# NTSB WPR18LA145: Sportavia Putzer RF5B Sperber, N66GL, Lookout Pass, MT, May 22, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 22, 2018, 14:00 local (20:00 UTC) - Place: Lookout Pass, MT - Coordinates: 47.456111, -115.697219 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.4561&lon=-115.6972&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-climb to cruise: Loss of lift](https://openairdocs.org/ntsb-events/500) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report February 5, 2019 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA-FSDO - NTSB case key (mKey): 97307 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA145 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97307/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97307 - Page: https://openairdocs.org/ntsb/WPR18LA145 ## Probable cause The pilot’s improper decision to continue flight toward rising terrain after the engine overheated, which necessitated a precautionary landing when the motorglider could not maintain altitude in downdrafts. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=8451016), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=8451016), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=8451016), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md) - [Object/animal/substance](https://openairdocs.org/ntsb-findings/03022000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-findings/03022000/cases.md?model=8451016), [All aircraft, 224 cases](https://openairdocs.org/ntsb-findings/03022000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-climb to cruise: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-events/900/sequence.md?model=8451016), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Enroute-climb to cruise: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=8451016), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Enroute-climb to cruise: Loss of lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-events/500/sequence.md?model=8451016), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Enroute-climb to cruise: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=8451016), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Enroute-climb to cruise: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Sportavia Putzer RF5B SPERBER, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=8451016), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The airline transport pilot reported that, during a cross-country flight and while climbing toward a mountain pass, the experimental, amateur-built motorglider's engine began to overheat. The pilot delayed the climb to allow the engine to cool down and continued toward the pass, which resulted in reduced terrain clearance. As the motorglider approached the pass, it encountered a downdraft, and the engine was unable to produce enough power to stop the descent. Due to the reduced altitude, the pilot realized that he would be unable to safely turn the glider around, so he executed a precautionary landing on a freeway. During the landing, the glider struck a freeway barrier. The pilot reported that, other than the engine overheating, there was no evidence of any preimpact mechanical anomalies with the glider that would have precluded normal operation. ## Factual narrative On May 22, 2018, about 1400 mountain daylight time, an experimental amateur-built Sportavia-Putzer RF5B Sperber motor-glider, N66GL, collided with a roadside barrier following an encounter with downdrafts near Lookout Pass, Montana. The airline transport pilot received minor injuries. The glider sustained substantial damage to the left wing, firewall, and empennage. The glider was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal cross-country flight. Visual meteorological conditions prevailed about the time of the accident and no flight plan was filed. The flight originated from Missoula, Montana at 1300 and was destined for Kellogg, Idaho. The pilot had recently purchased the glider in New York and was returning with it to Seattle, Washington. In preparation for the long cross-county flights, he modified the glider to include an extra fuel tank in the back seat adding eight gallons or 54 pounds. This additional fuel combined for a total fuel weight of 108 lbs. The pilot stated by the time of the accident, the extra tank was empty, and even when it was full, the glider was well within center of gravity (CG) limits. The pilot had been following the interstate 90 (I-90) freeway so that he had an emergency landing area if needed. On the accident leg of the flight he was flying towards Lookout Pass, the lowest point of rising mountainous terrain, at 4,692 ft msl. While climbing through 6,100 ft to his desired altitude of 8,500 ft mean sea level (msl), the engine oil temperature began to rapidly rise. He corrected this by leveling the glider off in order to cool the engine oil. At this point, he decided to continue towards the pass and to the destination airport, as it was closer than the departure airport. When the engine oil cooled to an acceptable level he continued the climb. After reaching an altitude of about 6,500 ft, the glider encountered a downdraft. The pilot applied maximum engine power and the engine oil started to heat beyond "red line", the oil pressure started to drop, and the glider continued to descend. The pilot determined he could not safely turn around and decided to make a precautionary landing on the west-bound lanes of the I-90 freeway. While descending, he observed a vehicle obstructing the landing area. He made a turn to the left to land on the eastbound traffic lanes. While in the turn, the left wing struck a freeway barrier and the glider yawed to the left. The engine then struck the barrier, and the glider came to rest upright against the barrier. A small fire ensued and was quickly put out by witnesses. A video of the accident was discovered online and shows the motor-glider descending towards the west-bound lanes of the freeway then turning left moments before impacting a barrier. The elevation of the accident site was 4,685 ft. The pilot reported no mechanical failures or malfunctions of the airframe or engine and stated, "the engine just got hotand didn't have the power to overcome the down draft." At 1400 mountain daylight time, the Mullan Pass automated surface observation system, located about 2 miles from the accident site, at an elevation of 6,089 ft, reported the wind from 130° at 7 knots. No turbulence was forecast. ## Aircraft - Registration: [N66GL](https://openairdocs.org/deregistered/N66GL-2019-09-13), registration cancelled 2019-09-13, S/N 51043, built 1974 (OpenAirDocs) - Reported make and model: SPORTAVIA PUTZER RF5B SPERBER (B) - Registry model: [Sportavia Putzer RF5B SPERBER](https://openairdocs.org/model/sportavia-putzer-rf5b-sperber) (registry code 8451016) (OpenAirDocs) - Registry engine: [Limbach 1700E](https://openairdocs.org/engine/limbach-1700e) (registry code 38602, reciprocating) (OpenAirDocs) - Category: Glider, amateur-built - Serial number: 51043 - Year built: 1974 - Engines: LIMBACH 1700E 3E 68 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Departed: MSO, Missoula, MT - Destination: S83, Kellogg, ID - Equipment: Onboard weather, Electronic flight bag or handheld device, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: minor; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; last flight review April 22, 2018; seat: front; flight hours: 28,350 total, 39 in this make and model, 26,000 as pilot in command, 39 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 7 knots - Visibility: 6 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 43 °F - Altimeter: 29.81 inHg - Observed at: MLP, 25 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 20180522005799A](https://openairdocs.org/incident/20180522005799A), May 22, 2018: Sportavia Putzer RF5B SPERBER, Lookout Pass, MT, Destroyed. On may 22, 2018, at 1448 MDT. A Sportavia Putzer glider, crashed onto highway 90 on the Montana state side, while enroute to seattle Washington. Visual… ## Docket (4 files) The files NTSB released with the investigation on November 1, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97307. 6.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 864 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467953&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot's Statement (item 2, .PDF, 195 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467954&FileExtension=.PDF&FileName=Pilot%27s%20Statement-Master.PDF - Photos (item 3, .PDF, 2 photos, 327 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467955&FileExtension=.PDF&FileName=Photos-Master.PDF - Video of Accident (item 4, MP4, 5.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467956&FileExtension=mp4&FileName=Video%20of%20Accident-Master 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.