Fair comment
Now here's another 'Chiropractic Special' ...
'Haggiography' - Lying Down on the Job in Walton-on-ThamesThe first part of Arthur Hagg's D.H.88 assignment had been to assess the feasibility of the A&AEE prone-pilot testbed concept. was feasible. This too was aimed at the new RAF High Speed Experimental Flight - not because such a design was expected to be especially fast but, rather, to determine the value of prone-pilot positions in future high-speed aircraft. By the time Hagg and his Walton Yacht Works team had turned their attention to the prone-pilot testbed, the HSEF was already losing interest in Hagg's genuinely high-speed proposals. [1] Regardless, Hagg's prone-pilot proposal owed something to the first of those single-engine conversion proposals.
Like the first single-engined concept, Hagg's prone-pilot proposal raised the original D.H.88 wings to a mid-fuselage position. There the similarity ended. Other than this wing repositioning, the Hagg proposal followed the A&AEE's prone-pilot concept quite closely. An obvious difference was that pilot's legs now lay below the wing centre section. The fuel tank above the raised wing was necessarily small. However, this was not seen as a problem as longer flights were not meant to be part of the A&AEE test programme. The Air Ministry accepted this proposal - as the D.H. HSP (for High-Speed Prone). Again, the terminology reflected use by the HSEF rather than an anticipated high speed.
Top Arthur Hagg's D.H.88 prone-pilot conversion as originally proposed, October 1937.
Model-makers at Walton produced a 1/18th scale test article for wind tunnel trials. The 24 foot low-speed wind tunnel at Farnborough produced some unanticipated results. Raising the wings obviously also raised the engines' thrustline. Unfortunately, scaled testing at Farnborough revealed that the resulting propeller wash was likely to create tailplane flutter. The only solution was to redesign the tailplane to raise the D.H.88's stabilizers and elevators up out of this propeller-generated turbulence. Fortunately, this could be accomplished through modifying existing components. Hagg also took the opportunity to refine the tail cone and introduce a tailwheel for better ground handling.
Bottom Revised D.H.88 (HSP) '
Prone Comet' conversion as completed, January 1938.
Actual modifications of
Comet K5084 airframe components were completed fairly quickly at Walton. Those components were assembled at RAF Martlesham Heath in late January 1938. With ground checks finished, testpilot Flt Lt H.M. Schofield took the rebuilt '
Prone Comet' into the air early on Thursday, 10 February 1938. [2] In his assessment, Harry Schofield ranked flying characteristics to be as good or better than the standard D.H.88. Visibility during take-off and landing were gauged of "an order of magnitude improvement" over the restricted sightlines from the standard, rear-cockpit
Comet. The choice to go with a prone-pilot conversion of K5084 were vindicated.
The rebuilt
Comet provided a wealth of test data on prone-position flying. Most of this test work was performed by Sqn Ldr D'Arcy Greig, DFC. [3] It was Greig who was at the controls of K5084 when it experienced an uncontrollable engine fire in flight on 13 June 1938. Greig was forced to take to his parachute over Gedgrave Hall. The burning aircraft came down in the North Sea off of Orford Ness. Settling in over 60 feet of water, no attempt was made to recover the wreckage of the D.H.88 HSP.
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[1] It was now concluded that service aircraft like the new Hawker
Hurricane fighter would be more than adequate to meet the needs of the RAF High Speed Experimental Flight. By the time that either of the single-engined Hagg proposals could be finished, sufficient
Hurricane fighters would be available to spare some for HSEF use.
[2] HSEF commander, (T) Wg Cdr Sidney Webster, had convinced RAF Reserve officer and former Schneider Trophy pilot, Flt Lt Schofield, to take on HSEF test pilot duties. Harry Schofield took unpaid leave from his employers, General Aircraft Ltd., to perform this work.
[3] D'Arcy Greig was another veteran of the original High Speed Flight. Now-Sqn Ldr Greig was seconded to the HSEF on leave from his CFI duties at the Central Flying School at RAF Upavon, Wilts.