Saturday, September 24, 2016

Aero L-39 Albatros, N139AJ, registered to and operated by Warbirds LLC: Accident occurred September 23, 2016 at Hampton Roads Executive Airport (KPVG), Norfolk, Virginia

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

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Richmond, Virginia

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

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


Location: Norfolk, VA
Accident Number: ERA16LA322
Date & Time: 09/23/2016, 1215 EDT
Registration: N139AJ
Aircraft: AERO VODOCHODY L 39
Aircraft Damage: Substantial
Defining Event: Flight control sys malf/fail
Injuries: 1 None
Flight Conducted Under: Part 91: General Aviation - Personal

Analysis 

According to the private pilot of the jet trainer airplane, the airplane was on final approach for landing about 100 ft above ground level and 60 ft from the runway threshold, when there was an "uncommanded" retraction of the flaps. He adjusted the airplane's pitch and advanced the throttle in order to compensate for the flap retraction, increasing the airspeed from 90 knots to 130 knots. The airplane touched down on the runway and the pilot applied the brake pedals, followed by the emergency brake. As the airplane began to veer toward the side of the runway, the pilot released the emergency brake and continued to apply brakes using the brake pedals. The airplane continued off the departure end of the runway, struck trees, and came to rest about 1,050 ft from the end of the 5,350ft-long runway. While impact-related damage prevented a functional test of the airplane's normal and emergency flap extension systems, an examination of the flap system components revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. It is likely that the airplane's increased speed at the time of touchdown resulted in the runway excursion.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
An uncommanded flap retraction for reasons that could not be determined, as a postaccident examination of the flap system did not reveal evidence of any preaccident anomalies.

Findings

Aircraft
Trailing edge flaps - Malfunction (Cause)

Factual Information 

On September 23, 2016, at 1215 eastern daylight time, an Aero Vodochody L39, N139AJ, was substantially damaged after it impacted trees during a runway excursion while landing at Hampton Roads Executive Airport (PVG), Norfolk, Virginia. The private pilot was not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight that was operated under the provisions of 14 Code of Federal Regulations Part 91.

According to the pilot, the airplane was on final approach to runway 28, about 100 ft above ground level and 60 ft from the runway threshold, when there was an "uncommanded" retraction of the flaps. He adjusted the pitch of the airplane and advanced the throttle in order to compensate for the flap retraction. The airplane touched down on the paved surface of the runway, the pilot applied the brakes, and then he applied the emergency brake. As the airplane began to veer toward the side of the runway, the pilot released the emergency brake, and continued to apply the brakes utilizing the brake pedals. The pilot stated that the "normal" braking action was insufficient to keep the airplane from over-running the runway. The airplane continued off the departure end of the runway, struck trees, and came to rest about 1,050 feet from the end of runway 28, which was a 5,350-ft-long runway.

An examination of the runway revealed that skid marks from the airplane began around 1,000 ft prior to the departure end of the runway and continued into the area where the airplane came to rest.

According to Federal Aviation Administration (FAA) records, the airplane was issued an experimental exhibition airworthiness certificate on December 12, 2007. It was powered by a Ivchenko, AI-25TL engine. According to the pilot, the most recent condition inspection was performed on September 1, 2016, at an airframe total time of 3,016.9 total hours. According to the emergency checklist located in the airplane, it was equipped with an emergency flap extension system. The pilot did not mention using the emergency flap extension system during the accident sequence.

An examination of the flap system, under the oversight of an FAA inspector, revealed that there were no disconnects or abnormalities in the flap mechanical actuation system besides the impact damage, which prevented a test of the flap system. The flap actuator was intact and no evidence of hydraulic leakage was noted. The emergency flap extension handle located to the right of the pilot's seat was moved without anomaly.

A review of the accident airplane's flight manual revealed, under the conditions that existed at the time of the accident, that the landing ground roll distance was approximately 2,000 feet, and was based on the circumstances of idle engine power, full flaps, and the speedbrakes retracted. 

History of Flight

Approach-VFR pattern final
Flight control sys malf/fail (Defining event)

Landing-landing roll
Runway excursion
Collision during takeoff/land 

Pilot Information

Certificate: Private
Age: 62, Male
Airplane Rating(s): Multi-engine Land; Multi-engine Sea; Single-engine Land
Seat Occupied: Front
Other Aircraft Rating(s): Helicopter
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: 04/20/2015
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  1450 hours (Total, all aircraft), 60 hours (Total, this make and model), 1100 hours (Pilot In Command, all aircraft), 90 hours (Last 90 days, all aircraft), 12 hours (Last 30 days, all aircraft), 3 hours (Last 24 hours, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Manufacturer: AERO VODOCHODY
Registration: N139AJ
Model/Series: L 39 ZO
Aircraft Category: Airplane
Year of Manufacture: 1974
Amateur Built: No
Airworthiness Certificate: Experimental
Serial Number: 330214
Landing Gear Type: Retractable - Tricycle
Seats: 2
Date/Type of Last Inspection: 09/01/2016, Condition
Certified Max Gross Wt.: 9700 lbs
Time Since Last Inspection:
Engines: 1 Turbo Jet
Airframe Total Time: 3016.9 Hours as of last inspection
Engine Manufacturer: IVCHENKO
ELT: Installed, not activated
Engine Model/Series: AL-25SERIES
Registered Owner: WARBIRDS LLC
Rated Power: 3000 lbs
Operator: WARBIRDS LLC  
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PVG, 23 ft msl
Observation Time: 1215 EDT
Distance from Accident Site: 11 Nautical Miles
Direction from Accident Site: 216°
Lowest Cloud Condition: Scattered / 1800 ft agl
Temperature/Dew Point: 26°C / 22°C
Lowest Ceiling: Broken / 2600 ft agl
Visibility:  10 Miles
Wind Speed/Gusts, Direction: 5 knots, 20°
Visibility (RVR):
Altimeter Setting: 30.06 inches Hg
Visibility (RVV):
Precipitation and Obscuration:

No Obscuration; No Precipitation

Departure Point: LYNCHBURG, VA (LYH)
Type of Flight Plan Filed:  None
Destination: Norfolk, VA (PVG)
Type of Clearance: VFR Flight Following
Departure Time: 1145 EDT
Type of Airspace: 

Airport Information

Airport: HAMPTON ROADS EXECUTIVE (PVG)
Runway Surface Type: Asphalt
Airport Elevation: 28 ft
Runway Surface Condition: Dry
Runway Used: 28
IFR Approach: None
Runway Length/Width: 5350 ft / 100 ft
VFR Approach/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:  36.937500, -76.308611 (est)



NTSB Identification: ERA16LA322
14 CFR Part 91: General Aviation
Accident occurred Friday, September 23, 2016 in Norfolk, VA
Aircraft: AERO VODOCHODY L 39, registration: N139AJ
Injuries: 1 Uninjured.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.


On September 23, 2016, at 1250 eastern daylight time, an Aero Vodochody L39, N139AJ, was substantially damaged after it impacted trees at the departure end of runway 28 at Hampton Roads Executive Airport (PVG), Norfolk, Virginia. The private pilot was not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight that was operated under the provisions of 14 Code of Federal Regulations Part 91. 


According to the pilot, the airplane was on final approach to runway 28 when there was an "uncommanded" retraction of the flaps. He adjusted the pitch of the airplane and advanced the throttle in order to compensate for the flap retraction. The airplane touched down on the paved surface of the runway, the pilot applied the brakes, and then he applied the emergency brake. The airplane began to veer off to the side of the runway, the pilot released the emergency brake, and continued to apply the brakes utilizing the brake pedals. The airplane continued off the departure end of the runway, struck trees, and came to rest about 1,050 feet from the end of runway 28, which was a 5,350-foot-long runway. 


An examination of the runway revealed that skid marks from the airplane began around 1,000 feet prior to the departure end of the runway and continued into the area where the airplane came to rest.


The airplane has been retained for further examination.

No comments: