Sharkmouth F-117A

Anyone who doubts the capability of the Sukhoi Flanker family does so at their peril. The whole reason the Raptor is being pushed so hard is because of them. They are long ranged, very capable in BVR and in close combat. The Russians were first with helmet mounted sights, high off boresight dogfight missiles with thrust vectoring. Just shows that the US does not have total superiority in innovation. The joint helmet mounted display system takes that concept and adds on it. The Saturn engines have improvements in the pipeline including a 3 stage blisk fan which improves stall margins and power. Like anything else though its all about money.

I saw it years ago on CBC. It was ok I guess, impressive aircraft for the time, fly by wire, proposed active radar homing Sparrow 2’s, internal carriage. In some ways the 50’s equivelent of the Raptor. Just not as maneuverable. Just a bomber interceptor. It’s easy to view the program through rose tinted glasses, it was expensive, it was a point design that would not have had the versatility demanded of a traditional fighter aircraft. If it had gone ahead though Canada would have had quite a leg up on the competition, the engine was acknowledged (if they got the bugs out of it) to be one of the most advanced in the world. Transsonic low pressure compressor, two spool, even had a radial afterburner. Very ambitious indeed.

I’m not saying Pratt & Whitney makes bad engines, but I just have a little more faith in General Electric.

Yeah, that’s why the F110 engine kept having failures and Tomcats and Fighting Falcons had to be stood down while they were fixed. For awhile the F110 wouldn’t even hold together even for a tv crew. During a documentry on supercarriers shot in the mid 90’s, an F-14D did a supersonic run over the boat and the engine blew up right on cue, whole aircraft was lost, and the crew was very fortunate to have survived. Also the YF120 engine WAS very advanced, they also had the only uncommanded engine shutdown in flight during that entire demonstration program. Very seldom has GE had a frontline fighter contract. The F-4 Phantom II being one of its few exceptions. And the F110 is a special case.

The F100 and the TF30 were some of the worst engines made mostly because they were the first of their type and they were state of the art. One was the worlds first afterburning turbofan and the other was the first fighter engine to have an 8 to 1 thrust to weight ratio.

The TF30 never made it as a true success and the F100 became a success only after massive engineering changes for durability plus training to fly them properly, only now is it recognized for its potential. GE engines have traditionally never gone state of the art with the exception of the J79, and aerodynamically it was pretty average, only the variable stators made it a stand out.

Name one GE engine that powered a front line fighter that had to push the state of the art just to perform its duty. Pratt had to develop an engine for each of 3 radical aircraft, the F-111, the F-14 and the F-15, the TF30 was the worst engine in Pratt’s history as it was basically a first stab at an augmented turbofan. The F401 engine was similar to the Air Forces F100 but with more airflow, it was cancelled because of the same family of problems the F100 had giving the Tomcat the “interim” TF30 but soldiered on with it for nearly 20 years before they got the F110. An engine specifically asked by the Air Force and Navy together to put pressure on Pratt to improve its products.

The F110 engine was derived from a bomber engine, had an advantage of airflow (more thrust) plus a more mature materials and design science compared to the F100, they’re not really the same generation of engines so its very difficult to make a direct comparision. Both engines have had problems, its very rare that an engine family does not have technical issues of one kind or another during its lifespan. Even the highly regarded F119 in the Raptor was designed with too low an airflow, suffered from poor turbine and compressor efficiency, and STILL has a subsonic cruise SFC deficiency. But would any pilot who’s ever flown that aircraft ever complain about it? NO, you’ll not find a single one. Its performance now has never once missed a beat, it airstarts fine, has excellent throttle response, very crisp. Few people nowadays would complain about the F404 engine in the Hornet, but its powder metallurgy turbine discs used to explode. During the first test of the XF120 engine it failed also. It is in the nature of engines to be some of the most difficult and protracted problems an aircraft can have.

At some levels i sympathize with you on the merits of the GE, but fact is they’ve had it easier compared to Pratt. They’ve always been number 2, even if they had a lead start in the 40’s and 50’s because of Whittle involvement. Pratt became hungry and made some very good engines, the twin spool J57 and J75 engines, some of which were operating in U-2 aircraft well into the 90’s before being replaced by the F118 derivative engine.

The Pratt/GE thing is a bit polarizing, bit like getting Chevy and Ford guys to be partisan, each have their fans and merits, each has had a period in which one had quality above the other, but by and large they are very close, very similar, equivelent talent expressed in different ways.

Considering it was a steel airplane, it’s weight was pretty good, intel types conferred with aerospace engineers after the Belenko defection and they said US tech couldn’t build a steel plane that light. The Russians always did go for welded structures, the Raptor even today has a lot of rivets and bolts. Lots of sub assemblies EBW yes, but bolted together.

Here is an article on the GE engine for the Dreamliner.

Much of the buzz around General Electric’s exhibit at this week’s Farnborough International Air Show outside London will be over an engine that doesn’t exist.

The GEnx, for GE Next Generation, is one of two new engines Boeing Co. has picked to power its planned 7E7 Dreamliner. It now resides largely in computer codes and digital designs at GE Transportation’s headquarters in Evendale.

The GEnx, which borrows heavily from technology GE has developed for decades, won’t actually be fired up for its first test until March 2006.

It isn’t expected to enter service until 2008.

But Boeing’s choice in April of the GEnx as one of two engines for the Dreamliner, was “enormous,” said GE Transportation president Dave Calhoun.

Boeing’s decision also had a direct affect on GEAE’s employees.

GE chairman Jeff Immelt told shareholders in April that GEnx eventually could generate $60 billion in revenue for the company.

GEAE, which has struggled since the Sept. 11 attacks crippled the nation’s airline industry, has about 250 engineers working on the engine now and expects to hire 160 engineers at Evendale in part to develop GEnx.

The Dreamliner, conceived as the 21st-century successor to the widebody 767 and 757 jets, will have a fuselage made of lightweight composite materials to reduce weight. As a result, Boeing says, the liner will be 20 percent more fuel efficient than the 767.

Boeing envisions building up to 3,000 twin-engine 7E7s during the next 20 years. Each will have 200-250 seats and fly such routes as Cincinnati to Tokyo.

After months of evaluation, Boeing picked the GEnx and a variant of Rolls Royce’s Trent engine to power the 7E7. The loser in the competition was Pratt & Whitney, which proposed an entirely new engine design. Buyers of the 7E7 can choose the engine to equip their aircraft, so additional competition for GE and Rolls Royce lies ahead.

So far, four airlines have announced firm plans to buy the 7E7, but Boeing says more than two dozen have put down deposits on the jets and some may announce formal orders at Farnborough.

A long wait

GE and global partners including Snecma Moteurs in France, IHI in Japan and FiatAvio in Italy are investing billions of dollars to make the GENX a reality. The payoff could be huge.

Forecast International, the Newtown, Conn., aerospace analyst, estimates the engine market for the 7E7 will be worth more than $40 billion over the next 25 years.

Calhoun cautioned that GE and its partners must wait patiently for the return on their investment. Aerospace is a long-cycle business, requiring huge outlays up front that sometimes aren’t returned in profits for decades.

“If things go as we hope, we’ll collect our first dollar on this multibillion dollar investment about 24 years from now. That’s how this business works,” Calhoun said last week before leaving for Farnborough. The Farnborough show, which opens Monday and runs through July 25, is a major gathering place for the world’s manufacturers of aircraft and their components, as well as buyers eager for an up-close view of the latest and greatest in aerospace gear.

But beyond the financial implications, GE needed its engines to be on the 7E7 simply to maintain its position in the market, he said.

The CF6 family of engines, which the GEnx is designed to replace, has been the backbone of GE’s commercial business for more than three decades.

The family, introduced in 1971, has given GE the lion’s share of the engine market for jets such as the Boeing 767, and the Airbus A300 and A330s, Calhoun said.

Without the GEnx to power the Dreamliners and other future wide-body aircraft, “that would have been a huge hit on the business,” he said. “We had to win.”

Composite blades

British-based Rolls and GE are using different approaches to power the 7E7.

Rolls’ variant of its Trent engine is called the Trent 1000. It will use hollow titanium fan blades and three separate shafts for the engine’s high, medium and low-pressure turbines, which Rolls says will mean less engine wear.

The GEnx incorporates technology that GE is using on a commercial engine for the first time.

Like the GE90 before it, the GEnx will use fan blades made of lighter-weight composites rather than metal.

GE is the only major commercial engine builder to use composite fan blades rather than titanium, and they’ve been an unqualified success, says Thomas Brisken, GEnx general manager at Evendale.

Only two composite blades have failed in eight years of operation over more than 4.5 million hours of flight, he said.

To save weight and thus improve fuel efficiency on the GEnx, GE will also use composites in the case surrounding the engine fan.

“That will take 400 pounds out of the case structure. That’s a really big step forward for us,” said Brisken.

GE has used composite fan cases on military engines, but the GEnx will be the first commercial engine with one.

High bypass ratio

Brisken, a 1967 Moeller High School graduate who has worked at GE for 33 years, says engine efficiencies are expected to produce about three-quarters of the 20 percent improvement in fuel efficiency Boeing is seeking.

Almost half of the GEnx improvement will come from using the highest-bypass ratio GE has ever employed in a commercial engine.

Modern turbofan engines are high-bypass, meaning most of the air passing through the fan goes around the compressor and combustor rather than through them to generate thrust. The GEnx will have a 9.5 bypass ratio, meaning about 9.5 times the amount of air will pass around the engine than through it.

The higher bypass ratio and higher overall engine pressure ratio will produce about 40 percent of the fuel efficiency improvements, Brisken says.

“The other 60 percent comes from taking each component to a better efficiency level,” he said. “Most of it comes through better computer codes we have today in analyzing it.”

To validate those digital designs, GE is undertaking the most extensive component-testing program for a new engine in its history.

This year, GE is running 13 separate component rig tests to validate various design features for the new engine.

One example: the number of fan blades.

In the past, the company has used 22 fan blades in an engine. But Brisken said: “Our computational codes indicate 18 blades is more efficient.”

So GE is running rig tests at NASA’s Glenn Research Center in Cleveland on fans using 22, 20 and 18 blades to verify the most efficient design, he said.

Final design close

The culmination of the engine component testing will come in January, when GE and its partners set the final design for the engine.

That will trigger a flurry of activity as the project is turned over to design engineers for final drawings and manufacturing and sourcing managers begin ordering components for the seven engines in the engine certification program.

The GEnx program now employs about 250 engineers, but that number will rise to more than 400 early next year as the program moves toward running the first engine in 2006, Brisken said.

GE expects to complete engine certification tests in July 2007.

Assembly of the finished engines will be at GE’s plant in Raleigh-Durham, N.C.

But the final design won’t end GE’s testing of the GEnx.

Beyond Federal Aviation Administration certification, GE plans to run two of the test engines the equivalent of three years of operation to further verify the technology.

By doing that, Brisken said, GE can take the engines apart and look for wear or other ways to improve the engines before the first airline customers are scheduled to bring the engines in for their first maintenance checks about 2011 or 2012.

http://www.enquirer.com/editions/2004/07/18/biz_airshow18.html

I think it was already done by HBO, but how about a proper movie about the Tuskegee airmen. Proving that black men can fly and fight as good as any in the army air corps. Their stats are pretty impressive if i remember correctly.