Saturday, September 26, 2020

Team Rocket F1 Rocket, N540LK and Cessna 172S Skyhawk SP, N108VK: Accident occurred September 25, 2020 at San Marcos Regional Airport (KHYI), Caldwell County, Texas

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

The National Transportation Safety Board did not travel to the scene of this accident. 

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; San Antonio, Texas

Location: San Marcos, TX
Accident Number: CEN20LA419
Date & Time: September 24, 2020, 19:18 Local 
Registration: N108VK (A1); N540LK (A2)
Aircraft: Cessna 172 (A1); Experimental Team Rockets F-1 (A2) 
Injuries: 1 Serious, 1 Minor (A1); 1 Minor (A2)
Flight Conducted Under:

On September 24, 2020, about 1918 central daylight time (CDT), a Cessna 172 airplane, N108VK, and an Experimental Team Rockets F-1 airplane, N540LK, were involved in a mid-air collision near San Marcos, Texas. The Cessna was substantially damaged and the F1 was destroyed. The flight instructor on the Cessna received minor injuries, the student pilot was seriously injured, and the F1 pilot received minor injuries. The Cessna was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 instructional flight and the F1 was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

San Marcos Regional Airport (HYI) is equipped with a control tower which was closed at the time of the accident. Aircraft in the traffic pattern were self-reporting on the Common Traffic Advisory Frequency (CTAF). According to the flight instructor on the Cessna, they had entered the traffic pattern at San Marcos Regional Airport (HYI) about 1910 and intended to perform a full stop landing. He indicated there were about 6 other airplanes in the traffic pattern when they entered a left downwind to Rwy 08. He heard the F1 enter the traffic pattern on downwind in front of them and then report he was performing a right 360° turn for spacing. The F1 was not visual or seen on Automatic Dependent Surveillance – Broadcast equipment (ADS-B) by the Cessna while it performed the 360° turn.

The F1 pilot said he entered the left downwind for Rwy 08 from the northeast and noticed an aircraft in front of him and about abeam the landing threshold. He announced and performed a 360° right turn for spacing and reentered the downwind. As he was abeam the Rwy 08 threshold he saw an airplane low and on downwind at his 2 o’clock position and .7-.9 miles away and heard that airplane request confirmation of his location. Because of traffic already on final to land and hearing that the traffic at his 2 o’clock was extending downwind he elected to extend his downwind as well. The F1 pilot extended his downwind west of Interstate 35 (which crosses the extended runway centerline for Rwy 08 about 2.25 miles from the threshold), turned inbound to land, and announced his position “over 35.” He confirmed visually he had no additional traffic in front of him, continued, and made a 1-mile position call and verified there was no traffic in sight in front of him. 

Recorded communications of the CTAF captured the Cessna report they were left base “over the stadium” and query the airplane making a right 360 if they had rejoined the downwind. The F1 pilot replied he was about to turn base, but he saw a Cessna below him and he would extend and rejoin the final. The Cessna responded “that might be us. We’re over the stadium turning a left base.” The F1 pilot responded that he would “extend a little bit and rejoin on the final.” The Cessna then stated “Ok, we see you up there on the base.” About 40 seconds later the F1 pilot reported he was “over 35” and the Cessna replied immediately after that they were on a 2-mile final. About 40 seconds later the F1 reported he was on a 1-mile final to Rwy 08. Ten seconds later the Cessna reported they were .8-miles to Rwy 08. There were no further transmissions from either involved airplanes.

The flight instructor stated he felt the F1 impact the Cessna from above and the left, and the F1’s propeller hit their windshield and top of their cowling. He said he could not control the airplane as it descended, and it hit the ground and flipped over. The F1 pilot said he experienced an impact from what he felt was the right side, 5 o’clock position shortly after making his 1-mile position call. He looked and saw another airplane impact his right side prior to impact with the ground. The Cessna came to rest on the airport perimeter road inverted and the F1 stopped a short distance away against the airport perimeter fence. The F1 pilot exited his airplane and assisted the occupants of the Cessna. The F1 subsequently caught fire and was destroyed.

The F1 was an experimental tandem two-seat low-wing monoplane which was not equipped with ADS-B. The Cessna was a 4-seat high-wing monoplane that was equipped with ADS-B.

Aircraft and Owner/Operator Information (A1)

Aircraft Make: Cessna 
Registration: N108VK
Model/Series: 172 
Aircraft Category: Airplane
Amateur Built: No
Operating Certificate(s) Held: Pilot school (141)
Operator Designator Code:

Aircraft and Owner/Operator Information (A2)

Aircraft Make: Experimental Team Rockets
Registration: N540LK
Model/Series: F-1 
Aircraft Category: Airplane
Amateur Built: Yes
Operating Certificate(s) Held: None
Operator Designator Code:

Meteorological Information and Flight Plan

Conditions at Accident Site: VMC 
Condition of Light: Dusk
Observation Facility, Elevation: KHYI,597 ft msl
Observation Time: 18:56 Local
Distance from Accident Site: 1 Nautical Miles
Temperature/Dew Point: 24°C /18°C
Lowest Cloud Condition: 
Wind Speed/Gusts, Direction: 7 knots / , 70°
Lowest Ceiling: 
Visibility: 10 miles
Altimeter Setting: 29.92 inches Hg
Type of Flight Plan Filed:
Departure Point: 

Wreckage and Impact Information (A1)

Crew Injuries: 1 Serious, 1 Minor
Aircraft Damage: Substantial
Passenger Injuries:
Aircraft Fire: None
Ground Injuries: 
Aircraft Explosion: None
Total Injuries: 1 Serious, 1 Minor 
Latitude, Longitude: 29.891657,-97.879091 (est)

Wreckage and Impact Information (A2)

Crew Injuries: 1 Minor 
Aircraft Damage: Destroyed
Passenger Injuries: 
Aircraft Fire: None
Ground Injuries: 
Aircraft Explosion: None
Total Injuries: 1 Minor 
Latitude, Longitude: 29.891657,-97.879091 (est)


  1. 172's ADS-B data is visible in Flightaware thru 700 foot on approach to RW 8, which is at 588 ft. elevation. No ADS-B data found for the F1.

    Did the F1's low wing hide the 172 for the whole way in on final?

  2. Listening to live ATC audio the collision occurred 15 min after the tower closed, heavy traffic calls getting stepped on. But both aircraft mentioned stadium and i35 within moments of each other... which could have been indication 1... 540lk announced 1 mile final shortly after n108vk announced "point eight" for the field rather than "short final" it sounds to me that both pilots were talking and announcing but they weren't listening. 540lk descended on top of 108vk. And will technically likely be the primary at fault party.

  3. Thankfully no one was killed. I know, I know, ADSB-In is not required except in "rule" airspace. Experience in a ADSB-In equipped aircraft and with a ADSB-Out receiver often provides a directional aid to visual search. Of course, listening up on the radios is a must. On a different but somewhat related subject, my insurance is up for renewal on a Beech C23, I have already been told by an AOPA Insurance rep that I can anticipate a 10-40% increase. At the rate GA aircraft are being destroyed it is looking more and more like it will be on the high side...

  4. video at

  5. The low wing pilot was in a faster plane in a busy trainer filled pattern. He should not have done a 360 for spacing on base with traffic on downwind, and incorrectly announcing his intentions and position - he did not rejoin downwind, instead he rejoined at base to final. Then both pilots - announcing on final, just carried on ...

    1. I agree... I cringe at the thought of doing a 360 in high-traffic, uncontrolled airspace due to the uncertainty of what you will encounter when you finish your turn. This might be common practice when the tower is open though.


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