Author Topic: The F35  (Read 678 times)

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Offline wilber

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Re: The F35
« Reply #60 on: June 19, 2019, 02:00:54 pm »
notwithstanding those NATO allies that don't have any intention of purchasing the F-35, presuming on the longer-term intentions of key NATO allies is particularly suspect... as in the recent pronouncements from France, Germany... and now Spain (formally announced at the recent Paris Air Show:

of course the British have their own 'Tempest' plan... what's wrong with all those Euro's... just why would they doubt the F-35?

on edit: can't forget Turkey's plan (since it was ousted from the F-35 program):

The Tempest is a 6th Generation concept at the moment, a step beyond the F-35 to be capable of manned and unmanned missions depending on the requirement. BAE is looking for a partner, it won't be viable without export customers.
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Offline wilber

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Re: The F35
« Reply #61 on: June 19, 2019, 03:33:57 pm »
The way I understand it, wings also contribute to parasitic drag. How they are configure to create lift is the lift induced drag. Wings do not always present the same drag, and by lowering the weight you can reduce that drag.

Lift producing drag is induced drag. Lowering the weight will reduce the angle of attack required to produce the required lift and consequently the wings frontal area which does reduce drag somewhat. Increasing speed will also reduce the angle of attack required. Leading edge flaps/slats and trailing edge flaps increase the wing's area and have the effect of increasing its chord (width) and camber (thickness) but the increased drag is still induced because it is increasing lift. Parasite drag from non lift producing surfaces contribute nothing. Drag increases as the square of the speed so fuel tanks and weapons hanging under an aircraft will produce four times as much drag at 400 Kts than at 200 Kts. Once the aircraft is at cruising speed it will take pure power to overcome that increased drag whereas internal fuel and weapons will have much less effect on the power required to maintain speed.
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Offline ?Impact

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Re: The F35
« Reply #62 on: June 19, 2019, 04:18:33 pm »
Once the aircraft is at cruising speed it will take pure power to overcome that increased drag whereas internal fuel and weapons will have much less effect on the power required to maintain speed.

Agreed, but the question is how much less. Two other items to note:

1. The body of the aircraft with internal bays will be larger, thus increasing overall drag.

2. A plane that drops external fuel tanks and weapons will decrease drag giving it an advantage on the return half of the flight.

Offline Omni

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Re: The F35
« Reply #63 on: June 19, 2019, 04:31:13 pm »
Agreed, but the question is how much less. Two other items to note:

1. The body of the aircraft with internal bays will be larger, thus increasing overall drag.

2. A plane that drops external fuel tanks and weapons will decrease drag giving it an advantage on the return half of the flight.

You can shape a fuselage to provide to lift. Fuel tanks and such hanging under wing can also be aerodynamically designed but they are still essentially parasite drag.

Offline wilber

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Re: The F35
« Reply #64 on: June 19, 2019, 04:36:17 pm »
Agreed, but the question is how much less. Two other items to note:

1. The body of the aircraft with internal bays will be larger, thus increasing overall drag.

2. A plane that drops external fuel tanks and weapons will decrease drag giving it an advantage on the return half of the flight.

Most of the fuel is carried in the wing, not the fuselage. Yes an aircraft with internal bays may have a larger fuselage but fuselages can also be designed to provide some lift (lifting bodies) and much less drag than external loads. Think loaded roof rack vs a larger trunk on your car.
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Offline segnosaur

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Re: The F35
« Reply #65 on: June 24, 2019, 11:10:32 am »
...Two other items to note:
...
2. A plane that drops external fuel tanks and weapons will decrease drag giving it an advantage on the return half of the flight.
There are 3 problems with that suggestion:

- Planes do not always drop all of their weapons during missions. For example, planes on an air-to-air mission may not need to fire their missiles if they do not encounter any opposing fighters. And planes may not drop bombs if the details of a mission changes (such as "The target was misidentified" or "There is too much risk of civilian casualties"). In those cases, a plane with its weapons held externally will have to deal with the extra parasitic drag throughout the entire mission

- Not all items carried externally can easily be dropped. For example, sometimes planes will carry special pods with electronics providing improved communications or sensors. Because many 4th generation fighters were not designed with the same avionics that the F35 was, they will probably need such pods more often

- Even in situations where a plane DOES use all its weapons... being in a 'clean' configuration on the way back isn't as useful as being clean before hand. You want the extra speed and efficiency at the start of the mission (when you have targets to hit) just as much, if not more, than when you've deployed your weapons.

Offline wilber

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Re: The F35
« Reply #66 on: June 24, 2019, 01:10:20 pm »
Aircraft that are patrolling won't drop anything if they don't have to.That stuff isn't cheap.
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Offline segnosaur

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Re: The F35
« Reply #67 on: June 26, 2019, 10:33:54 am »
A couple of new developments regarding the F-35:

First of all, they have been used in actual operations by Britain for the first time.

From: https://www.telegraph.co.uk/news/2019/06/24/britains-new-f35-stealth-jets-used-operations-first-time/
The first operational sorties were flown on June 16 from RAF Akrotiri in Cyprus, targeting the last remnants of the Islamic State of Iraq and the Levant (Isil)

Note that the planes didn't actually use any of their weapons, but then neither did other planes that were deployed in the same environment. Still, that's 3 different countries (after Israel and the U.S.) who have actually used their F-35s in 'real world' situations.

And it looks like the F-35 is due for some new upgrades. These include:
- New cockpit displays
- Improved computers
- The ability to carry external fuel tanks
- Support for new weapons (Meteor missile, Stormbreaker bomb, Joint Strike Missile, etc.)
- Electronic warfare upgrades (better detection and jamming abilities)
- A 'ground collision avoidance system', so if a pilot becomes disoriented the plane will keep from crashing
- Support to help detect and shoot down ballistic missiles
(https://www.popularmechanics.com/military/weapons/a28087978/f-35-new-features/)

These sorts of upgrades were expected, and supposedly one of the selling points of the F-35 was the ease of doing these sorts of changes.


Offline wilber

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Re: The F35
« Reply #68 on: June 26, 2019, 12:35:02 pm »
The RAF F-35's used in Cyprus were also F-35B,  STOVL versions.
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Offline wilber

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Re: The F35
« Reply #69 on: June 26, 2019, 12:51:53 pm »
Interesting that the first RAF squadron to operate the F-35 is 617, the Dambusters of WW2.

https://en.wikipedia.org/wiki/Operation_Chastise
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Offline waldo

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Re: The F35
« Reply #70 on: June 26, 2019, 07:08:07 pm »
These sorts of upgrades were expected, and supposedly one of the selling points of the F-35 was the ease of doing these sorts of changes.

magic 'future' beans won't get rid of the current problems! Highlights from the latest Pentagon Director, Operational Test & Evaluation (DOT&E) annual report:


Offline waldo

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Re: The F35
« Reply #71 on: June 27, 2019, 12:28:56 am »
And it looks like the F-35 is due for some new upgrades. These include:
- New cockpit displays
- Improved computers
- The ability to carry external fuel tanks
- Support for new weapons (Meteor missile, Stormbreaker bomb, Joint Strike Missile, etc.)
- Electronic warfare upgrades (better detection and jamming abilities)
- A 'ground collision avoidance system', so if a pilot becomes disoriented the plane will keep from crashing
- Support to help detect and shoot down ballistic missiles
(https://www.popularmechanics.com/military/weapons/a28087978/f-35-new-features/)

These sorts of upgrades were expected, and supposedly one of the selling points of the F-35 was the ease of doing these sorts of changes.

oh my! For these supposed upgrades, within what is referred to as "F-35 Block 4"... per the U.S. Government Accountability Office (GAO), no business case, no baseline cost, no scheduling estimate. I guess, after the decade+ F-35 debacle... go with what got you there/here!


Offline segnosaur

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Re: The F35
« Reply #72 on: June 27, 2019, 02:48:30 pm »
oh my! For these supposed upgrades, within what is referred to as "F-35 Block 4"... per the U.S. Government Accountability Office (GAO), no business case, no baseline cost, no scheduling estimate. I guess, after the decade+ F-35 debacle... go with what got you there/here!
Yes, there were management issues with the development of the F-35. And yes, there will probably be management issues in the future. Yes, there were excessive delays and in some cases cost over runs. It would have been great if they didn't have those problems, but its a big government project, and those are always going to have problems.

The important question though is not "what mistakes were made in the past", but "what is the plane like now/what can it achieve".

I would much rather have a plane that had dozens of delays and other problems but ended up being the best in its class, than a plane who's development went completely smoothly, but at the end of the day ended up with inferior performance/technology/etc.

I think the F-35 is a better plane than the Gripen/Super Hornet/etc. not because "gee wiz, its development went so smoothly" but because "This thing has some features that make it superior" (even if it was much later than expected).

Offline waldo

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Re: The F35
« Reply #73 on: June 27, 2019, 11:58:18 pm »
I would much rather have a plane that had dozens of delays and other problems but ended up being the best in its class, than a plane who's development went completely smoothly, but at the end of the day ended up with inferior performance/technology/etc.

I think the F-35 is a better plane than the Gripen/Super Hornet/etc. not because "gee wiz, its development went so smoothly" but because "This thing has some features that make it superior" (even if it was much later than expected).

your views on the F-35 can't be based on its current state. How can you ignore that last link to/extract summary from the Pentagon's DOT&E most recent annual report? Again, as below:
magic 'future' beans won't get rid of the current problems! Highlights from the latest Pentagon Director, Operational Test & Evaluation (DOT&E) annual report:



Offline segnosaur

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Re: The F35
« Reply #74 on: June 28, 2019, 11:47:36 am »
Quote
I think the F-35 is a better plane than the Gripen/Super Hornet/etc. not because "gee wiz, its development went so smoothly" but because "This thing has some features that make it superior" (even if it was much later than expected).
your views on the F-35 can't be based on its current state. How can you ignore that last link to/extract summary from the Pentagon's DOT&E most recent annual report? Again, as below:
I can say its better because:
- While it has problems, it has features that its competitors do not
- Its competitors often have problems of its own

For example, the Super Hornet has had to deal with problems with its air supply (https://www.navytimes.com/news/your-navy/2016/05/08/nothing-scares-hornet-pilots-more-than-losing-oxygen-and-it-happens-all-the-time/)