F-22 & Supercruise (1 Viewer)

[alan halvorson]

The F-22 Raptor fighter plane includes a feature called "Supercruise", which is defined as the ability to fly at a sustained speed greater than Mach 1.5 without use of an afterburner (according to what I've read). Current jet fighters have long been capable of supersonic speeds but only by use of a fuel-gulping afterburner, which severely limits the amount of time they can fly at those speeds. I have never come across an explanation as to how supercruise works. Does anyone have such an explanation, or a link to one?

 

[ChrisArmour]

It's just pure power, each of the F22's engines makes about 35,000 pounds of thrust w/out the afterburners. Standard thrust numbers from the F15 I believe start at about 23,000 pounds of thrust for each engine w/out afterburners. The F22 engines just contain so much brute force that they can propel the plane past mach w/out AB.

 

[Jack Briggs]

In addition, the F/A-22's use of thrust vectoring makes it extraordinarily maneuvarable even at super-high speeds. This is one truly amazing plane.

 

[alan halvorson]

Supercruise is just more thrust? That takes more fuel doesn't it? I believe there has to more to than just that, but maybe not. Wonder how about 50% more power was gotten from what probably is a similarly sized engine?

 

[ChrisArmour]

It's newer technology, the engines are way more powerful, and at the same time more effecient, it's one bad mofo. The F15 and F16 are getting up there in age for fighter aircraft, both aproximatly 30 years old, while they have received numerous upgrades over the years, they were still limited by their over three decade old design. Thirty years may not seem like much, but when you look at the fact that we have only been flying for less than a century, and how fast technology has advanced in that time frame, it stands to reason that the F22 would be so much of an aircraft than what we currently have. I cant wait for its inception into the Air Force, I was actually at Nellis AFB right before the F22 got there, they built all new buildings for it. To me the most impressive piece of technology found on the F22 isnt the thrust vectoring or the supercruise. It's the advanced weapons system found on this plane that makes it a real threat to the enemy, it can detect and "fire and forget" on enemy aircraft before they even know you are anywhere around, very impressive.

 

[Cary_H]

Alan....thrust is what it's all about and the more of it you make the more fuel required. The difference is that despite making increased thrust, getting it without dipping into reheat/afterburning lessens fuel consumption.
RH/afterburning is a grossly inefficient way to achieve additional thrust.
A big factor in engine design and development since day one has been the advances made in the fields of metallurgy and materials. Smaller,lighter,and more efficient engines that surpass the output levels of their predecessors stuffed into a smaller, lighter airframe (relative to their size anyway) has opened the door to making supercruise attainable.

 

[Brandon_T]

On a related note, we have a family friend who is in the Navy and in training to fly the F-22. He is very excited, but also nervous about recent internal talk of the project coming under serious problems that he didnt talk about. We have been hearing about this thing forever. I bought the F-22 game a long time ago, just cuz the thing looks bad ass.

Brandon

 

[Paul McElligott]

I'm not sure, but maybe the aerodynamics also help the supercruise as well. Not to be picky, but a Navy pilot wouldn't be flying the F-22, since it's an Air Force fighter. A Navy man would be training to fly the Super Hornet, if anything.

 

[ChrisArmour]

Or the new Joint Strike Fighter(which I believe is still in test phase anyway), which also happens to be a very impressive A/C. Unless of course he is going to transfer to the Air Force, but if he was training on the F22, he would already be in the Air Force.

 

[ChristopherDAC]

Of course, it doesn't have a credible mission [a Lockheed engineer told me that american pilots flying the latest MiGs and Sukhois could shoot down american pilots in F-15s; my answer is "who cares?" because it's a ridiculous scenario -- the amount of money our Defense department can't account for is seven times as large as the combined military budgets of every other country in the world], but that doesn't mean we shouldn't build it. We didn't build the B-70, so we're still stuck with the B-52 [which is now that old]. Anyway, I hope the tech for those better engines which make that supercruise possible will get into the civilian world sooner rather than later...

 

[Philip_G]

Boeing
Too bad lockheed has to be involved too...

 

[ChrisArmour]

I wouldnt say "stuck" with the B52, the B52 is a damn fine A/C and more than capable of completing it's mission. The fact that it's not scheduled to be replaced until 2045 is a testament to its design and adaptability.

 

[Kirk Gunn]

Doesn't decreasing drag/weight have anything to do with the F-22's superior performance and better gas mileage ?

My father was an engineer with GE building the F404's fuel system back in the early 70s - the engine in the F/A-18's. I was listening to 8-tracks when the engine for the US's most advanced fighter was built. (ok - the F/A-18e Super Hornet has recently hit the fleet....) We are a little overdue for some upgrades.

And weren't all B-52s airframes practically rebuilt in the late 70s/early 80s to lengthen their service time ? (at a cost well over building the original bomber). I don't think the original models could make it to 2045 without some serious re-design...

My favorite ATC quote was when an F-14 was coming in to land w/one engine out. ATC told the F-14 to hold off since a B-52 was also approaching with one engine out. The F-14 pilot responded: "Ah... the dreaded 7-engine approach". Could be legend, but pretty funny.

 

[Brandon_T]

Nevermind

 

[LDfan]

I'm gonna play devil's advocate here and ask "do we really need the F-22?". My answer would be no and why would we? It's way too expensive to sustain a decent sized fleet of them for the air force plus our current fighters are still very good.

Jeff

 

[ChrisArmour]

I say yes we do need this aircraft, if we want to maintain air superiority in this next millennium, we need a superior aircraft. Which our current fleet is not, we just have far superior training and support systems than any other country in the world, which keeps us on top. The F22 and the JSF are vital to our role as the worlds dominant Air Force.

 

[AjayM]

Here a good link - http://www.globalsecurity.org/milita...craft/f-22.htm

"Supercruise" is the term given to the capability of sustaining supersonic speeds for long periods of time. Conventional fighters, while capable of supersonic flight, can only sustain these speeds for relatively short periods as the result of excessively high fuel consumption using afterburner. The F-22's engines produce more thrust than any current fighter engine, especially in military (non-afterburner) power. Called "supercruise," this characteristic allows the F-22 to efficiently cruise at supersonic airspeeds without using afterburners. The F-22's engine is expected to be the first to provide the ability to fly faster than the speed of sound for an extended period of time without the high fuel consumption characteristic of aircraft that use afterburners to achieve supersonic speeds. It is expected to provide high performance and high fuel efficiency at slower speeds as well. This capability greatly expands the F-22's operating envelope in both speed and range over current fighters that must use afterburner to operate at supersonic speeds. The F-22 can cruise supersonically without afterburner and, therefore, can sustain these speeds for long periods. The enemy must react to any intruder and that reaction time to detect, aim weapons and launch, is severely reduced when the intruder is moving fast. At supercruise speeds, the F-22 (and its pilot) becomes less vulnerable to enemy missiles and aircraft simply because they cannot react fast enough.


Actually the cost to keep up an aging aircraft fleet get's to be about as expensive as buying a new one. Airplanes are basically "consumable" items, they get used for a period of time, then they are thrown away (there are people who buy these old planes and restore them, but the cost to do so is heart stopping). This is because the cost of overhaul becomes VERY expensive, especially when you start talking about the airframe itself. For instance, the Navy F-14 is due for retirement fairly soon, the cost to extend that retirement just a single year is over a billion dollars.

Next you get into the actual costs to fly the plane. The newer planes are much more economical to operate on a cost-per-hour basis, going back to the Tomcat example, the cost to fly the F-14 is double that of the F-18 per hour. Newer aircraft will be even more economical to operate.

Andrew

 

[LDfan]

Here is an interesting link given to me by a fellow HTF member.

http://www.pogo.org/p/defense/do-010...aldisarmB.html

Jeff

 

[Mike Voigt]

Gotta ask, though - didn't the SR-71 Blackbird have the capability for supercruise? It still holds the speed records, AFAIK, and I doubt they used afterburners the whole way. After all, these aircraft are reputed to have flown intercontinental distances, not exactly short trips...

 

[Yee-Ming]

I thought the Blackbird basically had a de facto ramjet engine? Which is basically a giant afterburner. AFAIK it was a huge fuel guzzler, the plane had to be refueled immediately after take-off, which consumes a fair bit, and probably refuelled on the way back as well. But it did hold flat-out speed records (Mach 3, I believe) as well as sustained high altitude crusing (80,000 feet?), but it basically flew in straight lines, i.e. no maneuverability at all, it just flew faster and higher than anything the Soviets could throw at it, making it untargetable.

As for whether the USA needs the F22, well, if you're selling F15s to everyone else (Singapore is making a decision in replacing its fighters, and the finalists are the F15, Rafale and Typhoon), you need a newer, "badder" plane, don't you?