ATL02LA145

NTSB accident investigation · Cessna 150H · Senoia, GA · July 28, 2002

Accident · No injuriesLimited investigationFinal report
Date
July 28, 2002, 09:06 local (13:06 UTC)
Place
Senoia, GA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N6486SCessna 150H
Weather
Visual (VMC) · Day
Status
Completed · report April 15, 2003
Report
Approved by Office Director
Parties
FAA - Atlanta FSDO - 11
Case key
55331

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 certificated flight instructor's failure to follow published procedures for the application of carburetor heat, which resulted in a loss of engine power due to carburetor ice formation, and subsequent collision with trees during the forced landing. A factor was the lack of suitable terrain for landing.

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.

Loss of engine power(total) - nonmechanicalManeuvering
Fuel system,carburetor - ice
Carburetor heat - not usedPilot in command(cfi)Cause
Procedures/directives - not followedPilot in command(cfi)Cause
Forced landingEmergency descent/landing
In flight collision with objectEmergency landing
Terrain condition - none suitable
Object - tree(s)Factor

Analysis

The student pilot and flight instructor performed a simulated engine failure with power at idle. When the throttle was advanced to recover from the descent, the engine did not respond. Attempts to restore engine power were not successful. During the forced landing, the airplane collided with trees. The flight instructor stated carburetor heat was used; the student pilot stated carburetor heat was not used. Examination of the wreckage revealed the tail section was separated, both wingtips displayed crush damage, and fuel was recovered. Examination of the engine revealed no defects that would have prevented normal operation. A review of induction icing probability curves reveals the temperature and dew point reported at the time of the accident fall within the "serious icing, glide power" range. The Owner's Manual for the Cessna 150 states the procedures for descent are as follows: 1. Mixture - rich, 2. Carburetor Heat - apply full heat before closing throttle.

Factual narrative

On July 28, 2002, at 0906 eastern daylight time, a Cessna 150H, N6486S, registered to Griffin Flight School, Inc., and operated by Peachtree Flight Center, collided with trees during a forced landing in Senoia, Georgia. The instructional flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual meteorological conditions prevailed at the time of the accident. The certificated flight instructor and the student pilot reported no injuries, and the airplane sustained substantial damage. The local flight departed Peachtree City Falcon Field in Peachtree City, Georgia, at 0830.

The flight instructor stated the student was performing a simulated engine failure with power at idle and had descended from 2,500 feet above mean sea level to 500 feet above the ground. When the throttle was advanced to recover from the descent, the engine did not respond. Attempts by the flight instructor to restore engine power were not successful. The flight instructor maneuvered the airplane for a forced landing, and it collided with a stand of small pine trees. The flight instructor stated carburetor heat was used during the simulated engine failure maneuver. The student pilot stated carburetor heat was not used during the maneuver. The flight instructor reported no abnormalities with the engine prior to the event; he stated the magnetos, carburetor heat, throttle, and mixture controls functioned normally during run-up and cruise.

Examination of the wreckage revealed the cowling was separated at the firewall, the lower tubes of the engine mount were broken, the tail section was separated, and both wingtips displayed crush damage. Fuel was observed leaking from the wreckage and was stopped by turning the fuel selector valve to the "off" position. About 12 gallons of fuel was recovered from the tanks.

On August 9, 2002, the engine was examined on the airframe at a recovery facility. The severed engine mounts were welded to stabilize engine movement. Repairs were made to the propeller spinner and oil filter adapter, which sustained damage during impact. Provisions were made for fuel supply, and the engine was started from inside the cockpit and controlled using the throttle and mixture controls. The engine ran smoothly at speeds ranging from idle to 2000 rpm. A magneto check was performed at 1500 rpm, and each magneto operated within normal parameters. The operation of the engine was limited to 2000 rpm for the safety of personnel. No defects were observed during the engine run that would have prevented normal operation.

A review of icing probability curves for conditions favorable to the formation of induction system icing reveals the temperature and dew point reported at the time of the accident fall within the "serious icing, glide power" range. The Owner's Manual for the Cessna 150 states in the Before Landing on page 1-2 the procedures for descent are as follows: 1. Mixture - rich, 2. Carburetor Heat - apply full heat before closing throttle.

Aircraft

Registration
N6486S
Reported as
Cessna 150H
Category
Airplane
Serial number
15067286
Airframe hours
4,947
Engine
Continental O-200-A, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Peachtree Flight Center
Registered owner
Griffin Flight School, Inc.
Last inspection
Annual · June 11, 2002 · 97 hours before
Departed
FFC · Peachtree City, GA
Airport
FFC · Peachtree City - Falcon Field

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
Flight instructor
Age
24
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Last flight review
February 28, 2002
Seat
Right
Flight hours
1,660 total · 100 in this make and model · 1,575 as pilot in command · 195 in the last 90 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
290° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 73 °F
Altimeter
30.17 inHg
Observed at
FFC, 5 nm away

Docket · 8

The files NTSB released with the investigation on January 17, 2003, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.4 MB in all.