# NTSB SEA02LA140: Blanik L-13, N70741, Belgrade, MT, July 31, 2002 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 31, 2002, 14:45 local (20:45 UTC) - Place: Belgrade, MT - Coordinates: 45.776668, -111.152778 - Nearby events: https://openairdocs.org/map.md?lat=45.7767&lon=-111.1528&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report April 8, 2003 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 55350 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02LA140 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55350/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55350 - Page: https://openairdocs.org/ntsb/SEA02LA140 ## Probable cause The glider pilot's improper in-flight planning decision and his failure to attain the proper touchdown point. Contributing to the accident were the inadvertent activation of the speed brakes, the pilot's failure to maintain altitude, the high vegetation and the ditch. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water encounter with terrain/water, landing - roll - in-flight planning/decision - improper, pilot in command (cause) - proper touchdown point - not obtained, pilot in command (cause) - speed brakes - inadvertent activation, pilot in command (contributing factor) - altitude - not maintained, pilot in command (contributing factor) - terrain condition - high vegetation (contributing factor) - terrain condition - ditch (contributing factor) - On ground/water encounter with terrain/water, landing - roll - terrain condition - high vegetation (contributing factor) - terrain condition - ditch (contributing factor) ## Analysis Just about the time the glider pilot was ready to initiate his base turn for the parallel sod runway, the tower controller asked him if he saw the traffic on a one mile final to the paved runway. According to the pilot, he then let go of the spoiler handle (the spoilers were partially deployed), in order to reach the microphone that was stored in a pocket on the right side of the glider. He advised the tower that he did not have the traffic in sight, put the microphone back in the pocket, and then reached back for the spoiler handle. At that time he discovered that the spoilers had deployed to the full open position. The pilot then immediately retracted the spoilers and made a turn to final. After turning final, the pilot realized that he probably would not be able to make it to the threshold of the sod runway, but because of the aircraft on final for the paved runway, he made the decision not to request a change to that runway (the threshold of which was approximately 2,500 feet closer to his position at the time). As the pilot continued on toward the threshold of the sod runway, he attempted to maneuver toward its right side in order to avoid some stakes that were between him and the runway threshold, and in order to land well clear of the paved runway. Ultimately the aircraft touched down approximately 200 feet short of the sod runway threshold and 50 feet to the right of its right edge. Although the initial touchdown in the tall weeds was uneventful, almost immediately after starting the landing roll, the aircraft impacted a ditch that the pilot had not been aware of. ## Factual narrative On July 31, 2002, approximately 1445 mountain daylight time, a Blanik L-13, N70741, impacted a ditch after landing short of the runway at Gallatin Field Airport, Belgrade, Montana. The aircraft was owned by Big Sky Soaring Inc., and operated by Sunbird Aviation. The private pilot and his passenger received minor injuries, and the glider sustained substantial damage. The 14 CFR Part 91 personal pleasure flight departed Gallatin Field Airport, Belgrade, Montana, approximately one hour prior to the accident, and was being operated in visual meteorological conditions. No flight plan had been filed. According to the pilot, he released from the tow plane just south of Saddle Peak, and soared Bridger Ridge until about 1430. At that time he called Bozeman Tower to report leaving the ridge and to request landing on the grass/sod runway located just to the right of the paved runway (see attached satellite image). The tower reported the current winds as 300 degrees at 20 knots, and instructed the pilot to report 30 seconds prior to entering the downwind for sod runway 30. When he was 30 seconds from a downwind entry, the pilot advised the tower of this position, and after being cleared to land on the sod runway, entered a left downwind. Just about the time the pilot was ready to initiate his base turn, the tower controller asked him if he saw the traffic on a one mile final to the paved runway. According to the pilot, he then let go of the spoiler handle (the spoilers were partially deployed), in order to reach the microphone that was stored in a pocket on the right side of the glider. He advised the tower that he did not have the traffic in sight, put the microphone back in the pocket, and then reached back for the spoiler handle. At that time he discovered that the spoilers had deployed to the full open position. The pilot then immediately retracted the spoilers and made a turn to final. After turning final, the pilot realized that he probably would not be able to make it to the threshold of the sod runway, but because of the aircraft on final for the paved runway, he made the decision not to request a change to that runway (the threshold of which was approximately 2,500 feet closer to his position at the time). As the pilot continued on toward the threshold of the sod runway, he attempted to maneuver toward its right side in order to avoid some stakes that were between him and the runway threshold, and in order to land well clear of the paved runway. Ultimately the aircraft touched down approximately 200 feet short of the sod runway threshold and 50 feet to the right of its right edge. Although the initial touchdown in the tall weeds was uneventful, almost immediately after starting the landing roll, the aircraft encountered a ditch that the pilot had not been aware of. Upon impacting the far wall of the ditch, the aircraft sustained substantial damage generated by the force of the collision. ## Aircraft - Registration: [N70741](https://openairdocs.org/aircraft/N70741), registered now, S/N 027341 (OpenAirDocs) - Reported make and model: Blanik L-13 - Registry model: [Let BLANIK L-13](https://openairdocs.org/model/let-blanik-l-13) (registry code 1360306) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 027341 - Airframe hours: 2100 - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Big Sky Soaring, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 7, 2002, 20 hours before - Departed: BZN, Belgrade, MT - Destination: BZN, MT - Airport: BZN, Gallatin Field, runway 30R, 2,000 × 150 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; last flight review June 1, 2001; seat: front; flight hours: 789 total, 80 in this make and model, 754 as pilot in command, 37 in the last 90 days, 15 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 20 knots, gusting 31 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 23 °F - Altimeter: 29.95 inHg - Observed at: KBZN ## 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 20020731018669A](https://openairdocs.org/incident/20020731018669A), Jul 31, 2002: Let L13BLANIK, Bozeman, MT, Substantial damage. (-23) Pilot states he requested sod to free active runway 30 and land into the wind. He planned to land short and was forced even shorter when he removed his… ## Other investigations on N70741 (1) 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. - [NTSB SEA99LA087](https://openairdocs.org/ntsb/SEA99LA087), Jun 17, 1999: Let L-13 (N70741), Belgrade, MT, substantial damage. Probable cause: The pilot in command's failure to maintain clearance from a parked airplane during his attempt to avoid a person on the runway. ## Docket (2 files) The files NTSB released with the investigation on December 31, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55350. 456 KB in all. - Supplement S (item 1, .PDF, 29 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40174164&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 426 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40465436&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.