# NTSB LAX92FA257: Waco UPF-7, N29926, Sedona, AZ, June 23, 1992 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: June 23, 1992, 11:25 local (18:25 UTC) - Place: Sedona, AZ - Coordinates: 34.939006, -111.940086 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.9390&lon=-111.9401&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal, 1 serious - Status: Completed, report June 30, 1993 - Report: Approved by Office Director - NTSB case key (mKey): 27436 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92FA257 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27436/pdf - Page: https://openairdocs.org/ntsb/LAX92FA257 ## Probable cause FUEL EXHAUSTION DUE TO THE PILOTS INADEQUATE PREFLIGHT PLANNING AND HIS FAILURE TO REFUEL THE AIRPLANE PRIOR TO DEPARTURE. FACTORS IN THE ACCIDENT WERE: 1) THE UNRELIABLE FUEL SIGHT GAUGES WHICH WERE CONTAMINATED WITH A TAR LIKE RESIDUE WHICH MAY HAVE PROVIDED AN ERRONEOUS INDICATION OF FUEL IN THE SYSTEM, 2) INADEQUATE AIRPLANE MAINTENANCE, AND, 3) THE UNSUITABLE TREE COVERED NATURE OF THE TERRAIN WHERE THE FORCED LANDING WAS ATTEMPTED. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - fluid,fuel - exhaustion (cause) - fuel system,fuel quantity float/sensor - unreliable (contributing factor) - aircraft preflight - inadequate, pilot in command (cause) - refueling - not performed, pilot in command (cause) - maintenance - inadequate, pilot in command (contributing factor) - Forced landing, descent - emergency - terrain condition - mountainous/hilly (contributing factor) - In flight collision with object, descent - emergency - object - tree(s) (contributing factor) - In flight collision with terrain/water, descent - uncontrolled ## Analysis THE PILOT WAS PROVIDING FOR HIRE SIGHTSEEING TOURS OF A SCENIC AREA OF SEDONA, ARIZONA, IN A VINTAGE BIPLANE. THE FRONT COCKPIT HAD BEEN MODIFIED TO ACCOMMODATE TWO PASSENGERS. NO RECORD OF AN APPROVED SEAT MODIFICATION IN ACCORDANCE WITH FACTORY SPECIFICATIONS OR A FAA FIELD APPROVAL WAS LOCATED. THE PILOT STATED THAT HE DEPARTED WITH 10 GALLONS OF FUEL ON BOARD FOR A 30 MINUTE TOUR. HE COULD NOT SAY HOW THE FUEL WAS DISTRIBUTED IN THE TANKS. HE ALSO SAID HE DID NOT USE A DIP STICK OR OTHER MEASURING DEVICE TO QUANTIFY THE FUEL LEVEL, BUT ESTIMATED THE TOTAL FUEL BASED ON CONSUMPTION ESTIMATES FROM PRIOR FLIGHTS. THE AIRPLANE HAS TWO 25 GALLON FUEL TANKS IN THE TOP WINGS WITH FLOAT SIGHT GAUGES UNDERWING. THE AIRCRAFT MAINTENANCE MANUAL STATES THAT 10 GALLONS OF FUEL IS THE MINIMUM REQUIRED FOR TAKEOFF IN THE TANK SELECTED. REGARDING THE SIGHT GAUGES, THE MANUAL STATES: 'AN ACCURATE READING CANNOT BE OBTAINED FROM THE GASOLINE GAUGES ON THE GROUND'. BOTH GAUGES WERE CONTAMINATED WITH A TAR LIKE SUBSTANCE ADHERING TO THE WIRE INDICATORS, WHICH RESEMBLED AN UNIDENTIFIED COATING FOUND INSIDE THE FUEL TANKS. EXAMINATION OF THE FUEL SYSTEM DISCLOSED THAT ONLY RESIDUAL FUEL REMAINED IN THE FUEL TANKS AND LINES TO THE ENGINE. FUEL SYSTEM CONTINUITY WAS ESTABLISHED. ## Aircraft - Registration: [N29926](https://openairdocs.org/aircraft/N29926), registered now, S/N 5423 (OpenAirDocs) - Reported make and model: WACO UPF-7 - Registry model: [Waco UPF-7](https://openairdocs.org/model/waco-upf-7) (registry code 9601302) (OpenAirDocs) - Registry engine: [Continental W670 series](https://openairdocs.org/engine/continental-w670-series) (registry code 17018, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 5423 - Engines: CONTINENTAL W670-6A 220 horsepower reciprocating - Damage: Destroyed - Flight: Part 91 - Operator: Out Of Arizona Biplane Tours - Registered owner: Ralph Ramsey DBA R&S Ent. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 23, 1992, 115 hours before - Departed: SEZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: rear; flight hours: 5,000 total, 146 in this make and model, 5,000 as pilot in command, 120 in the last 90 days, 80 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 40 statute miles - Lowest ceiling: 6,000 ft broken - Temperature: 84 °F, dew point -0 °F ## 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 19920623021529A](https://openairdocs.org/incident/19920623021529A), Jun 23, 1992: Waco UPF7, Sedona, AZ, Destroyed, 2 fatal. Engine quit on sightseeing flight. Struck trees landing in dry river bed. Fuel tanks were empty. Sludge in tanks. ## Other investigations on N29926 (2) 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 ATL91LA152](https://openairdocs.org/ntsb/ATL91LA152), Aug 5, 1991: Waco UPF-7 (N29926), Manning, SC, substantial damage. Probable cause: THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL DURING THE TAKEOFF ROLL, AND HIS FAILURE TO ABORT THE TAKEOFF IN A TIMELY MANNER ONCE THE AIRPLANE HAD DEPARTED THE RUNWAY SURFACE. A FACTOR IN THE… - [NTSB SEA77DYG10](https://openairdocs.org/ntsb/SEA77DYG10), Nov 20, 1976: Waco UPF-7 (N29926), Spokane, WA, 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.