# NTSB WPR14LA133: Peter W Stevens Bearhawk Patrol, N123WW, Salt Lake City, UT, March 8, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 8, 2014, 13:30 local (19:30 UTC) - Place: Salt Lake City, UT - Coordinates: 40.619445, -111.992774 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.6194&lon=-111.9928&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 21, 2016 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 88901 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR14LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88901/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88901 - Page: https://openairdocs.org/ntsb/WPR14LA133 ## Probable cause The pilot’s failure to maintain directional control during the landing roll. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Peter W Stevens BEARHAWK PATROL, 1 case](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=05632FC), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Peter W Stevens BEARHAWK PATROL, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05632FC), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Peter W Stevens BEARHAWK PATROL, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=05632FC), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Peter W Stevens BEARHAWK PATROL, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=05632FC), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot reported that, during the landing roll, the airplane slowed to about 10 to 15 mph as it came abeam four helicopters on a taxiway. The pilot further reported that the airplane's left side encountered a sudden blast of air and that the left wing lifted; he attributed the blast of air to rotor wash from the helicopters. The airplane spun hard to the right, exited the runway into a dirt area, and then stopped facing 180 degrees in the opposite direction. The left wing tip struck the ground during the excursion and sustained substantial damage. The pilot reported no mechanical malfunctions or failures with the airplane that would have precluded normal operation. The four pilots in the helicopters on the taxiway were conducting engine health indicator test checks using 30 percent power with two engines operating and 60 percent power with one engine operating, which was about half the power needed to hover. Federal Aviation Administration guidance advised pilots of small aircraft operating around helicopters to avoid operating within about three times the diameter of the helicopters' main rotor blades. The distance between the airplane and the helicopters when the airplane passed them abeam was calculated to be about 400 ft, which was over six diameters away; therefore, helicopter rotor wash likely did not contribute to the pilot's loss of directional control. ## Factual narrative On March 8, 2014, about 1330 mountain daylight time, a Peter W Stevens Bearhawk Patrol, N123WW, had a runway excursion during the landing roll at South Valley Regional Airport, Salt Lake City, Utah. The owner/pilot was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot was not injured; the airplane sustained substantial damage to the left wing. The cross-country personal flight departed Bountiful, Utah, at 1315. Visual meteorological conditions (VMC) prevailed, and no flight plan had been filed. The pilot reported that he landed on runway 34. He observed five Blackhawk helicopters hovering in formation on taxiway Bravo. The airplane had slowed to 10-15 miles per hour as it came abeam the helicopters. The pilot said that the left side of the airplane encountered a sudden blast of air, and the left wing lifted. The airplane spun hard to the right, exited the runway into a dirt area, and stopped facing 180 degrees in the opposite direction. The left wing tip struck the ground during the excursion, and sustained substantial damage. The pilot attributed the wind gust to the rotorwash from the helicopters. A Federal Aviation Administration (FAA) inspector determined that there were four helicopters on taxiway Bravo that were doing engine Health Indicator Test (HIT) checks. They were using 30 percent power with two engines operating, and 60 percent with one engine operating, which was about 1/2 the power needed to hover. The inspector used scaled airport construction diagrams to calculate that the distance from the helicopters to the airplane's location when it passed abeam was about 400 feet. The FAA Aeronautical Information Manual Section 7-3-7 and Advisory Circular AC 90-23G paragraph 10 stated that if a helicopter was in a stationary hover near the surface, the main rotors generated downwash producing high velocity outwash vortices to a distance of approximately three times the diameter of the rotor. They advised pilots of small aircraft to avoid operating within that distance. The diameter of the Blackhawk's main rotor blades was 53 feet 8 inches; three diameters computed to 176 feet. Wind reported at the nearest recording station was 360 degrees at 5 knots. ## Aircraft - Registration: [N123WW](https://openairdocs.org/deregistered/N123WW-2018-10-05), registration cancelled 2018-10-05, S/N P002-P05/P06-123, built 2013 (OpenAirDocs) - Reported make and model: PETER W STEVENS BEARHAWK PATROL - Registry model: [Peter W Stevens BEARHAWK PATROL](https://openairdocs.org/model/peter-w-stevens-bearhawk-patrol) (registry code 05632FC) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: P002-P05/P06-12 - Year built: 2013 - Airframe hours: 46 - Engines: ECI OX-360-H4A1N 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Stevens Peter W - Registered owner: Stevens Peter W - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, April 15, 2013 - Departed: KBTF, Bountiful, UT - Destination: U42, Salt Lake City, UT - Airport: U42, South Valley Regional, runway 34, 5,862 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 78; injuries: none; private, commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 25, 2013; seat: front; restraint: 3-point; flight hours: 1,812 total, 46 in this make and model, 1,812 as pilot in command, 29 in the last 90 days, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 28 °F - Altimeter: 30.37 inHg - Observed at: KSLC, 10 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 20140308002009A](https://openairdocs.org/incident/20140308002009A), Mar 8, 2014: Peter W Stevens BEARHAWK PATROL, West Jordan, UT, Substantial damage. Pilot stated the wind was dead calm and he was struck by the 5 blackhawks rotor wash, and the helicopters were on the ground. There were 4 blackhawks were on… ## Docket (2 files) The files NTSB released with the investigation on December 10, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88901. 2.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434795&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Inspector's Statement (item 2, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434796&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement-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.