Tuesday, March 10, 2020

Loss of Engine Power (Total): Beech F33A, N3291X; accident occurred June 07, 2018 near Annandale Ranch Airport (2XS7), Uvalde County, Texas


Engine accessory area

Oil filter and oil cooler

Oil filter and safety wire

External inspection of engine

The left magneto was thermally damaged and detached from its mounting pad.

The right magneto was thermally damaged.

Ignition harness exhibited thermal damage from the post-crash fire.

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entities: 
Federal Aviation Administration / Flight Standards District Office; San Antonio, Texas
Continental Motors; Mobile, Alabama 
Textron Aviation; Wichita, Kansas

Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms 


Location: Uvalde, TX
Accident Number: CEN18LA213
Date & Time: 06/07/2018, 1024 CDT
Registration: N3291X
Aircraft: BEECH F33A
Aircraft Damage: Destroyed
Defining Event: Loss of engine power (total)
Injuries: 1 Serious
Flight Conducted Under: Part 91: General Aviation - Personal 

On June 7, 2018, about 1024 central daylight time, a Beech F33A airplane, N3291X, experienced a total loss of engine power inflight and made a forced landing near Annandale Ranch Airport (2XS7), Uvalde, Texas. The pilot sustained serious injuries and the airplane was destroyed by a post-impact fire. The airplane was registered to and operated by a private individual under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time and no flight plan had been filed. The flight departed from Live Oak County Airport (8T6) George West, Texas, about 0930 and was en route to Sierra Blanca Regional Airport (SRR), Ruidoso, New Mexico.

On June 5, 2018, the airplane's annual inspection was completed at a maintenance facility located at Card Airfield (4XA2), Kenedy, Texas. The pilot reported that he flew the airplane from 4XA2 back to his home base 8T6 on June 6, 2018. The flight from 4XA2 to 8T6 was 31 nautical miles.

The pilot reported that on the morning of the accident flight he topped off the airplane's fuel tanks and departed 8T6. While en route the weather was clear and he received a transponder code for visual flight rules (VFR) flight following from air traffic control (ATC) and was cleared through 8,500 ft mean sea level (msl). He reported that "suddenly the manifold pressure dropped with a simultaneous engine explosion…the engine access doors were blown open…oil was spewing on the windshield…there was fire everywhere." He reduced the mixture, throttle, and propeller controls. After reporting the emergency to ATC, they issued vectors to the closest airstrip, 2XS7. The pilot added that it was very difficult to maintain glide speed because the nose was pitching upward. He reported that he had to hold the yoke forward as hard as he could in order to keep the nose down. During the descent he extended the landing gear. The pilot stated that there was a second explosion when the airplane collided with trees and rocks. The airplane was engulfed in flames as he removed his seatbelt and egressed. The pilot was airlifted to a local hospital and treated for 2nd and 3rd degree burns.

A review of the Federal Aviation Administration (FAA) air traffic control (ATC) data revealed that the airplane's recorded flight track began at 0937 about 5 nautical miles northwest of 8T6. The pilot was in contact with ATC and the airplane was in cruise flight about 8,500 ft msl and 110 nautical miles from 8T6 when the emergency was declared. At 1018 the airplane made a left descending turn toward 2XS7. The final radar return at 1023 showed the airplane about 2,300 ft msl (1,000 ft above ground level (agl)) on a 99° heading. Figure 1 shows the final radar track with the accident site and 2XS7 labeled.

Figure 1 – Radar track with the accident site and airport labeled.

The responding FAA inspector stated that the airplane was found among trees on the west side of 2XS7 about 500 yards from the threshold of runway 8. The post-impact fire consumed a majority of the airplane. The wreckage debris path began with the left horizontal stabilizer and elevator that were sheared off, followed by the left wing, the left wing tip fuel tank, and nosewheel. The right wing, right wing tip fuel tank, fuselage, main landing gear, and engine/engine compartment remained together at the final resting position. The fuel tanks were breached and there was evidence of a large fire around the airplane as seen in Figure 2.

Figure 2 – Right side of the accident airplane with significant fire damage.

The FAA inspector's examination of the wreckage revealed significant fire damage to the rear of the engine compartment at the engine accessory area. There was evidence of a thick white/grey, powdery ash covering the damaged accessory area. Also, there was an estimated 8-inch hole in the crankcase under the left magneto. As viewed from the hole in the crankcase, there appeared to be little to no oil inside the engine and very little oil around the outside of the hole. The top front section of the engine remained mostly free of damage and ash. The exhaust tubing and routing for the turbo-normalizing system showed no damage or apparent anomalies. Visual examination of the oil tubing, oil filter, and oil cooler revealed that some components had been consumed by fire. The oil filter was loose on its mount. The inspector recorded a video of the oil filter as it was manually rotated clockwise to tighten. The filter rotated about one-half of a full turn until the safety wire restricted further rotation. The filter was then rotated counterclockwise back to the original position until the safety wire again restricted rotation. The inspector reported that the oil filter was not completely tightened on it's mount when it was rotated clockwise but was unable to determine why there was additional space for rotation. The oil filter gasket had been consumed by fire. The exhaust manifold directly below the oil filter and oil cooler exhibited burn marks.

The wreckage was recovered to a secure storage facility where it was examined by the investigative team under the supervision of the NTSB IIC. The examination confirmed that the forward fuselage, firewall, engine and propeller were complete in one piece. The fuselage was mostly consumed by fire. The wings were impacted damaged and partially consumed by fire. The flight control cables exhibited overload separations in multiple locations. The rear of the engine and firewall sustained thermal damage but remained mostly intact. The cylinders remained attached to the crankcase. The No. 2 connecting rod was loose inside the large hole in the case. The engine was equipped with a turbo normalizing system in accordance with supplemental type certificate STC SE5222NM. The oil lines to and from turbo controller remained intact but the controller was separated from its mount.

The engine was removed from the firewall for further examination and a full tear down was conducted at the manufacturer's facility. The examination revealed that the left magneto was broken from its mount. There was a hole in the crankcase above the number two cylinder. The number two connecting rod was separated from the crankshaft. Some of the connecting rod was still attached to the No. 2 piston pin and was found in the No. 2 cylinder. The Nos. 3 and 4 connecting rods exhibited thermal damage consistent with a lack of oil lubrication. All the oil passages in the crankshaft and the crankcase were clear of any blockages. The No. 2 rod journal was thermally damaged and the oil passage was melted and smeared closed due to excessive heat. Excluding the mechanical damage from the internal engine components and the post-crash fire, the remainder of the engine exhibited normal operating signatures and no additional anomalies were noted. 

Pilot Information

Certificate: Private
Age: 72, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s):None 
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 3 Without Waivers/Limitations
Last FAA Medical Exam: 09/09/2016
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time: (Estimated) 

Aircraft and Owner/Operator Information

Aircraft Make: BEECH
Registration: N3291X
Model/Series: F33A
Aircraft Category: Airplane
Year of Manufacture: 1991
Amateur Built: No
Airworthiness Certificate: Utility
Serial Number: CE-1593
Landing Gear Type: Retractable - Tricycle
Seats: 6
Date/Type of Last Inspection: 06/05/2018, Annual
Certified Max Gross Wt.:
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 3215.8 Hours as of last inspection
Engine Manufacturer: Continental Motors
Engine Model/Series: IO-550-BA
Registered Owner: On file
Rated Power:
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KUVA, 942 ft msl
Distance from Accident Site: 15 Nautical Miles
Observation Time: 1015 CDT
Direction from Accident Site: 190°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 7 knots /
Turbulence Type Forecast/Actual:
Wind Direction: 90°
Turbulence Severity Forecast/Actual:
Altimeter Setting: 29.98 inches Hg
Temperature/Dew Point: 28°C / 21°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: GEORGE WEST, TX (8T6)
Type of Flight Plan Filed: None
Destination: RUIDOSO, NM (SRR)
Type of Clearance: VFR; VFR Flight Following
Departure Time: 0930 CDT
Type of Airspace: Class E

Airport Information

Runway Surface Type: Grass/turf
Airport Elevation: 1205 ft
Runway Surface Condition: Unknown
Runway Used: 08
IFR Approach: None
Runway Length/Width: 4000 ft / 50 ft
VFR Approach/Landing: Forced Landing; Straight-in

Wreckage and Impact Information

Crew Injuries: 1 Serious
Aircraft Damage: Destroyed
Passenger Injuries: N/A
Aircraft Fire: In-Flight and On-Ground
Ground Injuries: N/A
Aircraft Explosion: Unknown
Total Injuries: 1 Serious
Latitude, Longitude: 29.454444, -99.694167 (est)

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