NYC00LA054

NTSB accident investigation · Mooney 20J · New Milford, CT · December 17, 1999

Accident · No injuriesLimited investigationFinal report
Date
December 17, 1999, 15:00 local (20:00 UTC)
Place
New Milford, CT
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N43TPMooney 20J
Weather
Visual (VMC) · Day
Status
Completed · report November 30, 2000
Report
Approved by Office Director
FAA report
19991217041669A
Case key
48424

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

Failure of 3 of the 4 connecting rods for an undetermined reason.

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) - mech failure/malfCruise
Engine assembly,connecting rod - failure,totalCause
Reason for occurrence undetermined
Forced landingDescent - emergency
In flight collision with terrain/waterEmergency descent/landing
Terrain condition - berm

Analysis

The airplane experienced a propeller strike, and the engine was sent for a teardown inspection. The engine was reinstalled and then run for 0.4 hours. The pilot conducted a preflight, started the engine, and taxiing to the runway. A run-up check was completed, and no abnormalities were identified. The takeoff was uneventful, and the pilot executed closed traffic to a touch-and-go. Afterwards, he departed the traffic pattern, and climbed to 3,000 feet msl. The pilot configured the airplane for cruise flight. After approximately 30 minutes, the pilot proceeded back to the airport. While en route, he heard a loud 'bang,' and white smoke filled the cockpit. Unable to restart the engine the pilot executed a forced landing to a field. A teardown of the engine was preformed. The crankshaft nose seal was partially dislodged. The number 1 connecting rod was still attached. The number 2, 3, and 4 connecting rods had separated from the crankshaft. Damage to the connecting rod bearings was consistent with insufficient lubrication and high temperatures. No engine-oil-system pre-impact failures were identified.

Factual narrative

On December 17, 1999, at 1500 eastern standard time, a Mooney 20J, N43TP, was substantially damage during a forced landing near New Milford, Connecticut. The certificated commercial pilot was not injured, and visual meteorological conditions prevailed for the personal local flight. The flight originated from Danbury, Connecticut, no flight plan was filed, and the flight was conducted under 14 CFR Part 91.

According to the pilot, on September 26, 1999, the airplane experienced a propeller strike, and the engine was sent to the manufacturer for a teardown inspection in accordance with a mandatory service bulletin.

On the day of the accident, the pilot arrived at Danbury to see if the airplane was ready to be flown after having the original engine re-installed. In addition, a new 3 bladed propeller was scheduled to be installed, replacing the original 2 bladed one. The pilot found that the installation had been completed, and that the engine was successfully run for 0.4 hours without producing any leaks or anomalies. The pilot excepted the airplane, and conducted an "extensive" preflight inspection before starting the engine, and taxiing to runway 26. A run-up check per the checklist was completed, and no abnormalities were identified. The pilot did think the engine sounded different, but contributed it to the fact that the original 2 bladed propeller had been replaced.

With the run-up checks completed, the pilot radioed the tower. The pilot then taxied onto the runway and departed. The takeoff was uneventful, and the pilot executed closed traffic to a touch-and-go. On climbout, he requested a right turn to depart the traffic pattern to do some airwork north of the field. After reaching 3,000 feet msl, the pilot configured the airplane for cruise flight. He set the manifold pressure to 25 inches of mercury and the engine rpm to 2,500. After keeping the airplane in this configuration for about 10 minutes, the pilot proceeded back towards Danbury. En route, he decided to practice turns and slow flight, as well as an approach to landing stall to see if the new propeller made any performance differences. All three maneuvers were completed without any "problems or changes in the running of the engine."

After being airborne for approximately 25 minutes, and while in cruise flight at 3,000 feet msl, the pilot heard a loud "bang," and white smoke immediately filled the cockpit. After the bang, "the engine began to run rough and shake the plane." Because of smoke in the cockpit, the pilot opened the vent window and the air vents in the overhead. He declared an emergency. In addition, he advised Danbury Tower that his engine was running rough, and of smoke in the cockpit. Then, a second bang was heard by the pilot and the engine stopped. The pilot attempted a restart, which resulted in no movement in the engine, or propeller.

Familiar with the local area, the pilot knew he could not make it to an airport, so he decided to land in one of several playing fields located behind a high school currently under construction. The pilot lowered the landing gear and selected flaps to half. As the airplane approached the first field, the pilot realized it was going to fast to land so he setup for the second field. Still fast, the airplane did not touchdown until "near" the end of the field. The pilot then identified a ditch with a dirt bank next to it. He attempted to fly over the bank and land in a vacant cornfield. The main landing gear contacted the bank, shearing it off. The airplane continued on its belly for approximately 50 yards before coming to rest upright. The pilot secured both the electrical system and the fuel systems before egressing without injury.

On January 25, 2000, the engine was examined at Mattituck Aviation, Mattituck, New York. The crankshaft nose seal was partially dislodged. In addition, the crankcase was cracked, and had several holes in it. Through one of the holes, the base of a connecting rod was protruding. The crankcase was opened, and the crankshaft examined. The number 1 connecting rod was still attached. The number 2, 3, and 4 connecting rods had separated from the crankshaft. Damage to the connecting rod bearings was consistent with insufficient lubrication and high temperatures.

The engine accessory section was intact and free of damage. The engine driven oil pump rotated freely. The pump was disassembled. No pre-impact failures were identified. Examination of the oil sump revealed pieces of metal. In addition, 70 percent of the oil suction screen was filled with metal fragments. The intake side of the oil filter had metal fragments on its surface. After the oil filter, no contaminants were found. The crankcase oil journals were free of debris, along with the crankshaft and connecting rod journals.

Aircraft

Registration
N43TP
Reported as
Mooney 20J
Category
Airplane
Serial number
24-1104
Airframe hours
2,597
Engine
Lycoming IO-360, 200 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
The Sailing Port Corp
Airworthiness certificate
Standard, Normal
Last inspection
Annual · December 17, 1999 · 1 hours before
Departed
DXR · Danbury, CT

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
61
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
2,117 total · 1,574 in this make and model · 1,928 as pilot in command · 17 in the last 90 days · 3 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
270° at 10 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
39 °F, dew point 16 °F
Altimeter
30.00 inHg
Observed at
DXR, 20 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.