ERA21LA199

NTSB accident investigation · Mooney M20C · Warwick, NY · April 29, 2021

Accident · Serious injuriesClass 4 · LimitedFinal report
Date
April 29, 2021, 12:17 local (16:17 UTC)
Place
Warwick, NY · South Shore of Wickham Lake
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N6448UMooney M20C
Defining event
Takeoff: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 4 - Basic report with no Prelim publish
NTSB office
Eastern Region Aviation
Parties
FAA / FSDO
Case key
103004

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

A loose stand-off clamp which resulted in a throttle assembly malfunction, and the inability of the engine to produce full power during the attempted takeoff.

Findings · 1

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.

Engine controls: power leverAircraft › Aircraft power plant · MalfunctionMooney M20C: 1 caseAll aircraft: 95 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

On the day of the accident, the pilot decided to take his airplane on a flight around the traffic pattern at his home airport to practice a few takeoffs and landings. After pulling the airplane out of the hangar where he kept it, he performed a preflight inspection. He then performed an engine runup, then back taxied on the runway for takeoff. Once he was in position for takeoff, he advanced the throttle until it was full open, and at 65 mph and about 2/3rds of the way down the runway, he rotated. He immediately realized that the engine was not producing full power, and attempted to advance the throttle further, but he realized that the throttle seemed as though it was not advancing completely. He then nosed the airplane down to attempt to stay in ground effect and gain some airspeed. A lake was at the departure end of the runway, and he was already approaching the trees on the opposite bank. He then picked a spot between trees, turned the fuel off, and pulled the aircraft into a full stall prior to impact. Postaccident examination of the airplane revealed that the fuselage and wings were substantially damaged. Further examination also revealed that the throttle cable would resist efforts to fully open the throttle and would only move the throttle arm on the carburetor about 1/2 an inch, and when the throttle was fully open, the entire throttle cable would move through the firewall and bulge. After disconnecting the cable from the carburetor, the cable was found to be still under load, until a loose stand-off clamp that connected the throttle cable to the firewall was repositioned, which then allowed the throttle to function properly through its full range of motion.

Aircraft

Registration
N6448U
Reported as
Mooney M20C
Category
Airplane
Serial number
2195
Built
1962
Airframe hours
5,091.7
Engine
Lycoming O-360-A1, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · December 9, 2020
Departed
N72 · Warwick, NY
Airport
N72 · Warwick Muni, runway 21L, 2,150 × 28 ft, asphalt
Equipment
ADS-B, Auto-pilot, Stall warning system

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
55
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Without waivers/limitations
Last flight review
November 9, 2019
Seat
Left
Restraint
3-point
Flight hours
532.7 total · 8.5 in this make and model · 532.7 as pilot in command · 17.4 in the last 90 days · 4.4 in the last 30 days · 0.7 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
70 °F, dew point 52 °F
Altimeter
29.82 inHg
Observed at
KMGJ, 14 nm away
METAR
KMGJ 281554Z AUTO 17004KT 10SM CLR 21/11 A2982 RMK AO2 SLP097 T02110106

Docket · 4

The files NTSB released with the investigation on August 31, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 19.1 MB in all.