[sparky@home]

This is GE’s new engine, and its huge. The spec states that it’s as wide as the body of an entire Boeing 737.

Source : https://www.ge.com/reports/away-worl...maiden-flight/

[SmartCat]

I wonder why they did not use 777 as a test bed. Since 777 can take off and land with just one engine, they could have put the older GE90 engine on one side and the newer GE9X on the other.

[sandeepmdas]

Originally Posted by smartcat

I wonder why they did not use 777 as a test bed. Since 777 can take off and land with just one engine, they could have put the older GE90 engine on one side and the newer GE9X on the other.

They might have thought about a scenario where the other engine fails and 777 is on a new engine and a prayer.

Jokes apart, I think the two 747s that GE uses as test platforms are well wired-up with all test equipment already been onboard. So it could be just a matter of recalibrating them for the new host. These aircraft might also have all the necessary FAA certifications for experimental flying.

[Turbanator]

Originally Posted by sandeepmdas

I think the two 747s that GE uses as test platforms are well wired-up with all test equipment already been onboard. So it could be just a matter of recalibrating them for the new host. These aircraft might also have all the necessary FAA certifications for experimental flying.

Yes, they just cannot take any plane and start testing, from the same link, check this

One of the steps required to win FAA certification actually looks like fun — though the engines might object. It involves flights on GE’s Flying Test Beds. GE has two of them, each one a converted Boeing 747 packed with computers, electronics and other gear. The newer one, which GE acquired in 2011, can safely climb as high as 45,000 feet, some 5,000 feet above maximum cruising altitude.

https://www.ge.com/reports/into-thin...ngine-testing/

[Jeroen]

Originally Posted by Turbanator

. The newer one, which GE acquired in 2011, can safely climb as high as 45,000 feet, some 5,000 feet above maximum cruising altitude.
]

Not quite sure what they mean by that last sentence. You don't fly higher than your maximum cruising altitude, otherwise it would not be called a maximum cruising altitude. 747s are quite capable of cruising at 45.000ft. Quite a few other planes too, or near enough.

Jeroen

[SmartCat]

Originally Posted by Jeroen

Not quite sure what they mean by that last sentence. You don't fly higher than your maximum cruising altitude, otherwise it would not be called a maximum cruising altitude. 747s are quite capable of cruising at 45.000ft. Quite a few other planes too, or near enough.

That's a very confusing phrase 'max cruising altitude'. What GE means is -

At cruising speed (maximum fuel efficiency, around 900 km/hr probably), this bird can fly at 45,000 ft instead of the usual 40,000 ft. The actual maximum altitude of GE's 747 could be higher than 45,000 ft.

[Jeroen]

Originally Posted by smartcat

That's a very confusing phrase 'max cruising altitude'. What GE means is -

At cruising speed (maximum fuel efficiency, around 900 km/hr probably), this bird can fly at 45,000 ft instead of the usual 40,000 ft. The actual maximum altitude of GE's 747 could be higher than 45,000 ft.

Why would 40,000 be usual? There is no such thing as an usual cruising altitude, only a maximum. Cruising altitudes are chosen for max efficiency. Wind aside that is weight depended. During a long haul the most efficient cruising altitude changes constantly and planes adjust their cruising altitudes constantly as they burn of fuel and become lighter. Depending on where you are in the world they will increase their altitudes in steps of 2-4000 feet.

A fully loaded 747 might initially cruise at 30.000 feet, then move to 34.000, 38000. Actually cruising above 40.000 feet is not that common, not because it cant be done, but because the plane has to very light. So only during the last few hours of a very long flight, with a lightly loaded plane are you likely to find yourself over 40.000 feet, maybe 42-43.000. I dont think during all my flying years I have ever been above that, although certainly 747s are capable of it.

[sgiitk]

With the US not interested in the Super Airbus what will they do with such a massive engine. Is it more of a publicity stunt.

[A350XWB]

Originally Posted by Jeroen

Not quite sure what they mean by that last sentence. You don't fly higher than your maximum cruising altitude, otherwise it would not be called a maximum cruising altitude. 747s are quite capable of cruising at 45.000ft. Quite a few other planes too, or near enough.

The Maximum Operating Altitude of 747 in general, is 45100ft. Only the LCF is limited to 43100ft. (FAA certification data)
The explanation of GE's statement can be deduced from this page, at their website.

The test jet landed in Victorville with four GE CF6 engines slung under wings, the same kind that powers Air Force One. The engines will allow the 747 to reach 45,000 feet, 30 percent above the average cruising level of passenger aircraft and 5,000 feet higher than GE’s older 747 flying test bed.

The first 747 test bed of GE is a 747-121 (21-Customer code for PanAm), the 16th 747 ever built and was delivered to PanAm (Clipper Ocean Spray (N744PA & later N747GE)). This one is now stored.
The second one, acquired in 2011 from Japan Airlines, is a 747-446 (46-Customer code for JAL) (JA8910 & now N747GF).

Originally Posted by sgiitk

With the US not interested in the Super Airbus what will they do with such a massive engine. Is it more of a publicity stunt.

It is not a publicity stunt. This will power the 777X (777-8 & 777-9) program. As per GE, they already have around 700 orders for this engine. GE has engine exclusivity for this program, just like the 777-200LR, 777F and 777-300ER. But if you see, the thrust requirements for this engine is actually less than it's predecessor, the GE90.

[Jeroen]

Originally Posted by A350XWB

The explanation of GE's statement can be deduced from this page, at their website.
.

That makes more sense, thanks

The engines will allow the 747 to reach 45,000 feet, 30 percent above the average cruising level of passenger aircraft and 5,000 feet higher than GE’s older 747 flying test bed

It's in line with what I wrote earlier about cruising altitudes. Higher cruising altitudes allows for better fuel efficiency.

Jeroen

[Sutripta]

OT:- GE was supposed to develop 2 versions of an enhanced engine for the Tejas. Status?

Regards
Sutripta

[SmartCat]

Visual comparison between engine size of 777 and a Boeing 737

[R2D2]

Originally Posted by smartcat

Visual comparison between engine size of 777 and a Boeing 737

Great pic. TFS. The planes' fuselages remind me of an Orca lined up right behind a dolphin. Those B777 engines are huge!