WPR10CA334

NTSB accident investigation · Luscombe 8E · Tillamook, OR · July 4, 2010

Accident · Minor injuriesData collectionFinal report
Date
July 3, 2010, 18:20 local (Jul 4, 2010, 01:20 UTC)
Place
Tillamook, OR
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N2466KLuscombe 8E
Defining event
Approach-VFR pattern final: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed · report October 21, 2010
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
FAA FSDO
FAA report
20100703038949A
Case key
76550

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 certified flight instructor’s selection of an inappropriate landing surface and the loss of engine power as a result of the improper use carburetor heat. Contributing to the accident was the flight instructor's inadequate supervision.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Info processing/decision: decision making/judgmentPersonnel issues › Action/decision · Instructor/check pilotLuscombe 8E: 1 caseAll aircraft: 3,098 casesProbable cause
Attention/monitoring: task monitoring/vigilancePersonnel issues › Psychological · Instructor/check pilotLuscombe 8E: 1 caseAll aircraft: 330 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Response/compensationLuscombe 8E: 3 casesAll aircraft: 435 casesProbable cause
Ice/rain protection system: intake anti-ice, deiceAircraft › Aircraft systems · Incorrect use/operationLuscombe 8E: 1 caseAll aircraft: 108 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The certified flight instructor (CFI) indicated that he and his student pilot decided to land on the grass next to the runway because the student pilot “had no experience landing on sod.” The CFI stated that abeam the touchdown point they turned on the carburetor heat and that the approach was “normal but a bit low.” The CFI did not alert the student about the low altitude, assuming that they “could power over the tall grass and drop into the grass strip.” On short final the carburetor heat was turned off, and at an altitude of about five feet the student attempted to use power to maintain altitude. The engine did not respond and the student pilot did not reapply the carburetor heat. Subsequently, the airplane touched down short of the intended touchdown point. The CFI was unable to reach the controls prior to the aircraft nosing over. The CFI stated that he had previous experiences with the airplane failing to respond to throttle inputs during landing and that he should have known not to turn off the carburetor heat on short final. The aircraft sustained substantial damage to the fuselage and tail assembly. The CFI reported that there were no known mechanical malfunctions or failures prior to the accident. When plotted on a carburetor icing probability chart, the temperature and dew point fell within an area of the graph noting "Moderate icing cruise power or serious icing glide power."

Factual narrative

The certified flight instructor (CFI) indicated that he and his student pilot decided to land on the grass next to the runway because the student pilot “had no experience landing on sod.” The CFI stated that abeam the touchdown point they turned on the carburetor heat and that the approach was “normal but a bit low.” The CFI did not alert the student about the low altitude, assuming that they “could power over the tall grass and drop into the grass strip.” On short final the carburetor heat was turned off, and at an altitude of about five feet the student attempted to use power to maintain altitude. The engine did not respond and the student pilot did not reapply the carburetor heat. Subsequently, the airplane touched down short of the intended touchdown point. The CFI was unable to reach the controls prior to the aircraft nosing over. The CFI stated that he had previous experiences with the airplane failing to respond to throttle inputs during landing and that he should have known not to turn off the carburetor heat on short final. The aircraft sustained substantial damage to the fuselage and tail assembly. The CFI reported that there were no known mechanical malfunctions or failures prior to the accident. When plotted on a carburetor icing probability chart, the temperature and dew point fell within an area of the graph noting "Moderate icing cruise power or serious icing glide power."

Aircraft

Registration
N2466K
Reported as
Luscombe 8E
Category
Airplane
Serial number
5193
Airframe hours
4,064
Engine
Continental C85 Series, 85 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Linscheid Glen A
Registered owner
Linscheid Glen A
Airworthiness certificate
Standard, Normal
Last inspection
Annual · February 11, 2010 · 20 hours before
Departed
7S5 · Independence, OR
Destination
KTMK · Tillamook, OR
Airport
KTMK · Tillamook Airport

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
60
Injuries
Minor
Certificates
Private, Commercial, Flight instructor
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
April 21, 2009
Seat
Right
Flight hours
3,508 total · 200 in this make and model · 3,503 as pilot in command · 20 in the last 90 days · 15 in the last 30 days · 0 in the last 24 hours
Role
Student pilot
Age
48
Injuries
Minor
Certificate
Student
Medical
Class 3
Last flight review
July 3, 2010
Seat
Left
Flight hours
45 total · 21 in this make and model · 20 as pilot in command · 9 in the last 90 days · 8 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
290° at 14 knots, gusting 20
Visibility
10 statute miles
Lowest ceiling
None
Temperature
63 °F, dew point 54 °F
Altimeter
30.17 inHg
Observed at
TMK

Docket · 2

The files NTSB released with the investigation on July 22, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 539 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.