MiG 17 Projects, Prototypes and Experimental Variants

[Justo Miranda]

Fagot versus Fantail​

When the MiG OKB won the March 11, 1947 fighter contest, the MiG-15 production had priority to receive the most powerful RD-45 turbojet (the Soviet version of the Rolls-Royce Nene Mk.I).

The Lavochkin bureau stopped the La-168 development to concentrate their efforts in the design of the La-174, a new fighter that was 340 kg less heavy than the MiG and that would be powered by the less powerful RD-500 turbojet (Soviet version of the Rolls-Royce Derwent V).

The La-174 was a 90% scaled down version of the La-168 and it had no relation to the La-174 TK straight wing prototype.

The aircraft was flown on January 8, 1948, suffering dangerous tailplane flutter and crashed during testing on May 11, 1948.

The defect was corrected in the second prototype La-174D that flew on June 12, 1948.

Combats tests performed in the Tshkalovsk research center proved that the La-174D was superior to the MiG-15 in maneuverability, because its lower weight and excellent wing design compensated for the turbojet's lack of power.

In September 1948 the new fighter was accepted for production, alongside the MiG-15, and officially named Lavochkin La-15 in April 1949.

Operational tests with the 192nd IAP began in May 1949, at Kubinka-Moscow, but the unreliable hydraulic system resulted in undercarriage failures and landing crashes due to the extremely narrow track (1.70 m) of its landing gear.

The VVS had already had problems in 1943 with the landing instability of their Spitfires on rough-field operations and the frequent crashes of the La-15 at side wind were considered unacceptable for a front-line fighter.

Only 235 La-15 fighters were built between December 1948 and August 1949.

The shoulder mounted La-15 wings (with 37º 20’ swept, 25 % chord, 12% thickness, 6º anhedral and smaller span-chord ratio than those of the MiG) were based on those of the La-160. They were more resistant and rigid because they were not designed to accommodate the main undercarriage legs.

But the La-15 wings were more complex to produce, and their light airframe was not sturdy enough to withstand the recoil of a 37 mm cannon.

The more rugged design of the MiG-15 was cheaper and easier to produce.

If the La-15 had been used in Korea against the F-86 fighters it would surely have been more successful in dogfight than the MiG-15, but most Russian historians deny the La-15's involvement in the war.

On the contrary, there are reports in the CIA Current Intelligence Bulletin of multiple sightings of jet fighters with shoulder-mounted wings.

These aircraft were seen by American and British pilots of F-86E, B-26, RF-80 and F-51 aircraft of the UN forces in Korea.

Pilots believed it was a new type of MiG and referred to it in reports as “MiG-17” or “Type-15”.

In late March 1952 a “Type 15” was observed only 100 feet away by the pilot of an F-86E of 4th FIG, 335th FIS. (Report of Lt. James D. Carey published in Time Magazine on March 13, 1952).

According with the CIA-FOIA files and with the reports of the UN pilots, the “Type 15” was sighted 14 times, engaged 10 times, two aircraft were destroyed and 11 damaged.

According to the article published by V. Ilyin, V. Rudyenko and J. Martinek in the Czech magazine Zlinek (Nº 14, vol. 2, 1994) a VVS Fighter Regiment, with twenty-two La-15 airplanes, carried out combat operations in Korea suffering four crashes due to the poor condition of the airfield. The other machines were sent back to the USSR.

Additional information from the specialized authors Mikhail Zhikorov, Warren Thompson and Larry Davis were published at “Wings of Fame” (Volume 1, 1995) and

http://sovietwarplanes.com/board/index.php?topic=1534.0

https://www.aereimilitari.org/forum/topic/9275-lavochkin-la-15-in-corea/

http://sabre-pilots.org/classics/v133duck.htm

http://www.foia.cia.gov/

It is strange that the Soviets did not attempt to use the La-15 against the UN Sabres when the MiG-15s began to be systematically destroyed because of their inferior maneuverability.

So, what is the truth?

Lavochkin La-15 Fantail technical data

Power plant: one Klimov RD-500 turbojet rated at 1,590 kg thrust, wingspan: 28.9 ft. (8.83 m), length: 31.3 ft. (9.56 m), height: 12.8 ft. (3.9 m), wing surface: 179.6 sq. ft. (16.16 sq. m.), take-off weight: 8,500 lb. (3,850 kg), max speed: 638 mph (1,026 km/h), ceiling: 44,280 ft. (13,500 m), armament: three 23 mm NR-23 cannon, equipment: pressurized cockpit with (German) ultraviolet illumination of the instrument panel, ASP-1N gyroscopic gunsight (direct copy of the British Mk.IID), KUS-1200 speedometer, M-46 Machmeter, V-15 altimeter, RSI-6K R/T, S-13 gun camera and ejector seat.

To test the limits of the La-168 aerodynamic configuration, the La-176 prototype was built during the summer of 1948.

The new airplane was flown on September 22, 1948, fitted with 45-degree swept wings (25% chord) and three fences in each wing, reaching Mach 0.98 top speed only.

The RD-45 was replaced by a Klimov VK-1 (the Soviet version of the Rolls-Royce Nene Mk.2) with 2,700 kg thrust.

On December 26, 1948, the La-176 exceeded the speed of sound diving from 39,360 ft. (12,000 m) over the Black Sea.

On February 3, 1949, the prototype disintegrated in flight when the canopy locks failed near Mach 1.

Lavochkin La-176 technical data

Power plant: one Klimov VK-1 turbojet rated at 2,700 kg thrust, wingspan: 28 ft. (8.59 m), length: 36 ft. (10.97 m), wing surface: 203 sq. ft. (18.25sq. m.), take-off weight: 10,209 lb. (4,631 kg), max speed: Mach 1.021, ceiling: 49,200 ft. (15,000 m).

 

[Justo Miranda]

MiG 17 experimental variants

On July 10, 1947, the Truman Administration ordered the construction of 386 Convair B-36 heavy bombers under the Cold War policy of nuclear deterrence.

On June 26, 1948, the B-36 A entered in service. With 410,600 pounds (186,000 kg) takeoff weight and 8,000 miles (12,900 km) range, it tripled the gross weight of the B-29 and was able to carry two Mark III atomic bombs.

On December 9, 1948, the YB-36 prototype proved that it could fly at 46,000 ft. (14,050 m) over the Soviet air space without being intercepted by the new MiG-9 fighter with only 44,280 ft. ceiling.

Unfortunately for the SAC, the transfer of jet technology by the British government allowed that the Soviet fighter MiG-15A, with 50,840 ft. (15,500 m) ceiling were delivered to operational units early in 1949.

But in a real combat at 45,000 ft. the 360-degree turning radius of the MiG was 30,000 ft. and six minutes and the turning radius of the B-36 was 23,000 ft. and three minutes only.

Worse still, the MiG's poor maneuverability at that altitude required it to make attack and evasion trajectories that were very predictable for the American gunners, armed with sixteen remotely controlled 20-mm cannon, APS-13/23 search radars and AN/APG-32A gun laying radar.

The N-37 Soviet cannon had a low rate of fire of only 400 rpm and an effective range of 520 m. Flying at 1,000 km/h the MiG would only have been able to fire 25 rounds before entering the 1,000-yard lethal zone and would not have been able to maneuver to avoid it.

Additionally, the MiG-15 took 13.5 minutes to reach 50,000 ft. A considerable pilot skill was required to zoom climb and reach the B-36 bomber at the right moment, which greatly complicated intercepts.

The top speed of MiG-15 was limited to Mach 0.915 and that of the MiG-15 bis Fagot B to Mach 0.92.

During the transonic trials conducted on October 18, 1949, the modified prototype MiG-15 SE reached Mach 1.01, but it became clear that the MiG-15 bis would not be able to reach transonic speeds, due to its tendency to spontaneous rolling.

At the end of 1948 the MiG-OKB started the Project SI (Sverkhzvoukovoy Istrebitel-Supersonic Fighter) with the aim of correcting all the MiG-15 shortcomings.

One production MiG-15 bis was fitted with 45-degree (25% chord) swept wings which had already been tested in the Bisnovat 5-1 in July 1948.

The prototype SI-01 was flown on January 14, 1949, (powered by one Klimov VK-1 turbojet) suffering severe tailplane flutter and ailerons reversement problems when flying at 1,044 km/h.

The second prototype SI-02 was fitted with new Sickle wings, with double sweep of 49-degree inboard, 45.5-degree outboard (25% chord, 8.8 % thickness) and 3-degree anhedral.

This aerodynamic solution had already been proposed by Kurt Tank to improve the loss of lift at low speeds in the Focke-Wulf P.011.001 (January 1944) jet fighter project.

At the end of 1951 these wing leading extensions were flight tested in the pre-production jet fighter Tank IAE 33-03 Pulqui II.

Soviet designers added a third fence (at the point where the wing swept changed) in order to avoid loss of airflow in the upper surface at low speeds.

The SI-02 was flown on February 1, 1950, reaching 54,446 ft. and Mach 0.95 in level flight.

The airplane was fitted with a 4.26 sq. m enlarged tailfin and a 45-degree swept tailplane.

The possibility of using a more powerful version of the Nene Mk.II turbojet allowed the construction of an elongated fuselage up to 8,805 m.

During the flight trials the SI-02 revealed better high-speed handling qualities than the MiG-15 bis and was ordered into mass production, as MiG-17, on July 20, 1951.

Deliveries to the VVS began in 1952 and the new fighter was unveiled on June 20, 1953, during the Tushino Air Parade.

MiG-17 (Fresco A) technical data

Power plant: one Klimov VK-1 centrifugal turbojet rated at 2,700 kg static thrust, wingspan: 31.6 ft. (9.628 m), length: 37 ft. (11.264 m), height: 12.9 ft. (3.937 m), wing surface: 251 sq. ft. (22.6 sq. m), take-off weight: 11,788 lb. (5,340 kg), maximum speed: 692 mph (1,114 km/h), Mach 1.3 in dive, service ceiling: 51,168 ft. (15,600 m), armament: two nose mounted 23 mm Nudelman-Suranov NR-23 cannon and one 37 mm N-37D cannon, equipment: pressurized cockpit, ASP-3N gunsight, RSIU-3 Klen radio, ARK-5 Amour radio-compass, RV-2 Kristall radio-altimeter and ejector seat.

In late 1954 the MiG-OKB attempted to improve the maneuverability of the SI-01 prototype by replacing the wing fences with Sabre-style wing slats, but the installation proved too heavy, and the project was cancelled.

At the end of 1952 the reheated VK-1F turbojet, rated at 3,380 kg static thrust, allowed the new MiG-17F to achieve a top speed of 711 mph (1,145 km/h) and a service ceiling of 54,020 ft. (16,470 m.) but this performance improvement did not substantially change the physics of high-altitude combat against the B-36.

The problem needed a different approach.

The British bombers of World War II had two gun turrets, one dorsal and another in the tail, that were very effective against attacks performed from behind.

To avoid its defensive fire, the Germans developed the tactic Schräge Musik, that consisted of shooting against the belly of the bombers using angled upward-firing cannons mounted in the rear cockpit of the Messerschmitt Bf 110 night-fighters. The idea was not new (it has been used by British fighters against the Zeppelins during the World War I) but its advantage was to be able to shoot directly against the engines and wing fuel tanks that in a classical attack from behind were protected by the wing structure.

In 1953 one MiG-17 was extensively modified, as MiG-17 SN, with lateral air intakes and a new nose-mounted Makarov weapons turret. The 469 kg device contained three TBK-495 23-mm cannon able to rotate vertically through an arc of +27-degree and -9-degree.

The State test trials conducted in February 1954 revealed serious aiming difficulties when the large recoil forces altered the aircraft’s flight path in the opposite direction.

The setbacks suffered while experimenting and the 60 km/h drag produced by the turret convinced the OKB that such system would be useless, and the Project SN was abandoned.

The cannon-armed MiG Ye-151-1 fighter was designed in 1960 with two 30 mm Makarov TKB-539 guns mounted on a 360º rotating ring, the cannons could tilt +30º/-30º covering 60º cone of fire. The Ye-151-2 was designed with two TKB-495 rotating mount aft the cockpit to reduce the destabilizing recoil forces, but it was not possible to build an accurate weapon aiming system and no planes were built.

What made the B-36 basically obsolete in 1958 was the MiG-17 PM (Fresco E) armed with four AA-1 Alkali beam riding air-to-air missiles and one RP-2U Izumrud-2 (Scan Can) radar. The B-36 served for only ten years.

 

[Pioneer]

Some amazingly interesting information thank you Justo Miranda!!

Regards
Pioneer

 

[TJDougherty01]

For the MiG 17 fans: