ASN Wikibase Occurrence # 219246
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Sunday 9 December 2018 |
| Time: | 12:15 |
| Type: |  Mooney M20K 231 |
| Owner/operator: | Private |
| Registration: | N5756W |
| MSN: | 25-0822 |
| Year of manufacture: | 1984 |
| Total airframe hrs: | 2440 hours |
| Engine model: | Continental. TSIO-360-LB1 |
| Fatalities: | Fatalities: 0 / Occupants: 4 |
| Aircraft damage: | Substantial |
| Category: | Accident |
| Location: | NW of Lincoln Park Airport (N07), Lincoln Park, NJ -
 United States of America
|
| Phase: | Landing |
| Nature: | Private |
| Departure airport: | Lincoln Park, NJ (N07) |
| Poughkeepsie-Dutchess County Airport, NY (POU/KPOU) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
During cruise flight, the pilot noticed an increase in cylinder head temperature on two cylinders and unsuccessfully attempted to reduce the temperature. He reported that he soon heard "an explosion" and noted a hole in the engine cowling. He performed a forced landing to a golf course, during which the landing gear collapsed, which resulted in substantial damage to the right wing.
Postaccident examination of the engine revealed that the Nos. 1 and 2 connecting rods exhibited thermal discoloration consistent with a loss of lubrication. Additionally, the breakaway torques measured at 8 of the 12 through-bolts showed that they were below the manufacturer's specifications. The No. 2 main bearing saddles exhibited impingement damage, and the No. 2 bearing was partially rotated clockwise, which blocked the oil passages leading to the connecting rod bearings. The mating surfaces of the main bearing saddles had remnants of silk thread around the through-bolt holes, which was contrary to manufacturer guidance that prohibited placing silk thread in these areas. Given this information, it is likely that maintenance personnel applied silk thread to a prohibited area during an engine overhaul that occurred about 255.8 flight hours before the accident. This resulted in a loss of torque on the crankcase through-bolts, which allowed the No. 2 main bearings to shift, resulting in restriction of lubrication to that area and subsequent engine failure.
Probable Cause: Maintenance personnel's improper assembly of the engine during overhaul, which resulted in lubrication restriction due to a bearing shift and the subsequent engine failure.
Accident investigation:
 |
|
Sources:
NTSB
FAA register: https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=5756W%20
Location
Images:
Photo: FAA
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 09-Dec-2018 19:47 | Geno | Added |
| 03-Jul-2020 12:39 | ASN Update Bot | Updated [Operator, Nature, Departure airport, Destination airport, Source, Narrative, Accident report, ] |
| 03-Jul-2020 17:41 | harro | Updated [Destination airport, Source, Narrative, Photo, Accident report, ] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation