Douglas A-4D-5 Skyhawk. Radio control semi-scale sport model for .51 power.
Quote: "Douglas A-4D-5 Skyhawk by Stan Hines. Foam and frame team up to create a Semi-Scale Navy machine. Super Tigre .51 and a radio command send it across the blue.
This bantam jet with a wingspan smaller than a Cub may well go down in aviation history as the finest Naval attack aircraft ever built. Scrappy, durable, Herculean, gangly, this Tom Thumb of the Navy and Marines is affectionately known as the 'Ford' not only because of the obvious 4D, but more from its ease of maintenance and ability to bring its pilot home after a fight.
Conceived in 1948 by Edward H. Heineman, Chief Engineer of Douglas El Segun, do Division and first flown in June of 1954, it saw combat duty for the first time in 1964 in attacking North Vietnamese coastal routes. It was soon to become the favorite of the pilots who respected its ability to take great punishment and still get them home. I have some pictures of Fords flying with the rudder and much of the fin shot away; another of two mechanics standing in a hole shot through the wing and more, but these planes got back. It stayed in service as a first line ship until replaced by the F-4 Phantom. In all more than 2,500 of Heineman's 'Hot-Rods' have been delivered to the United States and a fair number to other countries such as Australia, Argentina and Israel to name a few.
The Navy wanted an attack plane capable of delivering a tactical nuclear device and after the then usual design competi-tion, awarded Douglas a contract for both prototype and production ships. This was a bold step considering that the A-4D represented a reversal of the trend toward larger and larger planes and abandonment of a near tradition in the Navy that carrier planes must have folding wings. The ultra-short delta wing was borrowed from the larger F4D-1 Skyray, but a conventional tail was added, probably from the D-559 Skyrocket. The result was a tiny plane having a dry weight of only 8,000 pounds, powered by a Wright J 65-W-2 engine capable of delivering nearly 8,000 pounds thrust which permitted the 'Ford' to carry over twice its weight in combat load at speeds well over 700 mph and still land at less than 100.
I had an opportunity to examine the plane and talk with a Marine pilot at Glyn-co Naval Air Station during an Open House weekend a few years ago and fell in love with it too. I'll admit to some weakness for Marine tales, however, having served three years in the Corps, including six months on a carrier. It was not until recently that I began experimenting with some stability calculations which convinced me that a near-scale R/C model was not only possible but also practical. So, it was off to the drawing board for my first delta wing, a military, semi-scale jet in Marine dress, of course.
The A-4D has gone through at least five major model changes in more than a dozen years including two place training types. One of the later versions (1961) is the A-4D-5 (A-4E) which was powered by a Pratt and Whitney J-52-P-3 giving nearly 10,000 pounds thrust. The length had increased from 39 to 43 feet and it could carry nearly 50% more load on its tiny, 27-1/2 foot wings. This is the model I chose to work with and that you see in the accompanying photographs.
The model, unlike its namesake, is not for everybody. It definitely is not for the beginner to build or to fly. Not that building it is that hard, but actually it is intended for an experienced radio modeler. After a few preliminary considerations of size, weight and power it was decided to draw the side view approximately to a 1 in to the foot scale. The final scale was about 10% larger, giving an overall model length of about four feet. The same scale is used for the wing chord, but I am not about to try to fly a model powered by an ST .51 that has a wingspan of less than 30 in. Early calculations indicated 45 in was probably a safe compromise, so construction of the fuselage was begun. Based on some earlier experience a strong skeleton would be needed with the proposed foam and balsa skin construction. For greater realism it was decided to try all hidden controls. As on the full size plane all control surfaces are aerodynamically balanced..."
A-4-D5, Flying Models, September 1973.
Direct submission to Outerzone.
Article, thanks to RFJ.
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