# NTSB LAX96LA005: Piper J3C-65, N59931, Tucson, AZ, October 9, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 9, 1995, 09:30 local (16:30 UTC) - Place: Tucson, AZ - Coordinates: 32.14965, -110.930145 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.1497&lon=-110.9301&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 29, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 29304 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX96LA005 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29304/pdf - Page: https://openairdocs.org/ntsb/LAX96LA005 ## Probable cause fuel starvation due to swelling of the carburetor needle valve tip, which restricted the fuel flow to the carburetor inlet. A factor in the accident was the use of automotive gasoline. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, takeoff - initial climb - fluid,fuel - automotive (contributing factor) - fuel system,carburetor - restricted (cause) - fluid,fuel - starvation (cause) - Forced landing, emergency landing after takeoff - In flight collision with object, emergency landing after takeoff - object - tree(s) ## Analysis During the takeoff initial climb, the engine lost power and the airplane collided with trees short of the intended forced landing area. Examination of the airplane revealed that it was using automotive gasoline. During a test run the engine operated at full rpm, then began to lose power output (300 to 400) rpm. Carburetor heat was applied, and the engine gained partial return of power. When the carburetor heat was removed, the engine returned to the previous running condition. A float level problem was suspected, and the carburetor was sent out for analysis at an overhaul shop. The aircraft owner subsequently decided to replace the carburetor with a different type, and the accident carburetor was lost in the overhaul process. Information Letter 8401 (12/15/84) from the EAA advises of a long standing problem with rubber tipped needle valves which swell when exposed to automotive fuels. The letter states that slow degeneration of in-flight engine power has been observed when the rubber needle valve tips swell and decrease the orfice size at the carburetor inlet. Sudden losses of power have also been reported during takeoffs in aircraft following a long period of inactivity. ## Factual narrative On, October 9,1995, at 0930 hours mountain standard time, a Piper J3C-65, N59931, collided with trees following a power loss during the takeoff and initial climb from Ryan Field, Tucson, Arizona. The aircraft was owned and operated by the pilot and was beginning a local area personal flight at the time. No flight plan was filed and visual meteorological conditions prevailed. The aircraft incurred substantial damage. The certificated recreational pilot, the sole occupant, was not injured. The pilot stated that after completing a preflight check he entered runway 33 for a normal takeoff at full power. At an altitude between 50 and 100 feet, the engine lost power and the pilot began a gentle right-hand bank with intentions of landing in a grassy area parallel to the runway. The pilot further stated that he attempted to maintain flying speed and landed short of the intended grassy area. The aircraft sustained substantial damage to the left wing, landing gear, and fuselage. There was no postcrash fire. FAA airworthiness inspectors examined the aircraft and determined that the aircraft was utilizing automotive gasoline and there were 5 gallons of fuel available in the tanks. The fuel selector was found in the off position. The pilot stated that he never used the fuel shut-off and assumed that the airport people shut off the fuel on the day of the accident. The FAA inspector turned the fuel selector on and got good fuel flow at the carburetor. A postaccident engine run was conducted by FAA airworthiness inspectors. They found the that the engine started and operated at full rpm, then began to loose power output (300 to 400) rpm. The inspector applied the carburetor heat and the engine gained partial return of power. When the carburetor heat was removed from the engine, it returned to the to the previous running condition. The inspector stated that he suspected a float level problem and sent the carburetor out for analysis at an overhaul shop. The aircraft owner subsequently decided to replace the carburetor with a different type and the accident carburetor was lost in the overhaul process. Information Letter 8401 (12/15/84) from the Experimental Aircraft Association advises of a long standing problem with rubber tipped needle valves which swell when exposed to automotive fuels. The letter states that slow degeneration of inflight engine power has been observed when the rubber needle valve tips swell and decrease the orfice size at the carburetor inlet. Sudden losses of power have also been reported during takeoffs in aircraft following a long period of inactivity. ## Aircraft - Registration: N59931 (not matched to a registry record) - Reported make and model: PIPER J3C-65 - Category: Airplane - Serial number: 8472 - Airframe hours: 5035 - Engines: CONTINENTAL A-65-8 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Robert P. Nelson - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 24, 1995, 122 hours before - Departed: RYN - Airport: RYN, Ryan Field, runway 33, 3,547 × 75 ft, dirt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: rear; flight hours: 705 total, 542 in this make and model, 602 as pilot in command, 38 in the last 90 days, 10 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 84 °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 19951009037079A](https://openairdocs.org/incident/19951009037079A), Oct 9, 1995: Piper J3C65, Tucson, AZ, Substantial damage. Lost power on takeoff. Collided with trees. Used auto fuel. Carb needle valve swelled. Cut fuel flow. Selector off 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.