CoA. Aero Reports (1953-1969)
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Browsing CoA. Aero Reports (1953-1969) by Author "Howe, D."
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Item Open Access Aeroplane design studies conventional and V.T.O.L. freighter aircraft (Academic Years 1959 and 1961)(College of Aeronautics, 1963-11) Howe, D.During the second year of their course in the Department of Aircraft Design, students have the option of working as a member of a team engaged in a design study. The subjects for the studies are chosen to represent the current interests of the industry and include unusual features considered to be worthy of investigation. Examples of these design studies are the F-59 freighter and its derivative the F-61, V. T.O. L. freighter. In a conventional role these designs are intended to carry a payload of up to 77000 lb. , over 800 nautical miles range, using four turboprop engines. V. T.O. L. capability is given to the F-61 design by the addition of two wing pods, each of which houses 22 lift engines. The application of boundary layer control in the form of blown ailerons and flaps has been investigated for the F-59 design. Both aircraft have been designed in detail. The major conclusion of the studies is that the application of V. T.O. L. to large freight aircraft is feasible, but further detailed work is necessary to resolve some flutter and noise problems.Item Open Access Aeroplane design studies mach 2.2 and mach 3.0 supersonic airliners (academic years 1960 and 1962)(College of Aeronautics, 1965-02) Howe, D.This report is divided into three parts. The first two of these describe the A-60, Mach 2.2 airliner and the A-62, Mach 3.0 airliner design studies respectively. Apart from the different cruise speeds these two aircraft were designed to meet the same basic requirements and the third part of the report is a comparison of them. The Mach 2.2 design was based upon the use of a slender, integrated, delta layout with six turbojet engines buried in the rear fuselage. It was intended to carry up to 120 passengers over transatlantic ranges. Although the chosen engine installation enabled a compact aircraft to be designed it did introduce severe structural and installation difficulties. A canard delta arrangement was proposed for the Mach 3.0 aircraft. Drooping of the wing tips for supersonic flight was found to confer important stability advantages without introducing an unacceptable weight penalty. The steel structure was designed around the use of both corrugated reinforced and honeycomb sandwich skins, the former being preferable. An interesting feature was the choice of a sealed, cryogenic, environmental control system. This was found to be very attractive but as it proved to be somewhat heavier than anticipated it is suggested that a good compromise could be obtained by using a more conventional system for subsonic flight phases. The major conclusion from the comparison between the two study aircraft was that in many respects there is very little to choose between them. However the Mach 2.2 aircraft represents a more logical step from existing airliner designs and presents fewer materials problems. As it is comparable economically it represents a better choice for a first generation supersonic design.Item Open Access Aeroplane design studies: bpropeller turbine and pure jet powered general purpose transport aircraft (academic years 1963 and 1965)(College of Aeronautics, 1967-05) Howe, D.The recent interest in the air bus conception of air travel is reflected in the aircraft chosen for study by the students in the Department of Aircraft Design during the 1963 and 1965 academic years. The first study was based upon the use of four propeller turbine engines to power an aircraft capable of carrying up to 40,000 lb. of payload over short stage lengths. Emphasis was placed on the need for operations with mixed passenger and freight loads and the fuselage layout incorporates two decks, the lower one of which is designed as a freighthold with nose loading doors. The second study was similar except that four wing mounted pure jet engines replaced the propeller turbines of the earlier design. The cruising speed is thus some 50 per cent higher with a Mach number limitation of 0.8. The two deck fuselage layout is retained, but with a rear loading door for the freighthold, and the wing has 28° of leading edge sweepback . An initial economic comparison of the two aircraft revealed that when the aircraft are operated over 250 n. mile stage lengths the direct operating costs of the propeller turbine powered design are some 20 per cent less than those of the pure jet version. This is mainly due to the much lower first cost of the simpler aircraft.Item Open Access Aircraft design studies: variable sweepback naval aircraft(College of Aeronautics, 1967) Howe, D.A preliminary survey of the possible applications of variable sweepback indicated that a substantial improvement in performance can be expected when the concept is applied to a naval strike aircraft. In order to assess this performance gain and to obtain experience of the engineering problems involved, the subject of the design study 'ay the students in the Department of Aircraft Design during the 1964 academic year was chosen to be a variable sweepback naval strike aircraft. The aircraft has a maximum take off weight of 60, 000 lb. and a limiting Mach number at altitude of 2. 5. Various payloads up to a maximum of 4000 lb. can be carried externally over ranges which vary up to 4000 n. miles according to the role. Alternative mechanical arrangements for the wing hinge system were investigated.Item Open Access Double shear strength of B.S.L.69 snap head rivets in L.72 and L.73 aluminium alloy sheet(College of Aeronautics, 1956-07) Howe, D.A limited series of tests has been carried out on single and double shear riveted joints using 1469 (D.T.D.327) snap head rivets and L.72 (D.T.D.610) and L.73 (D.T.D. 546) sheets. The specimens were similar to those used by the Royal Aeronautical Establishment (ref.1), the double shear specimens being essentially two single shear specimens placed back to back. In each case the 1 per cent, 2 per cent and ultimate strengths were found, the single shear values being in agreement with the equivalent R.A.E. tests (ref. 2). It was found that at high bearing stresses the permissible shear stress in the double shear joint falls below that of the single shear joint having the same nominal bearing stress, This reduction of permissible shear stress was found to increase with joint extension and to be independent of the sheet materials tested. Design curves are given.