J.I / J.II
Битва под Верденом продемонстрировала высокую значимость самолетов непосредственной поддержки наземных войск В связи с этим в ускоренном режиме был разработан штурмовой самолет AEG J I. Он был создан на базе AEG С IV и отличался от него усиленным вооружением: имел два пулемета LMG 08/15, установленных для стрельбы вперед-вниз под углом в 45· и один оборонительный турельный пулемет "Парабеллум" в задней кабине. Была установлена бронезащита экипажа и двигателя Бенц Bz.IV (200 л. с). Модификация J II, выпущенная в 1918 г., была в целом аналогична варианту J I, но имела некоторые отличия в конструкции и оборудовании. Всего было произведено более 600 самолетов JI и JII.
O.Thetford, P.Gray German Aircraft of the First World War (Putnam)
A.E.G. J I and J II
During 1917, formation and equipment of the Injanterie-Flieger units proceeded and, until specifically designed aircraft (e.g. Junkers J I, etc.) were available in sufficient quantity A.E.G. J Is and J IIs were allocated. Supply of these machines was a relatively simple matter, as the aircraft itself was virtually a C IV re-engined with a Benz and with a modified, armoured fuselage.
Powering the J I was the 200 h.p. Benz Bz IV, giving an increase of 40 h.p. over the Mercedes D III installed in the C IV. However, every ounce of this additional power was required to haul the extra 860 lb. of armour plate through the air. Armour plate extended from the nose to the aft extremity of the rear cockpit and was some 5.1 mm. thick. There were three panels either side of the fuselage, three underneath and a transverse bulkhead at the back of the rear cockpit to protect the observer from behind. The armour in no way formed part of the structure: it represented little more than sheets of steel fastened to the fuselage framework by set-screws entering clips clamped round structural members, with scant concession to shaping. In fact, the angular severity of the resultant nose contours was strongly reminiscent of a tank.
J Is were not fitted with any forward-firing armament, but two Spandau guns were bolted to tubular brackets on the rear cockpit floor. These fired forward and downwards at an angle of 45#' to facilitate Straffing of troops and harassing of ground targets, which were the prime duties of the A.E.G. J I. They were operated through Bowden wire controls from twin triggers mounted conveniently at the observer's right hand. Ammunition was belt-fed from a large supply drum mounted close to the guns. Rudimentary sighting was through a circular hole in the forward right-hand corner of the cockpit. For defensive purposes, the observer was equipped with the usual free-firing Parabellum gun on a ring mounting.
In the prototype machine the wing structure was identical with that of the C IV, but in operation, due to the added weight of the armour, the aeroplane was found to need a much greater degree of lateral control. To secure this without drastic revision of the flying surfaces, ailerons were added to the tips of the lower wings and simply connected to the upper ailerons with a rigid link strut, as the modus operandi was exactly the same as that of the earlier C type machine.
The remainder of the aircraft was almost pure C IV. Even the Daimler-Mercedes radiator was retained, though it now served a Benz engine. The number of spiral spring shock absorbers was reinforced to cater for the increased weight of the machine.
Later on, in 1918, a further development known as the J II was produced, but this differed little from the J I structurally. All control surfaces except for the lower ailerons, were now revised with large overhung horn balances which materially altered the appearance of the aircraft. To improve directional stability, the vertical fin was increased in area, raking up from the fuselage in a compound curve. The aileron link strut was located at the forward end of the operating crank instead of in the middle of the ailerons.
Altogether, according to the findings of the Inter Allied Commission immediately after the armistice, some 609 J type aircraft were produced by the A.E.G. concern.
Purpose: Armoured Infantry Contact Patrol.
Manufacturers: Allgemeine Elektrizitiits Gescllschaft (A.E.G.).
Power Plant: 200 h.p. Benz Bz IV 6 cylinder in-line water cooled.
Dimensions: Span, 13.460 m. (44 ft. 2 in.). Length, 7.200 m. (7.900 m. J II) (23 ft. 7 1/2 in.) (25 ft. 11 in. J II). Height, 3.350 m. (10 ft. 11 7/8 in.). Wing area, 33.18 sq.m. (358.4 sq.ft.).
Weights: Empty, 1,455 kg. (1,480 kg. J II) (3,201 lb.) (3,256 lb. J II). Loaded, 1,740 kg. (1,765 kg. J II) (3,828 lb.) (3,883 lb. J II).
Flight, August 29, 1918.
THE A.E.G, ARMOURED AEROPLANE.
Issued by the Technical Department (Aircraft Production) Ministry of Munitions.
THIS machine was brought down by an R.E.8 of 21st Squadron, near Hinges, on May 16th, 1918. It bears the date February 3rd, 1918, stamped on the main planes, and also on portions of the fuselage, and is the first of its type to have been secured.
This aeroplane is designed for the purpose of carrying out offensive patrols against infantry, and is furnished with armour, which affords protection for its personnel. This armour appears, however, to be more or less experimental. In general construction it closely follows the lines of the A.E.G. twin-engined bomber G. 105, reported on in I.C. 607, though the arrangement of the power plant is, of course, entirely different. A steel tubular construction is used practically throughout. The machine was badly crashed, and some details are, therefore, not available ; but the general arrangement drawings at the end of this report may be regarded as substantially accurate.
The leading particulars of the machine are as follows :- Area of upper wings, 190.4 sq. ft.; area of lower wings, 168 sq. ft.; total area of wings, 358.4 sq. ft.; area of upper aileron, 11.2 sq. ft. ; area of lower aileron, 10 sq. ft.; area of tail plane, 9.4 sq. ft.; area of fin, 7.6 sq. ft.; area of rudder, 6 sq. ft.; horizontal area of body, 48. 6 sq. ft.; side area of body, 54.8 sq. ft.; cross sectional area of body, 14.4 sq. ft.; area of side armour, 33 sq. ft.; area of bottom armour, 29.4 sq. ft.; area of armour bulkhead, 10.4 sq. ft.
Engine, 200 h.p. "Benz." Crew - pilot and gunner, 360 lbs.; armament - three guns; petrol capacity, 38 galls.; oil capacity, 3 galls. The principal dimensions are shown on the general arrangements drawings.
The manner in which the wings are constructed is exactly as shown in the report of the A.E.G. bomber - i.e., the spars consist of two steel tubes 40 mm. in diameter by .75 mm. thick. At their ends the upper and lower surfaces of the spars are chamfered away, and flat plates welded in position, so as to provide a taper within the washed-out portion of the wing tips. The wings were, unfortunately, so badly damaged that no accurate drawing of their section can be taken, but there is evidence that this very closely follows the section of the bomber, which has already been published. The ribs are of wood, and between each main rib is placed a half-rib joining the front spar to the semicircular section wooden strip which forms the leading edge. The wing construction is strengthened by two light steel tubes passing through the ribs close behind and parallel to the leading spar, which are used for housing the aileron control wires. The bracing against drag consists of wires and transverse steel tubes welded in position. At the inner end of the wings special reinforced ribs of light gauge steel tube are provided. The method of construction at this point is clearly shown in Fig. 1, which also indicates the manner in which the bracing tube is welded to a socket driven on the main spar. The spars are attached to the fuselage by plain pin joints.
The centre section of the upper surface is constructed in a similar manner to that of the wings, except that it is considerably reinforced, and the spars are larger in diameter. The leading spar has a diameter of 51 mm. and the rear spar 45 mm. The centre section is secured to the fuselage by a system of stream-lined steel struts, the feet of which terminate in ball-ends dropped into sockets, and there bolted in position. One of these struts is shown in Fig. 2. The centre section contains an auxiliary gravity petrol tank, and also the radiator, and is, therefore, substantially braced with steel tube transverse members. The wings are set with a dihedral angle of approximately 6 deg.
The aileron framework is of light steel tube throughout, the tube forming the trailing edge being flattened into an elliptical section. The ribs are fixed by welding. The framework of the ailerons on the upper wing is reinforced by diagonal bracing of light tube.
These are of light steel tube stream-line in section, tapered at each end, and terminating in a socket which abuts against a ball-headed pedestal carried on the wing spars; through the socket and the ball is passed a small bolt. The manner in which this attachment is carried out is exactly similar to that described in I.C. 607.
The whole of the fuselage is built up of steel tubes welded together, and having affixed at their junctions sheet steel lugs, which serve as the anchorage for the bracing wires. The diameter of the longerons and of the frame verticals is 20 mm., except the last three members adjacent to the tail, of which the diameter is 16 mm. The welding throughout the fuselage appears to be of very high quality. In Fig. 2 is illustrated a joint, which occurs in the fuselage immediately in front of the pilot's cockpit. The longeron is, from this point to the rear of the gunner's cockpit, fitted with a wooden strip taped in position. This joint shows the method in which the cross bracing wires are furnished with an anchorage. In one or two points in the frame construction the bracing wire lies in the same plane as the transverse tube, and to allow for this a diagonal hole is drilled through the tube and filled in with a small steel tube welded in place.
This consists of a triangulated arrangement of steel tubes carrying hollow rectangular section steel bearers, on which the crank chamber is slung. The bearers are well trussed both in the vertical and horizontal planes, and are shown in dotted lines in the general arrangement drawings. The engine bearers themselves are 2 mm. in thickness, and have an approximate section of 2 1/16 ins. by 1 1/2 ins.
The empennage possesses no particular points of interest, the planes having the usual steel tubular framework. The tail plane is not fitted with any trimming gear, but a method of adjustment is provided. This is shown in Fig. 3, which is self-explanatory. The diagonal struts which proceed from the base of the fuselage to the tail plane spar are fitted at each end with a method of adjustment shown in Fig. 4, allowing them to be extended as required according to the particular socket which is used to carry the leading edge of the tail plane. Neither the elevators nor the rudder are balanced. The rudder post is mounted on the end of the fuselage, as shown in Fig. 5, in which it will be seen that the vertical frame tube of the fin is very stoutly attached to the frame by a triangulated foot.
This is of the usual A.E.G. type, and is furnished with shock absorbers consisting of metal coil springs in direct tension, as is clearly shown in the general arrangement drawing.
The landing carriage axle has a diameter of 55 mm. The landing carriage struts, which are of similar section to those used between the planes, measure 70 mm. by 37 mm. At their upper ends they are furnished with ball and socket attachments similar to those of the interplane struts.
The wheels are fitted with 810 by 125 mm. tyres, and the track is 6 ft. 10 1/2 in.
The tail skid is unusually heavy, and it is a built-up construction of welded sheet steel. It is mounted on a stout tail post, which is reinforced by four stream-line steel diagonals. The forward end of the tail skid projects inside the fuselage and is there provided with four steel springs in direct tension. A sketch of the tail skid is given in Fig. 6.
This consists of the usual double-handled lever mounted on a transverse rocking shaft, which carries the elevator control cranks at each end. The upper ailerons are worked positively by wires which pass over pulleys on the wing spars at the outer struts, the outer and lower ailerons being connected by a stream-line steel tubular strut.
The 200 h.p. Benz engine possesses no new features, and has already been made the subject of an exhaustive report.
Underneath the pilot's seat are the two main petrol tanks, each of which contains 80 litres (equal to 16 gallons). These tanks are of brass, and are fitted with Maximall level indicators. The gravity tank, containing 27 litres (equals 5 1/2 gallons) is embedded in the centre section of the upper plane, where it forms the leading edge on the left-hand side. This tank is made of lead-covered steel. Cocks are provided, so that either the gravity tank or the pressure tanks, separately or together, can feed the carburettor.
It is of interest to note that the chamber which is used in connection with the Benz petrol supply system is not, as is usually the case, contained in the main tank, but is a separate fitting mounted on the side of the engine.
The radiator is of the Daimler-Mercedes type, measuring 32 1/2 ins. long by 11 1/2 ins. high and 6 ins. deep. This is fitted with imitation honeycomb tubes, of which there are 118 running vertically, each being fitted with 48 gills. The radiator is carried in a steel cradle, into which it is easily inserted from above, and this in turn is supported on specially built-up steel ribs. It is placed so that the tank which forms the upper part of the radiator lies about flush with the centre section of the top plane. The shutter or flap for controlling the water temperature is made of 3-ply wood stiffened with a light steel framework, and is mounted immediately behind the radiator, being worked by a handle within reach of the pilot. This handle is provided with a rack and pawl device. The shutter is 3 3/4 ins. deep, and is capable, therefore, of covering up about one-third of the total radiator surface. It will be noted that the position of the shutter behind the radiator is unusual.
Protection for the pilot and gunner is afforded by armour, which, is shown in the general arrangement drawing in thick lines. There are three panels at each side, and three panels at the bottom of the fuselage, an armour bulkhead being placed at the rear of the gunner's cockpit to protect him from behind. The armour is 5.1 mm. thick, and its total area is 105.8 sq. ft. The weight of the armour is thus approximately 860 lbs. Careful tests have been made to ascertain the effectiveness of this armour, and the following table gives the ranges at which these plates are safe or unsafe against penetration by bullets of various types. These figures may be taken as correct within the limit of a practical firing test.
Angle to Normal Safe range Unsafe range
Ammunition. degrees. yards. yards.
German A.P. 0 - 600
15 500 400
30 400 300
Mark VII. 0 probably 700 600
Armour 15 400 300
piercing 30 300 200
German Spitze 0 150 100
15 100 50
Mark VII. 0 50
The armour is undoubtedly too light to afford protection against British armour-piercing bullets fired from the ground at a lower height than 500 ft., while a machine armoured with it would have to fly at, at least, 1,000 ft. to be safe from all but a very low percentage of hits.
The armour does not appear to have been employed, as it might well have been, in a structural capacity - i.e., it is simply an attachment to the framework, to which it adds no material strength. Its appearance seems to point to the fact that it had been added by way of experiment, and that it was of a more or less makeshift character. It had, for instance, evidently been necessary to open out existing holes and cut new holes in the course of erection. The armour is attached by set screws to clips clamped on the fuselage members, as shown in Fig. 7.
In this machine the pilot is not provided with a gun, but the observer has to control three, of which two (Spandau) are fixed on the flooring of his cockpit, whilst the other (Parabellum) is carried on a rotatable mounting.
With regard to the fixed guns, these are secured to a couple of tubular steel brackets, mounted as shown in Fig. 8. The oval-section steel tubes, of which these brackets are composed, are welded to a light steel base, which forms a sort of tray, and is in turn bolted to the panel of armour which forms the floor of the cockpit.
Adjacent to these two guns, which fire forward at an angle of 45 deg., is a bracket carrying the belts of ammunition, which are fed from a large rotating drum.
In the right-hand front corner of the pilot's cockpit floor is a circular hole, which he would appear to use for sight purposes. The fixed guns are controlled by Bowden wires and triggers mounted on a diagonal frame member, convenient to the gunner's right hand, as shown in Fig. 9. The movable gun is of the Parabellum type, and the mounting is of the usual built-up wood variety. The gun cradle is, however, novel, the fixture for this purpose being illustrated in Fig. 10. It appears to be rather more handy than the usual German device, but is by no means lacking in weight. This fitting was in a very badly smashed condition. The vertical carrier is swivelled at its base, and is secured in position by sliding bolts engaging with teeth cut in the turned-up base plate. These sliding bolts are worked by a direct acting thumb lever. The turn-table is made of a single hoop of wood reinforced at the point where the gun is mounted by glued-on strips of ply-wood. A locking device of the type shown in Fig. 11 is fitted.
The transverse bracing in the immediate rear of the gunner's cockpit, at which point is mounted the armour bulkhead, suggests that it was the original intention for this aeroplane to carry a gun or guns firing downwards and backwards through a hole in the fuselage. The transverse arrangement of steel tubes and bracing wires is shown in Fig. 12.
Wireless and Heating.
The machine is fitted with the usual wireless leads and apparatus for heating, the dynamo being carried on a bracket attached to the fuselage immediately in front of the pilot's seat, where it is directly driven from the engine through a hand-controlled clutch. No wireless fittings, other than the dynamo and the leads, were found on the machine.
The instruments fitted to this machine are of standard type, and possess no new features of interest.
Fabric and Dope.
The fabric throughout is of good quality, but the dope appears to have been badly applied, as in many points it had completely peeled off the fabric.
The colours used are dark purple and daik green, and in contradistinction to the usual method by which they are arranged in well-defined polygons, are applied so as to give a cloudy effect, and appear to have been sprayed on.
A sample of the wing spar yields the following analysis :-
Carbon .098 per cent. Phosphor .014 per cent.
Silicon .011 per cent. Manganese .461 per cent.
Sulphur .017 per cent. Chromium .036 per cent.