Sunday, May 03, 2020

Flight Control System Malfunction/Failure: de Havilland DH-4, N32517; accident occurred May 02, 2020 at Bowling Green–Warren County Regional Airport (KBWG), Kentucky





Aviation Accident Final Report - National Transportation Safety Board

Additional Participating Entity: 
Federal Aviation Administration / Flight Standards District Office; Louisville, Kentucky

Investigation Docket - National Transportation Safety Board:


Location: Bowling Green, KY
Accident Number:ERA20CA168 
Date & Time: 05/02/2020, 0700 CDT
Registration: N32517
Aircraft: DAYTON-WRIGHT DH-4
Aircraft Damage: Substantial
Defining Event: Flight control sys malf/fail
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Flight Test 

Analysis

The pilot reported that, during the first flight test of the antique airplane, which was in the process of being restored, he had difficulty controlling the airplane in the roll axis. After takeoff, he noticed that the airplane required some right aileron to keep the wings level. After turning crosswind, the problem worsened, and required that he apply more pressure to the control stick (in the right aileron direction). As he turned downwind, he used nearly full right aileron to maintain control, and the force on the control stick was so high that he was unable to hold it with one hand. When he removed his left hand from the control stick to adjust the throttle, the airplane would roll toward the left. As the airplane approached the base leg, the pilot was unable to keep the wings level; the airplane entered a slip and he was unable to prevent the airplane from turning left. The airplane descended, touched down in the grass to the right of the runway, and came to rest nose down.

Examination of the airplane revealed that the aileron control system was continuous. However, due to the airplane damage, the rigging of the aileron system could not be evaluated.

The airplane sustained substantial damage to the forward fuselage, lower wing, and horizontal stabilizer.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
A primary control (aileron) system anomaly that progressively worsened during a test flight that resulted in a loss of control. The reason for the anomaly was not determined due to impact damage. 

Findings

Aircraft Aileron control system - Malfunction
Aircraft Lateral/bank control - Attain/maintain not possible
Not determined (general) - Unknown/Not determined

Factual Information

History of Flight

Takeoff Flight control sys malf/fail (Defining event)

Pilot Information

Certificate: Private
Age: 73, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Center
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 3 With Waivers/Limitations
Last FAA Medical Exam: 03/22/2019
Occupational Pilot: No
Last Flight Review or Equivalent: 01/10/2019
Flight Time:  946 hours (Total, all aircraft), 309 hours (Total, this make and model), 946 hours (Pilot In Command, all aircraft), 16 hours (Last 90 days, all aircraft), 3 hours (Last 30 days, all aircraft), 0.3 hours (Last 24 hours, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: DAYTON-WRIGHT
Registration: N32517
Model/Series: DH-4
Aircraft Category: Airplane
Year of Manufacture: 1918
Amateur Built:No 
Airworthiness Certificate: Experimental; Special Flight
Serial Number: 12459
Landing Gear Type: Tailwheel
Seats: 2
Date/Type of Last Inspection: 01/25/2020, Annual
Certified Max Gross Wt.: 4297 lbs
Time Since Last Inspection: 5 Hours
Engines: 1 Reciprocating
Airframe Total Time: 5 Hours at time of accident
Engine Manufacturer: Lincoln
ELT: Not installed
Engine Model/Series: Liberty V12
Registered Owner: Saving Liberty Dh4 Llc
Rated Power: 400 hp
Operator: Saving Liberty Dh4 Llc
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: BWG, 537 ft msl
Distance from Accident Site: 0 Nautical Miles
Observation Time: 0653 CDT
Direction from Accident Site: 279°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: Calm /
Turbulence Type Forecast/Actual:
Wind Direction:
Turbulence Severity Forecast/Actual:
Altimeter Setting: 30.12 inches Hg
Temperature/Dew Point: 13°C / 11°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Bowling Green, KY (BWG)
Type of Flight Plan Filed: None
Destination: Bowling Green, KY (BWG)
Type of Clearance: None
Departure Time: 0652 CDT
Type of Airspace: Class E

Airport Information

Airport: Bowling Green-Warren County Rg (BWG)
Runway Surface Type: Grass/turf
Airport Elevation: 547 ft
Runway Surface Condition: Dry; Vegetation
Runway Used: 03
IFR Approach: None
Runway Length/Width: 6501 ft / 150 ft
VFR Approach/Landing: Forced Landing; Traffic Pattern 

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 None
Latitude, Longitude: 36.964444, -86.419722 (est)








The Bowling Green man flying a restored, World War I-era de Havilland DH-4 biplane that crashed at the Bowling Green-Warren County Regional Airport on Saturday walked away from the wreckage mostly unscathed, which the pilot called a tribute to the aircraft’s grit.

“It’s a testimony to how well built this plane is,” said Dorian Walker, who said he had no serious injuries after the wooden plane crashed in a field at the airport Saturday morning. The DH-4 was the only original plane of its kind still flying, Walker said.

“It’s the first American-built warplane,” Walker said of the plane’s model, which was adapted from the British DH-4 after America entered WWI in 1917 with no combat-worthy aircraft at the time, according to the National Air and Space Museum.

Dubbed the “Liberty Plane,” it was in use by several bomber squadrons, and in the post-war period, became the principal aircraft used by the U.S. government when airmail service began in 1918. To this day, it’s remembered as the great-grandfather of the country’s warplanes, Walker said.

“It’s important to the American fabric of today,” Walker said.

Walker, along with the group that helped restore the aircraft – Friends of Vintage Flight – hoped to use it as an educational tool. It was scheduled to tour several U.S. Air Force bases and in France before the coronavirus pandemic forced those events to be postponed, Walker said.

“We’re not exactly sure what happened,” Walker said. As he made a loop above the airport, Walker said he began to notice control issues with the plane. He managed to return it to the airport before the crash landing, which wasn’t far from where he took off.

Dr. Darrell Tade, a major with the Civil Air Patrol, witnessed the crash and said he examined Walker after the crash, finding only minor injuries. While the takeoff seemed like a normal one, Tade said he noticed the left wing dip down on the landing.

“The pilot controlled it as well as anyone could have,” Tade said, crediting Walker for returning to the airport before the crash.

This is the second plane crash Walker has survived. Saturday’s crash followed a similar incident in August 2017 in which Walker was involved, but not as the pilot. That crash involved a 1917-vintage Curtiss JN-4 biplane known as the Jenny, which was ultimately repaired. The fate of the DH-4 remains uncertain, Walker said.

“We’ve got to investigate with the (National Transportation Safety Board),” he said.

Walker has 350 hours of flight experience flying older biplanes, he said. A team of technicians invested about 10,000 hours in the aircraft’s restoration.

“I think their spirit brought me down OK,” Walker said.

https://www.bgdailynews.com

1 comment:

  1. The group that reworked the bird spent a lot of effort, hope they can repair the bird this time. Surprising to see a Liberty-engine plane still being flown.

    https://www.facebook.com/friendsofvintageflight/

    ReplyDelete