-around at the Bates Field Airport near Odessa, Texas. The airplane was registered to the American Airpower Heritage Museum of Midland, Texas, and operated by The Confederate Airforce (CAF) of Midland, Texas. The flight instructor and the commercial pilot receiving instruction were fatally injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 instructional flight. The local flight originated from the Midland International Airport (MAF), Midland, Texas, at 1257. According to personnel from the CAF, the commercial pilot was undergoing his 7th hour of familiarization training in the accident airplane. Communication transcripts and radar data from the Midland Air Traffic Control (ATC) Facility revealed that the airplane departed MAF, climbed to 7,000 feet msl, and flew to a practice area southwest of the airport. The airplane maneuvered for approximately 40 minutes, and at 1353, reported to ATC that they would be "goin to Bates [Airport] for just a minute." No further communications, or distress calls, were received from the airplane. Radar data revealed that the airplane approached Bates Field from the east. It over flew the south end of the airport and executed a left teardrop turn to runway 34. According to witnesses at the airport, the airplane was on final approach to runway 34, approximately 150 feet agl, when they heard power applied to the engine. Subsequently, the right wing dropped, the airplane impacted the ground, contacted a steel pole, and came to a stop upright. A postaccident fire erupted beneath the engine and was extinguished by the initial responders. One witness, who was located on the airport, reported that at the time of the accident, the wind was from the south at 10 mph. Additionally, the following was written on a white notepad that was found in the cockpit: "Winds 180-16." PERSONNEL INFORMATION The flight instructor was issued an airline transport pilot certificate on May 15, 1996, and was issued his flight instructor certificate (airplane single-engine land and multi-engine land, and instrument-airplane) on February 18, 2001. According to a document that was provided by the CAF, the pilot was initially approved to fly the BT-13A on October 4, 1993. A Flight Resume Sheet that was dated December 1, 2000, revealed that the pilot had accumulated a total of 4,100 flight hours, of which 550 hours were in tailwheel equipped airplanes and 141.5 hours were in the BT-13A. The pilot completed his last biennial flight review on March 22, 1999, and the check was performed in the BT-13A. Additionally, the pilot held a second class medical certificate that was issued on April 6, 2000. The medical certificate stipulated that he "must have available glasses that correct for near vision." The commercial pilot receiving instruction was issued a commercial pilot certificate (airplane single-engine land) on July 22, 1988. According to documents that were provided by the CAF and dated April 29, 2001, the pilot was approved to begin transition into the BT-13A on April 26, 2001. The pilot had accumulated a total of 1,460 flight hours, of which 291 hours were in tailwheel equipped airplanes. According to the pilot's flight logbook, he completed his last biennial flight review on March 9, 2000. He held a second class medical certificate that was issued on April 4, 2000. The medical certificate stipulated that he "must have glasses for near vision." AIRCRAFT INFORMATION The blue and yellow World War II airplane was equipped with a Pratt & Whitney R985-AN1 radial engine and a two bladed, constant speed Hamilton Standard propeller. The airframe, engine, and propeller underwent their most recent annual inspections on May 3, 2001, and had accumulated a total of 2,228.7 hours, 254.4 hours since major overhaul, and 2,228.7 hours, respectively. The airplane was not equipped with a stall warning indication system. The following was noted on a notepad that was found in the airplane: "Flap Ind Inop" and "Fwd Tach Inop." According to the BT-13 Flight Manual, the stall speed with the flaps retracted is 75 mph. The stall speed with the flaps extended 30 or 60 degrees is 65 mph. METEOROLOGICAL INFORMATION At 1353, the weather observation facility at MAF, located 7 miles northeast of the accident site, reported the following weather conditions: a few clouds at 6,000 feet, visibility 10 statue miles, wind from 200 degrees at 13 knots and gusting to 20 knots, temperature 82 degrees Fahrenheit, dew point 54 degrees Fahrenheit, and an altimeter setting of 30.11 inches of mercury. At 1353, the weather observation facility at the Odessa-Schlemeyer Field Airport, Odessa, Texas, (located 9 miles northwest of the accident site) reported the following weather conditions: clear skies, visibility 10 statue miles, wind from 210 degrees at 11 knots and gusting to 19 knots, temperature 84 degrees Fahrenheit, dew point 55 degrees Fahrenheit, and an altimeter setting of 30.12 inches of mercury. WRECKAGE AND IMPACT INFORMATION A global positioning receiver (GPS) receiver revealed that the accident site was located at north 31 degrees 49.728 minutes latitude and west 102 degrees 14.805 minutes longitude. The linear energy path was 1,000 feet east of runway 16/34 and oriented along a magnetic heading of 080 degrees. The dimensions of the initial ground scar, which contained yellow paint chips, were consistent with the dimensions of a wing-tip. A green wing-tip navigation light lens was located adjacent to the initial ground scar. The second ground scar was located 45 feet beyond the initial ground scar and contained blue and yellow paint chips, a piece of the engine cowling, and a scar consistent with that of a propeller slash. The right wing was found fragmented between the second ground scar and the main wreckage. The main wreckage came to rest 121 feet beyond the initial ground scar. The final aircraft component, the "G" meter, was located 274 feet north of the initial ground scar. Flight control continuity was established for the aileron, flap, elevator, elevator trim, rudder, and rudder trim flight control systems. All cable separations displayed frayed and uneven cable strands, which are signatures of tension overstress. The flap system was designed so that the flaps could be manually operated through hand cranks, located on the left side of the front and rear cockpits. The hand cranks are turned clockwise to retract the flaps, and counterclockwise to extend the flaps. Approximately 31 turns are required to rotate the flaps between extended and retracted. The hand cranks were moved 10-11 turns in the clockwise direction before reaching their limit. The flap system was comprised of torque tubes and a gear box. The gear box was free to rotate when it was manipulated by hand. The front and rear cockpits were examined. The front cockpit's flap indicator indicated that the flaps were retracted, and the rear cockpit's flap indicator indicated that the flaps were partially extended. The rear cockpit's attitude indicator indicated nose high and right bank. The front and rear cockpit control quadrants revealed the following: throttle-full forward; propeller-full increase (low pitch); mixture-midrange. The cockpit fuel selectors, for both the front and rear cockpits, were in the right tank position. The fuel system was compromised during the impact. The right wing was fragmented, and its wet wing type fuel tank was destroyed. The left wing remained intact and contained an undetermined amount of fuel. The engine and propeller were examined at the accident site. The engine's accessories remained attache ## Aircraft - Registration: [N66791](https://openairdocs.org/deregistered/N66791-2002-01-08), registration cancelled 2002-01-08, S/N 3336, built 1942 (OpenAirDocs) - Reported make and model: Convair BT-13A - Registry model: [Convair BT-13A](https://openairdocs.org/model/convair-bt-13a) (registry code 2420204) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 3336 - Airframe hours: 2228.7 - Engines: Pratt & Whitney R-985-ANI 450 horsepower reciprocating - Damage: Destroyed - Flight: Instructional, Part 91 - Operator: Confederate Air Force, doing business as N/A - Registered owner: American Airpower Heritage Flying Museum - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, May 3, 2001 - Departed: MAF, Midland, TX - Airport: 71TA, Bates Field Airport, runway 34, 4,400 × 80 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: fatal; flight instructor, flight engineer, airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review March 22, 1999; seat: rear; toxicology performed; flight hours: 4,100 total, 142 in this make and model - Other flight crew; age 54; injuries: fatal; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; last flight review March 9, 2000; seat: front; toxicology performed; flight hours: 1,460 total ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 13 knots, gusting 20 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 54 °F - Altimeter: 30.11 inHg - Observed at: MAF, 7 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 20010514010969A](https://openairdocs.org/incident/20010514010969A), May 14, 2001: Cvac BT13A, Odessa, TX, Destroyed, 2 fatal. (-23)Flight instructor was scheduled to provide transition training in a BT-13 to another confederate air force (caf) pilot member. They were observed orbiting… ## Other investigations on N66791 (1) 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. - [NTSB FTW80DPA17](https://openairdocs.org/ntsb/FTW80DPA17), Sep 7, 1980: Cnsd Vultee BT-13 (N66791), Waco, TX, substantial damage 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.