On October 29, 2020, about 0939 PDT, a Cessna 310, N101G, was destroyed when it was involved in an accident near Henderson, Nevada. The pilot and passenger were fatally injured. The airplane was operated as a Part 91 personal flight.

ADS-B data indicate that the airplane departed from runway 12 at North Las Vegas Airport at 0929 and flew on a southeast heading for about one minute before turning southwest. The pilot's intended destination was Gillespie Field Airport, San Diego, California. At 0930, approximately 1 mile south of VGT at an altitude of 2,800 ft, the pilot contacted Las Vegas Terminal Radar Control and requested a change of destination to Henderson Executive Airport (HND), Henderson, Nevada.

At 0935, the pilot requested to proceed direct to HND and stated that he needed to shut down one engine. The controller approved the request and transferred communication to HND tower controllers. No further communication was received from the pilot. ADS-B data indicate that, about the time of the pilot's request to proceed to HND, the airplane turned to the east then southeast before data was lost at 0938. When the airplane began its turn to the east, its airspeed was approximately 86 knots. Airspeed briefly increased to 97 knots over the next minute, then gradually decreased to a final airspeed of 78 knots when contact was lost. (See video.)

The final portion of the accident flight was captured by a video taken on a cell phone by a witness, with additional video from security cameras. Security camera video shows the airplane rolling to its left before ground impact followed by a post-crash fire. Examination of the cell phone video at the NTSB Vehicle Recorders Lab found that the left propeller was not turning before ground impact, and that the right propeller was turning.

Another witness later reported observing the airplane fly south as it crossed a highway. According to the witness, it appeared as if the plane attempted to gain altitude (while losing airspeed) as it avoided hitting power lines that ran across the highway. The airplane appeared to nose down after crossing the power lines, then maintained its altitude for approximately 1,000'. Shortly thereafter, the airplane nosed down again, rolled "hard left," and impacted the ground. The witness stated that the left propeller was not spinning. Additionally, the airplane was flying about 15° to 20° right wing down before it rolled to the left and impacted the ground. Post-accident examination of the left engine revealed two holes in the crankcase above cylinders 3 and 4.

The crankcase was opened, and indications of fretting were present on main bearings 2 and 3. Additionally, no indication of lubrication was noted. The #2 main bearing was laterally displaced, indicating there was some bearing movement.

The left engine's three-blade propeller separated at the crankshaft propeller flange. Two of the blades remained straight with no bending or twisting deformation. One blade was slightly bent as a result of the impact. Examination of the right engine revealed signatures of power at the time of the accident.

Various components from the left engine were sent to the NTSB Materials Laboratory for further examination. The #4 main bearing inserts exhibited heavy rubbing damage, and metal had filled in much of the bearing groove, obstructing five of the six oil through-holes. All of the main bearing left inserts exhibited features consistent with melted and resolidified metal near the insert end face.

Maintenance records revealed an entry dated January 29, 2020, stating the left engine was "disassembled and inspected for low oil pressure." The entry stated: "alternator failure metal caused oil pressure problem." According to the entry, the connecting rod nuts and bolts were replaced, and the main bearings and rod bearings were replaced. Additionally, the alternator, oil cooler, and starter adapter were replaced with overhauled units.

The most recent annual examination was completed on April 18, 2020, at a Hobbs time of 1,197.2 hours. The entry in the logbook for the examination indicated cylinder compressions were: 1/62, 2/61, 3/64, 4/65, 5/62, and 6/64. The entry also stated the engine magneto to engine timing was checked and adjusted, and the spark plugs were serviced.

FAA Advisory Circular No. 43.13-1B, "Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair," states in part: "If cylinder has less than a 60/80 reading on the differential test gauges on a hot engine, and procedures in paragraphs 8-15b(5)(i) and (j) fail to raise the compression reading, the cylinder must be removed and inspected."

According to the AC, when performing a differential compression test, cylinders should be pressurized to 80 psi.

00:00 Intro
00:07 Witness cell phone video
00:14 Video #1
00:40 Video #2
00:54 Video #3
01:01 Video #4
01:19 Photos
01:27 Radar playback video
01:51 Accident investigation records

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