Hello All,

While looking up plans for old model rocket B/Gs (boost-gliders), I came across the plans for the SAI (Space Age Industries) Mini Bat kit (see: http://oldrocketplans.com/sai/saiK17/saiK17.htm ), which was a tailless boost-glider. (Of course, front motor boost-gliders which do *not* have V-tails, including the Mini Bat, have inverted vertical stabilizers so that the rocket motor exhaust won't impinge upon them.) Also:

Looking at the plans for the conventional (swept-wing, with conventional tail assemblies) Estes Falcon (see: http://www.airplanesandrockets.com/rockets/falcon.htm and http://www.spacemodeling.org/jimz/estes/k-13.pdf ) and the similar AMROCS Hawk (see: http://www.oldrocketplans.com/amroc.../amr101-150.htm ), it occurred to me that a tailless variant of such a boost-glider type is possible. By locating the swept wings farther back on the fuselage boom, or by using more sharply swept-back wings (or by doing both), a tailless front motor boost-glider having a planform like that of the tailless Northrop SM-62 Snark cruise missile (see: http://www.designation-systems.net/...app1/sm-62.html [this site also has material on the XSSM-A-3 Snark test vehicle]) could be built. In addition:

As well as being an effective tailless boost-glider (which could use either the motor-ejection method or a separating, streamer- or parachute-recovered motor pop-pod), a boost-glider of this design would eliminate or greatly reduce a problem of motor-ejecting front motor boost-gliders with conventional tail assemblies (which is discussed *here*: http://oldrocketforum.com/showthread.php?t=4843 ). The rearward-ejecting motor can break the model's tail boom just ahead of the horizontal stabilizer; this occurs because the tumbling spent motor case can strike the tail (which is often pitched up into the motor case's path by the model's reaction to the motor's ejection impulse, which causes a nose-down pitching moment--this happened to my father's Estes Falcon, whose tail boom he had to repair a few times). As well:

A contributory (or even primary) cause of tail boom breakage can also be the downward bending load that is suddenly imposed upon the boom by the upward-pitched horizontal stabilizer at ejection. In both cases, the tailless configuration could eliminate or reduce these stresses. Having no horizontal stabilizer, the rear end of the tailless model's tail boom presents a smaller "target" for the randomly-tumbling motor case to hit. The rear end of the model's tail boom is also not subjected to aerodynamically-caused bending stresses at motor ejection, because it has no horizontal stabilizer (those loads are distributed among the larger areas of the wings' outer portions).

I hope this information will be helpful.

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