One of the recommendations from the government testing of Lavochkin La-130 (Lavochkin La-9 prototype) was to further develop it into a long-range escort fighter. The resultant La-134 prototype (also sometimes referred to as La-9M) featured increased fuel and oil capacity. Armament was reduced to three cannons. The prototype flew in May 1947. The second prototype, La-134D had fuel capacity increased by an additional 275 l (73 US gal) with wing and external fuel tanks.
The first documented combat use of La-11 took place on April 8, 1950, when four Soviet pilots shot down an United States Navy Consolidated PB4Y-2 Privateer over the Baltic Sea, with all 10 of the Privateer's crew lost. Later the same year, two La-11 pilots shot down a USN Lockheed P2V Neptune over the Sea of Japan near Vladivostok; one USN crew member was killed.
On March 20, 1950, five La-11 pilots encountered a group of North American P-51 Mustangs north-west of Shanghai, although the P-51 pilots immediately retreated. On April 2, 1950, two P-51s were claimed by La-11 pilots over Shanghai. After that, MiG-15s of the Soviet 29th Fighter Regiment took over the air defence role. The ROCAF stopped bombing Shanghai that June and the Soviet units left in October 1950.
On November 30, 1951, 16 La-11 fighter pilots of the 4th Fighter Aviation Regiment, Chinese People's Volunteer Army (PVA) were escorting 9 Tu-2 PVA bombers to bomb the South Korean island of Taehwa-do (대화도/大和島), in the Pansong archipelago. They were attacked by more than 30 F-86 fighters of the United States Air Force: four Tu-2 bombers and three La-11s were shot down.
The main target of La-11 pilots during the Korean War was the Douglas A-26 Invader night bomber, although numerous skirmishes with P-51s also took place. Attempts to intercept Boeing B-29 Superfortress bombers proved fruitless. La-11 required 26 minutes to reach the B-29's cruise altitude and once there had a speed advantage of only 20 km/h (12 mph) making it easy for the B-29 to evade the attacker in a shallow dive.
On July 23, 1954, a Douglas C-54 Skymaster military transport aircraft, registration VR-HEU, operated by Cathay Pacific Airways on a civilian passenger flight en route from Bangkok to Hong Kong, was shot down by two La-11 fighters of the 85th Fighter Regiment, People's Liberation Army Air Force (PLAAF) off the coast of Hainan Island, killing 10 people in an incident that has become known as the 1954 Cathay Pacific Douglas DC-4 shootdown.
Although the four-engined propeller-driven Douglas (registered VR-HEU) was a C-54 Skymaster, the incident is known as "the DC-4 shootdown" because the C-54 is the military version of the Douglas DC-4, and the aircraft was flying a commercial passenger run.
Three days later, near the same location, two La-11s of the same unit were shot by 12 AD-4 airplanes of the US Navy.
During 1954–55, La-11 fighters of the PLAAF took part in the Battle of Yijiangshan Islands escorting the ships of the People's Liberation Army Navy and Tu-2 bombers.
Length: 8.62 m
Wingspan: 9.80 m
Height: 3.47 m
Wing area: 17.6 m²
Empty weight: 2,770 kg
Loaded weight: 3,730 kg
Max. takeoff weight: 3,996 kg
Powerplant: 1 × Shvetsov ASh-82FN air-cooled radial engine with a two-stage supercharger and fuel injection, 1,380 kW (1,850 hp)
Maximum speed: 674 km/h at altitude
Range: 2,235 km
Service ceiling: 10,250 m
Rate of climb: 758 m/min
Wing loading: 212 kg/m²
Power/mass: 0.37 kW/kg
Armament: 3 × 23 mm Nudelman-Suranov NS-23 cannons, 75 rounds/gun