[1]2 @ 7 1 4 @ 9 9 9 United St,,ates Patent Office Patented Aug. 9, 1955 2 fashion and at a speed substantially equal to the speed of the aircraft, so that there is no airplanebomb speed 2,714,999 differential disturbing the bomb accuracy, thereby enablin- bomb discharge at very high speeds, the bomb then JET PROPELLED BOMBING AIRCRAFT 5 dropping virtually vertically. Armand J. Thieblot ane. Rodger W. Davis, Hagerstovm, It will be seen that the high speed bombing aircraft of Md., assi-,-aors to Fairchild Engine 2nd Airplane Cor- this inventioi, enables aircraft bombing at highest practiporation, New York, N. Y., a corporation of Maryland cal aircraft speed with enhanced bombing accuracy, and that the load disoosition around the longitudinal axis, with Applicafion April 20, 1949, Se;rial No. 88,621 1(' reference to the- center of gravity, enables a large bomb 4 Claims. (C]. 244-74) This invention relates to aircraft, and has particular reference to high speed bombing aircrait. It is well recognized that the trend toward increased wei.-ht of bombs, requirin.- Jar.-er aircraft, presents numero,as problems. For example, bombs carried by hi.-h speed aircraft are necessarily carried inside the aircraft to prevent the dra.- ol' exteriorly mounted bombs, bLt then the high speed slip stream is 1:@kely to tear the bomb bay doors from the aircrafl when they are opened to dischar.-e the borr@b and the effort to co.-rect this condition by the use of unconventional sliding or collapsing doors flush with the fuse'@a.-e surface still presents a large opening when the bomb is dropped, thereby causing a considerable air drag which dangerously slows the craft over enemy territory. Also, the rev,-rse air flow 'rom the open bomb bay disturbs and impa@rs the accuracy of the bomb drop to a degree 0 which cantiot be tolerated in the desir.-d optimum design. Moreover, even u-tider the best of conditions of current practice, there is always a sp,-ed range above -,vhich bombs cannot be dropped satisfactorily be--ause the differential spe.-d above a certain ratio results in -yration and tum- 5 bling of the bomb when it en.-ages the slip stream, so that bombin@ acc,,iracy is difticu'lt to achieve and the large differentiai speed sorr,-etimes causes the bomb itself to disintegrate soon after dischar.-e. The desirable condition, therefore, is 'to discharge a lar,@e bomb from a high speed 40 aircraft in such a way that th.- airplane-bomb speed differential is noL so hi.-h as to cause the aforementioned difficult,'.es, which requires aircraft of new desi.-n and construction, includin@, a bomb discharge arrangement which will acconimodate a large bomb without materially increasing 4 @, the size ol. the airplane, or disturb the aerodynamic balance, considerin@ that the bomb is discharged at a time of high fjel consumitioi so that there is a sudden decrease in the disposable load at a critical time. In accordance with the present invention, a high speed f ,) borpbing aircraft is provided which is capable of carrying a vary lar.-e, heavv and loiig bomb without material increase in size and under such conditions that the opening of the bomb bay does not disturb the craft aerodynamically, the bomb discharge is not affected by the air stream, and the speed differential between the aircraft and the dischar.-ed bomb is not too great to impair the bomb accuracy or effectiveness, while a, the same time obtaining and maintaining optimum hi.ah speed. In a preferred embodiment of the invention, the air- 60 craft of this invention is of the canard type and has a fuselage of a shape as nearly approaching a perfect projec'@ile shape as is feasible, a relatively thin, hi.-hspeed, tapered, swep, mid-win.- hav-ing a slight amount of catliedral angle, a sin.-le horizontal elevating surface mounted 65 at the nose of the fusela-e and vertical fins on the win.a, one at each wing tip and one inboard therefrom with each fin terminating in a rudder. A group of jet type propulsion engines are mounted at the rear of the circular crosssection fuselage and surround a tubular tunnel-like bomb 70 bay in which is housed the lon.- torpedo or bomb for power discharge throu.-h the rear axial opening, torpedo and fuel load without affecting the aerodynamic efficiency or stability of the airplane, even though the disposable bomb and fuel loads simultaneously approach a minimum wheii th,-@ bomb is launched. For a more complete understanding of the invention, reference may be had to the accompanying drawings, in which: F'igures IA, IB and 1C jointly illustrate a horizontal axial section through the fuselage of the airplane of this invention as seen alon@ the lines IA-IA, 1B-IB and L@C-IC of Figs. 2A, 2B and 2C, respectively; Figs. 2A, 2B aiid 2C jointly illustrate a vertical axial section throu.- h the fusela.ae of the airplane of this invent-loii as seen alon,@ the lines 2A-2A, 2B-2B and 2C-2C o'l Figs. IA, IB and 1C, respectively; Fig. 3 is a rear end view of the fuselage as seen along the line 3-3 of Fig. 2C, showing the multiple power plant uits arratiged concentrically about the axial bomb tunn@-1; Fi,@,-. 4 is a transverse section through the fuselage as seen along the line 4-4 of Fig. 2B, showing the syrimetricaldispositio.- @ of the fuel tanks and the bomb bay pressure eqaal@zin,- ducts and engine air intakes.; Fig. 5 is ai-i air flow dia,-ram illustrating the boundary air induction system for supplying bomb bay pressure ea.ualization and the power plant combustion air, and l-i-. 6 is a front elevational view of the airplane. The drawings illusl,ra@e a generally canard type airpl-,tne in which fuselage 10 has a virtually perfect projectile shape, provided with a relatively thin tapered midv@,ing 11 haning a slight cathedral angle, best shown in Fig. 6, and with a simple horizontal elevator 12 mounted near the nose. The wing 11 is provided with veriical fins, the fi-,is 13 being mounted at the wing tips and the fins 14 being mounted inboard therefrom, as shown in Fig. 6, these fins being fitted with rudders operated in the usual way by conve-@itional mechanism, not shown. A@pproximately the forward third of the fuselage 10, qs showr, particularly in Figs. IA, 2A and 5, serves as the crew comr)artme@it 15 which is separated from the remainler of -the fucelage by a transverse bulkhead 16, a-tid -,@7hich inay be iiiierr-upted by the well 17 housing the extensible landing riose wheel 18. The crew compartment 15. is fitted with the pilot's seat 19, navigatoes and bcmbardier's seat 20, co-pilot and radio operator's seat 2i, engircer's seat 22 and the usual flight, observation, coi-,imutication and other instruments and equipiiient, all constitutin,a Dart of the fixed load. Exte@iding rearwardly from transverse bulkhead 16 for the remaini-@ig approximate two-thirds of the fuselage 10 and coa-- @ia'lly therewith, is a square tube 23 forming the fore-aild-aft bomb bay or bomb tunnel 24, whose rear opepitig 2j- may be Pormally closed by a suitable closure, su@e, as the "oran,ge peel" doors 26, shown open in Fig. 2C and closed in Fig. IC, each segmen', of which is connected to a power cylinder 26' operated from the crew corapartment 15. Mounted coaxially in the bomb tunnel 24 with its center of gravity C located at the airplane center of gravity, -,@ihich preferably lies between the front and rear spars of wing 11, is a bomb B, either suspended in i cradle 36 running on rails 37 as shown in Figs. 2B and 4,
[2]or in a torpedo tube, or otherwise in a mobile fashion for power discharge rearwardly in a manner forming no part of the present invention, but disclosed in detail in copending application Serial No. 88,622, filed April 20, 1949. Positioned at the rear of the annular space 27 formed between the wall of the fuselage 10 and the circular end of tube 23 is a circular series of combustion gas reaction or jet type engines E of conventional design, such as Westinghouse model 24C, for example. There may be eight of such en.-ines E, more or less, provided that they are symmetrically arranged for uniform thrust distribution about the axis of the fuselage 10 as shown in Fi.-s. 3 and 5. Also as there shown, the axes of engines E converge rearwardly so that their jets converge on the axis of the fuselage in general conformance with the characteristic boundary air flow bchind a blunt-tail projectile. Distributed symmetrically about the vertical axis in virtually the remainder of annular space 27 are independent fuel tanks 28, shown in Figs. 1B, 4 and 5. The fore-and-aft distribution of the fuel tanks also is symmetrical about the center of gravity of the airplane, as shown in Fig. 2B, and the fuel will be drawn ballastfashion from the tanks 28 so that the trim of the airplane will not be affected as the fuel is consumed. It will be understood that the lubricating oil load is similarly distributed and that wing tanks will be provided between the spars of wings 11 and so distribi-ited and used to maintain trim. The fixed flight load of crew and equipment in the crewcompartment 15 forward, and the fixed load of power plant engines E aft, are balanced about the center of gravity of the craft at all times and, with the fuel and oil distributed about the center of gravity and expended to maintain trim in the manner described the sudden change in the disposable load occasioned b@ the discharge of heavy bomb B will not alter trim or balance between maximum full load condition with full fuel and bomb load and the minimum load condition with no load and low fuel. Also occupying a portion of the annular space 27 in the fuselage 10 are the wells 30 in which the main retractable landing gear 31 is housed. Preferably, the landing gear 18, 31 is made light of weight for use only iri landing, when the load is light. Takeoff may be effected by a catapult or by means of a powered dolly which is jettisoned upon takeoff, whereby a considerable proportion of gross landing gear load is saved. The landing gear 18, 31 is extended prior to landing by conventional means, such as the hydraulic power cylinders 18' and 31' actuated from the crew compartment 15. As shown particularly in Figs. 2B and 5, forwardlydirected, shallow but circumferentiallv long air scoops 32 extend slightly above the skin surface of the fuselage 10 for collecting a portion of the boundary air layer moving at a relatively high speed over the skin surface of the fuselage. Scoops 32- communicate with one or more ducts 34 leading to the interior of the bomb tunnel 24,- preferably entering the latter at a point at or just ahead of the nose of the bomb B, so that a ram jet effect is obtained at hi.- h speed augmenting bomb discharge when rear door 26 is opened at that instant or when alternative flads 34' normally closing the duct 34 are opened, or bot@, by means shown in said copending application. Also, the air entering the bomb tunnel 24 from scoops 32 flushes products of combustion therefrom after bomb discharge in cases where explosive or rocket expulsion of the bomb is utilized. The rear scoops 33 communicate with longitudin3l ducts 35 extending through the annular space 27 to the engines E for supplying them with combustion-siipporting air under pressure for more complete fuel combustion, thereby adding to the thrust. These ducts 35 are distributed circumferentially around the annular space 2,714,999 4 27 as shown especially in Fig. 4. The scoops 32 or 33, or both, may be enlarged to obtain a greater pressure of rammed air for ram jet effect at very high airplane speed. 5 instead of impairin.@ the efficiency of the engines E, the segments of the oran.-e peel door 26 when open as shown in Figs. 2C, 3 and 5 as mi@-ht be supposed, the certain amount of deflection of the jet stream that is produced by the door segments in open position actually 10 i@-creases jet efficiency, particularly at high airplane speeds. In preparing the airplane of this invention for a bombing mission, the fuel and oil tanks 28 are filled and, being distributed about the center of gravity laterally and ,j Ion-itudinally, the fuel and oil as a large part of the disposable load does not shift the center of gravity of the aircraft. Likewise, the fixed load of engines E aft, and crew and equipment in compartment 15 forward, counterbalance each other about the center of gravity C. By utilizing fuel from tanks 28, in such a way and according to known practice, equally from tanks on opposite sides of the center of gravity, the center of gravity does not shift and the trim of the craft in flight is not affected. 3 The bomb B or other projectile is positioned by cradle 36 on rails 37 within tunnel 24, coaxially therewith, with the center of gravity of the bomb B coincident with the center of gravity of the airplane, so that it acts as a fixed load until ejected. @j As stated, it is preferred that the airplane be launched by catapault or from a powered dolly, so as to conserve fuel and make unnecessary heavy air-borne takeoff gear. After becoming airborne, the best rate of climb would be held until cruising altitude is reached, say 25,000 feet. @;5 This altitude would be maintained for a maximum distance of say, 3500 miles, at a speed of say, 550 miles per hour. At this elevation and speed the engine operation, aided by the boundary air entering scoops 33, would be economical as to fuel consumption. The last 500 n-tiles 4o to the target would be flown at low level at say, 550 miles per hour, the bomb ejected over the target, and after the next 500 miles, flown at the same speed, part, say half, of the engines E would be cut out and the remainder of the return trip, with light and decreasinug load, carried out ki 5 on reserve fuel. Landing on the light gear 18, 31 would be possible since virtually only fixed load remains at completion of the mission. Ejection of the bomb B does not materially affect the trim of the airplane, since their centers of gravity are - @) coincident. Also, being ejected coaxially with the fuselage into the core of the slip and jet streams, as indicated in Fig. 5, the bomb is not deflected by air streams even at high speed, especially since it is desirable to eject it at the speed of flight of the airplane as is explained in greater detail in said copending application. The opening of the door 26, if used, is such that the segments thereof do not extend a substantial distance into the slip stream, and to the extent that they do, the extension is symmetrical, so that the door segments are not injured and the air streams are not deflected so as to disturb the airplane flight, nor does the slip stream enter the open end of the tunnel 24 to disturb the flight of the projectile. Although a preferred embodiment of the invention has been illustrated and described herein, the invention is not limited thereby except to the extent defined by the appended claims. We
