# NTSB WPR13CA325: Boeing E75, N5176N, Bozeman, MT, July 14, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 14, 2013, 09:30 local (15:30 UTC) - Place: Bozeman, MT - Coordinates: 45.7775, -111.151947 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.7775&lon=-111.1519&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of lift](https://openairdocs.org/ntsb-events/500) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 12, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 87473 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13CA325 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87473/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87473 - Page: https://openairdocs.org/ntsb/WPR13CA325 ## Probable cause The pilot’s failure to maintain adequate airspeed during a turn, which resulted in a loss of lift and collision with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Boeing E75, 3 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=1380120), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=1380120), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Boeing E75, 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1380120), [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. - [Initial climb: Loss of lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Boeing E75, 1 case](https://openairdocs.org/ntsb-events/500/sequence.md?model=1380120), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Boeing E75, 3 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1380120), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Initial climb: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Boeing E75, 8 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1380120), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he and the pilot-rated passenger, departed from the turf runway in calm wind conditions. During the initial climb, the airplane’s climb rate was not as expected and he attributed this degraded climb performance to likely being the result of the addition of the passenger’s weight. Upon reaching 200 feet above ground level (agl), the pilot began a 180-degree turn to the north in an effort to gain altitude while avoiding maneuvering over obstacles and a more densely populated area. As the airplane entered the bank, the pilot felt a degradation in performance despite indications that both the engine power and airspeed were adequate. The airplane was not maintaining altitude and in an effort to avoid colliding into a subdivision, the pilot increased the bank angle. The airplane subsequently collided into terrain and came to rest in a ditch adjacent to the airport’s perimeter fence. During the accident sequence the airplane sustained damage to the wings and empennage. The pilot further stated that he believed the airplane’s descent during the turn was a result of either of the following: a downdraft, too high angle-of-attack attitude, or possible decrease in engine power output. He reported no mechanical malfunctions or failures with the airplane that would have precluded normal operation. The passenger opined that the accident was a result of the airspeed being too slow for the steep bank angle. ## Factual narrative The pilot reported that he and the pilot-rated passenger, departed from the turf runway in calm wind conditions. During the initial climb, the airplane’s climb rate was not as expected and he attributed this degraded climb performance to likely being the result of the addition of the passenger’s weight. Upon reaching 200 feet above ground level (agl), the pilot began a 180-degree turn to the north in an effort to gain altitude while avoiding maneuvering over obstacles and a more densely populated area. As the airplane entered the bank, the pilot felt a degradation in performance despite indications that both the engine power and airspeed were adequate. The airplane was not maintaining altitude and in an effort to avoid colliding into a subdivision, the pilot increased the bank angle. The airplane subsequently collided into terrain and came to rest in a ditch adjacent to the airport’s perimeter fence. During the accident sequence the airplane sustained damage to the wings and empennage. The pilot further stated that he believed the airplane’s descent during the turn was a result of either of the following: a downdraft, too high angle-of-attack attitude, or possible decrease in engine power output. He reported no mechanical malfunctions or failures with the airplane that would have precluded normal operation. The passenger opined that the accident was a result of the airspeed being too slow for the steep bank angle. ## Aircraft - Registration: [N5176N](https://openairdocs.org/aircraft/N5176N), registered now, S/N 75-5379 (OpenAirDocs) - Reported make and model: BOEING E75 - Registry model: [Boeing E75](https://openairdocs.org/model/boeing-e75) (registry code 1380120) (OpenAirDocs) - Registry engine: [Lycoming R680](https://openairdocs.org/engine/lycoming-r680) (registry code 41540, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 75-5379 - Engines: LYCOMING R680 215 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Aerobatic - Departed: BZM, Bozeman, MT - Destination: BZM, Bozeman, MT - Flight plan: Unknown - Airport: BZM, Bozeman Yellowstone, runway 11, 3,197 × 80 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; flight hours: 1,780 total, 611 in this make and model ## Weather - Conditions: Visual (VMC), Day - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 48 °F - Altimeter: 30.21 inHg ## 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 20130714011209A](https://openairdocs.org/incident/20130714011209A), Jul 14, 2013: Boeing E75, Bozeman, MT, Substantial damage. On July 14, 2013, at 0930 MDT, a Boeing E-75 (stearman), N5176N, struck the ground and entered an irrigation ditch just east of the Bozeman, Montana airport,… ## Other investigations on N5176N (1) 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. - [NTSB SEA92LA171](https://openairdocs.org/ntsb/SEA92LA171), Aug 1, 1992: Boeing B-75 (N5176N), Three Forks, MT, substantial damage. Probable cause: THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL. FACTORS INCLUDE A CROSSWIND GUST. ## Docket (1 files) The files NTSB released with the investigation on September 10, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87473. 2.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40399367&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.