FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1934
1934 - 0710.PDF
712 FLIGHT. JULY 12, 1934. THE AIRSPEED "ENVOY" High Speed, Retractable Undercarriage and Long Range are among the Chief . Features of the Latest Production of Airspeed, Ltd. IN the early part of last year Flight published the firstdetailed account of the Airspeed " Courier." This wasthe first British aeroplane to use a retractable under-carriage with all its attendant advantages. The "Courier," as will be seen from that description (March 23, 1933, page 266), was a successful attempt on the part of Mr. N. S. Norway and Mr. A. Hessell Tiltman to provide an aeroplane having a high cruis- ing speed but which was eco- nomical to operate. Since that time a considerable number of "Couriers" have been built, and recently the 277 h.p. Sid- deley " Cheetah " engine has been fitted instead of the " Lynx," thus raising the cruising speed to 150 m.p.h. Now, in response to a demand for a machine of rather better performance, but with the added safety of two engines, the "Envoy" has been pro- duced. The first of these has been built, with Wolseley en- gines, to the order of Lord Nuffield for the England-Aus- tralia race. Others of the type are under construction, and one, designated the . A.S.8, which will have supercharged "Cheetah" engines, will be flown in the race by Capt. T. N. Stack. As is usual >vith an aeroplane of this size for commercial pur- poses, the cabin accommoda- tion may be varied to s~iiiFthe purchaser. This first model will have seats for six passen- gers and one pilot. Obviously, by varying the number of passengers the amount of fuel carried may be altered and the range increased or decreased accordingly. With six passen- gers the tanks hold sufficient for a range in still air of 403 miles. Structurally the " Envoy " differs but little from the " Courier." In fact, the cuter wing-sections are interchange- able between the two types. Wings and fuselage are mainly THE AIRSPEED " ENVOY." WrTH TWO WOLSELEY A.R.9 ENGINES, DEVELOPING 206 H.P. EACH AT 2,420 R.P.M. DIMENSIONS Wing span...Height, overall Length, overallWheel track Engine centresMean chord Aspect ratioIncidence ... ft.52 9 34 12 12 6 in. 4 6 6 5 m (15,94) ( -,*») (10,53) 7.4 ( 9 ( 3,79) ,1,85) 2,05) Mean dihedral 8.08 to 12° at root, washed out at tips.5° AREAS Main plane with ailerons Ailerons, two Tail plane Elevators, two Fin Rudder TO" 31,5) 2,43) 2,14) 2,42) 0,69) WKIQHTS •Tare weight Disposable load ... tBalance (less crew, fuel and oil) Maximum permissible weight .. LOADINGS AND RATIOS Wing loading Power loading Ratio gross weight to tare weight PERFORMANCE Maximum speed at sea level Stalling speed, full load ... Cruising speed at 2,200 r.p.m. ... Best climbing speed Service ceiling Ratio of maximum speed to stalling Bpeed ... Take-off run, no wind, full load... Rate of climb, at sea level ... Everting high speed figure Range at cruising speed • Includes cabin lighting, navigation and landing lights, engine starting equipment, battery, pilot's seat and instruments, etc. t Available for payload, cabin equipment, furniture and decorations, lavatory, wireless equipment, etc. composed of plywood and spruce. The covering of the latter is three-ply wood, and of the former, doped fabric. The front portion of the fuselage, forming the cabin accommodation for the passengers and pilot, is practically of monocoque con- struction, with a three-ply skin. Particular care has been taken to ensure that the pas- sengers do not suffer from lack of light or ventilation. In the pilot's cockpit all the front win- dows can be opened so that they can be cleaned easily dur- ing flight. The centre-section, upon which the fuselage is mounted 'and which forms the cabin floor, carries both en- gines, the fuel tanks and both sides of the retractable under- carriage. This centre-section is built up as a single unit, with very heavy bracing be- tween the box type spars. The outer portions of the wings are attached to these spars by heavy steel bolts pass- ing through vertical hinges, which are secured to the spars by means of laminated steel plates, so that the extension planes can be quickly detached. These planes are heavily tapered both in plan form and profile, the section used being Clark Y.H. suitably " stepped " to give the necessary taper. Special precautions have been taken to ensure a high degree of torsional rigidity in the wings, so that the whole struc- ture is extremely stiff. The main-plane spars are of the box type of construction, with spruce flanges and three-ply webs. The webs are particu- larly interesting as the ply- wood used has the centre lami- nation double the thickness of those outside it. Moreover, this plywood is laid on the spar with the grain of the wood at 45 deg. to the spar axis. Tn this manner a high strength- weight ratio has been achieved. The wing ribs are of spruce, as is 'the drag-bracing system, whteh has been designed to provMe a high degree of tor- sq. ft. 339 26.2 23.0 26.0 7.45 15.7 lb. 3,077 2,223 1,377 5,300 ( 1,46) kg (i 395) (1 008) ( 625) (2 iOi) 15.6 lb./sq. ft. (76,17kg/m') 12.85 lb./h.p. (5,83 kg/h.p.) 1.72 m.p.h. kmlh 170 (273,6) 63 (101,4) 150 (241,4) 97 (156,1) 17,000 ft. (5 182 m) 2.7 265 yd. (242 m) 914 ft./min. (4,64 mfsec) 27.5 ... 403 miles (649 km)
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
