A very interesting bit on the Su-27, albeit a clean, demilitarized, lighter one, but even a heavier Su-30 should be able to boast a pretty credible performance wrt range and speed. Even if 35 mins on supersonic for a Su-30, with IFR, we are talking of a serious challenge for a light fighter force with shorter legs. No wonder the IAF is so happy with the Su-30, with its radar/weapons combo and such performance, its a far cry from the 30 min sortie MiG-21 at subsonic speeds.http://www.flightglobal.com/blogs/the-d ... e-flanker/
Flying the Flanker
By Dave Majumdar on 20 April, 2013 in UncategorisedA few years ago, Tactical Air Support was, for a brief period, an operator of a pair of privately-owed Soviet-built Sukhoi Su-27 Flankers. The company’s senior vice president and chief operating officer Gerry Gallop, who previously served as a US Navy instructor pilot at TOPGUN and who has flown the F-4 Phantom II, F-14A and B, F-15, F-16, the F/A-18 series and the A-4, a recalls some of his initial transition flights in the Flanker.One sortie that stands out in Gallops’ mind was a combination functional check flight and navigational training sortie over the Ukraine. “I had no idea I was going to be supersonic for 25 minutes,” he says.
“We climbed up to 20,000ft at 0.9 Mach and did some checks on the engines and then the next thing we were going to do was climb to 35,000ft and be at 1.35 Mach for the Mach lever checks, very similar the [Pratt & Whitney] TF30 [on the F-14A Tomcat]–you’re going to bring the throttle back to idle when you’re supersonic and it’s going to make sure the RPM stays high up enough to prevent an engine stall,” Gallop says. “We finish up at 20,000ft and I’m expecting to climb at 0.9 to 35,000 and accelerate to 1.35 Mach… Oh no… We just plug in the blowers, pull the nose up, accelerate to 1.35 in the climb, level at 35,000ft, check the engines, blowers back in, accelerate to 1.55, climbed it up to 47,000ft, and then we just brought it back to min burner.”“We brought it back to min burner, but I’m cruising at 1.3 Mach,” Gallop says. The two-seat Flanker was clean, Gallop says, and it was demilitarized–which means it weighed about 3000lbs less than the typical stock Su-27, but nonetheless, the jet was impressively fast especially at high altitude.
Slowing the Flanker down after almost 25 minutes of supersonic flight also showed interesting results. “I take it out of burner and I’m just at mil power and the speed dropped down to–I was still supersonic,” he says. “By the time we got done, 25 minutes supersonic, I looked at the gas and go ‘you know I could turn around fly back the way I came supersonic and still have a normal amount of gas left to land’,” Gallop says. “I had more fuel when I was done that profile than a single centerline Hornet had on the ramp.”The Flanker holds 9,400Kg (20,700lbs) of fuel, which is similar to an F-14 with two external tanks, Gallop says. “I’m up there clipping off 13 nautical miles a minute and I’m burning 110kg per minute,” he continues. “I took off with 9,400 and I’m burning 110kg per minute at Mach 1.3, so you look at that and go ‘I can be supersonic a long time and you look at how many miles you can fly at that speed.’”
Part of the reason the Flanker performs so well at those speeds is because the jet was optimized to perform in the transonic and low supersonic regime–between Mach 1.05 and Mach 1.2–but it will easily run to Mach 2+, Gallop says. “The thing can hold like 10 missiles, so you start hanging all those pylons and all those missiles on there and you’re not going to be a Mach 2 machine,” he says. “You not going to be doing Mach 1.3 in min burner, I guarantee it, but it just gives you an idea of how much power [the jet has].”
This was an old original model Su-27–one can only imagine what a brand new Su-35S coming off the production line can do with its twin Saturn 117S engines, which produce 31,900 lbs thrust each. The original Saturn AF-31F produce 27,560 lbs thrust each.