Sukhoi Su-27 variant
Sukhoi Su-27 Su-27P1M
The Su-27P1M is the modernised version of the Ukrainian Air Force's single-seat Su-27P interceptor, sister to the Su-27S1M within the national Su-27-1M programme carried out at the Zaporizhzhia aircraft repair plant (ZARZ "MiGremont"). Its distinguishing feature within the family is functional. The Soviet Su-27P was an air-defence interceptor with no air-to-surface capability; the upgrade to P1M standard added the use of unguided weapons against ground targets — bombs of 100 to 500 kilograms and S-8 and S-13 rockets — turning a pure fighter into a multi-role aircraft. It is the most visible change of mission in the whole programme. It shares the avionics package with the rest of the family: an N001 radar station upgraded with new receiver blocks, an SN-3307-02 satellite navigation receiver, ICAO-compliant Kurs-93M-V equipment and an A-511 transponder, and a solid-state SAVR-27U recorder. Airframe and engines are not replaced. The Su-27P1M was formally adopted on 5 August 2014 by order No. 499 of defence minister Valeriy Heletey, alongside the Su-27S1M, Su-27UB1M and Su-27UP1M.
History
From interceptor to multi-role
The Su-27P was the air-defence variant of the Flanker: optimised for interception and without an air-to-ground sighting system. The Ukrainian modernisation broke that limitation by enabling unguided weapons against surface targets — bombs of 100 to 500 kg calibre and S-8 and S-13 rockets — broadening the mission set of a fleet Ukraine could not afford to keep specialised.
Execution
The work was done at the Zaporizhzhia plant, with Ukrainian avionics and navigation suppliers taking part, and began in the early 2010s; upgrading to Su-27P1M and Su-27UB1M standard is the step sources place first within the programme.
Adoption
Defence ministry order No. 499 of 5 August 2014 formally adopted the Su-27P1M into the Ukrainian Air Force together with the other three variants of the family. The aircraft are officially described as modernised production aircraft fitted with an additional equipment kit, not as a new model.
Documentary gaps
No public breakdown of Su-27P1M numbers against the other subvariants has been found; the figure of "no fewer than twenty-two" aircraft refers to the Su-27-1M programme as a whole.