La-250A.

La-250A interceptor prototype and izd. 275A liquid-fueled air-to-air missile test launch footage.

Arguably the first Soviet plane to be designed as a 'weapon system complex', Lavochkin had the misfortune of having to rely on Klimov and later Lyulka to deliver their VK-9 and AL-7F-1 engines to power the La-250, and both failed to deliver on time. Same for the radar.

The La-250 can be considered a distant forerunner of the Tu-128, for a lot of the data from the project was transferred to Tupolev's OKB after Lavochkin's OKB was diverted to designing missiles instead.