Sukhoi Su-27 variant
Sukhoi Su-27 Su-27PD
Post-Soviet single-seat demonstrator with improvements such as an in-flight refuelling probe. NATO groups it under Flanker-B.
Image pending
History
A flying testbed
The Su-27PD was a post-Soviet single-seat demonstrator carrying improvements over the standard version, among them the in-flight refuelling probe later fitted to modernised export variants.