by Massimo Tessitori
The fuselage structure of Ar-2 is basically identical to that of SB, that is to say a metallic structure with duraluminium riveted skinning.
The fuselage hosts the crew compartments (navigator, pilot, gunner) and the bomb bay.
The covering of the top fuselage between 4-th and 8-th frames was carried out from "balenit", the plywood pasted by VIAM glue to wooden carrying parts of 5-th, 6-th and 7-th frames.
the seat of the pilot was moved on the left, while the instruments panel was moved on the right to allow the pilot to see through the windows of the navigator at landing and on a dive;
there was a PBP-1 sight (for dive bombing) in the pilot's cabin;
there were a diving gyro artificial horizon and an overload alarm on the pilot's instrument panel.
|rear gunner/radio operator cabin
Dorsal ShKAS was in dorsal installation TSS-1 (1000 cartridges), and was equipped with reflector sight K-8T; the installation TSS-1 had a field of fire of 90 degrees to the left and to the right, of 60 degrees upwards and of 30 degrees downwards.
The turret TSS-1 was an half ring on which the carriage with a head of a machine gun moved.
In cruising position, the machine gun settled down on the left board; for this purpose there was a small cut on the left side of fuselage (only in prototypes; in series aircrafts it doesn't appear) .
In shooting position, the transparent screen of the turret moved on rails forward and rose a little upwards, protecting the gunner from a pressing air stream.
While on early Ar-2s the transparent screen was symmetrical apart for a small metal plate on the left rear lip (photo on the right), on series aircraft the structure was slightly asymmetrical. Besides, the cut on the fuselage was smaller and oblique instead than vertical, and the gun barrel recess has disappeared. (photo below).
It is not clear how the gun barrel was located with the late type hood in closed position; probably it was at 6 o'clock in central position, but it could have been in any position when the trasparent nail was removed..
In facts, many of the photos of operative Ar-2s show that the rear trasparent nail was partially broken or removed.
few images show aircraft without the hood at all: perhaps it was removed because it was difficult to be opened in flight, as on MiG-3s.
ShKAS (image Lee Jong Tae)
The ventral ShKAS with sight OP-2P was placed inside a retractable fuselage turret MB-2 with a magazine of 600 cartridges; its firing field was of 30 degrees to the left and to the right and from 4-5 up to 55 degrees downwards.
|Images of the dorsal gunner position of late type from both sides.
Note the slight asimmetry of the frames.
Probably a space to protrude the gun remained between the sliding hood and the fuselage on the right side.
|Note that the frames of the ventral position doors are asymmetrical too.|
|No photos of Ar-2 bomb bay are available; however, it should be nearly
identical to that of SB, except for the use of two PB-3 horizontal bomb
racks instead of DER-23.
These two images are of an SB bomb bay.
(from Tupolev SB in action)
The image on the right, from the front, shows a six-cell container for
FAB-100 bombs, that were loaded nose up and secured to DER-34 bomb racks.
The image on the left (from the rear) shows two bombs in vertical position (probably FAB-50), and a dismountable platform with two DER-23 bomb racks (probably replaced by two PB-3 on Ar-2), able to carry two FAB-250 bombs in horizontal position, or one FAB-500 on its right side rack only.
Here are some possible load combinations for Ar-2:
|internal fuselage bay||under the wings||total weight|
|dive||1x FAB-500||2xFAB-500||1500 kg|
|horizontal flight||1x FAB-500||2XFAB-500||1500 kg|
|horizontal flight||2x FAB-250||4x FAB-250||1500 kg|
|horizontal flight||8x 100 kg||4x 100 kg||1200 kg|
|Here are drawings of some combinations of bomb loading for early SB.
It's likely that those combinations were possible for Ar-2 too for horizontal flight bombing only.
The drawing is interesting also because it shows the field of fire and the jobs of the crew.
|Besides, there was the possibility to bring underwing two containers
VAP-500 and/or two UHAP-500 that can carry all types of poisonous gas,
incendiary and smoking mixes.
Despite the availability of large amounts of Yprite and other gases in Soviet inventory, chemical weapons were never used against Germans for fear of a reprisal.
(here depicted on a SB; images from Tupolev SB in action)
The wing was divided in three parts: a central one, and one external
console for each side. All the wing was streghtened by two longarons.
The Ar-2 was moved by two Mikulin M-105R engines, moving two VIT1T-22E propellers with 3.1 m diameter; both props turned clockwards (seen from the front).
The reduction rate of engine gears was 0.59.
The engine nacelles were particularly aereodinamical; to improve penetration, the water and oil coolers were installed in the wing thickness.
The supercharger intake was located under the nacelles.
On this photo, the left supercharger intake appears closed by two small doors that open by rotating on central hinges when the landing gear is retracted to prevent ingestion of any solid object. This device doesn't appear on most photos of operative Ar-2, and not even on the other engine on this photo.
Water coolers were in tunnels inside the wing thickness, with inlets on the wing leading edge, and outlet on the wing uppersurface closed by 5 adjustable flaps (6 on prototypes).
There was a new lubrification system, with a water-oil cooler and a air-oil one on each engine; the air-oil had a circular intake on the wing leading edge.
The exhaust stacks were made by a couple of pipes for each engine; they pass through the wing, discharging fumes on the wing upper surface, as on SB-2M103.
They were shaped to give some thrust.
|Main landing gear
The landing gear was identical to that of SB and the main wheels protruded through openings on their doors, but the nacelles were closed on the back, differently than on SB.
The side rods of the leg were connected to the bay doors, that were moved by the leg retraction/extraction movement.
The tail surfaces had metallic frame and duraluminium skinning. The elevators and rudder had a duraluminium structure covered with fabric skin.
Each tail horizontal surface was streghtened by 3 wires, two (the lower ones) joined to the fuselage, and one (the upper one) to the stabilizator.
Both the rudder and elevators had trim tabs.
Note: the most of the images of this page are from M-Hobby
3/2003, a work of M.Maslov and N.Polikarpov