# NTSB NYC96LA134: Wsk Pzl-Krosno KR-03A, N32113, Hilltown, PA, June 28, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 28, 1996, 16:00 local (20:00 UTC) - Place: Hilltown, PA - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 1, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 39202 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC96LA134 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39202/pdf - Page: https://openairdocs.org/ntsb/NYC96LA134 ## Probable cause failure of a bolt on the tow hook which resulted in an uncommanded release of the tow rope, and forced landing of the glider. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - initial climb - glider launch/tow equipment - failure (cause) - Forced landing, descent - emergency - On ground/water collision with object, landing - roll - terrain condition - high vegetation ## Analysis The glider was being towed by a Cessna 310 airplane. During takeoff climb, as the aircraft crossed the departure end of the runway, at a height of about 200 feet, the tow rope separated from the tow airplane. The glider pilot set up for an off airport landing in a open field. During ground roll, the left wing caught on brush and the glider ground looped to the left. The tow hook was installed on the tail wheel leaf spring of the tow airplane. It was held in place by two bolts. One of the bolts failed and the unit separated from the leaf spring. Tension between the release line, and tow rope actuated the tow hook to the open position, which resulted in the release of the rope from the tow airplane. ## Factual narrative On June 28, 1996, about 1600 eastern daylight time, a homebuilt, Wsk Pzl-Krosno KR-03A glider, N32113, was substantially damaged during landing at Hilltown, Pennsylvania. The private pilot and passenger were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight which had been airborne for less than one minute, and was conducted under 14 CFR Part 91. The pilot reported that the glider was under tow, and as it neared the departure end of the runway (about 200 feet AGL), the tow rope became slack. He extended the spoilers, nosed over for a landing, and attempted to release the tow rope. When the glider passed over wires, the pilot felt the tug of the tow rope, and knew it was still attached. After touchdown in a field, the left wing caught on brush, and the glider was spun to the left, at which time the fuselage aft of the cockpit area was bent. The tow airplane was a Cessna 305. The tow hook was installed on the tail wheel leaf spring and held in place with two bolts. A release line ran from the tow hook to the cockpit, and was used to release the tow rope from the tow airplane. Examination revealed that one of the bolts that holds the tow hook on the tail wheel leaf spring had failed, and the tow hook separated from its mounting. Tension between the release line, and tow rope actuated the tow hook to the open position, which allowed the tow rope to be released. A check of the glider after the accident found the tow rope release operative. The tow rope would separate if tension was applied; however, when the release was actuated, and no tension applied to the tow rope, it would not separate from the glider. ## Aircraft - Registration: N32113 (not matched to a registry record) - Reported make and model: Wsk Pzl-Krosno KR-03A - Category: Glider - Serial number: 03-05 - Airframe hours: 821 - Engines: unknown - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Philadelphia Glider Council - Last inspection: Annual, April 1, 1996, 89 hours before - Departed: 0PA0, PA - Airport: PGC, Phl Glider Council, Inc., runway 25, 2,800 × 250 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 433 total, 6 in this make and model, 207 as pilot in command, 5 in the last 90 days, 4 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 4 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 63 °F - Altimeter: 30.00 inHg - Observed at: NXX, 10 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 19960628015819A](https://openairdocs.org/incident/19960628015819A), Jun 28, 1996: Trnsqp KR03A, Hilltown, PA, Substantial damage. Tow rope became slack on tow. Tow release jammed. Impacted towe thru brush line came off towplane. Release defect. 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.