Hanriot HD.22

Flight, December 1921

The Paris Aero Show - 1921

AVIONS HANRIOT
192, 194 and 196, Boulevard Bineau, Neuilly-sur-Seine.

   PROBABLY among British readers of FLIGHT, at any rate, the first recollection of a Hanriot aeroplane relates to the little monoplane which made Brooklands unsafe in the very early days of flying. That machine, affectionately known as "Henrietta," had a sort of boat-built body of approximately semi-circular section, and some unusual control levers, which one wobbled from side to side, mounted on the gunwales. From the early start (round about 1909 or so) Hanriot Pere has continued to design and build original machines, helped of late years by Hanriot Fils, who, one remembers, took his "ticket" as a youngster of about 14 or 15 in the early days of aviation. Speed machines have always been associated with the name of Hanriot, and as far back as 1913 or 1914 a very fine monoplane was flying regularly at Brooklands and Hendon, piloted by one Sabelli.
   For the Coupe Deutsch held in October last, Hanriots entered a cantilever wing monoplane, which, however, was not finished in time to take part in the race, unless M. Rost was to make his first test flight also an elimination flight for the race. This M. Hanriot refused to let him do, and so the machine was not entered. It was, however, credited with an extraordinarily high speed, as indicated by wind tunnel tests on a model, and great disappointment was felt at the non-starting of the machine in the race. Judging from an inspection of the machine as exhibited at the Grand Palais, one is inclined to think that the machine may quite conceivably be as fast as it was said to be. Its lines are good and there is no external resistance, except that offered by the undercarriage, which, as shown, was not of the "escamotable" type. We understand that there is a possibility of Mr. Tait-Cox testing the machine after the finish of the Salon, in which case we shall probably know something more definite about the machine's performance. Tait-Cox is an exceptionally fine test pilot, and we should like him to have the chance of flying such a speedy mount.
   As regards the construction of the Hanriot Avion de Course, it is built entirely of metal, with the exception of the wing covering, which is fabric. We have been unable to ascertain the details of the wing construction, but it is understood that spars as well as ribs are of metal. The fuselage is a triangulated structure of tubing, no bracing wires being used. There are three main longerons, braced by smaller tubes forming a series of triangles, and circular formers at intervals support the fuselage covering, which is of aluminium. Although this covering is a streamline casing only, and does not, presumably, take any part of the fuselage loads, it is of substantial thickness. A fairly hard pressure, applied with the hand failed to produce any appreciable local deflection in the covering. This may be partly due to the double curvature of the covering, which is known to strengthen a shell of this sort very considerably, as instanced in the Supermarine flying boats. The 300 h.p. Hispano-Suiza engine is mounted on a very substantial structure in the nose of the machine, formed mainly by steel strips riveted together to form box-section members. The engine is totally and neatly cowled-in, the camshaft casings being housed in aluminium troughs formed in the engine cowl.
   The wings, which are of the thick, high-lift type, are attached to wing roots formed on the top of the fuselage, and the absence of any external wing bracing results in a very neat and clean appearance. In this connection it is curious to compare the Nieuport-Delage monoplane which won the Coupe Deutsch and the Hanriot racer. While there is something slender and graceful about the Nieuport-Delage, something almost feminine, there is a look of strength and power about the Hanriot, which is nothing if not masculine. One would imagine that as regards speed the two machines should be fairly evenly matched, fitted as they are with the same type of engine. And it might seem reasonable to suppose that the Nieuport-Delage, with its thin wings and single lift strut on each side, coupled with a fuselage of much smaller cross-sectional area, would be a match for the Hanriot. However, although the Hanriot fuselage is "fatter" it is quite conceivably of better streamline form than that of the other machine.
   The pilot is placed fairly far aft, level, approximately, with the trailing edge of the wings. In front of him he has two radiators which rest on the top of the fuselage, with their tops leaning together. This arrangement would not appear to be calculated to improve the view, and one wonders why Hanriot has preferred this arrangement to fitting the ubiquitous Lamblins between the undercarriage struts. Certainly he is not likely to have done it without good and sufficient reason.
   An undercarriage of the usual simple Vee type is fitted, and one confesses to a certain amount of disappointment at not seeing the retractable undercarriage which was contemplated for the actual Coupe Deutsch race. As exhibited the undercarriage showed few features of interest, beyond the fact that circular pieces of fabric had been doped on to the sides of the tyres, so as to streamline as far as possible both wheels and tyres. These patches covered the whole wheel, with the exception of the actual tread of the tyres.
   The tail of the Hanriot racer is of ordinary type, but one noticed that the fin covering (of the upper fin) is a hollow shell of aluminium sheet, which appears held down to the fuselage by turn-buttons. Whether there are any internal attachments one is not able to say, but, if not, the attachment by means of turn-buttons does not appear any too secure. Where the lower edges of the fin cover overlap the top of the tail plane the joint is covered with a strip of fabric, doped on. Under the fuselage is an adjustable fin, which has a single pivot, and can be so set as to counteract the tendency to turn experienced when the engine is running "all out." The support of this fin does not look particularly substantial, but in view of the metal construction may be safe enough. Altogether the Hanriot monoplane is, in the main, a very fine piece of design, and the workmanship is excellent, especially as regards the various parts formed out of aluminium sheet by beating. The ailerons are covered with aluminium, and have their control tubes inside the wing.