Chance Vought F4U-7 Corsair, N965CV: Accident occurred May 14, 2019 at Jerome County Airport (KJER), Idaho

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

Investigator In Charge (IIC): Cawthra, Joshua

Additional Participating Person: Cara Barbera; Federal Aviation Administration; Boise, Idaho

Investigation Docket:  https://data.ntsb.gov/Docket?ProjectID=99515

Location: Jerome, Idaho 

Accident Number: WPR19LA157

Date & Time: May 14, 2019, 09:19 Local 

Registration: N965CV

Aircraft: Vought F4U-7 

Aircraft Damage: Substantial

Defining Event: Miscellaneous/other 

Injuries: 1 Minor

Flight Conducted Under: Part 91: General aviation - Personal

Analysis

Following an annual inspection, the mechanic who conducted the inspection was unable to conduct a test flight due to weather conditions but did perform several engine runs, during which he adjusted the fuel enrichment setting. The mechanic told the pilot before the accident flight that he would have to lean the engine manually while on the ground instead of using the auto-lean mixture setting, as the engine would run rich.

Before taking off, the pilot placed the mixture in the auto-lean position. The engine sputtered, and the pilot saw black smoke originate from the exhaust. The pilot then manually leaned the engine, and “it cleared up.” The pilot placed the mixture in the auto-rich position, performed a magneto check, then taxied onto the runway, but the engine “loaded up” a second time. The pilot stated that he manually leaned the engine, then moved the mixture to the auto-rich position while he advanced the throttle to 30 inches of manifold pressure. He said that he held this power setting for about 1 minute before initiating the takeoff. As the airplane accelerated past about 100 to 110 knots, the engine “coughed”, and the pilot reduced power to idle and aborted the takeoff but “ran out of runway.” The airplane exited the right side of the runway and impacted a dirt berm and fence before it came to rest upright.

Postaccident examination of the engine revealed no evidence of any mechanical malfunction that would have precluded normal operation and production of power, which included no evidence of preignition or detonation within each cylinder. During functional tests of the carburetor, it was found that, at high power settings, the fuel flow was lower than specified limits and would result in a lean fuel/air mixture. However, at lower power settings, the fuel/air mixture was within or slightly higher than specified limits. While it is likely that the lean fuel/air mixture at higher power settings could have resulted in detonation, no signatures were observed to suggest that it occurred.

The pilot stated that he wanted to get the airplane to an airshow and relied on the information provided to him by the mechanic. He reported that, in hindsight, he should have not flown the airplane and had the carburetor removed for overhaul.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot’s decision to fly the airplane with a known mechanical deficiency.

Findings

Personnel issues Decision making/judgment - Pilot

Personnel issues Use of equip/system - Pilot

Aircraft Fuel control/carburetor - Incorrect use/operation

Factual Information

History of Flight

Takeoff Miscellaneous/other (Defining event)

Takeoff-rejected takeoff Runway excursion

Takeoff-rejected takeoff Collision with terr/obj (non-CFIT)

On May 14, 2019, about 0919 mountain daylight time, a Vought F4U-7 airplane, N965CV, was substantially damaged when it was involved in an accident near Jerome, Idaho. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that the airplane had just finished undergoing an annual inspection that spanned 8 months. After arriving to the airport, he looked over the airplane and asked his mechanic if he had flown the airplane. The mechanic responded that he “couldn’t get it running;” however, “he adjusted everything, and got things working.” The pilot said that his mechanic told him that the engine was

“loading up” on the ground and that the engine would have to be manually leaned instead of using the mixture in the auto-lean position; however, it should not be a problem in the auto-rich position.

The pilot conducted a preflight inspection and taxied the airplane to the end of the runway, where he placed the mixture in the auto-lean position. He subsequently saw black smoke originate from the exhaust, and the engine sputtered. The pilot manually leaned the engine, and “it cleared up.” The pilot placed the mixture in the auto-rich position, performed a magneto check, then taxied onto the runway, where the engine “loaded up” a second time. The pilot stated that he manually leaned the engine, then moved the mixture to the auto-rich position while he advanced the throttle to 30 inches of manifold pressure. He said that he held this power setting for about 1 minute, and, after detecting no anomalies, he initiated the takeoff roll.

The pilot stated that, as the airplane accelerated beyond 100 to 110 knots, the engine “coughed” and he reduced power to idle and aborted the takeoff but “ran out of runway.” The airplane exited the right side of the runway and impacted a dirt berm and fence before it came to rest upright.

The mechanic reported that, while watching the airplane during the takeoff, the engine gradually came up to power, and appeared to reach full power. The mechanic said that, at the time he would have expected the airplane to become airborne, the airplane remained on the runway in a tail-high attitude. The mechanic said that about that time, the airplane was passing midfield, and the tail of the airplane appeared very high shortly before the pilot aborted the takeoff.

A video of the takeoff and accident sequence was captured by a witness located on the airport property. The video showed the airplane in a slight tail-low attitude during the takeoff roll. Shortly after the airplane passed the windsock and airport weather reporting station, a reduction in engine power was heard (refer to the following figure). Shortly thereafter, a streak of smoke originated from the left main landing gear. About 3 seconds later, as the tail of the airplane transitioned onto the ground, another streak of smoke originated from the left main landing gear. The airplane was observed exiting the right side of the runway and became airborne briefly before it impacted the ground and cartwheeled. 

The mechanic reported that, in the days before the accident, he secured the airplane and conducted an engine run at full power. The mechanic said that he made fuel enrichment changes on the ground and told the pilot that the engine would run rich on the ground and that he should manually lean it but to use auto-rich at full power. The mechanic added that the engine ran well for him during all previous engine runs. Additionally, the mechanic said that he did not test fly the airplane before the pilot’s arrival due to weather conditions and was later told by the pilot that he would fly it.

The pilot stated that, in hindsight, he should not have flown the airplane but that he did because he wanted to get the airplane to an airshow and relied on the information provided by the mechanic. The pilot stated that he should have removed the carburetor for overhaul instead.

Postaccident examination of the airplane revealed that the left-wing aft spar was structurally damaged. Examination of the engine by a mechanic under the supervision of a Federal Aviation Administration inspector revealed that magneto-to-engine timing was correct. Thumb compression was obtained on all cylinders. Borescope examination of the cylinders revealed no evidence of detonation or preignition.

The magnetos were removed and installed on a test bench. When tested, both magnetos functioned normally. The carburetor was undamaged and was removed for functional testing.

The carburetor was further inspected at the facilities of Vintage Carburetors, Tehachapi, California, under the supervision of a National Transportation Safety Board investigator. The carburetor was installed on a test bench and functionally tested at various settings. During the flow tests, the fuel flow rates for higher power settings were below, or leaner, than the specified fuel flow limits. At lower power settings, the fuel flow rates were either within or slightly higher than specified limits. The carburetor was removed from the test bench and disassembled and inspected. During the disassembly, the enrichment valve diaphragm was found intact; however, the diaphragm was noted to be stiff. According to representatives from Vintage Carburetors, the stiff enrichment valve diaphragm would cause the fuel flow at the higher settings to be lower than required and would affect the fuel flow in both the auto-lean and auto-rich settings. The company representative further stated that, when the diaphragm of the enrichment valve begins to stiffen, power settings from idle to high cruise power settings will run rich with the mixture lever in the auto-rich and auto-lean positions; however, at higher power settings, such as takeoff power, the fuel flow would be lean if the mixture lever is in the auto-rich position, inducing the possibility of detonation.

Pilot Information

Certificate: Commercial 

Age: 70,Male

Airplane Rating(s): Single-engine land; Single-engine sea

Seat Occupied: Center

Other Aircraft Rating(s): None 

Restraint Used: 4-point

Instrument Rating(s): Airplane 

Second Pilot Present: No

Instructor Rating(s): None 

Toxicology Performed: No

Medical Certification: Class 2 With waivers/limitations 

Last FAA Medical Exam: March 4, 2019

Occupational Pilot: No 

Last Flight Review or Equivalent: September 27, 2018

Flight Time: 2160 hours (Total, all aircraft), 51.6 hours (Total, this make and model), 1950 hours (Pilot In Command, all aircraft), 37.08 hours (Last 90 days, all aircraft), 12.7 hours (Last 30 days, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Vought

Registration: N965CV

Model/Series: F4U-7

Aircraft Category: Airplane

Year of Manufacture: 1952

Amateur Built:

Airworthiness Certificate: Experimental (Special)

Serial Number: 965

Landing Gear Type: Retractable - Tailwheel 

Seats: 1

Date/Type of Last Inspection: January 31, 2021 

Certified Max Gross Wt.: 12000 lbs

Time Since Last Inspection: 1632.8 Hrs 

Engines: 1 Reciprocating

Airframe Total Time: at time of accident

Engine Manufacturer: Pratt & Whitney

ELT: C126 installed, activated, did not aid in locating accident

Engine Model/Series: R2800

Registered Owner: On file

Rated Power: 2000 Horsepower

Operator: On file

Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual (VMC) 

Condition of Light: Day

Observation Facility, Elevation: KJER,4048 ft msl

Distance from Accident Site: 0 Nautical Miles

Observation Time: 14:53 Local 

Direction from Accident Site: 285°

Lowest Cloud Condition: Few / 11000 ft AGL 

Visibility 10 miles

Lowest Ceiling:

Visibility (RVR):

Wind Speed/Gusts: 5 knots / 

Turbulence Type Forecast/Actual: None / None

Wind Direction: 130° 

Turbulence Severity Forecast/Actual: N/A / N/A

Altimeter Setting: 29.97 inches Hg 

Temperature/Dew Point: 17°C / 7°C

Precipitation and Obscuration: No Obscuration; No Precipitation

Departure Point: Jerome, ID (JER)

Type of Flight Plan Filed: None

Destination: Rock Springs, WY (RKS)

Type of Clearance: None

Departure Time: 09:19 Local 

Type of Airspace: Class G

Airport Information

Airport: JEROME COUNTY JER 

Runway Surface Type: Asphalt

Airport Elevation: 4053 ft msl 

Runway Surface Condition: Dry

Runway Used: 09

IFR Approach: None

Runway Length/Width: 5001 ft / 75 ft 

VFR Approach/Landing: None

Wreckage and Impact Information

Crew Injuries: 1 Minor

Aircraft Damage: Substantial

Passenger Injuries:

Aircraft Fire: None

Ground Injuries: 

Aircraft Explosion: None

Total Injuries: 1 Minor 

Latitude, Longitude: 42.725276,-114.447219(est)

JEROME — A vintage aircraft didn’t quite make it off the runway at the Jerome County Airport early Tuesday morning.

Jerome County Sheriff’s Office responded to the crash of the 1950s-era F4U Corsair with Marine Corps markings at 9:19 a.m, according to a press release from Sheriff George Oppedyk. The plane attempted to take off when, for unknown reasons, it veered off the runway and through a fence.

John O’Connor, 70, was the pilot of the plane. He was the sole occupant and declined to be taken to the hospital by paramedics. The plane had significant damage to the landing gear, propeller and wings, Oppedyk said.

The Chance Vought F4U-7 Corsair is an American fighter aircraft that saw service primarily in World War II and the Korean War by the U.S. Navy and U.S. Marines.

Jerome Rural Fire Department and Magic Valley Paramedics assisted the Jerome County Sheriff with the incident, which is being investigated by the Federal Aviation Administration and the National Transportation Safety Bureau.

Crews used a crane to lift the damaged plane Tuesday afternoon.

Original article can be found here ➤ https://magicvalley.com

JEROME, Idaho (KMVT/KSVT) — A vintage airplane crashed Tuesday morning at the end of the runway at the Jerome County Airport.

The Jerome County Sheriff’s Office said the pilot was the only individual in the aircraft, and that the individual was treated by Magic Valley Paramedics and then released. Jerome Rural Fire District and sheriff’s office responded to the crash.

A sheriff's deputy said the fixed wing aircraft, an F4U Corsair, was traveling eastbound on the runway getting ready to take off. However the pilot was not able to complete the takeoff, and the plane hit a ditch before going air bound and belly flopping on the ground. He said there was no fire but the breaks were smoking. Emergency responders were notified at about 9:19 a.m.

"The pilot appeared to be either very minor injury, or no injury," said Jerome County Sheriff's Deputy Robert Nicholson. "Maybe a slight abrasion to the hand, but that was about it that I observed. I didn't know anything else that was too damaging."

Nicholson said however, it's possible the individual could've sought out or needed further medical treatment following being released by paramedics.

The National Travel Safety Board and Federal Aviation Administration have been notified and are believed to be coming to investigate. Deputy Nicholson, confirmed that the investigation has been handed back over to local authorities.

Story and video ➤ https://www.kmvt.com