Romantic Technofreak
16th November 2008, 13:02
Picture #9 showing nose details:
http://img.photobucket.com/albums/v475/Coridano/papermodelru.jpg
Text from paperplane.ru:
For the flying boats of the late thirties this type has enough high-altitude and seaworthiness qualities. Orders for production of these seaplanes were posted in Taganrog, where during 1937 - 1941 50 samples were built.
Under the name of MDR-6, 1941 renamed Che-2, there were several versions of the aircraft produced, characterized by the type and capacity of engines, size and shape of tail stabilizers, the retractable floats, shape and location of blisters, as well as of weapons.
During the Great Patriotic War, Che-2 planes were not onlyused for their intended purpose - reconnaissance at sea, search and destroy of enemy submarines and rescue of our pilots and crews of ships in distress. The situation at the frontier, especially in the first period of war, forced to use flying boats against the enemy's ground forces. Che-2-crews (the aircraft carrying bombs up to 1000 kg of different caliber) have attacked positions and clusters of enemy troops and carryied injured soldiers on urgent missions. Che-2s being equipped with additions to standard weapons, heavy machine guns or 20-mm cannons, as well as rockets of type RS-82, navy pilots successfully fulfill even the role of hunters of fascist seaplanes and torpedo bombers, as well as to conduct weather reconnaissance flights for the Soviet bombers sent against to Berlin.
My resume:
I found the text on paperplane.ru while searching for a hint to 50 serial samples, they are mentioned in my standard book (title on request, already often mentioned in other topics). The city of Taganrog is located on the Sea ov Asov and became occupied by German troops, so a continuation of the production there was not possible. Also, the further developed versions saw no serial production. Meanwhile, the USSR had imported Consolidated Catalinas, which finished the job.
High-performance seaplanes always have been a niche product, even in WWII. But samples like Kawanishi's Emily, or the below mentioned MDR-6B-1, show it was possible to reach the same performances for a seaplane as they are possible for a landplane. They were not really necessary for WWII warfare, but from the romantic position, you could construct a whole family of different seaplane types taking the tasks of landplanes, where it is either not at all or not fast enough possible, or too costly to set up an airfield for landplanes.
You can find more pictures and the original text on airwar.ru here:
http://airwar.ru/enc/sww2/mdr6.html
If you still like to read (take your time!), here is my translation:
Before the beginning of the Second World War the aviation of the navy of the USSR obtained several types of flying boats, including far-distance reconnoisaters, abbreviated "MDR". It was developed by a group of engineers, headed by the aircraft designer I.V. Chetverikov. For the first time in the domestic practice on the experimental seagoing aircraft, there was a wing in gull-wing form used, and the engine nacelles were established in the bend of wing. Subsequently, this innovation justified itself: this the wing scheme and the arrangement of engines created a sufficient distance between the propellers and the aqueous surface.
According to its data, MDR-6 exceeded the already employed hydro-aviation aircraft MBR-2M-34 and its implementation permitted modernization and improvement in the flight performances.
According to operational requirements of 1934 and demands of the type commission dated from December 4, 1936, the first seaplane MDR-6-2M-25E was built as long-range reconnoisater and light bomber. The installated engines of type M-25E from the production of the plant No. 19 were taken as stopgap measure in 1937 from the crashed aircraft ARK-3. The use of experimental nonserial engines was considered as provisional measure, which made it possible to conduct the tests of seaplane without delay.
In the case of the successful completion of the cycle of military tests it was intended to establish M-87 or M-62 engines as serial drive engines. They considered the latter most suitable: it gave increased takeoff power, had only insignificant gain in weight, and overall sizes of the M-25 engine family. Further, with the use of engines M-62 there were improvements in the take-off characteristics, rate of climb, increase in speed and savings of fuel expected.
Structurally, MDR-6 was an all-metal monoplane flying boat type. The cantilever wing of gull form had flaps with hydraulic control. In the outer wing section, it had nonretractable supporting floats. The ailerons had aerodynamic and weight balance. The boat had two steps within the sharply pronounced careen. After the elimination of basic defects, revealed during the first stage of military tests, the plant No. 45 produced the changed aircraft. The form of the main step became wedge-shaped, the second - descending to the wedge, with the water rudder.
This ensured stability and liquidated longitudinal vibrations on the run. They performed the nose of the boat to a straight line, after removing the edge, which created breakers and strong drops at the beginning of the takeoff. They made tail assembly semicantilever. To the control vanes they established trim tabs and mass balancing rigid control by motors was replaced by wire.
Fastening motors to the wing was accomplished by special "Motokoki", which laid on the wing, engine mountings were absent. The airscrews were of type VISh-6 with variable pitch and a diameter of 2,8 meters. Ten fuel tanks and even two oil tanks were placed in the wing. Their total capacity was 2160 and 240 liters.
The engine M-25E had the nominal yield of 710 hp, nominal revolutions - 2100 r/min, maximum altitude - 5400 meters, the takeoff power of 635 hp, weight - 453 kg.
Rifle armament consisted of three weapon emplacements. Nose rifle installation was a rotating turret of the type NU-DB-3 equipped with the machine gun ShKAS (Shpital'nyy-Komarnitskiy 7.62 mm rapid-fire aircraft machine gun) of caliber of 7,62 mm and gunsight KPT-5. The ammunition box with a capacity of 1000 rounds was established on the starboard. The bottom of the boat was covered with a detachable mat. The screen of the turret had a slot for the installation of a machine gun. In the absence of the machine gun the slot was shut by three detachable shields. For protection of the gunnery device from damages the slot of the turret was shut by a belt.
The center of the aircraft received a rotating turret of the type SU-DB-3, also equipped with the machine gun ShKAS of the caliber of 7,62 mm. The capacity of cartridges was increased - 2000 pieces. For convenience during a maneuver of the turret and selection of aiming angles there were steps made within its area on the bottom of the boat. Screen in flight could increase due to the chamois compressible part, rigidly fastened to it. There was a march detachable leather seat. The bracket for the oxygen apparatus was installed on the slidepath of the turret.
The hatch (meant is the downward-firing gun position under the tail, RT) rifle installation was, according to the type used in the aircraft DB-3, a machine gun type ShKAS of caliber of 7,62 mm on a pintle. The ammunition box with capacity of 1000 pieces it was located in a special area on the starboard. In the march position the machine gun was tipped up on the starboard. On the skin, on the left side, there was a rope on the carbine, by which the gunner brought it into shooting position.
The maximum bomb load of the aircraft was 1200 kg. The versions of the armament were: twelve FAB-100 or FAB-50, four FAB-250 or BRAB-220, two FAB-500. Large-caliber bombs FAB-500 and 250 were hung up on the locks of type DER-19, of which two ones were located under each wing of the plane. Bombs of type FAB-100 were hung up on the horizontal cassette holders of type DER-31M. The cassettes were fastened under each wing of the plane into the locks of of type DER-19.
Each bomb shackle, concluded in the fairing, had six front and rear oven prongs with the elongated set screws. For the survey and the setting to the safety device they made a fairing with four inspection holes. Inside the cassette there was a transmission, which consisted of two rollers, concluded within ball bearings. Roller had three fists, located in one plane. Six cross beams served for the installation of the locks of DER-31M.
The locks of cassette holders worked from ACE -5, according to the principle of the locks of DER-19. For one motion AC-5 dropped three bombs in the volley. For the locks of DER-31M it was taken the operating principle from ESBR-3. For cluster and flare bombs there were two locks of type DER-32. Ejectors were connected with the bomb shackles by an electrical installation. Bombsight was OPB-2. Large-caliber bombs rose with the aid of the winch BL-3, installed in the wings of the aircraft. Hanging-up of bombs to the cassette holders was done by hand.
During range trials, the possibility of application of universal aircraft spray tanks of type ChKhAB-500, from the plant No. 145 NKAP, was tested, intended for pouring from the aircraft OV and DB. Their overall dimensions were within the limits of the aircraft bomb FAB-500, they were hung up under the wing.
The crew consisted of four people: two pilots, navigator and radio operator-gunner. They were arranged in three sections of boat, divided by watertight partitions. In the radio operator's compartment, there was a radio station of type RSRM and a camera of type AFA-13 placed, in the cockpit the portable radio of type RSVS. For to operate the radio station on the float there was an emergency mast provided. Command connection was achieved by the SPU-3 pneumatic mail system, light trichromatic signaling and the radio station RSVS.
The second stage of the military tests of the first experimental aircraft MDR-6 built by the plant No. 45 in 1938 with the motors of type M-25E from an experimental series of the plant No. 19 (1936) was passed during the period from July 2 to 22, 1939, in Sevastopol (in the bay “Holland”, in the sea in front of the Konstantinovsky ravelin, and also in the Lake Donuzlav.
The test brigade consisted of: the chief engineer for the aircraft - Military Engineer of 2nd rank N.I. Chernishev, the chief pilot - Major Slobodchikov, the chief engineer for the armament - Major Tyutlyaev, the chief engineer for the chemical armament - Major Tyuplyaev, the chief engineer on VMG - Military Engineer of the 3rd rank Belkind, navigator - Senior Lieutenant Olkhovikov, co-pilot - Senior Lieutenant Efimenko, onboard mechanic - Military Technician of the 1st rank Salomatov, the assistant to the chief engineer for the aircraft - Military Engineer of 3rd rank Kolchinskiy, the assistant to the chief engineer for the armament - Military Technician of 1st rank Vorobyev.
The test program was affirmed by the chief of UA RKVMF (Workers' and Peasants' Navy) Division Commander Zhavoronkov and the military commissar of UA RKVMF Brigade Commissioner Alekseyev. Report for the results of tests were signed by the commander of VVS Black Sea fleet Brigade Commander Rusakov and military commissar of LII ARKVMF Battalion Commissioner Mochalov.
In the time of the tests all in all there were 14 check sequences and 39 flights: in the circle - 13, high-altitude - 10, normal - 16. There were resources spent: in air - 34 hours, for the test and the taxiings - 3 hours 40 minutes, for transfer - 1 hour 20 minutes.
From the total number of flights, 30 were performed on overload in the versions of long-range reconnaissance aircraft and bomber, with wind force from 1 to 8 m/s and waves from the calm to 0,5 meters. Maximum overload with the takeoffs and the landings reached 1,78. During the second stage of military tests on flutter the flight speed was led to 270 km/h according to the instrument. The temperature of surrounding air was equal minus 17 degrees. Maximum speed was 405 km/h, height at 5835 meters, there were no vibrations (during the first test maximum stages speed at the height of 5800 m was equal to 338 km/h). Turns were carried out with the bomb load on the cassettes: twelve FAB-100 with a gross weight of 5900 kg.
According to concluding documents, the aircraft MDR6-2M-25E by testing for overloads, seaworthiness, take-off and landing characteristics and flutter maintained. I will give impressions from the report of the test pilots:
“The aircraft is towed by the launch off the anchor-place ("crosspiece",??), and there they begin the starting of the motors. Because of the optimal performance of motors and the presence of the effective water control, MDR-6-2M-25E is very of maneuverable on the water. To taxi to the start is possible within 30 minutes on one motor with the revolutions from 500 to 1200 r/min.
The aircraft strictly maintains the undertaken takeoff course, does not have yaw on the takeoff and goes stably on the step. After detachment the machine is maintained normally above the water and, after reaching the speed of 150 km/h, smoothly is transferred to the climb angle. Loads on the steering control are easily removed by the trim tabs of the elevator.
In the level flight the aircraft is balanced well at all speeds, with any position and weight on the working alignments from 28% to 34% of "SAKh" (= "MAC" "mean aerdynamic chord"?). Transverse and longitudinal stability is good, there is no tendency towards a wing heaviness. In the case of the failure of motors it easily passes to the gliding condition. With failure of one of the motors the aircraft at the normal gross weight can continue to fly - for this is removed load from the foot by the trim tab of rudder, and to the working motor full throttle is given.
The Aircraft answers the controls without delay at normal load on the steering control, and load to 7000 kg we to govern in all flight conditions, it is easily balanced by trim tabs. The effectivity of controls for the takeoff, the flight and landing are sufficient.
Passage from the level flight to the turns is easily accomplished with the aid of the control vanes of aircraft, without a change in the control of motors and position of trim tabs. Optimal turn is at the bank of 60 degrees and speeds of 210 km/h. It turns stably - without tendencies towards dumping, stalling and pitching.
Entrance and exit from the spiral is accomplished with the aid of the control vanes - without the application of trim tabs and motors. In the spiral the aircraft is steady. Best spiral is at the speed of 180 km/h with the bank of 45 degrees.
The flutter phenomenon is not observed in all permissible flight conditions.
The passage of all regimes to the gliding condition is accomplished easily by control vanes. During the gliding, the aircraft is steady both in the longitudinal and in the transversal sense, there is no yaw. Optimum gliding speed with open flaps is 150-160 km/h according to the instrument (depending on load).
Landing depends on the position of the shields (??, panels? flaps?): with the open shields glide path is steeper abrupt, without the shields gliding angle is gently sloping, leveling-out smooth (as in MBR-2). Splashdown occurs at the speed of 110-115 km/h, path lasts 18-20 seconds, depending on load. It is steady on the path, there is no tendency towards turns and swaying.
The aircraft allows normal crosswind landing by force to 6-8 m/s, at angle to 65-70 degrees to the wind direction. After landing the aircraft taxis to the anchor place, or into the turn off range of motors, from where it is easily towed using the nose “duck” (some kind of fixing gear, RT) by the towing ends, supplied from any harbor launch.
The aircraft is convenient for the instruction of pilots by the presence of two seats, by duplicated equipment of control instruments and good identical survey. … In the technology of piloting it is simple and accessible to the mastery by an average pilot ".
Also, there was a number of the deficiencies noted , discovered in the process of tests. For example, the extremely severe conditions for the work of the screws (especially the left one), whose rigid impacts against the water are dangerous with takeoffs and landings of aircraft in the cargo carrier version and in the cases of flight into the wind, wave and the counterrecoil. It was assumed that the screw of the left motor will require exchange after 40-45 hours of operation.
The lubrication system did not provide a sufficient oil cooling. Fuel system required an alteration: it was necessary to ensure the possibility of the survey of wing tanks without disconnecting the wing. The capacity of the established tanks was sufficient for the flights of the aircraft in the version as bomber and insufficient for the version as long-range reconnaissance aircraft. Prolonged gliding had to be achieved due to an increase in the effectiveness of cowl flaps and installation of a shutter at the air intake into the radiator.
View from the navigator cabin was insufficient. Small windows on its boards did not ensure normal observation (the sector of survey composed of 60-70 degrees). As a result of the low sagging of boat the cabin was strongly flooded on the taxiings and the takeoff. The well arranged anchor winch, placed in the inconvenient upper hatch, was set under the the door and fastened on the left side. The anchor itself was located under the seat of the right pilot, from where to navigator had troubles to reach it. The conveniently located seat was a primitive device, unstable and with the least impact by foot on the hinged legs was removed. Because of the low seat position for the forward observation through the screen of the nose turret it was necessary to arise.
Intercommunication in the aircraft among the crew members was achieved via three-light signaling or the SPU-3 pneumatic dispatch tube - between the pilot and the navigator through the hatchway of the cabin or the open door. In air, light signaling worked well, SPU-3 worked badly, pneumatic dispatch tube did not work steadily.
In the navigator's compartment were absent “the ray” radio station box PAR-13, radio compass and radio direction finding station. Apparatus AFA-13 is located together with the entire installation in the radio operators compartment, which hampered photographing. It was proposed to transfer control of this apparatus to the navigator.
Visual orienting on leaving to the course was accomplished through the screen of the nose turret. For determining the aeronavigational elements they used the sight OPB-2. Connection with the pilot about the course was possible only written. Equipment for radio navigation aid was absent. During the celestial orientation they went out with the sextant into the upper hatch, but the blowing wind would interfere the work. For decreasing its pressure a hinged visor was required.
Pinpoint bombing showed that rough focusing of athe ircraft to the target was to accomplish difficultly because of the absence of windows in to the nose of the boat under the nose turret, since the target rapidly departed under the aircraft. Dropping was performed from ESBR-3 and AS-5.
One of the tasks of military tests there was resolution of a question about the seadrome for MDR-6. The aircraft could be stored in the hangar and under the open sky. Taking out from the hangar, movement by the area was produced with the aid of the tractor of the type KHTZ. In the movement without the tractor it needed the participation of 8 men.
Descent and lift from the water was carried out by two divers and technical personnel of 3 people. The time of descent with the removal of the trolley chassis was 3-5 minutes, while duration of ascent from water and installation of chassis - only 5-7 minutes. With the descent the aircraft was retained by the end, fixed to the tailed hook. For servicing of aircraft there were required: tractor KHTZ, crane PPK-35, the tailed hoist of the aircraft, launch “Yaroslav”, fuel servicing truck BZ-35, the heater of air-cooled engines APV-4N, water-and-oil-heater VMT-35, auto-starter GAZ-AA (for the starting under the winter conditions), tractor CHTZ (for towing on skis).
With the operation of boat, installation and repair work there did not appear problems - in the comparison with a number of other aircraft. Refueling from the fuel servicing truck BZ-35 by two hoses occupied 10 minutes, and for oil - to 30 minutes (in view of the small section of the filling hose). Defueling occurred for long, oil drain in the cold weather was hindered by the small sections of cranes at the output.
The inspection aisles throughout entire aircraft were small, which hampered inspection and repair of aggregates. Access to the motor was good, but there were deficiencies. For example, the impossibility of survey and removing the rear spark plugs without inspecting the cowlings, the impossibility of the pressure regulation of the gasoline motor pump on the spot (it was necessary to remove it and to insert it back to the motor). Removing and new mounting of an engine lasted 1,5-2 hours.
As a whole they came to the conclusion about the fitness of aircraft for the operation on the descents and the seadromes, which existed for the aircraft of type MBR-2.
The operation of armament on the seagoing aircraft had some special features. At temperatures below minus of 20-25 degrees the number defects of the locks DER-19 grew by the aircraft with the low wing arrangement (nothing mentioned about different wing arrangements, maybe it means "because of the low wing arrangement", RT).
Contact with salt sea water required frequent complete dismantling and cleaning of locks, which increases the period of combat readiness of the aircraft. On the seaplane it is necessary to have a mechanization, which will ensure bomb suspension with any flying weather on dry land, also, on the water, taking into account the redeployment of operational airfields.
Experience of operating armament under the sea conditions shows that the poor working of components, the lack of a good access for inspection and cleaning contribute to strong corrosion. Nose rifle installation and navigator's compartment of MDR-6 during taxiing and takeoff were flooded. After each flight turret and cabin had to be thoroughly cleaned. The hatch rifle installation was found out to become overflown by water, what hampereded to maneuver the weapon on the brace.
During the ground tests, also on floating, rifle installations SET (should be the dorsal turret, RT) and NU (should be the nose turret, RT),there were no deviations from the stress standards. The hatch installation was removed during the plant tests.
During the flight tests, moving weapon and turret NU was possible in all positions, at different heights and in the different outfit, difference consisted in the rapidity of the maneuver. It was completely possible to select aiming angles of traverse, but only to the end positions of the turret, where it is still possible to move the machine gun.
Survey was ensured by the screen: there is no favourite side, all points of the forward hemisphere were located in the gunner's field of sight. In the locking mechanism of screen there are no limiters, what could lead to the shooting through the power plant. The nourishment of machine guns caused no doubts. The slot of the turret shell ensured free penetration for the machine gun and retreat back into the cabin.
During the taxiing as a result of the low sagging of the boat, the filling by water of the cockpit, turret and machine gun occurred , the amount of filling depending on the wind force. Water remained on the bottom of the cabin and at low temperatures it froze, but did not render influence on the work of the dislocated armament.
The most convenient position of machine gun in air, when to use it is not necessary, was found out to be expanded to the right end position of the nose turret and elevated stem. In this position there was no wind blowing into the navigator's compartment, and the machine gun itself did not prevent the pilot from piloting machine.
The bracket of oxygen apparatus, installed on the slidepath of the turret, interfered with the placing bag for the cases and was sectional. The short hose of the oxygen apparatus did not make it possible to pass from midpoint to hatch without the switching to another instrument, which hampered shooting. Instrument panel was arranged conveniently - being located in the machine gun and after being turned, it was possible to see the displays of the instruments (don't think this is a really matching report of the arrangement, RT, but who knows?).
With the position of the gun station LU (should be the otherwise mentioned hatch rifle installation, RT) on the board back or forward to 30-40 degrees the circumscription of the boat reduced the sighting angle to 10 degrees. Feeding of cartridges was not led: components and cases, flying away in the direction of the gunner, reached the ropes of the water rudder. In the hatch cover water came through its opening and gave a shower to the gunner, machine gun and ammunition box. In shooting position, the gunner's cabin is narrow. The installation of the machine gun was insufficiently rigid. This increased the ellipsis of scattering and hampered focusing the machine gun. In march position the machine gun was easily removed.
The versions of bomb load, or the bomb suspension on to the float, were checked on dry land and on the water with the use of a raft built by plant No. 48, which did not maintain tests. On to the float a bomb FAB-500 was raised by the winch by one person, hanging it up on dry land needed three people - without the mechanization, from the trolley (I admire the physical fitness of Russian workers and peasants, but sorry, three people are not able to lift and fix a 500 kg-bomb without mechanical aid, RT). The mean time for to hang up four FAB-250 on dry land occupied 40-50 minutes. The hanging-up of twelve FAB-100 by five men took 45-50 minutes, including equipment with fuses.
As result of tests of the bomb armament it was found out that on the taxiing and takeoffs, the bomb positions and locks are showered by a strong water jet - especially first three from the board of boat. The locks of type DER-19 with the bomb release of type ESBR-3 and AC-5 worked smoothly. The use of sight OPB-2 is convenient. The locks of type DER-32 in minus temperatures did not maintain the tests.
A transfer from FAB-500 to FAB-32 in cassette racks was done. As result of their insufficient stability the outer and inner bombs vibrated during taxiing and takeoff. The locks of DER-31M worked smoothly with ESBR-3 and AC-5.
The bomb load of the aircraft by large-caliber bombs was 1000 kg: FAB-250: 4 pieces or FAB-500: 2 pieces. The demand of model commission for this parameter was 1500 kg (6 pieces FAB-250).
The mounting system of large-caliber bombs was recognized as satisfactory and was recommended to accept for the armament of production aircraft MDR-6 after insignificant modifications. For example, instead of two ESPR-3 they recommended to establish one ESPR-2, depending on ensuring clearness of bombs to be used; to prepare a raft for the bomb mounting on the float in any flying weather.
The finishing of holders was transferred to a special plant for the armament. After the elimination of defects of the cassette holders it was proposed to continue their test on the pre-production series of MDR-6. All components were to cover with anticorrosive varnish and to ensure access for inspection and cleanings. A rope “active-passive” is to be prepared for the removal of each bomb. The mounting of FAB-100 to the cassette holders was to be revised and tested.
The air battle of aircraft MDR-6-2M-25E with a flight of fighters of type I-16 was conducted on July 20, 1939, for one hour at the height of 1500-2000 meters. During the attacks of fighters the seaplane maintained cruising speed within the limits of 250-275 km/h (0,8-0,85 of the maximum). All aircraft were equipped with gun cameras “SLP”. It was intended to reveal the fire protection of the aircraft, to verify maneuvers of weapon and fire control.
In the case of the forced landing of one of the fighters, the air battle had to continue. The spare aircraft, which departs from its airfield, occupied the place of the leaving machine. It was proposed to perform all attacks of fighters on the heights from 3000 to 3500 meters. The firing distance of the fighters during the attacks was established to 200 meters. Reference point on the gun cameras was determined by the point of time given by meteorological station getting questioned on the telephone.
MDR-6-2M-25E flew along the route Lake Donuzlav - Stone Quarry Airfield, where it had to appear at a height of 3000 meters. The flight of fighters from the airfield took off after aircraft MDR-6 descended to the height of 1000 meters. The beginning of the air battle was considered to be the approach of the fighter flight to MDR-6 to the distance of 50-75 meters.
The crew of aircraft MDR-6-2M-25E consisted of test pilot Major Slobodchikov, navigator (and operator of the nose turret NU) Senior Lieutenant Khovikov, Military Engineer of the 2nd rank Chernishev, chief engineer for the armament (and operator of the gun station SET) Major Tyutlyaev, assistant of the chief engineer for the armament (and operator of the dorsal turret LU) Military Technician of the 1st rank Vorobyev.
They crew of the I-16 fighter flight consisted of: Regiment-commander Major Pavlov (leading), squadron commander Captain Shubikov (comrade), the assistant to squadron commander Senior Lieutenant Yashkin (comrade).
Procedure of air battle:
No. 1: checking of the fire protection of the seaplane in the rear hemisphere. They attack from the tail in the direction of course of MDR-6 at the identical height. This meant, flight leader opened fire from a distance of 500-300 m (3 photographs), comrade to the right - from a distance of 350-400 m (7 photographs), comrade to the left - from the distance of 650-500 m (18 photographs).
NU of aircraft MDR-6 could not respond attacks in the rear hemisphere. SET responded with the dispersion of fighters from the distance of 400-500 m (7 photographs), LU responded from the distance of 450 m (3 photographs).
No. 2: checking fire protection with the large angles of depression and with the attacks from the different directions in the lower hemisphere. They attack in the head-on course from below and from behind-below. The component of fighters goes in the head-on course by the disparagement of 400 meters. From the distance of 800 m there is the combined attack performed from the front-below and from behind-below. Aircraft MDR-6 after attack goes 1-2 minutes along the straight line, after which it must be turned by 180 degrees.
The fighter flight leader opened the fire from the distance of 500-300 m (13 photographs), comrade to the right - from the distance of 500-400 m (8 photographs), comrade to the left - from the distance of 400-500 m (24 photographs).
NU of aircraft MDR-6 responded to the attack, free fire from the distance of 800-900 m (48 photographs). SET could not respond , though fighters were dispatched below and they attacked from the tail. LU responded, fire was opened from the distance of 300 m (11 photographs).
No. 3: checking fire protection with the shooting of fighters at the fuel tanks. Direction of attack - on the identical course to the right on target course of 180 degrees. The fighter flight leader opened shooting from a distance of 400 m (8 photographs), comrade to the left - from a distance of 700 m (3 photographs), comrade to the right - from a distance of 400 m (10 photographs).
NU of aircraft MDR-6 could not respond attacks in the rear hemisphere. SET responded, fire was opened from the distance of 300 m (17 photographs). LU responded, fire was opened from the distance of 300-400 m (8 photographs).
No. 4: checking fire protection in the rear hemisphere. They attack in the identical course with the disparagement and to the left - on 600 meters. The component of fighters goes in the identical course. Initial position for the attack assumes from the distance of 800-600 m. Attack is performed under RTs-225 (whatever this means, RT). Counteracting the attack by climbing. MDR-6 afterwards goes 1-2 minutes along a straight line, then it is unexpectedly turned to 180 degrees.
The fighter flight leader opened the fire from a distance of 400-350 m (12 photographs), comrade to the left - from the distance of 500-600 m (4 photographs), comrade to the right - from the distance of 500-600 m (9 photographs).
NU of aircraft MDR-6 could not respond attacks in the rear hemisphere. SET responded from a distance of 400-500 m (4 photographs), LU responded from the distance of 400-300 m (12 photographs).
No. 5: checking fire protection during an attack on the head-on course with the passage of fighters in the zenith and tail attack. Direction of attack - on the head-on course on the nose with exceeding of 200 meters and with the subsequent passage for the attack under the tail.
The fighter flight leader opened opened fire from the nose to the distance of 1000 meters and from the tail - on the distance of 400 m (7 and of 8 photographs respectively). Comrade to the left attacked from the distance 600 meters from the nose (8 photographs) and 700-600 meters from the tail (23 photographs), comrade to the right - from the distance of 700 meters from the nose (0 photographs) and from the distance of 500 meters from the tail (13 photographs).
NU of aircraft MDR-6 responded to the attack from the distance of 500 m (10 photographs). SET responded attack from the nose on the distance of 700-600 m (14 photographs). LU responded from the distance of 600-500 m (10 photographs).
No. 6: checking fire protection during attacks from different directions. Simultaneous impact from three sides (“tongs”). Fighters go to exceed by 200-300 meters. They attack in the direction of flight, with the simultaneous impact from three sides - along the sides and into the tail. MDR-6 after attack goes directly, and then it is unexpectedly turned to 180 degrees.
The fighter flight leader produced 14 photographs from a distance of 600 and 300 m, comrade to the left - 7 photographs from the distance of 800 m, comrade to the right attacked, but the film was lit.
NU of aircraft MDR-6 could not respond attacks in the rear hemisphere. SET produced 20 photographs from the distance of 400-500 m, moreover it knew how to transfer fire from one aircraft to another. LU responded from the distance of 500 m (3 photographs).
No. 7: checking fire protection with the attack on the head-on course under RTs-500. The flight of fighters is located at one height with MDR-6, which goes along the straight line before the following attack. The fighter flight leader produced 7 photographs from a distance of 700-600 m, comrade to the left 3 photographs from the distance of 700 m, comrade to the right attacked, but there are no photographs.
NU of aircraft MDR-6 responded to the attack from a distance of 700-600 m (10 photographs). SET could not respond, fighters were dispatched in the direction VMG (??). LU did not respond - fighters passed by side.
Nos. 8 and 9: checking fire protection while being attacked from above and from below to the tail. During the second attack, the possibility of a passage of the gunner from the dorsal weapon emplacement to the hatch was checked. Attack occurred in the direction of flight on top - with the passage under the tail. Fighters were dispatched in the identical course with an exceeding of 1000 m. From a distance of 1000-800 m they occupied initial position for the attack, then they passed on the dive. MDR-6 after the attack no. 8 had to go on straight for 1-2 minutes, after which being turned by 180 degrees.
The fighter flight leader produced 10 photographs from the distance of 400 m with the second attack. Comrade to the left the first time attacked from the distance of 400 m (3 photographs), the second time - from the distance of 650-450 m (7 photographs). Comrade to the right in both cases attacked, but there are no photographs.
NU of aircraft MDR-6 could not respond attacks in the rear hemisphere. Focusing SET was prevented by the tail assembly. LU responded, there were 9 photographs produced from a distance of 350-200 m.
No. 9 (sudden): checking fire protection from a surprise attack of fighters. The direction of attack is arbitrary. MDR-6 had to maneuver with speed. Unexpectedly, 15 minutes after the end of air battle, fighters attacked from below to the tail. That action produced two photographs from the distance of 800-700 m, comrade to the left - 22 photographs from distance 1000, 600 and 400 meters.
NU of aircraft MDR-6 could not respond attacks in the rear hemisphere. SET responded at large angle of depression, from a distance of 400-300 m (3 photographs). LU responded from a distance of 400-300 m (4 photographs).
To this air battle, its participants Pavlov and Tyutlyakov gave estimations:
“… If the speed, at which the air battle was conducted, is cruising, then aircraft is not suitable for conducting an air battle against the contemporary fighters. Those more it cannot accomplish the task of reconnaissance, for a successful solution of which it is required a kind of speed, in order within the shortest periods to fly so far to the selected object and also to rapidly deliver information to command.
Fire and moral(!!, RT) superiority in the alien territory - both in the time and in the space - will always be on the side of enemy. Probability of hit (other conditions being equal) is large with the shooting from fixed arrays.
The experience of war showed that reconnaissance predominantly relied on high-speed machines because they were capable of avoiding aerial combat. Assertion is not well-off, that in view of the specific character of the theatre of naval operations for this aircraft, the sudden approach to the object and the less possibility of a prolonged pursuit being characteristic . Such considerations are possible only when enemy is considered not clever (:-), RT).
Relative to the arrangement of weapon emplacements, their maneuver, showed the presence of “dead” cones of fire, making conclusions of their use by a fighter and counter-movements of the reconnoisater is difficult, since the air battle was passed on the large distances. The boundaries of turning were not visible. Maneuver around the reconnoisater (angular displacement) was carried out slowly. Entire air battle was passed according to the principle “desired for the real”, i.e., “it is necessary that the fighters would attack us precisely so”.
But even this “air battle” makes it possible to understand: if the reconnoisater in combat does not begin, but repels attacks (with the presence of a sufficient speed), then enemy will attack predominantly from the rear hemisphere. Therefore the weapon emplacement of the navigator must be improved in order to conduct fire also upward and back. Otherwise the navigator during the longer part of the battle is inactive. On the close distances the tail attacks are safe for the fighters. Is also a safe attack from the steep pitching, with the subsequent pressing and withdrawal forward and downward.
The low speed of the reconnoisater makes it possible to attack it from the front. In this battle the fighters were able, according to the condition, to go in position so they could photograph the attack from the front.
For more precise conclusions on the effectiveness of the fire of the reconnoisater it is necessary to conduct the air battle at maximum altitude and speeds… “.
The navigator of the alder groves (??, translator's result is exact, RT) gave his estimation of the air battle:
“The attacking fighters grew with pretty visibility, they are revealed at a significant distance. This makes it possible for the pilot to give a signal to all weapon emplacements about a forward quarter attack even to actual opening fire from the fighters. Survey from the place of pilots is hindered only from below.
Gunners can report to the pilot about the attack in the rear hemisphere. If fighter “will sit down" in a “silence cone” of the aircraft MDR-6, pilot will obtain a signal, he will do swerving about, he will get out of the enemy fire and will grant the possibility to shoot to his gunner.
The optimal height of aerial combat for the aircraft MDR-6 is equal to 5800-6000 meters. To fighters in this situation it is difficult to attack, since they should have an altitude advantage of 1,5-2 thousand meters and a freedom for the maneuver.
To get out of the enemy fighter fire is possible on the speed, swerving about and opening fire by its weapon emplacements. Attacks in the forward half sphere can be reflected easily, since the unexpected surprise attack it is difficult to carry out by the enemy force because of the survey of the forward half sphere by both the gunner of the nose weapon emplacement and by the pilot.
As a result of the air battle it was revealed, that the fire protection of rear hemisphere was insufficient in the direction of the power plant and tail assembly, where there were formed large “silence cones”. The weapon emplacements of aircraft MDR-6 them did not cope with the attacks of the fighters from the tail (on one height and from the exceeding). It is desirable to increase aiming angles in the horizon and vertical lines. The diagram of the layout of weapon emplacements and the produced angles of traverse do not ensure mutual fire connection.
Hatch installation is necessary with the existing diagram of rifle armament MDR-6, but absence of the sight opportunities decreases its military value.
To attend SET and LU in the combat situation by a single gunner is impossible. The passage of one installation to another and back rapidly is harassed at high altitudes. This disrupts the principle of continuous air observation and introduces nervousness at the shooting, as a result of which both weapon emplacements can be weakened. If then gunner gets injured, this unavoidably turns off entire fire protection of the rear hemisphere.
Light signaling does not ensure the fire control on the aircraft, it is necessary to duplicate up the connection in the form of sound communication.
Survey from the rifle installations NU and SET is satisfactory; however, the closed cabin of NU superfluously tires the gunner.
Maneuvering weapons and repelment of attacks is necessary to verify on the altitude limit, including a large number of free attacks and after decreasing the distance of repelment of the fighters."
In the report for the results of military tests about the fire protection of the aircraft MDR-6 it was recognized to become better for this type of seaplane. The conclusion was made that the nose rifle installation NU-DB-3 completely provided protection of the forward hemisphere of the aircraft in the air battle with the fighters. In the different flight conditions, in the plus and minus regimes of temperatures the installation worked smoothly. 2480 cartridges in all were spent, maneuvering the weapon was satisfactory.
The installation was recommended for the adoption of the armament of production aircraft MDR-6 with the condition bringing angles of traverse to the values, indicated in the operational requirements, and the elimination of deficiencies.
Special attention was focused on the limited space for the gunner and selection of water deflection in the circumscription of the screen in order to avoid the entry of water into the cabin. To all components of turret and screen it was proposed to apply anticorrosive means. Instead of the sight KPT-5 sight PMP-3 was to be placed.
The central rifle installation of the type SET maintained testing, with the shooting in different flight conditions, in plus and minus temperatures it worked well. Angles of traverse corresponded to TTT, in all there were 1992 cartridges fired. Installation was recommended for the armament of production aircraft MDR-6. For an improvement of the dorsal installation it was proposed to establish a turret with an aerodynamic compensator of the type MV-3 and to alter the locking mechanism of the screen according to the type of turret MV-3. To easily place removable limiters, sight KPT-5 was to be replaced by PMP-3. It was recommended to change the circumscriptions of the boat on the boards so that in the gunner would get the opportunity of the selection of downward aiming angles.
Hatch rifle installation was evaluated positively and recommended for the armament of production aircraft MDR-6, if the defects noted in the report were eliminated and the vertical angles of firing were brought to TTT. In all there were 3511 cartridges fired. For an improvement in the hatch installation it was necessary to increase the cabin, to accomodate shooting in a lying-down position. But it was also to employ a power-supply system for the cartridges before it could act reliably.
MDR-6 with two motors M-25E passed the military tests, as a result of which it was recommended for serial production at the plant No. 45 and adoption for the armament of the aviation of RKVMF.
For finalizing the serial standard of Chetverikov MDR-6, they proposed a second batch of state preproduction tests . It was proposed to establish the higher-powered engines M-62 with variable-pitch propellers to the aircraft, to install wheel-ski chassis, to bring horizontal cassette holders, improve rifle and chemical armament, cooling system of oil, to carry out 100-percent protecting of fuel tanks and to bring their total capacity to 2200 kg. For one of the production aircraft to be released in 1940 it was intended to prepare machine-gun installations in the engine nacelles, after setting additional tests for them.
The majority of the production aircraft, which received the designation Che-2, was produced with the engines M-63, delivering a power of 1100 hp each. In spite of its large sizes, it was sufficiently light. The empty weight of Che-2 did not exceed 4100 kg, takeoff - 6700 kg. In the version as cargo transporter the flying boat weighed 7200 kg. Because of its aerodynamic shapes it possessed good flying and nautical data. Its maximum speed reached 360 km/h, ceiling - 9000 m.
For increasing the aerodynamical qualities of MDR-6, so that the flying boat could more or less be equal with the series bomber of the type DB-3, it was decided to let out modifications which were being designated “A”, and then “B” with the numbers from 1 to 5 in 1940 - 1946. “A” (1940) and “B” (1941) - two experimental models, almost similar, but with the distinct differences from the series type “N”. The modification “A” used the engines M-105 of in-line type. Floats were of special form so that they could be accomodated between the wing spars, in the form boxes on the rigid box counters with control by the electric system with spiral gear. The design of aircraft “A” was begun by the autumn of 1939. It was released in 1940; in 1940 - 1941 it underwent plant tests, but became damaged near Uglich, at the transfer to the place for conducting state tests.
MDR-6 the first modification.
MDR-6A modification of MDR-6 with M-105.
MDR-6B-1
was a modification of MDR-6. Engines were of in-line type M-105 delivering 1050 hp, outer parts of wing were considerably reduced (in favor of speed), floats came out a little; the tail assembly - spread; the forms of lamps and turrets - changed, turret is left for the rear only. The width of the boat remained as before - 1,9 m. Its construction was the same semi-monocoque body consisting of the pressed and bended profiles. Wing is two-spar, beam flanges - steel T-sections of 60x60x6 mm, its skin to the rear longeron - from 2 mm in the center section and in the bases of consoles to 0,8 mm at the wing tips, in the tail section - fabric. Engines M-105 had a smaller frontal area than M-63, even with the presence of the radiators, which were placed under the center section after its rear longeron. The aircraft was executed very purely, and generally this type could rightfully be considered as the most beautiful of the seaplanes, anywhere and anytime existed (Mirror, mirror on the wall,... RT). Speed reached 454 km/h at height 6000 m. the armament: three machine guns ShKAS and four bombs of 100 - 250 kg.
B -1 was released by the spring of 1941 and underwent plant tests. On October 26, the aircraft flew to the place, where it had to pass state tests. B-1 flew so far satisfactorily, but tests could not be brought to the end because of defects of the power plant. Moreover there were the difficulties with retracting the floats, which usually not completely entered into the wing because of the weak power of the lifting mechanism. The proximity of screws to the water because of the small height of the boat had to be recognized: drops and even waves fell into the screws. On the whole, further work on development of the type “B” was in prospect , on a finishing of the engine configuration and an increase in the flying range.
MDR-6B-2
had size and wing construction as B-1, being a development of it. Aircraft was released in 1943 with motor M-105. Radiators with the louver were frontal (as in aircraft SB). In comparison with B-1 the floats were still widened and increased in the volume and were completely not removed into the wing. The boat in essence preserved previous sizes and in connection with the increased mass sat more deeply in the water. Seaworthiness was limited, keel ribs on the sides and the bottom of the nose section helped little, takeoff from the wave was difficult. Flight-performance data were close to the characteristics “A”, but range as before was not sufficient.
MDR-6B-3
had size and wing construction as B-1. It was released in 1943; simultaneously with B-2. It differed from it only in terms of the engine (there were M-105PF established). Also the modification B-3 had a heavy armament: in the aft fuselage section there were two blisters arranged, carrying machine guns of type UB. Crew increased to 5 people. The mass of the aircraft grew in the normal version to 7200 kg, and as cargo transporter to 8200 kg (mass of fuel in both versions 1100 kg). For guaranteeing the required distance (3000 km) the following modifications were let out.
MDR-6B-4
built in 1944 and differed significantly from B-3. Boat was widened from 1,9 to 2,2 m and made higher in the center by 0,4 m, with the raised tail and new tail assembly. Rear step was a little placed back. Floats were made nonretractable, the supports were equipped with struts. It was necessary to refrain from their retracting, since the length of the supports grew and to remove the floats into the previous boxes was not possible. Fuel stock was increased to 2150 kg. Engines were of type VK-107, radiators frontal (as in B-3). Crew was 5 people. Blisters were newly designed and had increased ranges of fire. Armament: three UB machine guns and 1000 kg bombs. Fin-and-rudder area is increased due to the addition of a third (central) stabilizer. The mass of aircraft grew to 10 t.
MDR-6B-5
(1945) was the direct development of B-4 with engines of type VK-107A delivering 1650 hp, but with an elongated nose by 0,5 m and with the cockpit moved forward (in front of the screws). Center section was increased in size (as in B-4), the console being the same as in all seaplanes, floats nonretracble as in B-4, tail assembly spread, a little increased, without the central stabilizer. Radiators (with the louver at the output) under the wing between the longerons, screws were four-blade. Armament - three guns B-20, one of them installed in the nose of the boat (200 projectiles), two- on the turret SEB (aircraft electrified tower) with 300 projectiles. Bombs - four FAB of 100 - 250 kg or two FAB-500. Mass of armament - 125 kg, aeronavigational equipment - 69 kg, electrical equipment and connections - 172 kg, different equipment - 542 kg. The mass of the airframe - 2355 kg, power plant - 3067 kg. Empty mass of B-5 without the removable equipment - 5610 kg, i.e. it was equal to the flight mass of Che-2. The flight mass of B-5 became more than 10 t. Building of this aircraft was finished by the summer of 1945 and it satisfactorily underwent plant tests. The aircraft was transferred to state tests.
Regards, RT
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