FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1952
1952 - 0214.PDF
88 FLIGHT BRISTOL 175 .. . airframe structure at one end and fitted with a lever at the other; variation of the length of the lever provides variation of control- load. Large double-slotted flaps occupy the full trailing-edge span between the fuselage and ailerons. There are an inner and outer pair on each side, and the maximum deflection is 45 deg. The slat is fixed relative to the flap, and does not become operative until the flap exceeds an angle of 20 deg. Under-wing pr^ure refuelling is provided for, with one point in each outboard nacelle. The maximum rate is 150 gal/min, with a bowser pressure of 25 lb/sq in—half the pressure which the system is capable of withstanding. Emergency gravity-filling points are located beside the shut-off valves and fuel may also be off-loaded through the under-wing points by selecting the appro priate position on the manual four-way cock. The landing-gear consists of two four-wheel bogie under carriages, with hydraulic brakes on all wheels, and a nose under carriage with twin steerable wheels, the steering and castering range of which is 50 deg on either side. The nosewheels do not carry brakes. The track of each front pair of wheels on the main four-wheel bogies is less than for each rear pair. The hydraulic system provides power for undercarriage retraction, wheel-brakes and flying-control locks. The maximum operating pressure is 4,000 lb/sq in, but reducing valves are incorporated in the brake system, which requires only 1,500 lb/sq in. The electrical system of the aircraft has three main supplies: 200V A.C., I I2v D.C. and 28v D.C. The A.C. supply is used for the electro-thermal heating of airscrews, for windscreen de-icing and for the air-conditioning and refrigeration-fan motors. The ii2v D.C. is required for the starter motors, flap motors, and for the pantry, toilet, air-conditioning and lighting. Secondary sup plies from the 112v system, obtained via four inverters, are utilized as follows: No. 1: gyro compass, Zero Reader, inner-engine instruments and controls, and stand-by for No. 2; No. 2: co-pilot's instruments, autopilot, outer-engine instruments and controls, and stand-by for No. 1; No. 3: cloud collision-warning radar; No. 4: similar in type to No. 3, and used for the D.M.E. Supplies Nos. 3 and 4 act as stand-bys for each other. Most of the air-conditioning equipment is housed in the engine nacelles. The components are mounted individually and are readily accessible for maintaince. Two entirely separate and independent systems are provided, one in each wing, and they feed into the body independently through non-return valves. The out- U.S. Production to be Trebled F OR the first time since the Korean war began (writes a Washington correspondent) the U.S. aircraft industry can see plain sailing ahead for their military aircraft production pro gramme. They expect, if all goes well, a trebled output—18,000 machines a year—by next December^ But this long-delayed rise in production will not solve all the problems; there still are two main worries. The first is that when the industry gets its output up to 1,500 a month, by the end of this year, it will only be able to continue for a year or two at this rate, while the U.S. Air Force is being built up to a strength of 140 aircraft per group. After 1953 the problem will be to taper-off production to between 7,000 and 10,000 aircraft a year. Secondly, increasingly apparent progress by Russian designers has led their American opposite numbers to urge that broader specifications be offered, so that they can use their imaginations to meet Air Force needs. They point out that Britain, though hampered by controlled economy, has made some remarkable technical advances because her best designers have been given a free hand. The production of commercial and light aircraft has now been seriously affected by the shortage of material and the pre occupation of manufacturers with military orders. Only 65 com mercial aircraft were delivered in 1951, compared with 91 in 1950, and only 2,300 small machines were produced, as against 3,400 in 1950. The most significant development, incidentally, was the growth of helicopter activity, both in design and production. PERSONAL JET: Considerably modified since it first appeared, in semi- mock-up form, at last year's Paris Show, the SIPA 200 tourer-trainer made a successful first flight on January 12th in the hands of M. Roger Launay, the makers' chief test pilot. The Turbomeca Palas (330 lb thrust) has wing-root intakes and a tail-pipe at the rear of the nacelle. Carrying two, side by side, the little machine has a gross weight of 1,609 /B; its span is 22ft 5in; and it is credited with a maximum cruising speed of 236 m.p.h. Range at reduced speed and optimum altitude is said to be 435 miles. board nacelle contains the engine-driven blower, silencer, after-cooler and off-loading spill valves. The inboard nacelle contains the refrigerator, with its cooler and ground-running fan, while in the body are the water-separators, re-circulating fans, smoke filter and deodorizer, pressure-control valves and distribution system. Maximum cabin-altitude is 6,oooft up to 35,000ft, and, if it is desired, sea-level altitude can be maintained in the cabin up to 21,000ft. The maximum differential pressure is 8.3 lb/sq in. For ambient temperatures between — 70 deg C (- 94 deg F) and 27 deg C (80 deg F) the cabin can be maintained automatically at any selected value between 17 deg C (63 deg F) and 24 deg C (75 deg F). Two free-running refrigerators are provided to deal with very hot, humid conditions. The refrigerators, together with water separators, can keep the relative humidity in the cabins below 70 per cent for all possible hot and humid ambient conditions, while the humidity can be raised to 30 per cent by injecting steam from an electric boiler into the ventilating air. Some 25 lb/min of fresh unhumidified air is passed up wall ducts, while 7 lb/min of fresh air, cooled below cabin temperature, is available for the use of pas sengers through individual louvres. The freight holds are also air-conditioned. Full protection against severe continuous icing is provided. There are several systems, the principal one of which provides hot air for the wing leading-edge. Heat for this purpose is taken from an exchanger in each power plant, fed by hot gas tapped from between the two turbine stages. The tail unit, including the elevator horn balances, is de-iced electrically with the aid of heated external mats on the leading edges. This is a cyclic electrical system, as is that employed for the airscrew blades and spinners. The power plants themselves, and their air intakes, are de-iced with the aid of gases tapped from between the turbines, and the six forward windscreen panels are electrically heated for anti-icing and de-misting. PRINCIPAL DATA: BRISTOL 175 BRITANNIA (Four Bristol Proteus Turboprops) Span 140ft Length 114f Height 36ft 8in Track 31f Wing area 2,055 sq ft All-up weight 140,000 lb Volumetric payload ... ... ... ... ... ... ... 25,000 lb Still-air range with max payload ... . ... 4,000 st. miles Max. still-air range 5,600 st. miles Landing weight 110,000 1b Take-off distance (at 140.000 lb in 5 m.p.h. wind) 3,700ft Landing distance (at 140,000 lb in 5 m.p.h. wind) 2,800f Cruising speed at 35,000ft 367 m.p.h. British Aircraft to Scale SINCE we published, in our S.B.A.C. Show Number last September, several pages of plan-view drawings of "British Aircraft to Scale," there has been a demand for their reprinting in booklet form. Such a booklet has now been prepared. Several new types have been added that have appeared since the original publication, and there are now drawings of 85 different civil, Service and research aircraft. Apart from the interest provided by the scale contrasts— for example, the Dart Kitten (31ft 9m. span) is shown alongside the Brabazon (230ft)—British Aircraft to Scale forms a useful work of reference, for in addition to the illustrations there are detailed data tables on all current civil and military types. The drawings are by Barry Jones. The booklet is obtainable from newsagents at is 6d or by post (2d extra) from Iliffe and Sons, Ltd., Dorset House, Stamford Street, London S.E.i.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
