Yakovlev Yak-28

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McGreig

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(I'm not sure if this isn't more suitable for General Aerospace Discussion or The Bar but I've posted it here because the comments that inspired it are in this thread)

While Aleksandr Yakovlev was undoubtedly a political animal and may well have used rather ruthless, underhand methods to further his own career and aircraft designs, I'm puzzled by the unflattering comments in this thread regarding the Yak-28 and Yak-36/38.

First flown in 1952, the Yak-25's evolutionary descendants (including the Yak-28) were still operational in the mid Eighties and some of the reconnaissance/ECM machines survived the break up of the Soviet Union. To quote Bill Gunston, the Yak-25 "not only restored Yakovlev's reputation as a designer of successful combat aircraft but also led to a prolific and important family of derivative aircraft".

The last of these derivatives, the Yak-28, was built in reasonable numbers (from Yefim Gordon's OKB Yak - 435 interceptors, 183 trainers, 183 reconnaissance/ECM, 334 bombers plus an unspecified number of early Yak-28 and Yak-28B bombers and development aircraft) and the basic airframe could be successfully adapted for widely different roles.

The bombers, designed for supersonic high altitude flight, fell victim to changes in circumstances requiring operation at low altitudes and the Yak-28 generally had a relatively high attrition rate which investigation suggested was mostly due to pilot error, but neither of these circumstances was the fault of the design.

Given this, I don't understand how the Yak-28 family could be described as "disastrous".

Also, as far as I'm aware, the Yak-36M/Yak-38 "Forger" was never designed as a fighter but as a high subsonic, light attack aircraft with a secondary capacity to destroy enemy helicopters, AWACS and transport aircraft. Although considerable problems were encountered with the early versions, these had essentially been solved with the introduction of the final Yak-38M production run.

The two issues leading to the demise of the aircraft appear to have been the limited range/payload and loss of interest by the Russian Navy. The first of these could have been easily resolved by the addition of drop tanks but, incredibly, no suitable drop tanks were ever developed and the second was a consequence of the end of the Cold War and budget restraints - again not the fault of the basic aircraft design.

As a newcomer to this forum, maybe I'm missing something, but I'd be interested in other people's views.
 
Lets talk about the Yak-28P and Yak-28B/L/I separately.

The Yak-28P basically got a free ride to production not on its merits but due to the appalling reliability of the AL-7F engine which powered the Su-9/11 in the early 1960s. Late production AL-7F managed to struggle to 100, 150, and finally 200 hours service life (not TBO!).
More than half of the 20 Su-9s lost in the first 18 months of service were due to engine troubles. The only bright spot in fighter engine production in the USSR at this point was the R-11-300 engine, which was proving reasonably reliable in the MiG-21. Therefore Su-9 production was terminated and Su-11 production drastically cut, in favour of the Yak-28P (which, by virtue of using the R-11-300 and being twin engined was thought much safer) and MiG-21 developments.

It is important to realise that the USSR had just had its own equivalent of the Sandys White Paper. In 1958-59 35 aircraft projects and 21 engine projects were cancelled as obsolete in the new "missile age". Therefore only "modifications" of existing designs were permissable. The PVO were deeply unhappy with the Su-9 and turned to the Yak-28P instead, which as a modification of an existing type would be allowed into production. Also, the engine arrangement of the Su-9 gave too little room for an effective radar to be fitted, and the Yak-28P would fix this.

In service Yak-28P proved almost as unreliable as the Su-9. Its engines were too widely spaced to help in the engine-out situation, and ironically some problems surfaced with R-11F2-300 reliability . Its performance was distinctly lacking compared to the Su-9 - ceiling and top speed were much lower. It suffered from dangerous aileron reversals. On the bright side range was longer, and the radar (when it worked, which wasn't very often) superior.

924 Su-9 and 72 Su-11 were built. By contrast, only 436 Yak-28Ps were built in 4 years of production. Replacing the Yak-28P, 1,247 Su-15s were built. With the Su-15, Sukhoi fixed the two problems (engines and avionics) of the Su-9 and quickly replaced the Yak-28P in production. In desperation, Yakovlev sent his son to the Novosibirsk production line in 1964 as it prepared for Su-15 production to obtain details of the new engine intakes, and embarked on a crash redesign of the Yak-28P, called Yak-28-64, with fuselage mounted engines.

Performance of the Yak-28-64 was actually worse even than the production Yak-28P, and it had no chance of displacing the Su-15.

Regarding the Yak-28B/L/I series, the story is similar. Several advanced strike aircraft were under development, like Tupolev's "132" transonic low level bomber, and Yakovlev projects like Yak-35MV. These were cancelled in the late 1950s/early 1960s, and only modifications of existing types were to be considered. Su-7B & Yak-28 were regarded as already completed; therefore they entered service. Neither was entirely satisfactory, and production numbers of both were limited by Soviet standards.

Yak-28 production was very difficult; reliability was poor, the avionics seldom worked, and production kept changing through the production run with 10 different versions in total. Yak28B/BI were built in small numbers only. 111 Yak-28L were built, but the Lotos datalink bombing system was next to useless. Yak28I with Initsiyativa radar was a little better, eventually, once the radar was debugged sufficiently to actually work, and 223 were built.

The Su-17 and (eventually) Su-24 supplanted it.

Perhaps "disastrous" is the wrong word; it did fly, mostly. I meant disastrous in terms of Yakovlev's standing with the armed forces, not really in terms of the aircraft themselves, which were merely obsolete in conception and unreliable in service. No Yakovlev proposals were taken seriously for years afterwards.

Regarding the Yak-36M/38, this was never an operational aircraft. It could be best described as the world's best ejection seat test environment, and helped the Russians to build a really first class ejection seat design in the K-36. The design was flawed by reliance on 3 engines all working at once, something that Soviet engine building technology of the time couldn't provide. Unable to get a custom engine designed, they had to reuse the engines from the MiG-23PD. Just like HSA found with the Harrier, the battle for VTOL to work was to squeeze enough power from the engines to actually lift a worthwhile payload as well as the aircraft. Despite the best efforts of BSEL & later Rolls-Royce, world leaders in engine design, the Harrier still struggled until the invention of STOVL. Yak-36M couldn't really manage it, and the design made short takeoffs less useful than to the Harrier, not least because of the tiny wing sized for minimum weight not lift. It barely lurched off the deck with full internal fuel and a rocket pod under each wing; the idea of it carrying external fuel as well just makes no sense. Yak-38 squeezed enough extra power to make it work more reliably, but didn't fix any of the core problems.

The Russians were quite aware of this, but it gave Yakovlev something to do and gained Navy pilots flying experience (mostly in how to eject, of course).

The Yak-41M is not really much better. It stuck with the same basic powerplant idea, but newer engine technology gave more thrust, which is good. Unfortunately, as they found, vectoring a jet engine in full afterburner downwards results in lots of heat, which is bad, and nasty things happen to the aircraft underbelly if its made from, say, aluminium. If you look at the belly of the Yak-41M it looks like they've scabbed on some steel plating to compensate.Not to mention the state of the runway afterwards. Even the deck of an aircraft carrier could find the experience wearing.

It had the dead weight of 2 lift engines occupying internal space better used for, say, fuel. Yes, it was supersonic, but its aerodynamics weren't exactly going to put Sukhoi/Mikoyan out of the fighter business (tiny wing!). It still had a LOT of work to do to get to a viable operational system when the USSR collapsed.
 
This seems to be the best thread for this video documentary about the Yak-28:


The Yak-28 occupies a strange place in Cold War aviation history—mass produced, widely used, yet almost completely forgotten. On paper it promised speed, range, and versatility; in reality, it became known for difficult handling, questionable design compromises, and a reputation that made flying it anything but comfortable. Yet despite its flaws, the aircraft would evolve into what could be argued as one of the Soviet Union’s most adaptable platforms, serving as everything from a tactical bomber to interceptor and eventually pioneering electronic warfare roles. We take a look at the ambitious jet that tried to do everything—but at the end of the day was superseded by more reliable platforms.​

CONTENTS
00:00 Intro
00:56 Background
01:57 Yak-28 Development
05:00 Entering Service
05:42 Specs & Performance
11:37 Issues & Retirement
15:41 Conclusion
Click to expand...
 
Not a big fan of NAPFA2G for Soviet stuff but yeah, I actually know a few ex Yak-28 pilots who loved it. All documents apparently burned in 1992. Necessary for PVO to have the interceptors to fill gaps. Of course, if PP variant docs appeared it would be a veritable gold mine.
 

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