In a spin

 

Inspired by master spinner Rich Stowell’s salute to Harry Hawker 100 Years of Intentional Spins (do make sure you watch it) I looked up that original account of the first described spin recovery by Wilfred Parke.

What follows is Flight magazine’s original account of the event, with a PDF of the full, original article down below.

From Flight, August 31st, 1912

Salisbury Plain, Sunday, August 25th

Here is the true story of one of the worst experiences in mid-air from which any pilot has extricated his machine in absolute safety, and as the circumstances precisely represent the hypothesis of the most debated problem among pilots at the present time, the following particulars should be studied with the closest attention by all.

Avro G

At four minutes past six this morning Lieutenant  Parke, RN, accompanied by Lieutenant Le Breton, RFC as observer, started on the Avro biplane (60 hp Green engine) from Salisbury Plain for the three hours’ qualifying flight in the Military Trials.

At ten minutes past nine, having more than completed the required duration, he was returning from the direction of Upavon for the express purpose of alighting in front of the sheds.

The direction of flight was practically towards due south ; the wind was blowing approximately from the south-west, with a tendency to back southwards. He was, therefore, flying virtually up wind. The speed of the wind was estimated about 10–15 mph by the pilot, and the maximum air speed of the machine with the present propeller is about 60 mph, as tested over the measured distance yesterday. The engine was pulling well, and the machine in perfect trim. There was bright sunshine and some clouds.

Flight's sketch of the incident, with the lettered points described in the text.
Flight’s sketch of the incident, with the lettered points described in the text.

Throughout the flight an altitude of between 600 and 700 ft. was maintained, and the pilot, observing that he was still at this height, decided that he had sufficient room for a spiral glide. At the point A, in the diagram, he closed the throttle without switching off (which kept the engine just turning) and immediately proceeded to glide round down wind.

At the point B, having completed a half spiral, Parke thought the machine was in an unnecessarily steep attitude, and was insufficiently banked for the turn he was making. He therefore elevated, and believes that he may also have given a momentary touch to the warp, which two operations were for the purpose of reducing the steepness of the descent and increasing the bank respectively.

The machine at once started a spiral nose-dive.

At point C, Parke opened the throttle full out, in the hope that the propeller might pull the nose up, for he was aware (and had also confirmed the fact during this flight) that the machine was slightly nose-heavy with the throttle closed. The engine responded instantly, but failed to produce the desired effect on the machine; it may or may not have accelerated the descent, but the fall was already so rapid that the maximum engine speed was unlikely even to be equal to it.

The Avro Type G at Larkhill, August 1912
The Avro Type G at Larkhill, August 1912

Also at point C, he drew the elevator lever hard back against his chest and put the rudder hard over to the left with his foot so as to turn the machine inwards, this being the proper action in an incipient side-slip and, therefore, naturally to be tried in an emergency such as this. The warp was neutral. These operations failed utterly to improve the conditions.

From C to D the machine was completely out of control, diving headlong at such a steep angle that all spectators described it as vertical and stood, horror stricken, waiting for the end. According to Parke, the angle was very steep, but certainly not vertical; he noticed no particular strain on his legs (he still kept the rudder about half over to the left) nor on his chest, where he wore a wide belt strapping him to his seat.

He had already removed his right hand  from the control wheel in order to steady himself by grasping the upright fuselage strut between the windows. He did this not for support against the steepness of the descent, but because he felt himself being thrown outwards by the spiral motion of the machine, which he described as ‘violent’.

The absence of pressure on the legs and arms appears to be evidence that the machine was falling as fast as the pilot, who was, therefore, unstable on his seat, and without a fulcrum until he fastened himself to the framework by the grip of his hand.

Parkes2

It was Parke’s recognition that the predominating force was the spiral motion, as distinct from the dive, that caused him to ease off the rudder and finally push it hard over to the right (i.e. to turn machine outwards from the circle), as a last resort, when about 50 feet from the ground. 

Instantly, but without any jerkiness, the machine straightened and flattened out—came at once under control and, without sinking appreciably, flew off in perfect attitude.

Parke made a circuit of the sheds in order to get into position for landing in a good place up wind, and proceeded to alight in the usual way without the least mishap. Thus did he and his observer (who, having no belt and rather cramped accommodation, was thrown up against the front wall of the cabin) escape at the last moment from what looked like certain death. Indeed, they effected a perfect landing with the machine none the worse for its severe straining, save a slight stretching of some of the lift-wires under the main planes.

Avro Type G

In an interesting addendum, Flight went on to point out:

“Of the many important and interesting aspects of the case, one is obviously related to the value of flying high. But for the room available for the fall, disaster was unavoidable. For the first 100 ft. the descent was normal, but, afterwards, acceleration to something in the order of 90 m.p.h. (speed suggested by de Havilland) took place, and the machine fell about 450 ft. whilst more or less out of control—which is a lesson those who have not yet learnt would do well to bear in mind.”

Interesting, because this comment became a sad pointer to Parke’s death just a few months later, on Sunday December 18th, 1912, when his Handley-Page monoplane spun from a low level turn as Parke attempted that other famously lethal manoeuvre – turning back to his departure field with engine trouble.

Flight Page

 

 

Download the full article (pdf, 1.1MB)

Parke’s Dive (Flight, Aug 31st, 1912)

 

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One thought on “In a spin

  1. I should probably point out that opening the throttle “full out” is not a recommended spin recovery procedure in any airplane I can think of. In fact, it could easily be a fatal mistake.

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