Kolb TWINSTAR accident near La Porte, Texas, July 15, 2018
On July 15, 2018 at about 2:00 pm local time, a 1992 Kolb TWINSTAR, an amateur-built aircraft,, registered N3135J, was substantially damaged in an accident during approach (VFR pattern base) near La Porte, Texas (La Porte Municipal Airport). It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain airspeed during a visual approach for landing, which resulted in an exceedance of the airplane's critical angle of attack and a subsequent aerodynamic stall at an altitude too low for recovery.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 15, 2018 · about 2:00 pm local time
- Place
- La Porte, Texas · La Porte Municipal Airport · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Kolb TWINSTAR III, built 1992, amateur-built
- Registration
- N3135J · no longer on the register · serial 3-12
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The private pilot, who had recently purchased the experimental amateur-built light-sport airplane, and a passenger were conducting a local flight in day visual meteorological conditions. Witnesses stated that the airplane departed and remained in the airport traffic pattern. While the airplane was on approach to the runway for landing, witnesses heard the engine power decrease then and immediately increase. The airplane appeared to enter an aerodynamic stall from a low altitude and impact terrain in a nose-low attitude. Postaccident examination of the airplane revealed no evidence of mechanical malfunctions or failures that would have precluded normal operations. Based on available information and examination of the wreckage, it is likely that the pilot did not maintain sufficient airspeed while maneuvering during the approach for landing. The airplane subsequently exceeded its critical angle of attack and entered an aerodynamic stall at an altitude too low for recovery. The pilot's logbook was not located during the investigation, and the pilot's experience level in experimental and light-sport airplanes was not determined. Additionally, it could not be determined if the pilot had obtained transition training in the accident airplane, which was classified as a low-inertia/high-drag airplane. Low-inertia/high drag airplanes are particularly susceptible to unintentional aerodynamic stalls due to their margin between low cruise speed and stall speed and their tendency to experience significant airspeed decay with increased load factor (such as during a turn). Toxicology revealed that the pilot was using pain and allergy medications at the time of the accident; however, whether the pilot had impairing levels of either of the medications around the time of the accident or whether the potentially-impairing medications degraded his ability to safely operate the airplane could not be determined.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aerodynamic stall/spin during approach (VFR pattern base) defining event
- Loss of control in flight during approach (VFR pattern base)
- Collision with terrain or object (not controlled flight into terrain) during approach (VFR pattern base)
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land
- Flight time: 2,400 hours in all; 7 in this make and model
- Medical certificate: BasicMed
- Seat: left
- Injury: fatal
The aircraft
- Last inspection: condition inspection, March 21, 2018; 8 hours since
- Maximum gross weight: 1,000 lb
- Seats: 2
- Landing gear: fixed
- Engine: Rotax 582 (piston); 0 hours total
The flight
- Departed from: T41 La Porte TX at 1:55 pm
- Destination: T41 La Porte TX
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 270° at 8 knots
- Visibility: 8 statute miles
- Sky: scat at 2,000 ft
- Temperature: 86°F (30°C), dew point 77°F (25°C)
- Altimeter: 30.05 inHg
- Observation at 2:50 pm from EFD, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on July 9, 2019. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Witness Statements | PDF, 4 pages | View Download |
| 2 | Witness Statement | PDF, 1 page | View Download |
| 3 | Record of Conversation - Sgt. Boles | PDF, 1 page | View Download |
| 4 | Excerpt of Pd Report | PDF, 2 pages | View Download |
| 5 | Excerpts of Aircraft Logbook | PDF, 3 pages | View Download |
| 6 | Toxicological Report | PDF, 1 page | View Download |
| 7 | Photo Array | PDF, 4 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N3135J the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.