FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1926
1926 - 0523.PDF
JULY £9, 1926 THE HANDLEY PAGE "HENDON" New Slot-Control Machine Demonstrated SINCE Mr. Handley Page in this country and Dr. Ing. Lach- mann in Germany first invented the slotted aerofoil more or less simultaneously, the progress made with this device has appeared somewhat slow, certainly more so than many enthusiasts had expected, and it is a somewhat curious fact that hitherto not a single commercial aeroplane in use in this country has been fitted with slotted wings. In Germany, on the other hand, at least three machines have been built incorporating this feature. The Udet firm of •Munich produced a slotted-wing monoplane last year. The Albatros Works, of Berlin-Johannisthal, turned out a news- paper carrier, a biplane with slotted wings, early this year designed by Dr. Lachmann, and finally another Udet machine was entered at the eleventh hour for the German seaplane competition that is just coming to a close at Warnemunde. In this country, on the other hand, the slotted wing has so far been used on service type of aircraft only, of which the Handley Page Company has built several. One of the latest to be produced at Cricklewood is the " Hendon," a torpedo carrier fitted with Napier " Lion " engine. Hitherto regarded as one of our " secret " machines the " Hendon " has now been " released," and on Tuesday of last week, July 20, a demonstration took place at Cricklewood, at which a number of representatives of the press, as well as certain foreign Air Attaches, and others interested, were present. The " Hendon " was piloted by Handley Page's chief test pilot, Capt. Wilcockson, who took up a number of passengeis from among the visitors present. The machine certainly flew remarkably slowly when the wing slots were open, and the pilot put it through a number of evolutions to show the effectiveness of the lateral control. His flat turns were particularly impressive. It was noticed that in taking off with slots open and flaps down, the " Hendon " climbed at a very steep angle, but apparently the rate of climb was not out of the ordinary, and in point of fact, we are informed that the rate of climb is better with slots closed, although the angle of climb is then not so good. When flying slowly the machine was approximately on an even keel, which was also its attitude when descending along a flight path steeply inclined to the horizontal. This is, of course, explained by the fitting of trailing edge flaps interconnected with the slots, since the effect of the flaps is virtually to increase not only the camber, but angle which the wing chord forms with the centre line of the machine. In descending at an angle which would certainly correspond to a stalled condition on a normal machine, the' " Hendon " appeared to be under perfect lateral control, and whatever may be the merits of the slotted wing for giving increased lift (and this is a subject upon which opinions seem to differ very considerably), there cannot, we think, be any question that the slot-cum-flap lateral control does very definitely provide that extra safety in the stalled condition which results from ample lateral control. The diagram printed on p. 460 shows how the slots and flaps on the " Hendon " are arranged. The auxiliary aerofoil, which is of the single surface (i.e., flat sheet) type, is divided into a long centre portion and two shorter end portions. The centre portion may be described as providing a " lift slot," while the end portions are " control slots." By this is meant that the central slot and the central trailing edge flap, used in conjunction, give extra lift, while the end slots, the auxiliary aerofoils of which are inter-connected with short trailing edge flaps, are, of course, used to obtain powerful lateral control. In flight with lift slot partly open, the two aerofoils of the control slots are slightly less open than the main slot, and with the lateral control " full on," one control slot closes altogether, while the other opens fully, i.e., its aerofoil moves out level with the lift slot aerofoil. In taking off and landing when maximum lift is required, all slots are open and all flaps down, although the control flaps still retain a further movement for lateral control, and in this condition lateral control is obtained mainly by raising the flap and closing the slot on the rising side, thus decreasing the lift on that side. We understand that in a more recent arrangement an even more effective control action is obtained, but even with the present arrangement there can be no doubt that very powerful lateral control is obtained, and we understand that it is claimed that this is not accompanied by the usual necessity for a very powerful rudder, as the forces on the two sides are approximately balanced as regards yawing moments. For illustrations see pages 459 and 460. AIR MAILS THE Postmaster-General announces that a new edition of the Air Mail Leaflet, embodying particulars of certain changes in the Air Mails, has been issued. A copy may be obtained free on application at any Head or Branch Office, or from the Secretary (Air Mails), General Post Office, London. E.C.I. A summary of the chief Air Mail changes is given below. For further particulars reference should be made to the Leaflet. The Air Route numbers quoted refer to the new Leaflet. Letter Air Mails.—(i) A new Route 2, from London to Lyons, Geneva and Marseilles, offering advantage each week- day for letters to the destinations mentioned, and, on Fridays, an opportunity of overtaking the weekly Indian Mail. In combination with the existing Route 1 (London to Bale), an advantage is offered on most days of the week for letters to Egypt, and to neighbouring countries, (ii) A new Route 4, by ordinary afternoon service from London to Paris, con- necting in Paris with the air service next morning for Nurem- berg, Prague, Vienna, Budapest, Belgrade, Bucarest and Constantinople, (iii) New direct Air Mails by Route 5 to Frankfort-on-Main and Munich, (iv) By Route 7, an increased advantage for letters to Finland through the use of the Stock- holm-Helsingfors air service, (v) By Route 9, from London to Moscow, advantage is given for letters to the Far East. (vi) Advantage is now offered for letters to some of the Provinces of Canada, and an increased advantage for letters to many parts of the United States, (vii) The rate of air fee payable on Air Mail letters for Denmark, Sweden and Norway has been reduced from Ad. to 3d. per oz. Parcel Air Mails.—The following changes have been intro- duced :—(i) Reductions in the rates of postage on air parcels for Holland, and for German - if sent by air as far as Cologne only, for distribution thence by train, (ii) New direct parcel Air Mails to Hamburg and Berlin, (iii) An official air parcel service to Switzerland, (iv) Acceptance of heavy parcels (i.e. of parcels weighing from 11 1b. to 22 lb. each) in the ser- vices to Germany and Switzerland. VACANCIES FOR APPRENTICE CLERKS, R.A.F. THE Air Ministry announces that sixty vacancies exist in the Royal Air Force for well-educated boys, between the ages of 15A and 17, to enter as apprentice "clerks. Approximately 40"of the posts will be filled by means of an open competition, which will be held by the Civil Service Commissioners in October at various centres and the remaining 20 by direct entry of boys who have obtained an approved school certi- ficate. Successful candidates will be required to complete a period of 12 years' regular Air Force service after reaching the age of 18, in addition to the training period. At the age of 30, they may return to civil life or may be allowed to re-engage to complete time for pension. Detailed information regarding the apprentice clerk scheme can be obtained from the Secretary, Air Ministry, Kingsway, London, W.C.2. Boys entered under this scheme undergo a two years' course of training in clerical duties, typewriting, shorthand, book-keeping and practical office routine, during which time their general education is continued under qualified school- masters. The apprentice clerks are paid 7s. per week for the first year and 10s. 6d. per week afterwards until they have both attained the age of 18 and have been posted for duty after passing their final examination. The subsequent commencing rates of pay, varying from 21s. to 31s. (yd. -per week, depend upon the degree of success achieved at this examination. In addition, they receive free board and lodging. An opportunity will be given to all apprentice clerks to volunteer for training as airman pilots, of whom a. few are periodically selected for commissioned rank. 461
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
