rynopot wrote:
@Mfezi - will the new Migs still require engine maintenance at short intervals, which Russia will only do themselves?
Or has the engines' maintenance turn around times improved? And will Russia give countries license to do the maintenance themselves?
I understand this was always the main argument for NOT buying Russian fighters.
Ryno
Obviously, I haven't seen the Egyptian contract and can only guess at the maintenance agreements. But on the engines in general - the Russians have done a huge amount of work on improving quality and increasing both time between overhauls and total service life of their engines over the last 20 years or so. A lot of that was pushed by the Indians, who operate a mix of Western and Russian types and wanted to get their Russian aircraft closer to the maintenance requirements of the Western types. Of course, the Russians also realized that if they want to compete on the world market, they would have to sort out these issues. By the way, even our work with them on the SMR-95 pushed them to increase service life and improve efficiency and, in the case of the RD-33 specifically, reduce the characteristic smoking of the earlier engines when selecting full power.
So, to give you some idea: I have heard from some people that the original RD-33, as developed in the 70's, would have to be factory overhauled every 300 hours or thereabouts. This is probably what you are referring to? On the new RD-33MK, which I believe also now powers the Egyptian aircraft, the total service life has been increased to 4000+ hours and the time between overhauls is, according to various sources that I have read, in the region of 1000 hours. Unfortunately, I have no idea what level of servicing or overhauls can be done outside Russia, but I presume a factory overhaul every 1000 hours of service would be much more palatable for most clients than every 300 hours.
As for the AL-31 family of engines powering the Sukhoi aircraft - I don't know exactly what the original TBO and service lives were on the early Su-27 models, but they were better than for the RD-33. I have seen in some books that the factory spec said 500 hours TBO with a 1500 hours service life on the original models - so better than the RD-33 but still not at Western standards. The slightly newer ones used by the Indian Air Force on the Su-30MKI have a mean time between overhaul of 1000 hours and a service life of supposedly 3000 hours. Saturn claims that for the AL-41F1S used in the modern Russian Air Force Su-35S and Chinese Air Force Su-35, you can go 1500 hours before the first overhaul and then it is 1000 hours MTBO with a 4000 hours total life. Keep in mind, 4000 hours is probably also roughly the service life of the actual airframes into which they go.
Anyway, these modern numbers are in line (or, in some cases exceed) modern Western Engines. What I don't know, and to answer that you would have to ask an operator of the latest types, whether these engines actually achieve the design MTBO in operational service. I simply don't know the answer to that question, but on paper at least service and overhaul intervals should not really be as important a factor in aircraft selection when choosing between Western and Russian types, as it may have been in the 80's or 90's, when their whole philosophy was so different from our modern Western one.