Ryan Field Airport
Aircraft Accident/Incident Report

Tucson, Arizona 85706
Monday, October 9, 1995 9:30 MST

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

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.

Event Information

Type of Event Accident
Event Date 10/9/1995
Event Day of the Week Monday
Time of Event 930
Event Time Zone Mountain Standard Time
Event City TUCSON
Event State ARIZONA
Event Country --
Zipcode of the event site 85706
Event Date Year 1995
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport RYAN FIELD
Event Location Nearest Airport ID RYN
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 2415
Weather Briefing Completeness Unknown
Investigator's weather source Witness
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 13000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 50
Air Temperature at event time (in degrees celsius) 29
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1689
NTSB Notification Source --
NTSB Notification Date Oct 9 1995 12:00AM
NTSB Notification Time 1050
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 7 2000 4:39PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N59931
NTSB Number LAX96LA005
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name PIPER
Aircraft Model J3C-65
Aircraft Series Identifier J3C-65
Aircraft Serial Number 8472
Certified Max Gross Weight 1220
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Feb 24 1995 12:00AM
Airframe hours since last inspection 122
Airframe Hours 5035
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ROBERT P. NELSON
Aircraft Owner Street Address 3814 E. 4TH STREET, #224
Aircraft Owner City TUCSON
Aircraft Owner State AZ
Aircraft Owner Country
Aircraft Owner Zipcode 85716
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code RYN
Departure City
Departure State
Departure Country
Departure Time 930
Departure Time Zone MST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Takeoff
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 33
Runway Length 3547
Runway Width 75
Sight Seeing flight No
Air Medical Flight No
Medical Flight --