# NTSB CEN20LA419: Cessna 172S, N108VK, San Marcos, TX, September 25, 2020

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Class 3 · Limited · Final report
- Date: September 24, 2020, 19:18 local (Sep 25, 2020, 00:18 UTC)
- Place: San Marcos, TX
- Coordinates: 29.891657, -97.879091 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.8917&lon=-97.8791&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining events: [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250); [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250)
- Highest injury: Serious injuries
- Injuries: 1 serious, 2 minor
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Central Region
- Parties: FAA
- NTSB case key (mKey): 102041
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA419
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102041/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102041
- Page: https://openairdocs.org/ntsb/CEN20LA419

## Probable cause (aircraft 1)

The F1 pilot’s failure to see and avoid the lower altitude Cessna while on final approach for landing. Contributing to the accident were the restrictions to pilot visibility inherent to low- and high-wing airplanes, and both pilots’ failure to recognize the conflict that developed between their airplanes.

## Findings

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

- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Cessna 172S, 41 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2072439), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Perception/orientation/illusion: perception](https://openairdocs.org/ntsb-findings/02022040): Personnel issues › Psychological · Instructor/check pilot, aircraft 1; cases with it: [Cessna 172S, 2 cases](https://openairdocs.org/ntsb-findings/02022040/cases.md?model=2072439), [All aircraft, 61 cases](https://openairdocs.org/ntsb-findings/02022040/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause), aircraft 2; cases with it: [Escobar Luis E TEAM ROCKETS F1, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=05627OT), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Perception/orientation/illusion: perception](https://openairdocs.org/ntsb-findings/02022040): Personnel issues › Psychological · Pilot, aircraft 2; cases with it: [Escobar Luis E TEAM ROCKETS F1, 1 case](https://openairdocs.org/ntsb-findings/02022040/cases.md?model=05627OT), [All aircraft, 61 cases](https://openairdocs.org/ntsb-findings/02022040/cases.md)

## Sequence of events

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

- [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250) (defining event), aircraft 1; cases with it: [Cessna 172S, 7 cases](https://openairdocs.org/ntsb-events/250/sequence.md?model=2072439), [All aircraft, 196 cases](https://openairdocs.org/ntsb-events/250/sequence.md)
- [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250) (defining event), aircraft 2; cases with it: [Escobar Luis E TEAM ROCKETS F1, 1 case](https://openairdocs.org/ntsb-events/250/sequence.md?model=05627OT), [All aircraft, 196 cases](https://openairdocs.org/ntsb-events/250/sequence.md)

## Analysis (aircraft 1)

A low-wing Team Rockets F1 airplane and a high-wing Cessna 172 airplane were involved in a mid-air collision on final approach for landing. The airplanes entered the downwind leg of the traffic pattern within one minute of each other, with the F1 in front of the Cessna. There were four other airplanes in the traffic pattern or communicating on the airport’s common traffic frequency at that time. Shortly after entering the traffic pattern, the F1 pilot announced and performed a right 360° turn to increase spacing with the preceding airplane. The instructor onboard the trailing Cessna could not see the F1 and asked if the F1 had completed the turn. The F1 pilot responded that he was about to turn base, but he saw a Cessna below him and that he would extend downwind before turning to final. The instructor onboard the Cessna began a turn to base and reported that they saw the F1. About 45 seconds later, the F1 pilot reported that he was on final approach over a highway about 2 miles from the runway, which indicates he did not extend his downwind sufficiently to attain sufficient separation. The Cessna crossed the highway about the same time and also reported a 2-mile final. About 45 seconds later, the F1 pilot reported a 1 mile final. The instructor onboard the Cessna then reported a .8-mile final. Shortly after the last radio calls from the two airplanes, the F1 impacted the Cessna on the Cessna’s top left side. Both airplanes impacted the ground short of the runway. The Cessna flipped over and the F1 came to rest against a fence and caught fire. The Cessna sustained substantial damage and the F1 was destroyed. The F1 pilot recalled an airplane making position calls on final, which he assumed was behind him. He said that he had a clear view of the runway while on final and he did not see any traffic between him and the runway. It is likely that the low-wing configuration of the F1 prevented the F1 pilot from seeing the Cessna below him. Likewise, the occupants of the high-wing Cessna were restricted from seeing the F1 above them. Although the F1 pilot stated that he would extend his downwind leg, he did not extend it enough to gain safe separation from the Cessna, which resulted in the F1 and the Cessna arriving at nearly the same geographical point on 2- mile final at the same time. The standard position reports issued by both pilots were sufficient for the pilots to have had awareness of each other’s position on final; however, neither comprehended the conflict between their airplanes, possibly due to the high volume of radio calls from other aircraft in the traffic pattern and both pilots’ increased attention on preparing for landing.

## Factual narrative (aircraft 1)

On September 24, 2020, about 1918 central daylight time (CDT), a Cessna 172 airplane, N108VK, was substantially damaged and a Team Rockets F1 airplane, N540LK, was destroyed when they were involved in a mid-air collision near San Marcos, Texas. The flight instructor onboard 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 CFR Part 91 personal flight. San Marcos Regional Airport (HYI) was equipped with an air traffic 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), and a recording of the radio communications during the time of the accident was obtained. The Cessna was equipped with a GoPro camera mounted in the aft interior of the cockpit that captured video of the pilots and communications during the accident flight. The F1 was a tandem, two-seat, low-wing monoplane which was not equipped with Automatic Dependent Surveillance – Broadcast (ADS-B) equipment. The Cessna was a 4-seat, high-wing monoplane that was equipped with ADS-B. The Cessna entered the left downwind about 1912 for a full-stop landing. The student pilot was flying the airplane when they entered the pattern and there were 6 other airplanes in the traffic pattern or communicating on the CTAF at that time, including the F1. The F1 pilot stated that, when he entered the left downwind for runway 8 from the northeast he noticed an airplane in front of him and abeam the landing threshold. He announced and performed a right 360° turn for spacing and reentered the downwind. The instructor in the Cessna heard the F1 enter the traffic pattern on downwind, but he did not see the F1 perform the 360° turn and he tried to locate it using ADS-B. As the F1 was abeam the runway 8 threshold, the Cessna queried if the airplane that performed the 360° turn had rejoined the traffic pattern. The F1 pilot responded that he had and was about to turn left base, but he saw a Cessna below him on downwind at his 2 o’clock position and 0.7 to 0.9 miles away. The instructor took control of the airplane, announced they were “over the stadium turning left base,” and started a left turn. The “stadium” referenced was the Texas State University football stadium, located 2.9 miles east of the approach end of runway 8. At 19:15:40, the F1 pilot announced he would extend his downwind and “rejoin on the final.” Another airplane announced that they were on a short final a few seconds later. About 15 seconds later, the instructor continued a left turn and reported via radio that he saw another airplane “over the stadium.” At 19:16:24, the F1 pilot reported “over [Interstate 35 (I35)] inbound for landing on final for runway 8.” I35 passes under the flight path to runway 8 about 2.25 miles east of theapproach end of the runway. The F1 pilot stated that he visually cleared his flight path at that point and did not see another airplane on final until the collision occurred. Nine seconds later, the Cessna reported that they were on a 2-mile final to runway 8. At 19:17:20 the F1 pilot reported he was on a 1-mile final. The instructor quickly looked outside, including upward and backward, and at 19:17:25 the Cessna radioed they were at 0.8 mile on final. There were no additional radio calls from either airplane for the remainder of the flight. The instructor continued to look outside until 19:17:52, when he focused his attention toward the runway. The Cessna’s altitude indicated 750 ft mean sea level (155 ft above ground level) at that time. The F1 pilot recalled an airplane making position calls on final, which he assumed was the airplane he had seen at his 2 o’clock and that it was behind him. He stated, “I had a clear, clear view of the runway, there was no traffic at all between me and the runway,” and “Obviously, to what I understood they were behind me because obviously they were not between me and the runway.” The F1 pilot said that he felt and saw the other airplane impact from the right side, 5 o’clock position shortly after he made his 1-mile position call and before the impact with the ground. The instructor stated that he felt the F1 impact the Cessna from above and the left, and the F1’s propeller hit the windshield and top of their cowling. He said that he could not control the airplane as it descended, and it hit the ground and flipped over. The Cessna came to rest inverted on the airport perimeter road 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 Cessna sustained substantial damage to the fuselage, empennage, and both wings. The Federal Aviation Administration (FAA) Airplane Flying Handbook (AFH), Chapter 7, provides the following information to pilots: When approaching an airport for landing, the traffic pattern is normally entered at a 45° angle to the downwind leg, headed toward a point abeam the midpoint of the runway to be used for landing. The pilot should ensure that the entry leg is of sufficient length to provide a clear view of the entire traffic pattern and to allow adequate time for planning the intended path in the pattern and the landing approach. Banking from time to time can uncover blind spots. A mid-air collision is most likely to occur between two aircraft going in the same direction.

## Aircraft 1

- Registration: [N108VK](https://openairdocs.org/deregistered/N108VK-2023-09-16), registration cancelled 2023-09-16, S/N 172S8932 (OpenAirDocs)
- Reported make and model: CESSNA 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (registry code 2072439) (OpenAirDocs)
- Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 172S8932
- Year built: 2001
- Airframe hours: 5020
- Engines: LYCOMING I0360 SER A&C 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Airworthiness certificate: Standard, Normal; Standard, Utility
- Last inspection: 100 hour, August 20, 2020
- Departed: 50R, Lockhart, TX
- Destination: Same as departure
- Airport: KHYI, San Marcos Regional Airport, runway 08, 6,330 × 100 ft, asphalt
- Equipment: ADS-B

## Aircraft 2

- Registration: [N540LK](https://openairdocs.org/deregistered/N540LK-2022-03-05), registration cancelled 2022-03-05, S/N 021, built 2014 (OpenAirDocs)
- Reported make and model: Team Rockets F1
- Registry model: [Escobar Luis E TEAM ROCKETS F1](https://openairdocs.org/model/escobar-luis-e-team-rockets-f1) (registry code 05627OT) (OpenAirDocs)
- Registry engine: [Lycoming IO-540-C4B5](https://openairdocs.org/engine/lycoming-io-540-c4b5) (registry code 41651, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 021
- Year built: 2014
- Airframe hours: 170
- Engines: Lycoming IO-540-C4B5 250 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, September 15, 2020
- Destination: Same as departure
- Equipment: Auto-pilot

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Flight instructor, aircraft N108VK; age 29; injuries: minor; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 15, 2020; seat: right; restraint: 3-point; flight hours: 342 total, 108 in this make and model, 269 as pilot in command, 97 in the last 90 days, 36 in the last 30 days, 1 in the last 24 hours
- Student pilot, aircraft N108VK; injuries: serious; student; medical: unknown; seat: left; restraint: 3-point; flight hours: 16 total
- Pilot, aircraft N540LK; age 56; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review January 1, 2020; seat: front; restraint: 5-point; flight hours: 1,600 total, 200 in this make and model, 1,500 as pilot in command

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: 70° at 7 knots
- Visibility: 10 statute miles
- Temperature: 75 °F, dew point 64 °F
- Altimeter: 29.92 inHg
- Observed at: KHYI, 1 nm away
- METAR: KHYI 242356Z AUTO 07007KT 10SM CLR 24/18 A2992 RMK AO2 SLP123 T02440178 10272 20244 56007

## FAA reports on this event (2)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20200924022222A](https://openairdocs.org/incident/20200924022222A), Sep 24, 2020: Cessna 172S, San Marcos, TX, Destroyed. Aircraft (a) N108VK - CFI was instructing student mostly on pattern work and landings along with a few other maneuvers that were covered on the way over to…
- [Accident 20200924022231A](https://openairdocs.org/incident/20200924022231A), Sep 24, 2020: Escobar Luis E TEAM ROCKETS F1, San Marcos, TX, Destroyed. Aircraft (a) N108VK - CFI was instructing student mostly on pattern work and landings along with a few other maneuvers that were covered on the way over to…

## Docket (11 files)

The files NTSB released with the investigation on April 15, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102041. 46.2 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 N108VK (item 1, PDF, 11 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11465149&FileExtension=pdf&FileName=6120_N108VK_Copy_Redacted-Rel.pdf
- Pilot/operator aircraft accident report, NTSB form 6120.1 N540LK (item 2, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11992401&FileExtension=pdf&FileName=6120_1%20HYI%20-LE%20N540LK_Copy_Redacted-Rel.pdf
- N108VK CFI statements (item 3, PDF, 5 pages, 201 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13143064&FileExtension=pdf&FileName=Estes%20Statement%20and%20Emails_Redacted-Rel.pdf
- Record of conversation N540LK pilot (item 4, PDF, 4 pages, 511 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13066083&FileExtension=pdf&FileName=Record%20of%20Conversation%20-%20Pilot%20N540LK-Rel.pdf
- Witness statements (item 5, PDF, 2 pages, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11992325&FileExtension=pdf&FileName=Witness%20Binder_Redacted-Rel.pdf
- Record of conversation witness (item 6, PDF, 1 page, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13065962&FileExtension=pdf&FileName=Record%20of%20Conversation%20-%20Witness%20N30LU%20CFI-Rel.pdf
- CTAF communications transcript (item 7, PDF, 11 pages, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13142601&FileExtension=pdf&FileName=CEN20LA419_CTAF%20Communications_Redacted-Rel.pdf
- Photos (item 8, PDF, 3 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13142472&FileExtension=pdf&FileName=Photos%20CEN20LA419-Rel.pdf
- N108VK adsb raw data (item 9, XLSX, 12.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13066073&FileExtension=xlsx&FileName=ADSB%20N108VK-Rel.xlsx
- N108VK flight track (item 10, PDF, 2 pages, 25.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13066600&FileExtension=pdf&FileName=N108VK%20ADSB%20Flight%20Tracks-Rel.pdf
- Onboard image recorder - specialist's factual report_CEN20LA419 (item 11, PDF, 21 pages, 745 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13675320&FileExtension=pdf&FileName=Onboard%20Image%20Recorder%20-%20Specialist%27s%20Factual%20Report_CEN20LA419-Rel.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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