LAX96LA248

NTSB accident investigation · Cessna 150H · San Carlos, CA · June 27, 1996

Accident · Minor injuriesLimited investigationFinal report
Date
June 27, 1996, 12:42 local (19:42 UTC)
Place
San Carlos, CA
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N7260SCessna 150H
Weather
Visual (VMC) · Day
Status
Completed · report December 16, 1996
Report
Approved by Office Director
FAA report
19960627015409A
Case key
29485

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The failure of the flaps to retract due to the installation of an incorrect fuse and the inadequate maintenance/inspections performed on the system; and the pilot-in-command's failure to maintain an adequate airspeed while maneuvering for a forced landing, which resulted in an inadvertent stall/mush.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionTakeoff - initial climb
Electrical system,fuse - incorrectCause
Electrical system,fuse - corrodedCause
Maintenance,annual inspection - inadequateOther maintenance personnelCause
Flight control,flap - disabled
Raising of flaps - not possiblePilot in command
Forced landingEmergency landing after takeoff
Loss of control - in flightEmergency descent/landing
Airspeed - not maintainedPilot in commandCause
Stall/mush - inadvertentPilot in command
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The CFI stated that on the fifth touch and go the student landed, moved the flap selector to the up position, then added full power to takeoff. The student rotated and lifted off from the 2,600-foot-long runway just as the CFI realized that the flaps had not retracted. The flaps did not respond to repeated movement of the selector handle. At this point, the aircraft had passed the end of the runway and would not climb as the airspeed began to decay. The instructor said he attempted to land the aircraft in a clear area straight ahead; however, touched down hard and collapsed the nose gear. A ground witness observed the takeoff attempt of the aircraft and reported that after gaining about 100 feet of altitude it seemed to began losing altitude. The witness saw the flaps in the full down position and noted that the aircraft seemed to be slowing down and losing altitude at a more rapid rate. He said the aircraft nose rose, then the aircraft stalled and descended nose down to ground impact. Examination by an FAA airworthiness inspector revealed that the flaps were in the full down position. The flap system fuse in the cockpit was a 20 amp fast blow fuse and was found burned out. The parts manual specifies a 15 amp slow blow fuse. Corrosion deposits were found on the fuse and the fuse holder. No other discrepancies were found with the flap system. The fuse was replaced and the system functioned satisfactorily. An annual inspection was completed 1 month and 27 hours prior to the accident. The maintenance manual specifies that all fuses must be checked during each 50-hour and annual inspection. Cessna reported that during certification flight testing the Cessna 150H demonstrated the capability for a positive climb gradient of 175 feet per minute with full flaps at sea level on a standard day.

Factual narrative

On June 27, 1996, at 1242 hours Pacific daylight time, a Cessna 150H, N7260S, collided with the ground during a forced landing attempt from the takeoff initial climb at the San Carlos, California, airport. The forced landing was precipitated by a failure of the flaps to retract. The aircraft was operated by Transair of San Carlos, and was on a local area dual instructional flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft sustained substantial damage. The certificated commercial pilot/flight instructor and his dual primary student sustained minor injuries. The flight originated at San Carlos on the day of the accident at 1219 as a traffic pattern operation engaged in touch-and-go operations.

The instructor stated that they had performed four touch and go's in the traffic pattern. During the accident sequence, the student landed and moved the flap selector to the up position, then added full power to takeoff. The student rotated and lifted off from the 2,600-foot-long runway just as the instructor realized that the flaps had not retracted. The flaps did not respond to repeated movement of the selector handle. At this point, the aircraft had passed the end of the runway and would not climb as the airspeed began to decay. The instructor said he attempted to land the aircraft in a clear area straight ahead; however, touched down hard and collapsed the nose gear.

A ground witness observed the takeoff attempt of the aircraft and reported that after gaining about 100 feet of altitude it seemed to encounter a problem, then began losing altitude. The witness observed the flaps in the full down position and noted that the aircraft seemed to be slowing down and losing altitude at a more rapid rate. He said the aircraft nose rose, then the aircraft stalled and descended nose down to ground impact with the left wing and nose, followed by the right wing.

An examination of the aircraft by an FAA airworthiness inspector from the San Jose, California, Flight Standards District Office revealed that the flaps were in the full extended position. The flap system fuse in the cockpit was determined to be a 20 amp fast blow fuse and was found burned out. The Cessna Aircraft Parts Manual for the aircraft specifies a 15 amp slow blow fuse for the flap system. Corrosion deposits were found on the fuse and the fuse holder. Under the supervision of the inspector, company maintenance personnel conducted an inspection of the flap system and found no other discrepancies. The fuse was replaced and the system functionally checked in accordance with the Cessna maintenance manual. The flap system passed the functional check.

Review of the aircraft maintenance records disclosed that an annual inspection was completed 1 month and 27 hours prior to the accident. The Cessna Aircraft maintenance manual for the Cessna 150 specifies that all fuses must be checked during each 50-hour and annual inspection.

An engineering representative from Cessna Aircraft Company was contacted and he reported that during certification flight testing the Cessna 150H demonstrated the capability for a positive climb gradient with full flaps. At sea level on a standard day, and at gross weight, the aircraft is capable of 175 feet per minute.

Aircraft

Registration
N7260S
Reported as
Cessna 150H
Category
Airplane
Serial number
15067960
Airframe hours
4,890
Engine
Continental O-200A, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Transair
Registered owner
Timothy J. Graf
Airworthiness certificate
Standard, Normal
Last inspection
Annual · May 3, 1996 · 27 hours before
Departed
SQL
Airport
SQL · San Carlos, runway 30, 2,600 × 75 ft, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
30
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Right
Flight hours
440 total · 3 in this make and model · 350 as pilot in command · 168 in the last 90 days · 41 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
340° at 7 knots
Visibility
40 statute miles
Lowest ceiling
None
Temperature
68 °F, dew point 52 °F
Altimeter
30.00 inHg
Observed at
SQL, 1 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.