# NTSB CEN16LA256: Gulfstream American AA 5, N26908, Cheyenne, WY, July 7, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 7, 2016, 11:55 local (17:55 UTC) - Place: Cheyenne, WY - Coordinates: 41.159442, -104.817497 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.1594&lon=-104.8175&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 20, 2017 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 93563 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN16LA256 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93563/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93563 - Page: https://openairdocs.org/ntsb/CEN16LA256 ## Probable cause The airplane’s encounter with low-level wind shear during takeoff, which resulted in an off-airport landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Aircraft capability: climb capability](https://openairdocs.org/ntsb-findings/01061010): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Gulfstream American AA-5A, 1 case](https://openairdocs.org/ntsb-findings/01061010/cases.md?model=3970104), [All aircraft, 183 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md) - [Wind: windshear](https://openairdocs.org/ntsb-findings/03034020): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Gulfstream American AA-5A, 1 case](https://openairdocs.org/ntsb-findings/03034020/cases.md?model=3970104), [All aircraft, 90 cases](https://openairdocs.org/ntsb-findings/03034020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) (defining event); cases with it: [Gulfstream American AA-5A, 1 case](https://openairdocs.org/ntsb-events/390/sequence.md?model=3970104), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Gulfstream American AA-5A, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3970104), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The flight instructor and student pilot were departing on an instructional cross-country flight when, just after takeoff, the airplane encountered wind and turbulence. The instructor had difficulty maintaining altitude and elected to perform an off-airport precautionary landing, during which the right wing sustained substantial damage. A weather study revealed conditions conducive to low-level wind shear and turbulence at the accident site at the time of the accident. Although the instructor had received an abbreviated weather briefing before departure, the briefing did not advise of the potential for low-level wind shear. It is likely that the encounter with wind shear during departure made it difficult for the airplane to maintain altitude. ## Factual narrative On July 7, 2016, about 1155 mountain daylight time, a Gulfstream American CORP AA-5A airplane, N26908, was substantially damaged during a forced landing after departing Cheyenne Regional Airport/Jerry Olson Field (KCYS), Cheyenne, Wyoming. The flight instructor and student pilot were not injured. The instructional flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and a visual flight rules flight plan had been filed for the flight. The flight was originating at the time of the accident and was en route to Eppley Airfield (KOMA), Omaha, Nebraska. The flight instructor stated that the takeoff was normal; however, at the departure end of the runway, between 300 and 400 feet above the ground, "the wind started blowing from all directions" and he had difficulty maintaining control of the airplane. The flight instructor had difficulty maintaining altitude and elected to land the airplane on the road next to a school. During the landing roll, the flight instructor maneuvered the airplane to avoid hitting construction workers directly ahead of him. The right wing hit a construction sign and was substantially damaged. The pilot stated that there were no mechanical anomalies with the airplane or engine at the time of the accident. A weather study was conducted by a meteorologist with the National Transportation Safety Board. The National Weather Service charts depicted a low pressure system over southeast Wyoming and a mid-level trough just west of the accident site. Winds at the 700-hPa level were westerly around 10 knots, whereas winds at the 500-hPa level increased to 60 knots. There were no AIRMETs, SIGMETs, or center weather advisories valid for the accident site at the time of the accident. One PIREP in the area reported moderate "chop" between 6,500 feet and 8,500 feet mean sea level. The terminal aerodrome forecast valid at the time of the accident forecast winds from 300° at 12 knots gusting to 20 knots. Cheyenne Regional Airport had the closest official weather station to the accident site, 2 miles south-southeast of the accident location. The observation taken at 1153 reported wind 090° at 9 knots, and clear skies. The observation taken at 1208, after the accident, reported wind from 090° at 7 knots. The closest non-official surface observation site (5 miles west of the accident site) reported wind from 274° with gusts to 19 knots at 1215. Weather service radar depicted a dry-line boundary at the accident site, at the time of the accident. Wind speed and direction changed with altitude associated with this dry-line boundary and would have had a corresponding increase in low-level turbulence and low-level wind shear. A search of official weather briefing sources revealed that the flight instructor contacted Lockheed Martin Flight Service at 0853 on the morning of the accident and received an abbreviated briefing for the flight from Rock Springs, Wyoming, to Cheyenne,Wyoming. There was no record of the flight instructor receiving or retrieving any additional weather information before the accident flight. ## Aircraft - Registration: [N26908](https://openairdocs.org/deregistered/N26908-2018-02-27), registration cancelled 2018-02-27, S/N AA5A0805, built 1979 (OpenAirDocs) - Reported make and model: GULFSTREAM AMERICAN CORP AA 5 (A) - Registry model: [Gulfstream American AA-5A](https://openairdocs.org/model/gulfstream-american-aa-5a) (registry code 3970104) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: AA5A0805 - Year built: 1979 - Airframe hours: 2710 - Engines: LYCOMING 0-320 E2G 150 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Tomorrows Aeronautical Museum - Registered owner: Tomorrows Aeronautical Museum - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 7, 2016 - Departed: CYS, Cheyenne, WY - Destination: MDW, Chicago, IL - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 62; injuries: none; commercial, flight instructor, flight engineer; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 4, 2014; seat: right; restraint: 3-point; flight hours: 17,786 total, 123 in this make and model, 9,555 as pilot in command, 120 in the last 90 days, 27 in the last 30 days, 8 in the last 24 hours - Student pilot; age 16; injuries: none; seat: left; restraint: 3-point; flight hours: 8 total, 8 in this make and model, 0 as pilot in command, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 39 °F - Altimeter: 30.10 inHg - Observed at: CYS, 2 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 20160707010859A](https://openairdocs.org/incident/20160707010859A), Jul 7, 2016: Gulfstream American Corp AA-5A, Cheyenne, WY, Substantial damage. On 07/07/2016 at 1050 MDT, N26908, a Grumman cheetah AA-5A, impacted the ground approximately 1.5 miles northwest of cheyeene regional airport (cys). There… ## Docket (11 files) The files NTSB released with the investigation on April 21, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93563. 70.7 MB in all. - Pilot's Email Statement (item 1, .PDF, 97 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451354&FileExtension=.PDF&FileName=Pilot%27s%20Email%20Statement-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 473 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451355&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Weather Study Report (item 3, .PDF, 5.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451356&FileExtension=.PDF&FileName=Weather%20Study%20Report-Master.PDF - Weather Attachment 1 (item 4, .PDF, 163 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451357&FileExtension=.PDF&FileName=Weather%20Attachment%201-Master.PDF - Weather Attachment 2 (item 5, .GIF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451358&FileExtension=.gif&FileName=Weather%20Attachment%202-Master.gif - Weather Attachment 3 (item 6, .GIF, 28.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451359&FileExtension=.gif&FileName=Weather%20Attachment%203-Master.gif - Weather Attachment 4 (item 7, .GIF, 7.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451360&FileExtension=.gif&FileName=Weather%20Attachment%204-Master.gif - Weather Attachment 5 (item 8, .GIF, 20.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451361&FileExtension=.gif&FileName=Weather%20Attachment%205-Master.gif - Weather Attachment 6 (item 9, .PDF, 20 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451362&FileExtension=.PDF&FileName=Weather%20Attachment%206-Master.PDF - Weather Attachment 7 (item 10, .PDF, 327 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451363&FileExtension=.PDF&FileName=Weather%20Attachment%207-Master.PDF - Weather Attachment 8 (item 11, WAV, 6.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40451364&FileExtension=wav&FileName=Weather%20Attachment%208-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.