Individually Owned: 150,657
Corporate Owned: 137,281
Mammoth Lakes Airport
Aircraft Accident/Incident Report
Mammoth Lakes, California 93546
Sunday, April 28, 1996 13:45 PDT
NTSB Narrative Summary Released at Completion of Accident
The pilot performed a static engine run-up, and with no discrepancies noted, he commenced the takeoff. Upon reaching between 25 and 50 feet above the runway during the initial climb, the normal 35 inches of manifold pressure (MP) was observed being produced by the left engine. However, the right engine only produced between 18 and 20 inches of MP. The airplane veered right and settled into the rough/uneven terrain near the airport. The airport's elevation is 7,128 feet mean sea level, and the calculated density altitude was over 8,200 feet. An examination of the right engine's turbocharger assembly revealed the absolute pressure controller was set lower than the manufacturer's specifications required. Also, the wastegate butterfly valve was mechanically binding in its housing and would not fully close.
NTSB Probable Cause Narrative
the partial failure of the right engine turbocharger wastegate butterfly valve to fully close due to mechanical binding and the low setting of its associated absolute pressure controller. A related factor was the high density altitude which reduced the engine's ability to produce adequate manifold pressure.
Event Information
| Type of Event | Accident |
| Event Date | 4/28/1996 |
| Event Day of the Week | Sunday |
| Time of Event | 1345 |
| Event Time Zone | Pacific Daylight Time |
| Event City | MAMMOTH LAKES |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93546 |
| Event Date Year | 1996 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | MAMMOTH LAKES |
| Event Location Nearest Airport ID | MMH |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 1 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 7128 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1350 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 270 |
| Weather Observation Facility ID | MMH |
| Elevation of weather observation facility | 7128 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| 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) | 14 |
| Dew Point at event time (in degress fahrenheit) | -10 |
| Wind Direction (degrees magnetic) | 110 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| 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 | 3 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 737 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 29 1996 12:00AM |
| NTSB Notification Time | 820 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 9:57AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N5752X |
| NTSB Number | LAX96LA180 |
| 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 | Cessna |
| Aircraft Model | 320 |
| Aircraft Series Identifier | 320 |
| Aircraft Serial Number | 320-0052 |
| Certified Max Gross Weight | 5200 |
| 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 | 4 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Mar 4 1996 12:00AM |
| Airframe hours since last inspection | 231 |
| Airframe Hours | 3059 |
| ELT Installed | Unknown |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | MAYNARD L. JENKINS, JR. |
| Aircraft Owner Street Address | 14985 OSBORNE CT. |
| Aircraft Owner City | MORGAN HIL |
| Aircraft Owner State | CA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 95037 |
| Operator is an individual? | -- |
| Operator Name | |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 978 HAMPSWOOD WAY |
| Operator City | SAN JOSE |
| Operator State | CA |
| Operator Country | |
| Operator Zip code | 95120 |
| 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 | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | MMH |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1345 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | Q99 |
| Destination City | SAN MARTIN |
| Destination State | CA |
| Destination Country | |
| Specific Phase of Flight | Takeoff |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 9 |
| Runway Length | 7000 |
| Runway Width | 100 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |