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Quoted

Sukhoi Su-7 Shershen Russian Naval Jet Fighter
In April 1944, the Sukhoi OKB (Design Bureau) started development of a jet fighter designed for the Aviatsiya Voenno-Morskogo Flota (AV-MF, or Naval Aviation). The AV-MF desired a jet aircraft suitable for operation both from land bases as well as from aircraft carriers. Initial design work focused on a single-engine aircraft that used the Lyulka TR-1 axial turbojet which was then in development. A single-engine design was preferred in order to keep size and weight to a minimum, although the safety factor of a twin-engine jet was acknowledged. The TR-1 turbojet failed due to low reliability and high fuel consumption, and the attempted TR-1A improvement was similarly deemed insufficient. However, initial prototypes of the aircraft used the TR-1A while a better alternative, the Lyulka TR-2, was in development.

In September 1944, Sukhoi proposed two alternatives to the AV-MF, both of which carried the Su-7 moniker, but received different project code-names. The first design, "Sposobnyi" (Capable) had a twin-boom layout and resembled a distant cousin of the deHavilland Vampire and the Spartan Bullet, while the second design, "Otradnyi" (Pleasant or Cuddly) had a more conventional configuration. The Otradnyi design was deeemed more technically challenging but the AV-MF instructed Sukhoi to concentrate on it rather than the Sposobnyi proposal. (A major concern with the Sposobnyi proposal was that fewer aircraft could be carried, since the twin boom tails couldn't be folded up.) Sukhoi produced the first prototype two years later, and the first flight took place in October of 1946 with a TR-1A engine. Flight testing revealed numerous issues, not least of which was the insufficient engine. The Lyulka TR-2 did not become available for testing until mid-1947, when the second prototype entered operation.

The Sukhoi Su-7 was a very compact aircraft, and the designers spent considerable effort reducing the aircraft's overall weight in order to improve both performance and, most importantly, range. The type received the informal moniker "Shershen" (Hornet).

In late 1947, the AV-MF evaluated the Su-7 against the Alekseyev I-21 prototype and the German Dornier Do.335 naval jet fighter. The Su-7 had significantly less range and a lower rate of climb than the other two fighters, although top speed was highly comparable, and the Su-7's lighter weight translated into a substantial agility edge. Although the Su-7's swept wings were expected to result in a higher landing speed, evidence from landing trials demonstrated that the Su-7's landing performance was largely similar to the Do.335.

Despite recognizing shortcomings with the Su-7, the AV-MF ordered the Su-7 into production during October of 1947. The first aircraft entered service from land bases in February 1948; most aircraft were flown from AV-MF's land bases rather than aircraft carriers, with only Kulikovo, Chesma, and Kazan operating Su-7s for any length of time. The type had a poor safety record as no twin-seat trainer variants were available, and between the type's introduction in February 1948 and its retirement in 1952, a quarter of the airframes were written off due to accidents, mostly due to pilot inexperience. Despite this poor record, experienced pilots felt the Su-7 handled significantly better than its closest equivalent, the I-212.

In mid-1948, the AV-MF instructed Sukhoi to stop further development of the Su-7 in favor of the Su-9, an alternative design that addressed many of the Shershen's shortcomings.

General characteristics
Crew: One pilot
Length: 11.33 m (37 ft 2 in)
Span: 11.59 m (38 ft 0 in)
Height: 3.4 m (11 ft 2 in)
Wing Area: 22.4 m²
Empty Weight: 4015 kg (8,852 lbs)
Loaded Weight: 6130 kg (13,514 lbs)
Powerplant: 1 × Lyulka TR-2 turbojet, 21 kN (4,721 lbf) thrust

Performance
Maximum Speed: 932 km/h (503 knots, 579 mph)
Cruise speed: 695 km/h (375 knots, 432 mph)
Range: 1,375 km (854 mi)
Ceiling: 12,345 m (40,502 ft)
Rate of Climb: 26 m/s (5,118 ft/min)

Armament
- 4 × 23mm Nudelman-Suranov NS-23 cannons in nose, 75 rpg

Quoted

Alekseyev I-21 / I-212 Russian Naval Jet Fighter
Semyon Alekseyev, who had served as a senior associate designer under Lavochkin during the early 1940s, received control of his own design bureau in November of 1945. Alexseyev had previously handled, amongst other projects, the navalized Lavochkin fighters, and in December 1945 Alekseyev received instructions to work on a twin-engined carrier-based fighter for the Aviatsiya Voenno-Morskogo Flota. The AV-MF had already organized design work on another naval jet fighter, the Sukhoi Su-7, but issues with the Su-7's Lyulka engines and other ongoing design issues prompted the Russian leadership to strongly demand another alternative in case the Su-7 project failed. Additionally there was some lingering uncertainty about the Su-7's 35-degree swept wing. Alekseyev, who was simultaneously observing the Russo-German joint development of the Bf.329 / I-168, petitioned several times to be permitted to use a swept wing, but this was rejected.

Alekseyev and team worked swiftly enough on their proposed design that their first prototype flew in January 1947, only three months after the Sukhoi design. Initial testing was positive, although marred when the prototype crashed in April in an accident deemed to result from pilot error. Another prototype (dubbed the I-211), flew in September and showed sufficient improvement. The AV-MF tested the I-21 against the competing Su-7, as well as the German Dornier Do.335, with which it shared many similarities. The Su-7 showed a decided edge in maneuverability, but the twin-engined I-21 and Do.335 had superior rates of climb and longer effective ranges.

Although the Su-7 was judged to have a higher growth potential, the AV-MF decided to purchase both aircraft. The Su-7, being a smaller aircraft, was used from the Russian Navy's mid-sized carriers (Kulikovo, Chesma, and Kazan) primarily in the fleet defense role, whereas the larger and longer-ranged Alekseyevs were deployed to the large fleet carriers, permitting their use as strike escorts. Neither the Su-7 nor the I-21 had long production lives. Both were removed from production and frontline service with the arrival of the Sukhoi Su-9 in 1949, and completely retired from service in early 1952.

General characteristics
Crew: 1 (pilot)
Length: 14.75 m (48 ft 5 in)
Wingspan: 12.8 m (42 ft)
Height: 4.38 m (14 ft 4 in)
Wing Area: 27.3 m²
Empty Weight: 6,025 kg (13,283 lbs)
Loaded Weight: 9,920 kg (21,870 lbs)
Max Takeoff Weight: 11,871 kg (26,171 lbs)
Powerplant: Two Aviadvigatel M-99 turbojets, each rated at 15 kN

Performance
Maximum Speed: 932 km/h (503 knots, 579 mph)
Cruise Speed: 740 km/h at 8,500 m // 695 km/h (375 knots, 432 mph)
Range: 2,600 km
Service Ceiling: 14,205 m
Rate of Climb: 30 m/s

Armament
- 4 × 23mm Nudelman-Suranov NS-23 cannons in nose, 75 rpg
- Up to 800 kg ( lb) of payload on four external underwing hardpoints

Variants
- I.21: General series designation.
- I.211: Second prototype, only one built.
- I.212: Pre-production prototype, twelve built in 1947.
- I.21K: First production series, December 1947 to October 1948.
- I.21bis: Second production series, October 1948 to February 1949.
- I.213: Proposed upgrade, prototype flew December 1948, never ordered.