From Alex Imrie’s ‘Vintage Corner’ in Aeromodeller, Jan. 1993 (pp. 14-15) Vintage Rocket Recent issues of American model magazines show that there is currently an interest in powering models with rockets. We have long had model rocketters [sic] but now it seems that the idea of using rocket power might provide a 'new' means of getting our models upstairs. The high power units currently available require launching ramps and R/C in sophisticated airframes so that approach is at least, new - but rocket power has actually been with us from the beginning of model flight The writer knows nothing of current rocket practices or safety codes and the models mentioned here are only presented because of their vintage origins - how you power them will need some investigation before you 'light the blue touch paper'! VE Johnson, who was the editor of the 'Models' column in 'Flight' before WW1 made some interesting comments on this mode of power in answer to one of his correspondents L F Hutcheon in the January 4 1913 issue. Hutcheon related how he powered a single stick pusher fitted with a wheeled undercarriage: the model was only 18 inches span but was 29 inches long and weighed 1.1/2 ounces without the rocket. It was tried off an oilcloth runway; on the third attempt the model rose to about 4 feet and covered 20 yards only descending because of 'switchbacking' due to over-elevation. The experiments came to an end since the stock of rockets (price 3 a penny) were exhausted and it was early closing day. Hutcheon was of the opinion that a more powerful rocket fitted to a correctly trimmed model would yield a flight of some 300 yards and stated 'A point about cheap rockets is that they do not explode at the termination of their sparks, etc, a decided gain. An advantage about a rocket plane is that the fuselage need not be over strong, as the strain and torsional forces of the rubber are entirely done away with. Also since there is no torque, etc., the flight path is far more likely to be a straight one.' Johnson replied that he had made a number of experiments with penny rockets some three years earlier and had obtained a flight of 150 yards and mentioned that a competitor at one of the early Crystal Palace K&MAA competitions flew a rocket powered model '...to the great disgust of the other competitors, whose language and remarks... were far more forcible than polite...' The model made one flight at a great height covering 100 yards but dived vertically smashing itself to 'smithereens'. Since then Johnson had not seen a rocket-plane in any competition but felt that some use could be made of the rocket in 'aeronautical work'. Because of take-off difficulties he thought that a seaplane might be more suitable for this form of power. He felt that a large rocket would prove better than small ones due to the former's slower burning and longer duration. '...As the ingredients of the rocket composition are consumed the weight naturally becomes less, and the rocket should be attached at the centre of gravity of the machine if possible. We should also have the centre of thrust or reaction pass through the centre of pressure. In fact, owing to the extremely energetic nature of the motive power, it is, perhaps, even more important than usual, that the centres of gravity, of head resistance should be coincident and the propulsive action of the rocket pass through this same point.' Johnson went on to say that the rocket was not the only form of gunpowder motor to have been put on the market for powering models, and had in his possession a rocket-driven turbine to which a propeller could be attached, but added that satisfactory results had not been obtained. He further mentions the Saxon or Chinese Flyer which was a rocket-driven propeller, the actual boss and blades being hollow with suitably placed orifices at tips, filled proper composition'. After a treatise on making your own gunpowder, Johnson concludes with the statement '…we are not advocating "rocket" motors for model aeroplanes - we merely wish to place few quiet unbiased facts before our readers, leaving them draw their conclusions…' The A-M Rocket 'Plane One of the free plans given away with this magazine in June 1939 was a twin-boom all-balsa machine powered by the so-called 'penny rocket' The drawing is reproduced here and no instructions are necessary but it worth quoting following. "As mixtures difficult dangerous to prepare unless you have previous experience with them, I am recommending ready-prepared type, which may be bought at most toy shops for a penny. "If however, you want something more elaborate, mind you are not served with the explosive type, as coloured stars are apt to be rather superfluous. About launching, the designer, J R Singer Craigie, said "balance each wing tip on an empty bottle... light the touch paper and stand clear If you have put the correct down thrust in the rocket, the plane will climb steeply to about fifty feet, and pull out into a good flat, but rather fast, glide.' It is a coincidence, perhaps, that the other model on the free plan that month was a beginner's duration mode] by Howard Boys, one of our pioneer modellers who did indeed conduct experiments into 'the proper composition' at various times and produced his 'Flaming Ptero', 'Fire Engine' and flying scale DH 108 'Swallow' experiments that appeared in the SAM 35 Yearbook No 1 and working drawings for the models mentioned must exist in some larger collections of vintage model plans. All-American Rocket Model Joe Ott's All-American Rocket model [M3] This is apparently the third version and differs from the 3-view drawing in several respects. All 'struttery' is split bamboo. Joe Ott, the famous American pioneer designer and kit manufacturer (see December 1987 Vintage Corner) created this 'rocket-ship' in 1930, and the design was Number 6 in his list of Sky Flyer plans. The model was described in both Joe's Popular Aviation model articles (March 1931) and in his book also published in 1931, 'Model Airplanes, Building and Flying'. There are differences between these versions, and these are not merely confined to the outlines of flying surfaces and the undercarriage configuration. The model in the photographs labelled M3 has a built-up tail unit of greater area than the bamboo outlines shown in the 3-view drawing, also the fuselage of M3 has twice as many fuselage bays, additionally a thinner airfoil section and reduced dihedral were used on the model described in the book. Obviously the reduction in the numbers of structural members was to decrease weight and so improve the flying performance The original models were of 45 inches wingspan, but Joe recommended to build the design in a 30 inch span size and quoted weight of 1.1/2 ounces for the finished model (less rocket). The type of rocket required was of the small variety, having a diameter of not more than 1/2 inch and weighing not more than one ounce. Material sizes quoted were: fuselage longerons 1/16in square; fuselage formers 1/16in sheet; wingspars 1/16in x 1/4in; leading edge 1/8in square; trailing edge 1/8in x 3/16in; all ribs from 1/32in sheet. All fuselage and undercarriage struts from bamboo slightly thinner than 1/16in x 1/8in. The tailunit is bent from bamboo; make the piece wide enough when bending to shape in order to split three outlines of approx 1/16in square from it. These bamboo outlines are covered on one side only with tissue. The wheel size is 1.1/2in diameter, the axle being reinforced on each side of the spat with a small triangular piece of thin plywood extending up to the front strut junction where the model is secured with a rubber band. The flying instructions included this note: 'Unless the model carries the weight of the rocket well while gliding, after being launched from the hand, it will not fly unless the rocket has extreme power. Care should be taken that the rocket is not too powerful and will tear the model to pieces during flight.' Built in the manner described obviously rules out the present day high powered rocket units and if the commercially sold 'Guy Fawkes' rockets are unsuitable, perhaps some of our Jetex enthusiasts might be able to devise a means of powering this unusual vintage model, whose class has been rather neglected to date.