N4555W – Ground Loop Incident

Incident Type

Minor Incident

Investigation Status

Damage Estimate Received

Membership Status


NTSB Number


Damage Photos


Tail No.


Pilot Certificate

Flight Instructor

Total Time

5327 Hours

Time in Make/Model

Time in last 30 days

Approximate Damage

$ 10000

METAR Data (If Available)

Pilot Report

First flight with CFI to begin working on tail wheel endorsement. CFI was in the front seat. I was in the back seat. CFI was PIC. I was not manipulating the controls. He was demonstrating high speed taxi. First a full length run on 28R. The tower gave permission to do a 180 at end and high speed taxi back on 10L. Nearing the end of 10L speed was too high and he failed to decelerate soon enough, he turned too fast onto taxiway A to avoid going off the end of the runway and the plane ground looped. Ground loop caused left lower wing tip to strike the pavement. Taxied back to the hanger. Upon inspection, fabric torn on bottom of left wing tip, fabric wrinkled on top of left wing tip, left wheel strut bent, left wheel pant pressed against left tire, left wheel broken. No other apparent damage. I have no basis for estimating cost of repairs above and put in $7,500 above as a place holder

Passenger/Witness Report

As the instructor, I was demonstrating for my student a high-speed taxi on runway 10L. I misjudged the distance remaining to the end of the runway, so when I chopped the throttle, and brought the tail down, I tried to brake as aggressively as I could. The tail started to come up, so I did not add any more braking. I tried to cheat a high-speed taxi onto the taxiway, when the ground loop occurred. There was no prop strike, but there was damage to the left wing tip and left main landing gear and wheel. My student was not controlling the airplane, so 100% of the blame rests on my shoulder.

Additional Information

ATC Audio

FlightAware Track

NTSB Report

Coming Soon

Eyewitness Video

Board Files (Password Required)

Additional Narrative

As a result of the Membership Committee requesting a full committee meeting, there is additional information from the DoS in the investigation.


Reinstatement Recommendation - Member

Member Name:

Alan Ackerberg
Not applicable, the member was not at the controls and not under the instruction of Mr. Henshall.

Reinstatement Vote - Member

Reinstatement Recommendation - Instructor

Instructor Name:

Mark Henshall
As reported by CFI Mark Henshall:

The high-speed taxi is a fairly standard training maneuver that Tailwheel instructors will do with their students to teach skills needed for the landing roll out. I have given 668.6 hours of dual in tailwheel airplanes, and I demo this skill literally for every student, and then I have THEM perform the maneuver, with me controlling the throttle and guarding the rudder pedals and stick. I always do this on the first or second lesson. When it comes to Tailwheel training, 98% of our time is spent with touch and goes and ground handling, since in the air there is a little difference between a tailwheel and a tricycle airplane.

Regarding the incident in question, it was me at the controls not the student, and I misjudged the distance remaining to the end of the runway. Despite the stick being full aft and maximum braking (without nosing over), I knew we were going to run off the end of the runway. So I try to cheat a high-speed taxi onto taxiway A, but we were going to fast. This is when the ground loop occurred. Looking back on the situation, had I continued straight and ran off the end of the runway, I am pretty sure we would’ve had more damage, because likely the airplane would have nosed over in the dirt and resulted in a prop strike, which would have resulted in a necessary engine tear down.

Recommendations for Remediation from Paul Miko Tailwheel Instructor.

The high-speed taxi is a necessary part of tailwheel training. I propose making high speed taxi demonstrations a very structured demonstration that spells out exactly how, when and where we are going to perform them. I recommend that Mark writes up detailed specifics for MYF and SEE and we will disseminate them among the tailwheel instructors. Also somewhat unrelated, I suggest we move Mark to the purview of Zach Harris who supervises all of the tailwheel instructors that I know of. It will help standardization.

Reinstatement Vote - Instructor

This incident has been closed.

What is your vote for the reinstatement of Mr. Mark Henshall from the SI Recommendation?
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