What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Pilot statement:
The planned flight was a personal training session in my Waco biplane. Weather conditions at Renton municipal airport (krnt) were VFR. ATIS was reporting clear skies, wind calm and visibility greater than 6 miles. Airport NOTAMS listed reil's and nob out of service but these would have no effect on my flight.
I was flying solo from the rear cockpit of the plane. I was cleared by the tower for a fractoria departure using runway 16. Once cleared of the area by tower, I proceeded to the lake sammamish and carnation valley practice areas.
My practice consisted of clearing turns, steep turns, slow flight, approach to landing and accelerated stalls. Once complete I contacted Renton tower and was given the east channel arrival. I was subsequently cleared to land runway 16. ATIS had changed but the same conditions existed, VFR, clear skies, wind calm and visibility greater than 6 miles.
With calm winds being reported and observed I set up for a tail low (semi-stall) landing. The approach and landing was clean and uneventful. With all wheels down and power to idle I steered the plane down the centerline.
Nearing the final stages of the landing rollout I noticed what seemed to be a listing of the plane to starboard. I was puzzled at what might be causing this but applied left rudder to correct. As the plane slowed, the rudder lost its effectiveness. The listing returned along with a slight swerving to the right. A moment later the plane entered a ground loop, turning 180 degrees to the right and coming to a stop off the runway in the turf.
I immediately contacted the tower and told them I was fine. I asked and received permission to exit the aircraft to inspect for damage. I found that the left lower wing had struck the turf, the aileron was damaged and the fabric under the wing had been punctured. The left front wheel pant was cracked. I returned to the cockpit and asked the tower for permission to taxi back to the hangar.
It is believed that the right swerve and ultimate ground loop was caused by inadvertent minor application of the right brake.
A Waco aircraft company mechanic has been dispatched to test for any mechanical dragging of the starboard brake. Then to facilitate the aircraft's repairs.
The owner of Waco advised that it is also very possible that I inadvertently applied braking pressure during the rollout. He suggested a new foot position that he and other Waco pilots employ. By holding ones heals together and toes apart, forming a "v", a pilot could be assured that inadvertent brake pressure wasn?t being applied. Then when it's time to use the brakes, return the feet to parallel. He also suggested the wearing of street or soft shoes. Not rigid pilot boots as I was wearing.
The damaged components are being returned to the factory in battle creek, Michigan for repair. They have estimated the repairs to cost $10,000. Waco mechanics will return with the repaired parts and re-certify the plane to "airworthiness".
When the plane is ready to fly, Waco will be sending a factory CFI to continue my training at my request.
As the FAA filed it
PILOT STATEMENT:
THE PLANNED FLIGHT WAS A PERSONAL TRAINING SESSION IN MY WACO BIPLANE. WEATHER CONDITIONS AT RENTON MUNICIPAL AIRPORT (KRNT) WERE VFR. ATIS WAS REPORTING CLEAR SKIES, WIND CALM AND VISIBILITY GREATER THAN 6 MILES. AIRPORT NOTAMS LISTED REIL'S AND NOB OUT OF SERVICE BUT THESE WOULD HAVE NO EFFECT ON MY FLIGHT.
I WAS FLYING SOLO FROM THE REAR COCKPIT OF THE PLANE. I WAS CLEARED BY THE TOWER FOR A FRACTORIA DEPARTURE USING RUNWAY 16. ONCE CLEARED OF THE AREA BY TOWER, I PROCEEDED TO THE LAKE SAMMAMISH AND CARNATION VALLEY PRACTICE AREAS.
MY PRACTICE CONSISTED OF CLEARING TURNS, STEEP TURNS, SLOW FLIGHT, APPROACH TO LANDING AND ACCELERATED STALLS. ONCE COMPLETE I CONTACTED RENTON TOWER AND WAS GIVEN THE EAST CHANNEL ARRIVAL. I WAS SUBSEQUENTLY CLEARED TO LAND RUNWAY 16. ATIS HAD CHANGED BUT THE SAME CONDITIONS EXISTED, VFR, CLEAR SKIES, WIND CALM AND VISIBILITY GREATER THAN 6 MILES.
WITH CALM WINDS BEING REPORTED AND OBSERVED I SET UP FOR A TAIL LOW (SEMI-STALL) LANDING. THE APPROACH AND LANDING WAS CLEAN AND UNEVENTFUL. WITH ALL WHEELS DOWN AND POWER TO IDLE I STEERED THE PLANE DOWN THE CENTERLINE.
NEARING THE FINAL STAGES OF THE LANDING ROLLOUT I NOTICED WHAT SEEMED TO BE A LISTING OF THE PLANE TO STARBOARD. I WAS PUZZLED AT WHAT MIGHT BE CAUSING THIS BUT APPLIED LEFT RUDDER TO CORRECT. AS THE PLANE SLOWED, THE RUDDER LOST ITS EFFECTIVENESS. THE LISTING RETURNED ALONG WITH A SLIGHT SWERVING TO THE RIGHT. A MOMENT LATER THE PLANE ENTERED A GROUND LOOP, TURNING 180 DEGREES TO THE RIGHT AND COMING TO A STOP OFF THE RUNWAY IN THE TURF.
I IMMEDIATELY CONTACTED THE TOWER AND TOLD THEM I WAS FINE. I ASKED AND RECEIVED PERMISSION TO EXIT THE AIRCRAFT TO INSPECT FOR DAMAGE. I FOUND THAT THE LEFT LOWER WING HAD STRUCK THE TURF, THE AILERON WAS DAMAGED AND THE FABRIC UNDER THE WING HAD BEEN PUNCTURED. THE LEFT FRONT WHEEL PANT WAS CRACKED. I RETURNED TO THE COCKPIT AND ASKED THE TOWER FOR PERMISSION TO TAXI BACK TO THE HANGAR.
IT IS BELIEVED THAT THE RIGHT SWERVE AND ULTIMATE GROUND LOOP WAS CAUSED BY INADVERTENT MINOR APPLICATION OF THE RIGHT BRAKE.
A WACO AIRCRAFT COMPANY MECHANIC HAS BEEN DISPATCHED TO TEST FOR ANY MECHANICAL DRAGGING OF THE STARBOARD BRAKE. THEN TO FACILITATE THE AIRCRAFT'S REPAIRS.
THE OWNER OF WACO ADVISED THAT IT IS ALSO VERY POSSIBLE THAT I INADVERTENTLY APPLIED BRAKING PRESSURE DURING THE ROLLOUT. HE SUGGESTED A NEW FOOT POSITION THAT HE AND OTHER WACO PILOTS EMPLOY. BY HOLDING ONES HEALS TOGETHER AND TOES APART, FORMING A "V", A PILOT COULD BE ASSURED THAT INADVERTENT BRAKE PRESSURE WASN?T BEING APPLIED. THEN WHEN IT'S TIME TO USE THE BRAKES, RETURN THE FEET TO PARALLEL. HE ALSO SUGGESTED THE WEARING OF STREET OR SOFT SHOES. NOT RIGID PILOT BOOTS AS I WAS WEARING.
THE DAMAGED COMPONENTS ARE BEING RETURNED TO THE FACTORY IN BATTLE CREEK, MICHIGAN FOR REPAIR. THEY HAVE ESTIMATED THE REPAIRS TO COST $10,000. WACO MECHANICS WILL RETURN WITH THE REPAIRED PARTS AND RE-CERTIFY THE PLANE TO "AIRWORTHINESS".
WHEN THE PLANE IS READY TO FLY, WACO WILL BE SENDING A FACTORY CFI TO CONTINUE MY TRAINING AT MY REQUEST.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.