# NTSB SEA02TA110: Bell 206B, N1087L, Rainier, WA, June 25, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: June 25, 2002, 15:56 local (22:56 UTC) - Place: Rainier, WA - Coordinates: 46.881111, -121.771385 - Nearby events: https://openairdocs.org/map.md?lat=46.8811&lon=-121.7714&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report May 13, 2003 - Report: Approved by Office Director - Parties: DOI Office of Aircraft Services, FAA-FSDO - NTSB case key (mKey): 55056 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02TA110 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55056/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55056 - Page: https://openairdocs.org/ntsb/SEA02TA110 ## Probable cause The pilot's failure to maintain aircraft control while trying to land. Rough/uneven terrain, inaccurate performance data calculations, inadequate in-flight planning and lack of familiarity with the geographic area were factors. ## Analysis The pilot reported that he was dispatched to Mount Rainier to provide air support for a rescue mission of an injured hiker. Load calculations prepared by the pilot indicated that the helicopter would be operating at the high end of its performance capabilities. The pilot also reported that this was his first time operating on Mount Rainier. After a briefing, the pilot took one climbing guide from one helibase, and then picked up a climbing ranger from another location before proceeding to the site where the injured hiker was located at about the 10,000 to 10,400 foot level. Since the pilot was unfamiliar with the mountain, the guide and ranger also provided assistance to the pilot in where to go. The pilot was to drop off the guide and ranger at about the 9,000 foot level. After flying over the site to survey the ground conditions on the glacier which consisted of crevasses and uneven ground from avalanche debris, and to check helicopter performance, the pilot attempted to land at several locations on the glacier between about 8,000 feet and 9,000 feet. The pilot then chose a location in which he positioned the helicopter nose into the slightly rising terrain. The climbing ranger stated that the landing skid from the aft cross tube forward was on the ground. The terrain from the aft cross tube back sloped down about 5 degrees. After the pilot set the helicopter down slowly on the ground, he used the pedals to test for compaction. The pilot stated that as he was lowering the collective, the helicopter suddenly pitched and he applied forward cyclic and lifted off the ground. The helicopter began to rotate clockwise. The pilot applied left pedal input which did not have any effect. The pilot realized that he had no tail rotor control and lowered the collective and impacted on the glacier with the nose pointing downhill. Both occupants on board the helicopter and one witness located about 500 feet above the accident site reported that after the helicopter set down, it appeared to them that the helicopter slid backwards which lowered the tail and raised the nose of the helicopter. The witness above the accident site stated that he thought that the pilot would have landed perpendicular to the terrain slope so that the skids would not act like skis when weighted and slide downhill. Prior to recovery of the helicopter from the glacier, it was lost in a crevasse and covered by snow and rock fall. The load calculation prepared by the pilot was reviewed after the accident. It was found that for the actual conditions at the accident site, the helicopter was operating from 60 to 285 pounds over its allowable load for hover out of ground effect performance. ## Factual narrative HISTORY OF FLIGHT On June 25, 2002, at 1556 Pacific daylight time, a Bell 206B, N1087L, registered to Aero Copters and operated by the National Park Service as a public use flight, collided with the terrain on Mount Rainier, Rainier, Washington. Visual meteorological conditions prevailed and a company visual flight rules flight plan was in effect. The helicopter was substantially damaged and the commercial pilot and two passengers were not injured. The flight originated from Seattle, Washington, with two stops on Mount Rainier before proceeding to the Carbon Glacier located on the northern face of Mount Rainier. During an interview with the pilot, he reported that Aero Copters was contacted to dispatch a helicopter to the Kautz helibase at Mt. Rainier. The pilot's trip records indicated that the flight departed Boeing Field, Seattle, Washington, at 1315, and arrived at Kautz helibase at 1355. At the helibase, the pilot was given a briefing and issued a mission to take one climbing guide from the Kautz helibase and pickup a National Park Ranger from Camp Schurman. The mission was to then proceed to the Carbon Glacier to drop off the guide and the ranger to aid in the rescue of an injured hiker. Earlier in the day, an Army CH-47 (Chinook) had hoisted in two other Park Service personnel to about the 9,200 foot level to assess the hiker's injuries and provide medical attention. The injured hiker was located between 10,000 to 10,400 feet. The pilot reported that prior to departing Kautz helibase, he completed a "load calculation," which indicated that the results of the calculations were at the high end, but within operating parameters. The Load Calculation form was signed off by both the pilot and the helicopter manager. At 1518, the helicopter departed from Kautz helibase with the climbing guide and proceeded to the west side of the mountain in order to survey the landing site at Carbon Glacier. The pilot stated that he made about three passes to orient himself to where the injured hiker was located, and to the potential landing sites as well as checking helicopter performance for that elevation. He then proceeded to Camp Schurman to pick up the climbing ranger. The flight arrived at Camp Schurman, however, the climbing ranger was above Camp Schurman at Emmons Flats where he had prepared a landing zone. The pilot repositioned the helicopter and the climbing ranger boarded the helicopter, sitting in the left rear seat behind the climbing guide in the front left seat. The flight departed Emmons Flats at 1540. Upon reaching the Carbon Glacier, the pilot flew over the site where the injured hiker and previously inserted ground party were located, then proceeded to the landing spot suggested by the ground party. The pilot stated that he hovered in close to the spot and attempted to land but then decided that he did not like this spot and repositioned lower down the hill. A landing was made at this lower location. The pilot reported that the climbing party then radioed him and asked if he could reposition higher up the hill. The pilot stated that he still had "plenty of power reserve" and took off again. The pilot found a spot that he believed was used by the Chinook earlier in the day. The pilot hovered over the spot, however, there were crevasses and cracks in the snow in close proximity to the landing spot. The pilot chose another spot and set down slowly on the snow with the helicopter facing upslope. The pilot slowly lowered the collective and moved the pedals to test the compaction of the snow with the landing skids. The pilot stated that at this point he did not believe that the collective was all the way down when the helicopter suddenly pitched and he applied forward cyclic control. When questioned as to which direction the helicopter "pitched," the pilot reported that, "I think I believe that the tail pitched down more than the nose pitched up." "It felt like the back end fell more than it felt like the nose came up." The pilot stated that he thought that he had reached the droop stop limit because the helicopter "had that kind of hopping vibration." The pilot applied forward cyclic and raised the collective to lift off the snow. The helicopter started to yaw to the right and he applied left pedal input which did not have any effect. The pilot realized that he had no tail rotor control and lowered the collective and the helicopter impacted the glacier with no additional movement and the nose pointing downhill, 180 degrees from the initial landing heading. The front seat climbing guide reported that he met the pilot at the Kautz helibase. The guide did not receive a full briefing of the mission, but it was his understanding from a discussion with the Air Mission Advisor that he was going on the helicopter in order to help the pilot locate the site where the injured hiker and ground crew were, help the pilot find his way around the mountain, and that the pilot needed somebody experienced onboard to tell him where they were going. After the safety briefing at the helicopter, the pilot and climbing guide had a brief discussion as to which way around the mountain they would go to get to Camp Schurman. It was decided to go around to the west side in order to look at Carbon Glacier where the ground team was located on Liberty Ridge before proceeding to Camp Schurman to pick up the climbing ranger. The site was located and the pilot flew low over the area. The guide stated that communications with the pilot were a bit difficult because he was not provided with a flight helmet compatible with the aircraft's avionics. The guide had to listen through his flight helmet and talk through a headset microphone. Because of the difficulties the guide was having communicating, he was not sure if the pilot intended to land and drop him off at the Carbon Glacier, or proceed to Camp Schurman to pick up the climbing ranger. Since the pilot was on his first trip to Mount Rainier and didn't know the location of Camp Schurman, the climbing guide told the pilot that they needed to go to Camp Schurman to pick up the climbing ranger. They then proceeded to Camp Schurman to pick up the climbing ranger. Without shutting down, the climbing ranger boarded the helicopter and was seated directly behind the front seat guide. The front seat climbing guide stated that later he found out that the climbing ranger was more experienced in helicopter operations and should have been seated in the front. It was also learned that the climbing ranger did not have a flight helmet available for intercom communications, and was only wearing his climbing helmet. The flight then continued to the site. The climbing guide stated that the pilot circled around the site then the pilot pointed to an area where he would have liked to land. The climbing guide stated that this was in the fresh avalanche debris of the main stream of debris and it was his opinion that the pilot did not understand the glacier and the hazards of the mountain. The climbing guide instead pointed the pilot to the spot where the Chinook had hoisted in the ground crew. This spot looked to the climbing guide to be the most level. The area was near a large crevasse and a plug of ice bridging it. The pilot started to put down in this spot then pulled off and did not land. The pilot instead repositioned several hundred feet lower and landed. After some communication with the ground party to see if the pilot could reposition higher, the pilot took off and repositioned higher up the mountain and landed to one side of a crevasse, but the climbing guide saw cracks in the surface and said that he could not get out safely without being properly secured (roped). The pilot then lifted the helicopter up and repositioned to the spot he originally tried to land but didn't touch down on. The spot was just below the crevasse and the slope was on a sligh ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, landing - performance data - inaccurate, pilot in command (contributing factor) - lack of familiarity with geographic area, pilot in command (contributing factor) - terrain condition - rough/uneven (contributing factor) - in-flight planning/decision - inadequate, pilot in command (contributing factor) - aircraft control - not maintained, pilot in command (cause) ## Aircraft - Registration: [N1087L](https://openairdocs.org/deregistered/N1087L-2016-09-01), registration cancelled 2016-09-01, S/N 3004, built 1980 (OpenAirDocs) - Reported make and model: Bell 206B - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Registry engine: [Allison 250 SER 317HP](https://openairdocs.org/engine/allison-250-ser-317hp) (registry code 03011, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 3004 - Engines: Allison 250-C18 317 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft, Public use - Registered owner: Aero Copters Inc. - Airworthiness certificate: Standard, Normal - Departed: Camp Schurman, WA - Destination: Mt. Rainier, WA - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; flight instructor, airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review February 15, 2002; seat: rear; flight hours: 6,851 total, 862 in this make and model, 6,700 as pilot in command, 110 in the last 90 days, 62 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 77 °F, dew point 48 °F - Altimeter: 30.17 inHg - Observed at: SMP, 30 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 20020625018439A](https://openairdocs.org/incident/20020625018439A), Jun 25, 2002: Bell 206B, Carbonado, WA, Substantial damage. (-23) Helicopter operating at the 8800 ft. level on Mt. Raniers carbon glacier for rescue of climbers. Pilot had the skids resting on the snow for 8-10… ## Docket (18 files) The files NTSB released with the investigation on March 19, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55056. 13.7 MB in all. - Supplement S (item 1, .PDF, 36 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178540&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 324 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453007&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot's Transcribed Statement (item 3, .PDF, 765 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178542&FileExtension=.PDF&FileName=Pilot%27s%20Transcribed%20Statement-Master.PDF - Guide 1 Transcribed Statement (item 4, .PDF, 654 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453008&FileExtension=.PDF&FileName=Guide%201%20Transcribed%20Statement-Master.PDF - Guide 2 Transcribed Statement (item 5, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178546&FileExtension=.PDF&FileName=Guide%202%20Transcribed%20Statement-Master.PDF - Rescuer Transcribed Statement (item 6, .PDF, 741 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178547&FileExtension=.PDF&FileName=Rescuer%20Transcribed%20Statement-Master.PDF - Form 67 Pilot's Calculations (item 7, .PDF, 207 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453009&FileExtension=.PDF&FileName=Form%2067%20Pilot%27s%20Calculations-Master.PDF - Figure 4-5 Hover Out of Ground Effect (item 8, .PDF, 156 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178551&FileExtension=.PDF&FileName=Figure%204-5%20Hover%20Out%20of%20Ground%20Effect-Master.PDF - Load Calculations by OAS (item 9, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178553&FileExtension=.PDF&FileName=Load%20Calculations%20by%20OAS-Master.PDF - Area A Calculation with Pilot's Load Calculation (item 10, .PDF, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178556&FileExtension=.PDF&FileName=Area%20A%20Calculation%20with%20Pilot%27s%20Load%20Calculation-Master.PDF - Area B Calculation with Pilot's Load Calculation (item 11, .PDF, 83 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178557&FileExtension=.PDF&FileName=Area%20B%20Calculation%20with%20Pilot%27s%20Load%20Calculation%0D%0A-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 12, .PDF, 371 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453010&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Photo 1. View of glacier and surrounding terrain above accident site. Digital Image (item 13, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178559&FileExtension=.PDF&FileName=Photo%201.%20%20View%20of%20glacier%20and%20surrounding%20terrain%20above%20accident%20site.%20%20Digital%20Image-Master.PDF - Photo 2. View of wreckage. Digital Image (item 14, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178560&FileExtension=.PDF&FileName=Photo%202.%20%20View%20of%20wreckage.%20%20Digital%20Image-Master.PDF - Photo 3. View of wreckage and crevasses. Digital Image (item 15, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178562&FileExtension=.PDF&FileName=Photo%203.%20%20View%20of%20wreckage%20and%20crevasses.%20%20Digital%20Image-Master.PDF - Photo 4. View of wreckage near crevasse and snow bridge. Digital Image (item 16, .PDF, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178563&FileExtension=.PDF&FileName=Photo%204.%20%20View%20of%20wreckage%20near%20crevasse%20and%20snow%20bridge.%20%20Digital%20Image-Master.PDF - Photo 5. Forward view of wreckage. Digital Image (item 17, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178569&FileExtension=.PDF&FileName=Photo%205.%20%20Forward%20view%20of%20wreckage.%20%20Digital%20Image-Master.PDF - Photo 6. Left side view of wreckage. Digital Image. (item 18, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40178571&FileExtension=.PDF&FileName=Photo%206.%20%20Left%20side%20view%20of%20wreckage.%20Digital%20Image.-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.