# NTSB DEN02TA037: Douglas/Basler DC-3C, N115Z, Casper, WY, April 5, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: April 5, 2002, 08:45 local (15:45 UTC) - Place: Casper, WY - Coordinates: 42.908332, -106.46389 - Nearby events: https://openairdocs.org/map.md?lat=42.9083&lon=-106.4639&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report April 1, 2003 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 54488 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN02TA037 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54488/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54488 - Page: https://openairdocs.org/ntsb/DEN02TA037 ## Probable cause The copilot's inadvertent retraction of the landing gear. A contributing factor was the use of inappropriate medication by the copilot. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Gear retraction on ground, taxi - to takeoff - gear retraction - inadvertent, copilot/second pilot (cause) - use of inappropriate medication/drug, copilot/second pilot (contributing factor) ## Analysis The pilot said that the airplane had taxied out for departure on runway 3. He said that he and his copilot were completing the checklist for departure when the copilot noticed high hydraulic pressure on the landing gear system. The copilot began the landing gear pressure relief procedure, but instead performed the landing gear retraction procedure. The pilot called out to the copilot to intervene, but the left main landing gear had already commenced retracting. The airplane settled onto its left wing damaging several intercostal ribs and wrinkling the left wing's skin. The copilot said that he had taken two capsules of an over the counter medication (Benadryl Allergy) on the morning of the accident. This medication, known as diphenhydramine, commonly results in drowsiness, and has measurable effects on performance of complex cognitive and motor tasks. ## Factual narrative On April 5, 2002, at 0845 mountain standard time, a Douglas/Basler DC-3C, N115Z, was substantially damaged when its left main landing gear collapsed while standing at Natrona County International Airport, Casper, Wyoming. The airline transport pilot, the commercial copilot, and one passenger were not injured. The airplane was being operated by the U.S.D.A. Forest Service, Boise, Idaho, under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the public use cross-country flight that was preparing to originate at the time of the accident. An IFR flight plan had been filed. The pilot said that the airplane had taxied out for departure on runway 3. He said that he and his copilot were completing the checklist for departure when the copilot noticed high hydraulic pressure on the landing gear system. The copilot began the landing gear pressure relief procedure, but instead performed the landing gear retraction procedure. The pilot called out to the copilot to intervene, but the left main landing gear had already commenced retracting. The airplane settled onto its left wing damaging several intercostal ribs and wrinkling the left wing's skin. The copilot said that he had taken two capsules of an over-the-counter Federal Aviation Administration non-approved medication (Benadryl Allergy) on the morning of the accident. This medication, known as Diphenhydramine, commonly results in drowsiness, and has measurable effects on performance of complex cognitive and motor tasks. In Annals of Internal Medicine 2000; 132:354-363, states that the effect of a normal 50 mg dose of Diphenhydramine on simulated driving is noted to be worse than the effect of a 0.10% blood alcohol level. ## Aircraft - Registration: N115Z (not matched to a registry record) - Reported make and model: Douglas/Basler DC-3C - Category: Airplane - Serial number: 33567 - Airframe hours: 16433 - Engines: Pratt & Whitney PT6-67R 1281 horsepower turbo prop - Damage: Substantial damage - Flight: Public aircraft, Part 91 - Registered owner: U.S.D.A. Forest Service - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, February 8, 2002, 116 hours before - Departed: CPR, Casper, WY - Destination: MSO, Missoula, MT - Flight plan: IFR - Airport: CPR, Natrona County Intl Arpt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; last flight review March 8, 2002; seat: left; flight hours: 3,134 total, 461 in this make and model, 1,808 as pilot in command, 33 in the last 90 days, 33 in the last 30 days, 8 in the last 24 hours - Co-pilot; age 50; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review August 28, 2001; seat: right; flight hours: 3,562 total, 1,409 in this make and model, 1,794 as pilot in command, 92 in the last 90 days, 44 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC) - Wind: 0° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 39 °F, dew point 27 °F - Altimeter: 30.22 inHg - Observed at: CPR ## 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 20020405005579A](https://openairdocs.org/incident/20020405005579A), Apr 5, 2002: Doug DC3C, Casper, WY, No damage. (-23)As the aircraft was being prepared for take-off, the co-pilot noticed high hydraulic pressure on the landing gear. He attempted to relieve the pressure… ## Docket (4 files) The files NTSB released with the investigation on December 10, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54488. 533 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 343 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424526&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Supplement E (item 2, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40170722&FileExtension=.PDF&FileName=Supplement%20E-Master.PDF - Supplement S (item 3, .PDF, 29 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40170723&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Other Pertinent Forms and Reports - Email (item 4, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424527&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports%20-%20Email-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.