# NTSB IAD02LA071: Burkhart Grob G103 Twin Astir, N4446W, Unionville, PA, July 5, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 5, 2002, 14:00 local (18:00 UTC) - Place: Unionville, PA - Coordinates: 39.900821, -75.740409 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.9008&lon=-75.7404&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 26, 2003 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 55171 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD02LA071 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55171/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55171 - Page: https://openairdocs.org/ntsb/IAD02LA071 ## Probable cause The pilot's evasive maneuver to avoid a collision with a departing airplane, which resulted in a landing short of the runway. A factor was the pilot's decision to land on the runway opposite the one in use. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Abrupt maneuver, approach - vfr pattern - final approach - evasive maneuver - initiated, pilot in command (cause) - wrong runway - selected, pilot in command (contributing factor) - Undershoot, approach - vfr pattern - final approach - On ground/water encounter with terrain/water, landing - terrain condition - crop - terrain condition - ditch ## Analysis While on a left downwind for runway 07, the glider pilot saw a tow plane and glider departing runway 25. The pilot had elected to land on runway 07 because it was the runway he had used to depart earlier, but the winds had changed and the runway in use at the time was runway 25. When he turned on to final approach, the pilot realized he was getting close to the tow plane, and ducked under it to avoid a collision. The glider landed short of the runway, into a field with crops, and subsequently went into a ditch. ## Factual narrative On July 5, 2002, about 1400 eastern daylight time, a Burkhart Grob G103 Twin Astir glider, N4446W, was substantially damaged after it landed short of runway 07 at the Ridge Soaring Gliderport (79N) Unionville, Pennsylvania. The certificated commercial pilot and the passenger were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91. In a written statement, the pilot stated that when he was on left downwind for runway 07, he saw a tow plane and a glider taking off on runway 25. The pilot had elected to land on runway 07 because it was the runway he had used to depart earlier, but the winds had changed and the runway in use at the time was runway 25. When he turned on final approach, the pilot realized he was getting close to the tow plane, and ducked under it to avoid a collision. The avoidance maneuver resulted in the glider landing short of the runway, and subsequently colliding with a ditch. A witness observed the glider when it was on short final approach to runway 07. He said the glider appeared low and touched down short of the runway in a field with crops about 2 1/2 feet high. The glider traveled about 20 feet, then hit a ditch that separated the field from the approach end of runway 07. The left wing of the glider came up and the glider pivoted on the right wing. The tail boom fractured, but remained attached to the airframe by pushrods. The witness also noted that the winds were from the northwest at 5 to 10 knots. The pilot reported a total of 8,000 flight hours, of which, 300 hours were in gliders. He also reported that there were no mechanical anomalies with the glider. Two Federal Aviation Administration (FAA) inspectors performed an examination of the glider. According to an inspector, the fuselage was fractured aft of the wings. Weather at University Park Airport, State College, Pennsylvania, 4 nm southeast, at 1347, included winds from 360 degrees at 8 knots, and visibility 20 statute miles. ## Aircraft - Registration: [N4446W](https://openairdocs.org/aircraft/N4446W), registered now, S/N 3822-K-81, built 1983 (OpenAirDocs) - Reported make and model: Burkhart Grob G103 TWIN ASTIR - Registry model: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g103-twin-astir) (registry code 1660202) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 3822-K-81 - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Knauff And Grove Inc - Airworthiness certificate: Standard, Normal - Departed: 79N, UNIONVILLE, PA - Airport: 79N, Ridge Soaring Glideport, runway 07, 3,325 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review May 8, 2002; flight hours: 8,000 total ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 8 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 50 °F - Altimeter: 30.12 inHg - Observed at: UNV, 4 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 20020705021479A](https://openairdocs.org/incident/20020705021479A), Jul 5, 2002: Grob G103TWNASTIR, Unionville, PA, Substantial damage. (.19) On July 5, 2002, at approximately 1400 eastern daylight time, a burkhart Grob G103 twin astir glider, N4446W, was substantially damaged after it landed… ## Docket (3 files) The files NTSB released with the investigation on June 24, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55171. 713 KB in all. - NTSB Form 6120.1/2 (item 1, .PDF, 618 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461207&FileExtension=.PDF&FileName=NTSB%20Form%206120.1%2F2-Master.PDF - Witness Statement (item 2, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461208&FileExtension=.PDF&FileName=Witness%20Statement-Master.PDF - Summary of Interview (item 3, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180006&FileExtension=.PDF&FileName=Summary%20of%20Interview-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.