Upon thinking a bit more about the Yak-141 and those thrust figures for the lift engines and the main swiveling engine, I would think that ground erosion/deck warping would have been a huge issue for the 141. While the thrust to weight figures are impressive, that is a tremendous amount of high velocity thrust. The Pegasus engine on the Harrier moved a huge amount of air at relatively modest velocities- while the YAK’s seemed to move a modest amount of air at high velocities. The Harrier could conduct rough field ops, but as noted in the flight manual could easily “dig it’s own grave” in soft terrain. I think the YAK would have been even worse in that regard.

Well that was certainly a problem in the case of Yak-41M. In fact the exhaust gases from R-79 lift/cruise engine nozzles had a temperature of 980-1050C and velocity of 950-980 m/s (by Y. Gordon). In most cases the AK-90F heat resistant tiles were used to protect the area from their influence (e.g. on the launch pads on Baku aircraft carrier, later renamed to Admiral Gorshkov). There are even rumors that the main reason why Yak-41M did not perform a vertical start during Farnborough 92 airshow, were objections of the organizers, who were afraid of potential airfield damage. Harrier definitely enjoyed an advantage here, the question is whenever it was really that much important in operational use. Does anyone know how this problem is solved in F-35B?

Takeoff weight thrust-weight ratio of 1.25 guarantees a vertical takeoff with any conditions:
22200 kgs: 1.25 = 17760 kg
10400 kg (empty) + 4300 kg (fuel) + 100 kg (pilot) + 126 kg (gun ammunition) + 2834 kg (weapons) = 17760 kg

All sources give the maximum takeoff weight in vertical mode as 15800kg so I don’t think there is much argument with this. Also, the thrust of R-79 in vertical mode was closer to 12500kG (see below).

As for a dead weight, absolutely. Separate lift engines are problematic for a host of other reasons. Interestingly the only weight I was able to find on the RD-41 was 290kg (with 9,000+ lbs thrust). Find that thrust to weight hard to believe, anyone have a hard number on RD-41 weight?

In general the biggest problem with Yak-38 was not with the configuration but rather with the underwhelming performance of its engines, which made the great idea looks very bad. In the case of Yak-41M the engines were finally performing like they should be to make the design effective. The RD-41 engine indeed had a mass of 290 kg (Y. Gordon) with thrust of 4100kG, although P. Butowski gave a TWR of 16.7, what will result in even lower mass. It may look astonishing, but we have to remember that the average working time of RD-41 was just 40 s for takeoff/landing sequence (the maximum time for single use was 2.5 minutes). As for the R-79 it was a really interesting design, with the afterburning thrust of 15500kG in cruise mode, 14000kG in vertical mode (although when losses where included it was closer to 12500kG) and 11000kG of military thrust. The dry mass was about 2750 kg, so the TWR was about 5.65. At first it may look nonspectacular, but I guess the weight of the vectoring nozzle was the main reason for this. I must say it’s quite surprising to me that R-79 was never further developed (version without vectoring), as it was the most powerful fighter engine of its time and had a rather high potential for further growth (the uprated version was already underway from what I found).

As ijozic said, the Yak-41M was not a rival to the MiG-29K and Su-33. It was intended for the Kiev-class carriers (Kiev,Minsk, Novorossiysk and Admiral Gorshkov) and after their scrapping it was deemed unnecessary, as Kuznetsov was able to carry more efficient designs. It does not mean that Yak-41M was a bad plane – it was a truly remarkable design. However, at the beginning it was planned rather for an interceptor role, what led to some inherent limitations of the airframe. Situation changed on 20th May 1986, when the Communist Party Central Committee gave a directive, according to which the Yak-41 had to become a multi-role platform (although IIRC the air-to-ground role in a bit more limited extent was planned from the beginning). This led to change of the name to Yak-41M, which had an updated S-41M (M002) radar (a N001 Zhuk derivative, from what I read a bit simplified one), but the first flying prototype was already finished in December 1985, so no significant changes to the original layout were possible. While it was capable to carry similar weapons array as MiG-29K (including R-77, Kh-31, Kh-35, Kh-58 etc.), the number of hardpoints was just 4 and the maximum load was 2600 kg or 1000 kg (for 120m take off run and vertical start respectively). In terms of performance it was also inferior to both Fulcrum and Flanker, as its maximum speed was 1800 km/h and the maximum range is given as 1400 (vertical start, clean configuration) or 2100 (with normal take off and 1000kg loadout). I would also expect that in terms of maneuverability it was behind both MiG-29K and Su-33, due to much higher wing loading, lower g-limit (7.0G) and generally interceptor-oriented design. To conclude, while as a VTOL aircraft it was years ahead of Harrier in terms of airframe performance, it was simply not enough to rival conventional designs for the place on Kuznetsov and in fact it was never intended to do so.

Right.. So show me those facts of yours, what is the thrust of the “export” RD-33MK, “Russian” RD-33MK and what are the construction changes having been done to achieve that thrust increase?

They probably used valyrian steel and mithril…
and seriously, RD-33 started as a give-it-all-and-die-quickly engine, with very short longevity. It was already a great achievement that they’ve managed to improve longevity so greatly in series 3, without downgrading the performance. The RD-33MK offers 9000 kG in comparison to 8300 kG of RD-33 (series 3 included) so this is, most probably, this significant thrust increase we are talking about, as all MiG-29s currently used by RuAF use the latter, less powerful engine (IIRC SMTs fly with series 3). The RD-33 for years have been underdeveloped in comparison to AL-31 mainly due to much higher interest in Su-27 than in MiG-29 platform, so it shouldn’t be surprising that improvements in thrust of AL-31 are comparatively bigger, as there were money to fund them. Also, looking on the history of AL-41F1 engine and its tests, we would be well aware if any significant modification to RD-33 were underway, as demonstrators would be already flying on testbeds for year or two.

My bad, when you said

I assumed that there are 2 distinct versions for Mig-35
land based weight 11600 kg and sea based Mig-35 weight 12400 kg. If no landbased version was bought then that left us with sea version.

Ok there is one, uniform platform: 9.41 which was developed from MiG-29K for India (first flight 20.01.2007). It appears in following, naval versions:
-MiG-29K/KUB (9.41/9.47) ordered by India in total amount of 45 planes (41 and 4 respectively IIRC)
-MiG-29KR/KUBR (9.41/9.47) ordered by Russian Navy in total amount of 24 planes (20 and 4) with a few new radar modes, Russian IFF and other minor changes
9.41 and 9.47 airframes are identical, with only difference being 630l fuel tank in 9.41 in the place of second pilot.

Then, there is MiG-29M/M2 (9.41S/9.47S), which is the same airframe, but without naval stuff: folding wings, arrestor hook etc. (and as a result is a bit lighter). First flight on 24.12.2011, ordered by:
-Egypt 46 planes
-Syria 12 planes (status of this order is problematic)

Sometimes MiG-29M/M2 occurs under designation MiG-35 (still 9.41S), however in most cases this name is reserved for the most advanced configuration (with AESA radar and other stuff). There were two demonstrators of MiG-35 in such meaning: “961” and “967”(used in Zhuk-AE tests), which were intended for MMRCA competition. “961” had an airframe of MiG-29K from the second production batch and “967” was remade MiG-29KUB prototype “947”. Later, both planes were turned back to MiG-29K standard and two new airframes were adopted as testbeds: “741” and “747” and they serve in this role up to this day. As of today there are no orders for this most advanced configuration, although one from the RuAF is expected in near^TM future under designation MiG-35S and MiG-35ST (rumors say about 28 planes).

All this planes share the same airframe (except for naval/land based differences) and the same engine RD-33MK.

don’t put your own explanation for the purpose of visit and type of aircraft. Egypt has more than 100℅ devaluation after saudi cutoff there aid. I will be surprized it goes there. how much Venezuela bought fighters after devaluation. It is time for Egypt to sell Mistral to Russia.

Ok, so I repeat: for whom are they being made?

it won’t be the export model. The same restriction on RD93 technology for JF17. The higher thrust versions are delayed exported.

If they are delayed for export they must surely exist and have some designations. What are they?

Su-27S ferry range is 3700 km
Su-35 ferry range is 4500 km

I’m afraid that 4500km is for Su-35S equipped with two 2000l drop tanks. Without it the most common values are around 3600km.