F135 diameter and weight

[disconnectedradical]

Interesting. I recall finding the Tinker news release and thinking 3,700lbs seemed a bit light for the F135, but 6,400 sounds a bit high.
The power module and skid for COD weighs around 7k.

I wonder if the weights from the shipping instructions includes protective crate similar to the power module skid for COD.
This also lists the engine weight as 3,750lbs:
https://www.aviationtoday.com/2022/12/1 ... rons-2030/

"Raytheon also said that AETP is “significantly heavier” than the 3,750 pound dry weight F135, but declined to disclose how much heavier and referred that question to the F-35 Joint Program Office (JPO). Defense Daily will add any response from the F-35 JPO"

Unless that is just the weight of the power module.

Looking through the T.O.-00-85-20, it looks like it's describing the engine mounted on the cart so it would be the engine itself without anything else, although it probably includes lubricants and stuff too. It does jive with what P&W said though about the F135 weighing 1,500 lbs more than the F119, and the T.O.-00-85-20 says that the F119 weighs about 5,000 lbs. The Tinker AFB's 3,750 lbs for F135 may just be the power module, or maybe with the afterburner and nozzle removed.

[Corsair1963]

The only number that I have seen is the 3,750lbs.

[f119doctor]

3750 lbs is approximately what a F100-229 weighs. The F135 is at least 50% bigger, and that volume is not all air. I would believe the tech order.

[disconnectedradical]

The only number that I have seen is the 3,750lbs.

3,750 lbs was never realistic, especially when P&W said that the F135 weighs 1,500 lbs more than the F119. And dry weight and wet weight aren't that different, the F110-GE-400 dry weight was 4,494 lbs and wet weight was 4,592 lbs.

[milosh]

I see Wikipedia also changed weight spec. To me it sound not logical to be 6.4k lbs.

I did consider 3.8k lbs unrealistic but 6400lbs is also unrealistic in my pov.

I am not expert at all but still if 6.4k is weight it mean engine don't even have 7:1 ratio on max AB?

[f119doctor]

You also have to remember that the F135 is carrying some additional items:

1. All of the aircraft generators and pumps are mount directly to the engine gearbox, instead of an airframe mounted AMAD like the F-15/16/22. This makes the gearbox heavier, even though the total aircraft weight is reduced

2. The F135 has ECS air coolers mounted inside the fan duct to be cooled by bypass air, and ducting for the coolers on the outside of the engine - adds weight to the engine

3. The multi function turbine exhaust case holds the AB spraybars, acts as the flame holder, supports the back of the low turbine, and has a low observable function. Weighs more than a traditional exhaust case and flame holder.

4. Has a 2 stage low turbine that was necessary for the F-35B lift fan power extraction, but wasn’t really needed for the CTOL version. Adds weight.

And it is a very long life design. All these things make it a pretty beefy engine.

[willhan]

When it comes to thrust-to-weight ratio, I've always had a question: Is the weight used to calculate thrust-to-weight ratio not the whole weight of the engine?

I came across a description in an article (unfortunately, I can't find the article now):

1. If a component belongs to the propulsion system but is installed on the airframe rather than on the engine, then the weight of this component is not counted in the engine's dry weight;

2. If a component is installed on the engine but serves the aircraft rather than the engine, then the weight of this component is also not counted in the engine's dry weight.

And I saw a similar description in a British paper, which seems to confirm the above:

"The weight of the propulsion group which includes the engines, engine exhaust, reverser, starting, controls, lubricating, and fuel systems are handled together as the total propulsion group weight...Propulsion system weight = 1.377 x Engine weight x Number of engines."

However, this paper refers to civil aircraft, and I'm not sure if fighter jet are similar. Moreover, it seems that British standards and US standards are also different.

Can I understand it this way:

• Engine contract weight ≈ 1.377 x Engine dry weight

And:

• Thrust-to-weight ratio = Thrust / Dry weight

Instead of:

• Thrust-to-weight ratio = Thrust / Contract weight

Please correct me if I'm wrong.

[f119doctor]

I was not considering the weight of the aircraft accessories in the F135 weight. But the fact that they are mounted directly on the engine gearbox means the gearbox itself has to be bigger and heavier with provisions to mount those accessories.

In the F15, F-16, and F-22, the engine gearbox is smaller, just mounting the engine fuel pump and engine generator, with a PTO shaft running to an Aircraft Mounted Accessory Drive (AMAD) with the airframe accessories attached. These stay with the aircraft when the engine is removed, with only the PTO shaft being disconnected. This setup is more maintenance friendly, but weighs more in total than having the airframe accessories hard mounted to the engine gearbox.

[gta4]

I can give everyone a final say on the weight issues of F119 and F135.

There are accessories on aircraft engines. Some are meant to contribute to aircraft functions, some are meant to contribute to engine functions. The former is not counted in engine weight, while the latter is.

This is due to the fact that pre-installing some accessories onto engines simplifies assembly.

The weight you can see from the "packaging card" of F119, is definitely more than the actual dry weight, which is used for T/W calculation.

So the F119 wiki page is definitely wrong.

[disconnectedradical]

Dry weight is just weight of engine without fluids. But definitely include accessories. For example, F110-400 difference between dry weight and wet weight is less than 100 lbs.

F110-400 dry weight: 4,494 lbs, wet weight: 4,592 lbs.

[gta4]

Dry weight is just weight of engine without fluids. But definitely include accessories. For example, F110-400 difference between dry weight and wet weight is less than 100 lbs.

F110-400 dry weight: 4,494 lbs, wet weight: 4,592 lbs.

The engine function related accessories are included in the dry weight, as your file shows.

However there are other accessories related to aircraft functions are are pre-installed on the engine to simplify assembly. These are ignored in dry weight. I am pretty sure on that.

[zwz]

Dry weight is just weight of engine without fluids. But definitely include accessories. For example, F110-400 difference between dry weight and wet weight is less than 100 lbs.

F110-400 dry weight: 4,494 lbs, wet weight: 4,592 lbs.

He is correct, at least from China's military standard:

[disconnectedradical]

What does a Chinese publication have anything to do with this?

Also one of the forum members here, f119doctor who actually worked on the F119 says that it weighs about 5,000lbs, and it also matches up with P&W’s statement that the F135 weighs about 1,500lbs more, and that engine weighs 6,422 lbs.