FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1951
1951 - 1864.PDF
14 September 1951 average ground speeds—a direct function of penetration. The general control and handling of the Sky has received favour- able comment from the pilots who have flown it. The controls appear to be well matched and effective, and the ailerons are powerful enough to change the path of the aircraft from a 45 deg banked turn in one direction to a similar turn in the opposite direction in less than 6 sec. The first prototype of the Sky—which, incidentally, is on view at the South Bank Exhibition—first flew just over a year ago, and since that time considerable development work on the type has been carried out. Several modifications have been incorporated in later aircraft. At an early stage in the prototype trials, for instance, it was decided that it would be advantageous on later aircraft to have the tare e.g. slightly farther forward than was originally in- tended. This meant that, to maintain the same e.g. range, light pilots had to carry less ballast than was previously the case, while for heavy pilots ballast could be added to the tail, the overall result being a lighter flying weight for the aircraft. The prototype trials also indicated certain faults in the design of the dive brakes. It was found that brakes of the original size did not limit the terminal velocity to the speed expected, die reason for the error being attributed to a slight over-estimate of the total drag. The trouble was easily overcome by increasing the brake area. It was also found at the same time that the brakes were heavy to close at speeds in excess of 60 m.p.h. Attempts to rectify this, by altering the balance of the_ areas between the top and bottom brake and by cutting ventilation holes in the brake surfaces, met with only limited success. The trouble was eventually overcome by pivoting the bottom brake surface so that it was free to move through an angle of 30 deg on the operating arms; this allowed it to take up a more favourable attitude in the air stream when the brake was near the closed position, thus considerably reducing the loads on the operating mechanism. It now seems possible that the British team for the 1952 Inter- national Gliding Contest may be equipped with Skys, and the makers are doing all in their power to see that the aircraft supplied for this event are developed to give the best possible performance. A scheme has already been prepared for replacing the landing wheel with a jettisonable undercarriage; this alone should add an extra point to the gliding angle, which, it is hoped, may eventually stand at between 1 in 31 and 1 in 32. The Sky as an aircraft can already be claimed to be a consider- able success, but it still remains to be seen if the sales will be suffi- cient to repay the relatively large sums of money which have gone into the development of the type. Slingsby Sailplanes estimate that they will be able to produce the type at a lower figure than that SLINGSBY SKY (Hich-parformanc* Sailplane) DIMENSIONS Spin 59ft Lenith 25ft 4in Tare weight 550 Ib Max. all-up weight 8001b Wing are* ... 187 sq ft Aspect ratio ... 18.7 Aerodynamic twist ... ... ... 5 deg over tapered portion Aileron area 15.6 sq ft (each wing) Tailplane and elevator area 21.6 sq ft Fin and rudder area 14.5 sq ft PERFORMANCE* Best gliding ratio 1 in 29 «t 46 m.p.h. Min. sink ' 2.1 ft/sec at 41 m.p.h. Glide ratio at 60 m.p.h in 24 Glide ratio at 80 m.p.h in 16 Flying speed at 6ft/sec sink 73.5 m.p.h. Max. dive speed 124 m.p.h. (terminal velocity with air brakes open) Max. aero towing speed ... ... ... ... ... ... ... 80 m.p.h. * Based on manufacturers' estimates for first prototype. 359 Wing-root attachment details. The lower main-spar booms pick-up on a fitting on frame 8, while the upper booms are united by a central pin- The diagonal rear spar picks-up on frame 9. In the foreground is a part- section of an attachment pin of sliding-bolt type with locking plunger. for which the Weihes and similar craft are being produced abroad,and this should put the Sky in a favourable position for the export market. The prestige value of a product of this kind, and itsinfluence on the sales of other types produced by the firm, must also be taken into account. The headquarters of Slingsby Sailplanes are at Kirby Moorside, near Pickering, Yorks. J.C.R. Mr. F. N. Slingsby, designer of the Sky, secures his harness before being launched on one of the development flights of a prototype. INTERNATIONAL ASTRONAUTICS LAST week the second international Congress on Astronautics(the first was held in Paris last year) assembled at Caxton Hall, London. One of the first results of the meeting was the setting-up of an International Astronautical Federation with the objects of promoting the achievement of space flight as a peaceful, instead of a military, project; of issuing technical information directed toward such an end; and of stimulating public interest in Ac subject. First president of the new Federation is Dr. Eugen Sanger, °ne of the more prominent of the German rocket pioneers who now is employed by the French Air Ministry. Discussion also took place as to the eventual establishment of an international astronautical research institute. Of the 63 delegates to the Congress—which was organized by the British Interplanetary Society—no fewer than 24 were German; by far the largest national group. Countries represented at the Congress were Argentina, Austria, France, Germany, Great Britain, Italy, Spain, Switzerland, and the U.S.A. One of the striking things about this aggregation of enthusiasts is that, although to the lay observer untutored in the esoteric mysteries of space travel, thewholesubject presents a rather fanciful picture, each and every one of the delegates to the Congress is unshakably convinced that, given only time and money, the astro- nautical ventures they talk about will certainly come to pass. They say that they already have all the fundamental and technical knowledge they require—they need no new inventions. An impres- sive assertion. We cannot help feeling, however, that the amount of money required—it must, at lowest, be measured in millions—puts out of court the possibility of obtaining such a sum from any other source than government; and no government is likely to over- load its exchequer without the compulsion of a military aim.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
