# NTSB FTW96LA392: Beech H35, N5428D, Boulder, CO, September 19, 1996 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 19, 1996, 17:15 local (23:15 UTC) - Place: Boulder, CO - Coordinates: 40.019187, -105.250396 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.0192&lon=-105.2504&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report March 31, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 19983 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW96LA392 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19983/pdf - Page: https://openairdocs.org/ntsb/FTW96LA392 ## Probable cause a loss of engine power due to a plugged fuel tank vent which resulted in fuel starvation. A factor was the lack of suitable terrain for the forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, takeoff - initial climb - fluid,fuel - starvation (cause) - fuel system,vent - blocked(total) (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency descent/landing - terrain condition - none suitable (contributing factor) - terrain condition - rough/uneven ## Analysis At an altitude of 200 feet above ground level, following a touch and go landing, a total loss of power occurred and a forced landing was conducted on rough and uneven terrain. Examination of the aircraft provided evidence that the left fuel tank, which had been selected, had a totally blocked fuel vent due to a mud based insect nest. The nest was internal in the vent and could not be seen during normal inspection. The aircraft had not been flown in 20 days prior to the accident flight. ## Factual narrative On September 19, 1996, at 1715 mountain daylight time, a Beech H35, N5428D, made a forced landing due to a loss of power 1 mile north of Boulder Municipal Airport (1V5), Boulder, Colorado. The private pilot and his passenger received minor injuries and the aircraft sustained substantial damage. Visual meteorological conditions prevailed for this local area personal flight conducted under Title 14 CFR Part 91 and no flight plan was filed. The flight departed 1V5 earlier in the afternoon. According to the pilot, he was at 200 feet above ground level (agl) off the departure end of runway 8, following a touch-and-go landing, when the engine lost power. He said he turned left toward an open field and conducted a forced landing with the landing gear down and 10 degrees of flaps selected. His statement said he struck a small ditch during landing roll and the nose landing gear collapsed. The aircraft slid on its nose across rocky/rough terrain and the engine separated before the aircraft came to a stop. The pilot and his passenger exited through the right rear window because the cabin door was jammed. They incurred minor injuries during impact and egress. In a telephone interview, the pilot said he had approximately 10 gallons of fuel in the left tank and had selected that tank to feed the engine a short time before power was lost. Examination of the aircraft by an FAA inspector provided verification that the left tank was selected. Due to wing damage, fuel quantity could not be verified. The FAA inspector said both propeller blades were bent rearward and bore both longitudinal and chordwise gouges and scratches. Both blades had leading edge damage and the ground contained propeller slash marks. Examination of the engine provided no evidence of mechanical preimpact failure or malfunction and examination of the fuel system provided evidence that the left tank vent was plugged with a material that had the appearance and consistency of a mud constructed insect nest. The vent tube was totally plugged and the material was not visible while conducting a normal inspection of the tube. According to available information, the aircraft had been flown 17 hours in the last 90 days, 1.7 hours in the last 30 days, and the accident flight was the first flight in the last 20 days, with takeoff and flight, until shortly before the accident, conducted with the right fuel tank selected. ## Aircraft - Registration: [N5428D](https://openairdocs.org/deregistered/N5428D-2014-10-27), registration cancelled 2014-10-27, S/N D-4934, built 1957 (OpenAirDocs) - Reported make and model: Beech H35 - Registry model: [Beech H35](https://openairdocs.org/model/beech-h35) (registry code 1151520) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: D-4934 - Airframe hours: 3921 - Engines: Continental O-470-G 240 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Jorge A. Newberry - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 1, 1996, 40 hours before - Departed: 1V5 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; private; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 1,343 total, 213 in this make and model, 1,317 as pilot in command, 17 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 14 knots, gusting 22 - Visibility: 75 statute miles - Lowest ceiling: 15,000 ft broken - Temperature: 59 °F, dew point 37 °F - Altimeter: 30.00 inHg - Observed at: BJC, 15 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 19960919028709A](https://openairdocs.org/incident/19960919028709A), Sep 19, 1996: Beech H35, Boulder, CO, Substantial damage. Aircraft practicing touch and go landings. Experienced engine failure just after takeoff, crashed. ## Other investigations on N5428D (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 OAK67D0218](https://openairdocs.org/ntsb/OAK67D0218), Jan 15, 1967: Beech A35 (N5428D), Visalia, CA, substantial damage 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.