A third aircraft, designated 'Aircraft 200B', which introduced some changes to meet these additional requirements. The radar, a new and more advanced type called the RP-6 Sokol (Falcon), needed a much larger radome which in turn required alterations to the intake arrangement (trials had shown that overall the Toriy-A was unreliable and underdeveloped). Uprated engines were also fitted and to feed them there were now three inlets, the bottom supplying the lower front engine while two more, of an 'elephant ear' type, were set on the sides of the upper nose to pass through to the rear power unit. The nosewheel was moved forward, each main gear had just one large wheel and there were now two ventral fins. A new wing was also fitted that looked very similar to the old form but which used a different method of construction and housed more fuel.
The '200B' flew on 3rd July 1952 with a mock-up radar installed. The real equipment was used for the first time during a flight made on 10th September. The test programme embraced 109 flights but, all in all, the 'Aircraft 200' series, also known as the La-200, presented another disappointment to Lavochkin in that it failed to gain a production order. By now a new prototype from Yakovlev was also under test, the Yak-120, and this was accepted for squadron service. In November 1953 orders were given to end testing on the '200B' and fit the Sokol radar into the Yak-120. The two versions of 'Aircraft 200' took 2.6 and 2.8 minutes respectively to reach 5,000m (16,404ft) and their ceilings were 15,150m (49,705ft) and 14,125m (46,342ft).