Monday, February 25, 2019

Piper PA-25-235 Pawnee, owned and operated by the Skyline Soaring Club under the provisions of Title 14 Code of Federal Regulations Part 91, N90866: Fatal accident occurred October 07, 2017 near Front Royal-Warren County Airport (KFRR), Front Royal, Warren County, Virginia

Steven B. Zaboji

Zaboji, 76, lived in Reston, Virginia, and has been an aviation enthusiast for most of his life. A highly experienced pilot, Steve logged 12,000 hours of flight time in a wide variety of single and multi-engine aircraft and was a flight instructor and mentor to many in the aviation community. Steve was also a frequent writer and speaker for aviation publications and organizations. 

On Facebook, Zaboji’s son, Chris Zaboji, wrote:
It is with great sadness that I write tonight, my father, Steven Zaboji, was in a fatal aircraft accident this afternoon. It’s hard to believe and we are all still in shock, doubting that the reality is true. Being able to share aviation with him made us very close, and to lose such a mentor is heartbreaking.

The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Herndon, Virginia
Skyline Soaring Club; Front Royal, Virginia
Lycoming Engines; Williamsport, Pennsylvania

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


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

http://registry.faa.gov/N90866 

Steve Zaboji

Location: Front Royal, VA
Accident Number: ERA18FA006
Date & Time: 10/07/2017, 1345 EDT
Registration: N90866
Aircraft: PIPER PA 25-235
Aircraft Damage: Destroyed
Defining Event: Loss of control in flight
Injuries: 1 Fatal
Flight Conducted Under: Part 91: General Aviation - Glider Tow 

On October 7, 2017, about 1345 eastern daylight time, a Piper PA-25-235 airplane, N90866, was destroyed when it impacted terrain during initial climb after takeoff from Front Royal-Warren County Airport (FRR), Front Royal, Virginia. The airline transport pilot was fatally injured. The airplane was owned and operated by the Skyline Soaring Club under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the airport, and no flight plan was filed for the local glider tow flight.

According to the glider flight instructor, he was providing an introductory glider flight to a passenger in the glider. The passenger was seated in the front seat, and the instructor was seated in the rear seat. He stated that the takeoff from runway 28 was normal and that he then looked away from the tow plane briefly to adjust a video camera. When he looked back toward the tow plane, he did not immediately see it but then noted that it was below and right of the glider. Additionally, the flight instructor noticed slack in the tow rope that attached the glider to the tow plane. He then released the tow rope, turned the glider 180°, and landed uneventfully. While approaching the runway, the glider flight instructor saw a fireball from where the tow plane had been descending. Several witnesses at the airport stated that the takeoff appeared to be normal but that the tow plane then pitched down, descended below the glider, and turned right before impacting terrain.


Steve Zaboji

Pilot Information

Certificate: Airline Transport; Commercial
Age: 76, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land
Seat Occupied: Single
Other Aircraft Rating(s): None
Restraint Used: 4-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): Airplane Multi-engine; Airplane Single-engine; Instrument Airplane
Toxicology Performed: Yes
Medical Certification: Class 2 With Waivers/Limitations
Last FAA Medical Exam: 10/01/2015
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  11953 hours (Total, all aircraft)

The tow plane pilot, age 76, held airline transport and commercial pilot certificates with an airplane multiengine land rating and an airplane single-engine land rating, respectively. Additionally, the pilot held a flight instructor certificate with airplane single- and multiengine and instrument airplane ratings. His most recent Federal Aviation Administration (FAA) second-class medical certificate was issued on October 1, 2015. At that time, the pilot reported a total flight experience of 11,953 hours. The pilot's logbook was not recovered.

The glider flight instructor held a commercial pilot certificate with ratings for airplane single-engine land, airplane single-engine sea, airplane multiengine land, instrument airplane and glider. He also held a flight instructor certificate with a rating for glider. His most recent FAA second-class medical class medical certificate with issued on March 30, 2017. The glider flight instructor reported a total flight experience of 1,580.2 hours; of which 107.7 hours were in gliders. 

 It was a solemn scene inside the KFRR terminal in the hours after the fatal crash.

Aircraft and Owner/Operator Information

Aircraft Make: PIPER
Registration: N90866
Model/Series: PA 25-235 UNDESIGNATED
Aircraft Category: Airplane
Year of Manufacture: 1981
Amateur Built: No
Airworthiness Certificate: Restricted
Serial Number: 25-8156005
Landing Gear Type: Tailwheel
Seats: 1
Date/Type of Last Inspection: 02/02/2017, Annual
Certified Max Gross Wt.: 2900 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 8265 Hours as of last inspection
Engine Manufacturer: LYCOMING
ELT: Not installed
Engine Model/Series: O-540-B2C5
Registered Owner: SKYLINE SOARING CLUB
Rated Power: 235 hp
Operator: SKYLINE SOARING CLUB
Operating Certificate(s) Held: None 

The single-seat, low-wing, fixed-tailwheel airplane was manufactured in 1981. It was powered by a Lycoming O-540, 235-horsepower engine and was equipped with a Hoffman four-blade, fixed-pitch wooden propeller. Review of the maintenance records revealed that the tow plane's most recent annual inspection was completed on February 2, 2017. At that time, the airframe had accumulated about 8,265 total hours of operation, and the engine had accumulated 468 hours since overhaul.



Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: FRR, 703 ft msl
Distance from Accident Site: 1 Nautical Miles
Observation Time: 1355 EDT
Direction from Accident Site: 110°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 10 knots / 15 knots
Turbulence Type Forecast/Actual: None / None
Wind Direction: 230°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.01 inches Hg
Temperature/Dew Point: 29°C / 14°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Front Royal, VA (FRR)
Type of Flight Plan Filed: None
Destination: Front Royal, VA (FRR)
Type of Clearance: None
Departure Time: 1344 EDT
Type of Airspace:  

The recorded weather at FRR, at 1355, was wind from 230° at 10 knots, gusting to 15 knots; visibility 10 statute miles; clear sky; temperature 29°C; dew point 14°C; and altimeter 30.01 inches of mercury.



Airport Information

Airport: Front Royal (FRR)
Runway Surface Type: Asphalt
Airport Elevation: 703 ft
Runway Surface Condition: Dry
Runway Used: 28
IFR Approach: None
Runway Length/Width: 3007 ft / 75 ft
VFR Approach/Landing: None

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Destroyed
Passenger Injuries: N/A
Aircraft Fire: On-Ground
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude: 38.920278, -78.263056 (est) 

The wreckage was consumed by a postcrash fire and located in the backyard of a residence, about 1,600 ft northwest of the departure end of runway 28. A small crater was observed in the grass, consistent with engine contact, and fragments of the propeller were also located near the crater. The main wreckage came to rest upright about 65 ft north of the crater. The tow rope was also located along the debris path.

The left main landing gear (MLG) had separated and was located left of the main wreckage. The right MLG and tailwheel remained attached. All major components of the tow plane were accounted for at the scene.
The flaps and ailerons were located with their respective wing, but the wings were consumed by fire. Control cable continuity was confirmed from the left and right ailerons to the control stick in the cockpit. Continuity was also confirmed from the elevator and rudder to the control stick and rudder pedals, respectively. No readable instruments were recovered from the cockpit.

The engine had separated from the airframe and was resting in front of it. The four wooden propeller blades had separated from the hub. Two of the propeller blade roots remained attached to the hub. The engine's valve covers were removed, and oil was noted throughout the engine. The top spark plugs were removed, and the propeller was rotated by hand. Camshaft, crankshaft, and valve train continuity were confirmed to the rear accessory section. Thumb compression was attained on all cylinders. Borescope examination of the cylinders was unremarkable for the pistons and valves. The bottom spark plugs were then removed from the engine. All spark plug electrodes were intact, and no damage was noted. The engine-driven fuel pump was removed from the engine. The screws that attached the engine-driven fuel pump to the engine were noted to be finger tight, as were the screws that secured the pump; however, when the pump was disassembled, disintegration of the internal components was noted, consistent with thermal damage. The carburetor was disassembled, its plastic floats were melted, and its needle was intact. The fuel inlet screen to the carburetor was present and exhibited some debris, consistent with fire damage. The oil filter was opened, and no contamination was observed. Both magnetos sustained thermal damage and did not produce spark when rotated via an electric drill. The oil suction screen was absent of debris.

About 145 ft of tow rope was recovered at the accident site; about 5 ft of rope at the Tost reel (spool of rope on the tow plane) was presumed consumed by fire. Additionally, about 10 ft of rope aft of the tow plane was consumed by fire. The other (glider) end of the tow rope appeared separated, and a section of that rope was retained for further examination. The Tost weak link ring assembly (end of rope that attaches to glider) was not located. The tow rope adjacent to the guillotine was examined further, and no guillotine or other marks were noted on the tow rope.

The pilot's seat was equipped with a four-point inertial reel harness system, and the inertial reel had sustained impact and fire damage. The lock control was in the "full-aft" position and would not move. The cable was fully retracted to the stop in the inertial lock reel and would only move about 1/8 inch. The cable had separated at a length consistent with the 90° pulley wheel, and the pulley wheel remained intact and attached to the airframe. The examination did not reveal evidence of any preimpact malfunctions with the airframe or engine. 

The ‘X’ marks approximate location of crash in relation to airport on Warren County map.

Medical And Pathological Information

The Office of the Chief Medical Examiner, Manassas, Virginia, performed an autopsy of the tow plane pilot. The cause of death for the pilot was "blunt force trauma to the neck, torso, and extremities, thermal injuries, and blunt force trauma." According to the autopsy report, the pilot's heart weighed 560 grams; the average heart weight for a 190-lb man, the pilot's weight, is 367 grams with a range of 278 to 484 grams. In addition, the pilot had mild-to-moderate atherosclerosis, described as 50% stenosis in the proximal and 75% stenosis in the distal right coronary artery. He also had 50% stenosis in the left anterior descending coronary artery. The autopsy report did not note any evidence of heart attack.

The FAA's Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma, conducted toxicological testing on a specimen from the pilot. The testing detected atorvastatin, a cholesterol lowering drug that is not considered impairing, in the blood and liver.

According to FAA records, at the time of his last medical examination in October 2015, the pilot was 71 inches tall and weighed 190 lbs. The pilot reported that he had hypertension, high cholesterol, and coronary artery disease. Although the coronary artery disease was diagnosed by cardiac catheterization in 2004, he did not report this to the FAA until 2015. The catheterization revealed that the disease was nonocclusive and mild to moderate. His personal records indicated that he subsequently had annual cardiac calcium scoring and that, when his results increased significantly in early 2015, he underwent a thalium stress test that showed that he had transient ischemic dilation. 

From Ridgeway Rd. looking east back down the runway the towplane and glider were departing westward from. The entrance to the accident scene is about a third of a mile further down Ridgeway to left.


Tests And Research

Video Study

The glider flight instructor recorded two videos on a GoPro Hero 5 video camera that included most of the flight. Although the videos did not capture the tow plane's ground impact, they captured portions of the tow plane's flight just before impact. Copies of the videos were forwarded to the National Transportation Safety Board Vehicle Recorders Laboratory, Washington, DC, for further examination.

When the first video ended, the tow plane and glider were on the upwind leg of the airport traffic pattern, during initial climb, and the glider's altimeter indicated about 890 ft mean sea level (msl) (about 200 ft above ground level). The glider's airspeed indicated about 60 knots, and the glider's position relative to the tow plane was consistent with a high-tow position (that is, the glider was positioned slightly above the wake of the tow plane). The recording stopped for unknown reasons, and a new recording about 5 seconds later.

At the start of the second video, the tow plane was not visible in the camera's field of view. After about 5 seconds, the glider's blue spoiler/brake handle was nearly full aft, and the yaw string was about 45° right. The glider's instruments indicated about 940 ft msl and about 70 knots. The tow plane's right wing came into view right of the glider's nose and below the glider. At 7 seconds, the glider's nose yawed right, and the yaw string was nearly 90° right. At 8 seconds, the glider's yellow tow rope release handle moved aft momentarily. Relative to the glider's movement, the tow plane's right wingtip moved down and left, out of the camera's field of view. At 9 seconds, a snapping sound was heard, followed by the tow rope release handle being extended about 6 inches and dangling down. In the last frame in which the tow plane was visible, its elevator appeared to be in the "up" position. The glider then turned left and returned to the airport.

About 13 seconds elapsed between the end of the first video and when the tow plane is visible in the second video. Based on the glider altimeter readings that can be seen in the videos, the glider climbed about 50 ft during this time, from 890 to 940 ft msl. Video analysis showed that the tow plane altitude relative to the glider decreased by 63 ft during these 13 seconds (based on an estimated tow rope length of 160 ft).

Materials Examination

Microscopic examination of the tow rope separation revealed features indicative of overstress separation, consistent with the tow rope breaking while the glider was still attached to the tow plane. Additionally, a dark band with a metallic sheen was visible on the rope near the separation, indicating that the separation point was near the Tost weak link.

Additional Information

According to the FAA Glider Flying Handbook (FAA-H-8083-13A), "One of the most dangerous occurrences during aerotow is allowing the glider to fly high above and losing sight of the towplane. The tension on the towline caused by the glider pulls the towplane tail up, lowering its nose. If the glider continues to rise, pulling the towplane tail higher, the tow pilot may not be able to raise the nose. Ultimately, the tow pilot may run out of up elevator authority." Further review of the handbook revealed, "Upon losing sight of the towplane, the glider pilot must release immediately."

Airport Manager Reggie Cassagnol’s vehicle leaves the scene.

NTSB Identification: ERA18FA006 
14 CFR Part 91: General Aviation
Accident occurred Saturday, October 07, 2017 in Front Royal, VA
Aircraft: PIPER PA 25-235, registration: N90866
Injuries: 1 Fatal.

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 either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

On October 7, 2017, about 1345 eastern daylight time, a Piper PA-25-235, N90866, was destroyed when it impacted terrain during initial climb from Front Royal-Warren County Airport (FRR), Front Royal, Virginia. The airline transport pilot was fatally injured. The airplane was operated by the Skyline Soaring Club as a glider-tow flight conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight.

According to the flight instructor in the glider that was being towed, he was providing an introductory glider flight to a passenger in the glider. The passenger was seated in the front seat and the instructor was seated in the rear seat. He stated that the takeoff from runway 28 was normal and he momentarily looked away from the tow airplane at a low altitude. When he looked back, he did not immediately see the airplane and then noted that it was below and to the right of the glider. Additionally, the flight instructor noticed slack in the cable attaching the glider to the airplane. He then released the cable, performed a 180° turn, and landed on runway 10 uneventfully. While approaching the runway, the flight instructor saw a fireball from where the airplane had been descending. Several witnesses at the airport stated that the takeoff appeared to be normal, but then the airplane pitched down, descended below the glider and turned right before impacting terrain.

The wreckage was consumed by a postcrash fire and located in the backyard of a residence, about 1,600 ft northwest of the departure end of runway 28. A small crater was observed in the grass, consistent with engine contact and fragments of the propeller were also located near the crater. The main wreckage came to rest upright, on a magnetic heading of 315°, about 65 ft north of the crater. The tow cable was also located along the debris path. The left main landing gear had separated and was located left of the main wreckage. The right main landing gear and tailwheel remained attached. All major components of the airplane were accounted for at the scene. The flaps and ailerons were located with their respective wing, but the wings were consumed by fire. Control cable continuity was confirmed from the left and right ailerons to the control stick in the cockpit. Continuity was also confirmed from the elevator and rudder to the control stick and rudder pedals, respectively. No readable instruments were recovered from the cockpit.

The engine separated from the airframe and was resting in front of it. The four wooden propeller blades separated from the hub and two of the propeller blade roots remained attached to the hub.

The single-seat, low-wing, fixed tailwheel airplane was manufactured in 1981. It was powered by a Lycoming O-540, 235-horsepower engine, equipped with a Hoffman four-blade, fixed-pitch wooden propeller. Review of the maintenance records revealed that the airplane's most recent annual inspection was completed on February 2, 2017. At that time, the airframe had accumulated about 8,265 total hours of operation and the engine had accumulated 468 hours since overhaul.

The pilot held an airline transport pilot certificate with a rating for airplane multiengine land. He also held a commercial pilot certificate with a rating for airplane single-engine land. Additionally, the pilot held a flight instructor certificate with ratings for airplane single-engine, airplane multiengine, and instrument airplane. His most recent Federal Aviation Administration second-class medical certificate was issued on October 1, 2015. At that time, the pilot reported a total flight experience of 11,953 hours.

The recorded weather at FRR, at 1355, was: wind from 230° at 10 knots, gusting to 15 knots; visibility 10 statute miles; clear sky; temperature 29° C; dew point 14° C; altimeter 30.01 inches of mercury.

The wreckage was retained for further examination. The flight instructor in the glider recorded a video of most of the flight. While the recording did not capture the actual impact of the airplane, it captured portions of the airplane's flight just prior to impact. A copy of the recording was forwarded to the NTSB Vehicle Recorders Laboratory, Washington, DC, for further examination.

2 comments:

Anonymous said...

Maybe the glider pilot shouldn't have been playing with his camera in a critical phase of flight. Electronic gadgets in the cockpit are now the norm but just like sterile cockpit rules for unnecessarily talking, we should develop good habits of when not to fiddle with these devices. It only took a few seconds of inattention for the glider to lose sight of the tow plane and the result was tragic.

Anonymous said...

After reading the article I totally agree with the above poster. Glider pilot should have been flying the plane more precisely to prevent him from pulling the tow planes tail upward most likely causing him to lose control and crash. I feel extreme sympathy for the son that lost his father in this crash. I too lost my father but to natural causes which makes it a little easier to bear.