Air Safety- Come in Spinner

Despite my frantic efforts to stop the tum, including a large burst of throttle, the starboard wing struck the building with an almighty bang. The aircraft was spun round by the force of the impact collapsing the port undercarriage leg and when the poor old Firefly finally came to rest, the spinner was actually inside the building. The shock to the building caused the plaster lining to disintegrate, sending a plume of white dust spiralling into the sky which evidently gave the impression that the aircraft had exploded!

A picture subsequently taken from inside the building, and which to my shame forever after featured prominently in the squadron line book, had the words “come in spinner” under it, taken from the title of that famous book which recently ran as a series on ABC TV.

After the dust had literally settled, and I had extracted myself from the aircraft, I was left with the puzzle as to what had happened?

At this point a description of the aircraft’s braking system is necessary. Like most British military aircraft of that era, the Firefly had pneumatic brakes which consisted of air bags which when pressure was fed to them expanded, forcing the brake shoes onto the drum. The system operated to a maximum of 110psi at each wheel and could be progressively controlled by a hand lever on the control column. A relay valve connected to the rudder bar provided differential braking, ie, if the rudder bar was neutral, pressure went to both brakes. As the rudder bar was progressively deflected to one side, the pressure was progressively directed to that side until with full rudder, only that side was braked.

The Firefly was an easy aircraft to taxi as it had a big rudder which was very effective when used with ajudicious burst of throttle. The technique was to use full rudder, a squeeze of brake if necessary, and throttle to help, particularly on windy days. We always taxied with care as you couldn’t see over the nose and a sudden stop was to be avoided. In addition we had had it drummed into us early on in our training that the brakes were only an aid to taxying, and that excessive use could lead to the bags bursting through a build up of heat.

At this stage of my flying career I had about three hundred hours in the Firefly and a fair amount of deck landing experience. The latter in particular soon developed your skills in taxying the aircraft as you had to be able to control it on a rolling deck with not much room to manoeuvre.

Returning to the accident, after a little thought it was pretty clear to me that the relay valve had jammed, locking the brakes on on the starboard side and that is what I put in my accident report. However, nothing could be found wrong with the valve on subsequent test. Imagine my surprise when sometime later, an entry appeared in my log book to the effect that the cause of the accident was pilot error!

Matters were handled in a very summary fashion in those days and my squadron commanding officer had decided that as nothing could be found wrong with the brakes, I must have been taxying too fast and lost control.

In the manner of a court of appeal, I requested to see Commander (Air) who in the FAA command structure is in charge of all flying at the Air Station.

I was greeted by the great man with a friendly “what’s the problem Norm”? and after I had politely set out my views on the matter I was informed that “the finding will stand Lee”. It didn’t take too much nouse to work out that I was in a no win situation and that it would be prudent to accept my lot and let the matter stand.

Time passed by and several years later I was posted to the flying instructor’s course at East Sale. During the ground phase of the course we went into the forces acting on an aircraft in flight and on the ground in considerable detail, more so than had been the case during my initial flying training course.

One day as we were discussing the forces in a ground loop, it slowly dawned on me that something had been missing in the investigation into my accident; I should add that the entry in my log book still rankled!

On return to NAS Nowra I immediately requested copies of the photographs of the accident which in my ignorance I had not studied in any detail at the time.

There was the evidence plain to see. Only the starboard wheel had left a skid mark, yet the port undercarriage leg had collapsed with the weight imposed on it. Clearly the starboard brake had been braking heavily and unless I had momentarily gone completely dyslexic and mistaken my right foot for my left, it could only have been caused by a failure of the relay valve!

However, the moral of the story is that innocent as I might have been, in those days of tailwheel aircraft there was no excuse for a taxying accident. We had it drummed into us that you should always be travelling slowly enough to be able to stop the aircraft in the circumstances prevailing at the time.

I wonder what is being taught nowadays?

I’ve still got the entry in my log book, however!