# NTSB GAA17CA466: AB Sportine Aviacija LAK 17, N128LA, Uvalde, TX, August 2, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 2, 2017, 13:25 local (18:25 UTC) - Place: Uvalde, TX - Coordinates: 29.211389, -99.743614 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.2114&lon=-99.7436&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Glider tow event](https://openairdocs.org/ntsb-events/510) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 15, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA/ FSDO - NTSB case key (mKey): 95742 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA466 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95742/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95742 - Page: https://openairdocs.org/ntsb/GAA17CA466 ## Probable cause The ground crewmember’s failure to fully engage the tow hook release arm during preflight, which resulted in the premature release of the glider at insufficient altitude to complete a safe landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuselage: aerial tow equipment section](https://openairdocs.org/ntsb-findings/01035301): Aircraft › Aircraft structures · Incorrect use/operation (probable cause); cases with it: [AB Sportine Aviacija LAK-17A, 1 case](https://openairdocs.org/ntsb-findings/01035301/cases.md?model=056080H), [All aircraft, 7 cases](https://openairdocs.org/ntsb-findings/01035301/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Ground crew (probable cause); cases with it: [AB Sportine Aviacija LAK-17A, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=056080H), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Glider tow event](https://openairdocs.org/ntsb-events/510) (defining event); cases with it: [AB Sportine Aviacija LAK-17A, 1 case](https://openairdocs.org/ntsb-events/510/sequence.md?model=056080H), [All aircraft, 45 cases](https://openairdocs.org/ntsb-events/510/sequence.md) - [Initial climb: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [AB Sportine Aviacija LAK-17A, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056080H), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The glider pilot reported that he was competing in a national soaring championship competition and that his flight was the last of several glider tows for the day. He added that the launch procedure required that every glider have a tow rope laid out next to the glider, and then a ground crewmember would hook the Schweizer tow ring first to the Schweizer tow latch on the tow airplane and then attach the Tost tow ring to his Tost-equipped glider. He further added that his glider was loaded with water ballast so that the glider could operate at maximum gross weight for competition purposes. The glider pilot reported that the takeoff roll and liftoff were normal, but about 100 to 150 ft above ground level (agl), "the tow rope spontaneously released from the tow plane." He added that he immediately pulled his rope release handle and pitched forward to land in a grass overrun area past the departure runway, but the glider "had too much airspeed and too little area to land." Subsequently, he pulled up to avoid a "solid line of trees," entered a "gentle" right turn, and impacted a "favorable brushy area." The glider was destroyed during the impact sequence. The glider pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation. The tow airplane pilot reported that this was his seventh and last tow of the day. He added that the tow rope was attached to his airplane by a ground crewmember, and then he was given instructions to "take up slack and launch as usual." He further added that the takeoff and climb out of ground effect were normal, but about 300 ft agl, the tow airplane was climbing too fast, and he radioed, "was that a rope break?" The tow airplane pilot did not receive a response, so he continued his climb. Shortly thereafter, he observed that the glider was no longer on tow and then witnessed the impact. The tow airplane pilot reported that he subsequently completed a normal landing, which included a low pass and rope release. When he moved the rope release handle to drop the rope, he felt a "lighter than normal release pressure on the tow handle." The ground crewmember who attached the tow rope to the tow airplane and glider reported in a written statement that he "made sure the tow rope ring was placed in the proper location at the back of the mechanism." He added that he "placed the latch over the top beam in the vertical position locking the ring in place." He further added that he "made sure there was no tension on the release cable" and used his weight "in both a straight back and back and up direction assuring the tow ring was securely locked in place." The glider contest manager reported that the tow airplane involved in the accident was the only airplane with a Schweizer tow hitch. The other tow airplanes being used were equipped with Tost tow hitches. The manager reported that for future contests, only tow airplanes equipped with Tost tow hitches will beused. A Federal Aviation Administration (FAA) aviation safety inspector reported that the glider tow rope and tow rope rings were found intact just beyond the end of the departure runway, and no anomalies were observed. He added that he performed a functional check of the tow hitches on the tow airplane and glider, and no anomalies were observed. FAA Advisory Circular, "Acceptable Methods, Techniques, and Practices – Aircraft Alterations," AC No. 43.13-2B, stated, in part: "The Schweizer is a simple over center L-hook type with a rubber tension block to preload the release lever." The FAA Glider Flying Handbook stated, in part: Schweizer Tow Hook Prior to use, the tow hook and release arm should be inspected for damage, cracks, deformation, and freedom of movement on the pivot bolt. Visually check the tow hook and ensure that the hook properly engages the release arm. Inspect the rubber spacer for general condition and check the condition of the release cable. Inside the cockpit, check to see that the manual release lever is not rubbing against the aircraft seat or any other obstructions, and check the security of the release handle assembly and the cable attachment. It is likely that the ground crewmember did not fully engage the tow hook release arm during preflight, and that, during the initial climb, the tow ring prematurely released from the tow airplane. ## Factual narrative The glider pilot reported that he was competing in a national soaring championship competition and his flight was the last of several glider tows for the day. He added that, the launch procedure required that every glider have a tow rope laid out next to the glider, and then a ground crewmember would hook the Schweizer tow ring first to the Schweizer tow latch on the tow airplane, and then attach the Tost tow ring to his Tost equipped glider. He further added that, his glider was loaded with water ballast so that the glider could operate at maximum gross weight for competition purposes. The glider pilot reported that the takeoff roll and liftoff were normal, but about 100 to 150 ft above ground, "the tow rope spontaneously released from the tow plane." He added that he immediately pulled his rope release handle and pitched forward to land in a grass overrun area past the departure runway, but the glider "had too much airspeed and too little area to land." Subsequently, he pulled up to avoid a "solid line of trees," entered a "gentle" right turn, and impacted a "favorable brushy area." The glider was destroyed during the impact sequence. The glider pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation. A Federal Aviation Administration (FAA) aviation safety inspector reported that the glider tow rope and tow rope rings were found intact just beyond the end of the departure runway and no anomalies were observed. He added that he performed a functional check of the tow hitches on the tow airplane and glider and no anomalies were observed. The tow airplane pilot reported that this was his seventh tow, and last tow of the day. He added that the tow rope was attached to his airplane by a ground crewmember, and then he was given instructions to "take up slack and launch as usual." He further added that the takeoff and climb out of ground effect were normal, but about 300 ft above ground, the tow airplane was climbing too fast and he radioed, "was that a rope break?" The tow airplane pilot did not receive a response, so he continued his climb; shortly thereafter, he observed the glider was no longer on tow and witnessed the impact. Subsequently, the tow airplane pilot reported that he completed a normal landing, which included a low pass and rope release. When he moved the rope release handle to drop the rope, he felt a "lighter than normal release pressure on the tow handle." The ground crewmember, who attached the tow rope to the tow airplane and glider, reported in a written statement that he, "made sure the tow rope ring was placed in the proper location at the back of the mechanism." He added that he, "placed the latch over the top beam in the vertical position locking the ring in place." He further added that he "made sure there was no tension on the release cable" and used his weight "in both a straight back and back and up direction assuring the tow ring wassecurely locked in place." The glider contest manager reported that the tow airplane involved in the accident was the only airplane with a Schweizer tow hitch. The other tow airplanes being used were equipped with Tost tow hitches. The manager reported that for future contests, only tow airplanes equipped with Tost tow hitches will be used. The FAA Advisory Circular, Acceptable Methods, Techniques, and Practices – Aircraft Alterations, AC No. 43.13-2B, stated in part: "The Schweizer is a simple over center L-hook type with a rubber tension block to preload the release lever." The FAA Glider Flying Handbook stated in part: Schweizer Tow Hook Prior to use, the tow hook and release arm should be inspected for damage, cracks, deformation, and freedom of movement on the pivot bolt. Visually check the tow hook and ensure that the hook properly engages the release arm. Inspect the rubber spacer for general condition and check the condition of the release cable. Inside the cockpit, check to see that the manual release lever is not rubbing against the aircraft seat or any other obstructions, and check the security of the release handle assembly and the cable attachment. ## Aircraft - Registration: [N128LA](https://openairdocs.org/deregistered/N128LA-2018-03-06), registration cancelled 2018-03-06, S/N 151 (OpenAirDocs) - Reported make and model: AB SPORTINE AVIACIJA LAK 17 (A) - Registry model: [AB Sportine Aviacija LAK-17A](https://openairdocs.org/model/ab-sportine-aviacija-lak-17a) (registry code 056080H) (OpenAirDocs) - Category: Glider - Serial number: 151 - Year built: 2004 - Airframe hours: 429.76 - Engines: Solo 2350 26 horsepower reciprocating - Damage: Destroyed - Flight: Glider tow, Part 91 - Airworthiness certificate: Special, Experimental (Special); Special, Restricted (Special) - Last inspection: Annual, March 17, 2017 - Departed: UVA, UVALDE, TX - Destination: UVA, UVALDE, TX - Airport: UVA, Garner Field - Equipment: Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: none; commercial, flight instructor; last flight review July 16, 2017; seat: single; restraint: 4-point; flight hours: 1,241 total, 159 in this make and model, 1,224 as pilot in command, 48 in the last 90 days, 23 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 64 °F - Altimeter: 30.00 inHg - Observed at: KUVA, 2 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 20170802010279A](https://openairdocs.org/incident/20170802010279A), Aug 2, 2017: Ab Sportine Aviacija LAK-17A, Uvalde, TX, Substantial damage. On August 2, 2017, N128LA launched from Garner Field (kuva), in Uvalde, Texas, as part of a soaring competition that was being held there. The glider, a… ## Docket (8 files) The files NTSB released with the investigation on November 22, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95742. 7.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458351&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation (FAA Inspector) (item 2, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458352&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(FAA%20Inspector)-Master.PDF - Tow Pilot Statement (item 3, .PDF, 300 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458353&FileExtension=.PDF&FileName=Tow%20Pilot%20Statement-Master.PDF - Record of Conversation (Tow Pilot) (item 4, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458354&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Tow%20Pilot)-Master.PDF - Ground Crew Member Statement (item 5, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458355&FileExtension=.PDF&FileName=Ground%20Crew%20Member%20Statement-Master.PDF - Record of Conversation (Glider Contest Manager) (item 6, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458356&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Glider%20Contest%20Manager)-Master.PDF - FAA Glider Flying Handbook_Towing Operations (item 7, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458357&FileExtension=.PDF&FileName=FAA%20Glider%20Flying%20Handbook_Towing%20Operations-Master.PDF - Accident Photos (item 8, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458358&FileExtension=.PDF&FileName=Accident%20Photos-Master.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. --- 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.