AERO VODOCHODY L-139

Full Narrative

HISTORY OF FLIGHTOn April 19, 2023, about 1837 central daylight time, an Aero Vodochody L-139 Albatros 2000 airplane, N1390A, sustained substantial damage when it was involved in an accident near Bridgeport, Texas. The front-seat pilot and the rear-seat flight instructor sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
The purpose of the flight was for the pilot to receive a flight review with the flight instructor. She flew the tandem seat airplane to the Perot Field/Fort Worth Alliance Airport (AFW), Fort Worth, Texas, to pick up the flight instructor. She reported that she does not remember anything from the accident flight.
A review of ADS-B data showed that the airplane departed from AFW about 1816. The airplane traveled to the northwest toward the Bridgeport Municipal Airport (XBP), Bridgeport, Texas. The airplane overflew the airport and performed a low approach to runway 18. The airplane, which did not land, climbed, turned to the west, and then turned to the north overflying Lake Bridgeport. The airplane then performed a teardrop-style turn to the north of XBP and oriented the airplane to the south to land on runway 18. The last several data points of the ADS-B data show that the altitude and the airspeed gradually decreased while on approach to runway 18. The ADS-B data terminated about 0.42 miles to the north of the approach end of runway 18.
The airplane impacted a large tree on private property. The airplane then impacted terrain, additional trees, and a barn before it came to rest upright in a second barn. Both wings and most of the empennage were separated due to the impact sequence. First responders extracted the pilot and the flight instructor from the wreckage.
The flight instructor reported that a no-flap landing was being practiced. He reported that while on a straight-in approach about one mile from runway 18, the airplane encountered a “large flock of large birds.” The flight instructor, who was not flying at the time, was looking for possible bird strike damage sustained to the wings, the engine, and the empennage. While looking for the possible bird strike damage, he felt the sink rate increasing. He then initiated a go-around. As the nose of the airplane started to rise for the go-around, it impacted the top of a large tree.
After the airplane impacted the tree, the airplane came to rest upright and traveled on the ground before coming to rest partially inside of a barn. The distance of where the airplane impacted the large tree to the approach end of runway 18 was about 0.38 miles. The flight instructor was able to shut off the fuel supply to the engine and used a cellular phone to contact first responders. Due to the damaged barn structure, the front and rear canopies could not be opened by the pilots. First responders later were able to extract both occupants.
A pilot-rated witness observed the airplane during the accident approach while she was on the ramp at XBP. She reported that the main landing gear was up, the flaps were retracted, and she did not hear any abnormal engine noises. When the airplane disappeared behind a tree line, she contacted first responders.
A review of the available radar data for the accident flight was performed to check for radar returns consistent with the presence of birds with the accident flight path. The review of the radar data was not able to confirm the presence of birds. PERSONNEL INFORMATIONPilot
According to FAA records, the pilot held a type rating for the Beechcraft RA-390S airplane and was authorized to operate the Aero Vodochody L-39 Albatros series airplanes. The pilot satisfactorily completed a pilot in command proficiency check in the accident airplane on March 11, 2022.
Flight Instructor
According to FAA records, the flight instructor was authorized to operate the Aero Vodochody L-29 Delfin series airplanes, the Aero Vodochody L-39 Albatros series airplanes, the British Aircraft Corporation BAC-167 Strikemaster series airplanes, the British Aerospace Corporation Hawker Hunter Series airplanes, the British Aerospace Corporation Jet Provost series airplanes, and the Temco TT-1 series airplanes.
Headsets
The two pilots were not wearing flight helmets, nor were they required by regulation. The two pilots were both wearing Bose A20 aviation headsets. According to Bose, this model of headset was an active noise cancelling headset. AIRCRAFT INFORMATIONThe airplane was part of the Darkstar Air Racing Team, which the pilot owned.
The Aero Vodochody L-139 Prototype Aircraft Flight Manual discusses the background of the airplane and stated:
The L139 is a single engine, two-seater, subsonic aircraft manufactured by Aero Vodochody of the Czech Republic. The aircraft is intended for basic and advanced training including weapons system training and fighter lead-in training.
According to Aero Vodochody, this airplane was the only L-139 manufactured by them.
The airplane was equipped with a Honeywell N2 Digital Electronic Engine Control unit; however, the unit did not have the capability to record engine data.
According to the airplane’s most recent FAA Program Letter, the airplane performed exhibition flights and was planned to perform at various air shows and at air races across the country. The airplane was maintained through an FAA-approved inspection program. METEOROLOGICAL INFORMATIONThe calculated density altitude at XBP was 3,120 ft. AIRPORT INFORMATIONThe airplane was part of the Darkstar Air Racing Team, which the pilot owned.
The Aero Vodochody L-139 Prototype Aircraft Flight Manual discusses the background of the airplane and stated:
The L139 is a single engine, two-seater, subsonic aircraft manufactured by Aero Vodochody of the Czech Republic. The aircraft is intended for basic and advanced training including weapons system training and fighter lead-in training.
According to Aero Vodochody, this airplane was the only L-139 manufactured by them.
The airplane was equipped with a Honeywell N2 Digital Electronic Engine Control unit; however, the unit did not have the capability to record engine data.
According to the airplane’s most recent FAA Program Letter, the airplane performed exhibition flights and was planned to perform at various air shows and at air races across the country. The airplane was maintained through an FAA-approved inspection program. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest on a property that is used for ranching purposes. During the impact sequence, the wings and empennage became separated from the fuselage. The airplane sustained substantial damage to the fuselage, both wings, and the empennage. All major structural components of the airplane were found at the accident site. The main landing gear was found in the retracted position.
Leading edge damage was observed on all the engine inlet fan blades. There were some pieces of small branches and dirt located forward of the engine inlet fan blades.
No signs of bird remains were observed on the airframe or in the engine.
During the recovery operation, about 132 gallons of fuel were recovered from the airplane.
Data from an Electronics International MVP-50T engine monitoring unit was extracted. A review of the data showed the engine performance parameters were normal during the accident flight. The engine power increased from 36% to 92% N1 during the last five seconds of recorded data.
An airplane performance study was conducted by the NTSB. The study revealed that after the airplane performed a low approach to runway 18, the engine power was reduced during the subsequent climb out and the throttle was not increased until the airplane was on the final approach and approximately 124 ft above field elevation. ADDITIONAL INFORMATIONRetracted Flaps Landing
The airplane’s flap system is hydraulically operated and electrically controlled. The Aero Vodochody L-139 Prototype Aircraft Flight Manual discusses operations with retracted flaps and states:
For landing with flaps up, increase approach and landing speed by 15 KIAS.
Bird Strikes
The FAA Aeronautical Information Manual (AIM) discussing migratory bird activity and states in part:
Bird strike risk increases because of bird migration during the months of March through April, and August through November.
This document also discusses methods for reducing bird strikes and states in part:
Avoid overflight of known areas of bird concentration and flying at low altitudes during bird migration. Charted wildlife refuges and other natural areas contain unusually high local concentration of birds which may create a hazard to aircraft.
Inflight Bird Strike Damage Assessment Guidance
The Department of the Air Force Instruction 91-212 Bird/Wildlife Aircraft Strike Hazard (BASH) Management Program provides guidance on inflight bird strike damage assessments and states in part:
Aircrews experiencing enroute bird strikes should abort the mission when practicable. While some engine ingestions or a windscreen strike may be readily apparent from the flight deck, the damage from any engine, fuselage, wing, tail, or radome strikes cannot be adequately assessed inflight. Continuing a mission may cause greater structural or engine damage and lead to a serious emergency.
A review of the FAA AIM did not contain any guidance on inflight bird strike damage assessments. FLIGHT RECORDERSThe airplane was not equipped with a crashworthy flight data recorder, nor was it required by regulation. MEDICAL AND PATHOLOGICAL INFORMATIONPilot
According to the postaccident medical records of the pilot, ketamine, fentanyl, and midazolam were administered to the pilot during her post-accident care. She was admitted to the hospital for treatment of her injuries.
Hospital toxicological testing detected amphetamine in urine collected from the pilot at 2116 on the accident date. Toxicological testing by the FAA Forensic Sciences Laboratory detected amphetamine at 69 ng/mL in blood collected from the pilot at 2018 on the accident date, and at 2084 ng/mL in urine collected from the pilot at 2116 on the accident date. FAA testing also detected phenylpropanolamine in the pilot’s urine. Other substances detected by the pilot’s postaccident toxicological testing (ketamine, norketamine, and midazolam) were attributable to medications administered after the accident, as verified by review of hospital records.
Amphetamine is a prescription medication and a Schedule II controlled substance. Amphetamine may be prescribed for attention-deficit/hyperactivity disorder, attention-deficit disorder, narcolepsy, and obesity. Amphetamine usually carries a warning that the drug may impair the ability to operate a vehicle or machinery, and that care should be taken until the effects of the drug are assessed after initiation of use. At lower doses, amphetamine has few effects on cognitive functioning and use may result in an enhancement of some psychomotor tasks, including improved reaction time, less fatigue and increased alertness; however, use may increase willingness to make high-risk choices. Amphetamine use at higher doses may cause poor impulse control and altered cognition, including inability to focus on divided attention tasks, worsened reaction time, and depressed reflexes. Amphetamine can also be used recreationally by users seeking euphoric effects, increased alertness, and the relief of fatigue.
Phenylpropanolamine is a minor metabolite of amphetamine. Phenylpropanolamine can also be used in illicit drug production to make amphetamine. Phenylpropanolamine was previously available in the United States as a nasal decongestant and weight loss ingredient in multiple over the counter and prescription products. In 2000, the U.S. Food and Drug Administration requested that all drug companies discontinue marketing products with phenylpropanolamine for human use due to a small increased risk of brain bleeding.
According to the FAA, amphetamine is a “do not issue/do not fly” medication.
Flight Instructor
According to the flight instructor’s post-accident medical records, he was taken to the hospital by first responders and was admitted for treatment of injuries. The hospital did not perform toxicological testing, and NTSB attempts to secure hospital specimens for additional testing were unsuccessful.