# NTSB SEA02LA042: Cessna 172, Concrete, WA, February 20, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 20, 2002, 08:00 local (16:00 UTC) - Place: Concrete, WA - Coordinates: 48.529724, -121.691665 - Nearby events: https://openairdocs.org/map.md?lat=48.5297&lon=-121.6917&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 8, 2003 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 54239 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02LA042 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54239/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54239 - Page: https://openairdocs.org/ntsb/SEA02LA042 ## Probable cause The pilot's failure to maintain adequate clearance/altitude while reversing course and turning towards rising, tree covered terrain in downdraft conditions. Contributing factors were trees, rising terrain, downdrafts and the pilot's in-flight decision to turn towards rather than away from steeper terrain during his course reversal. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - altitude/clearance - inadequate, pilot in command (cause) - object - tree(s) (contributing factor) - terrain condition - rising (contributing factor) - in-flight planning/decision - poor, pilot in command (contributing factor) - weather condition - downdraft (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - rising ## Analysis The pilot was following the Skagit River eastbound approximately 1500-1800 feet above sea level when he observed rain showers ahead and he decided to execute a course reversal. He initiated a left turn at 75 miles per hour utilizing two "notches" (20 degrees) of flaps and noted a sink rate. He then applied full power and raised the flaps to one "notch" (10 degrees) during which the sink rate continued. The pilot reported that it "felt like the aircraft was getting sucked down." As the aircraft continued in its left turn towards the rising, tree covered hillside, the pilot executed a controlled crash into the trees and terrain. A topographic chart of the vicinity of the accident showed that the terrain gradient was considerably shallower to the south, and that the left turn initiated by the pilot placed the aircraft flying towards higher gradient terrain. The pilot reported that he had been using carburetor heat throughout the flight and that the aircraft's engine had been performing as expected. ## Factual narrative On February 20, 2002, approximately 0800 Pacific standard time, a Cessna 172, C-FISS, registered to and operated by a private individual, and borrowed/being flown by a Canadian certificated commercial pilot, was substantially damaged during an in-flight collision with trees and subsequent collision with terrain while maneuvering. The pilot, who was the only occupant aboard the aircraft, was uninjured. The accident site was located three nautical miles east of Concrete, Washington, at an elevation of 850 feet above mean sea level. The pilot reported scattered clouds and rain showers at the time of the accident, and no flight plan had been filed. The flight, which was personal, was operating in US airspace under 14CFR91 at the time of the accident. The flight departed Langley, British Columbia, approximately 0700, destined for Chilliwack, British Columbia, approximately 27 nautical miles to the east-northeast of Langley. The pilot hiked out from the accident site and reported the accident to law enforcement officials with Skagit County. The pilot was subsequently interviewed on February 22 and submitted a written statement as part of his NTSB Form 6120.1/2 (both attached). He reported that he departed Langley, British Columbia (BC), en route to Chilliwack, BC, and decided to detour into US airspace in the vicinity of the Skagit River following it until reaching Lake Shannon and then returning to Canada. He continued, reporting that he was flying about 1500 feet in elevation roughly eastbound along the river (the River's approximate elevation between 200 and 300 feet above sea level near Concrete). Passing Concrete he noted rain showers ahead and decided to make a 180-degree turn for the return leg. He indicated that he had been using carburetor heat without problems and noted no engine performance problems during the flight. He executed a left turn at 75 miles per hour utilizing two "notches" (20 degrees) of flaps. During the turn he noted a loss of altitude and compensated with power. As the sink rate continued he raised the flaps to one "notch" (10 degrees) and applied full power. He indicated that the sink rate continued and reported in his interview that it "felt like the aircraft was getting sucked down." He reported that as the turn progressed he could see trees and rising terrain ahead, which he tried to avoid. And, that when he determined impact was unavoidable he pulled back on the control column to execute a controlled stall into the trees (refer to NTSB Form 6120.1/2 and ATTACHMENT PI-I). The pilot provided a diagram showing his track over the ground superimposed on a topographic map of the vicinity of the accident site (refer to NTSB Form 6120.1/2). This diagram, along with CHART I (attached) showed the aircraft commencing its left turn about two nautical miles east of Concrete and turning towards rising terrain. The gradient of the terrain rise to the north (direction of the turn) was considerably steeper than the gradient to the south. The pilot also reported that he believed he had encountered a severe downdraft in the vicinity of the accident site. ## Aircraft - Registration: C-FISS (not matched to a registry record) - Reported make and model: Cessna 172 - Category: Airplane - Serial number: 28779 - Airframe hours: 3294 - Engines: Lycoming O-360-A1A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Dick, Lawrence - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 21, 2001, 21 hours before - Departed: YNJ, LANGLEY, BC - Destination: YCW, CHILLIWAK, BC ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; medical: class 1, valid medical--no waivers/lim.; last flight review February 15, 2002; seat: left; flight hours: 4,000 total, 1,000 in this make and model, 3,500 as pilot in command, 60 in the last 90 days, 26 in the last 30 days ## Weather - Conditions: Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 2,400 ft overcast - Temperature: 36 °F, dew point 36 °F - Altimeter: 30.20 inHg - Observed at: AWO, 29 nm away ## Docket (3 files) The files NTSB released with the investigation on December 20, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54239. 2.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40389114&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Attachment PI-I (item 2, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40173692&FileExtension=.PDF&FileName=Attachment%20PI-I-Master.PDF - Chart I (item 3, .PDF, 196 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40173693&FileExtension=.PDF&FileName=Chart%20I-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.