Ask anything Thread


Ashbringer_NEU

New Member
Registered Member
I find this statement unusual to say the least, and question its veracity, please post a link authenticating this statement. That is a rather bizarre proposition, to carry an external load that prohibits full control movement is simply not SOP? its just not, so please verify this statement with a credible link or withdraw it? Thanks Brat

Looks like Bro Kwai has already addressed this error of the Bro? Ashbringer, I can state with absolute certainty that is a "krock", simply NOT true, and rather than discuss your statement, it should be corrected by you sir. There are a lot of unreliable posts on the internet, whoever proposed such non-sense is def not a reliable source.
[/QUOTE]




Thanks bro, I admit that I should be more cautious when I claimed my first statement about flaps, I read the issue on a website which I thought was usually reliable, and I directly believe it, I'd like to apologize for the situation it caused, it is my fault.

Like I said before, I am not a pilot or engineer in relative divisions, so I usually learn these military information from from websites, and I tried to choose the most trustworthy information, but from the pictures and analysis you guys replied me, I think the flaps' issue maybe not true, I mean from those pictures the distance between flaps and missiles seems long enough, and yes like you said, it is hard to believe that a multifunctional fighter will have such issue. I will see if I can contact the editor of my picture, and ask him about his conclusion. I do not want to stir up dispute, I just want to know how he get his conclusion.

Again, I apologize for my hasty statement.
 

Ashbringer_NEU

New Member
Registered Member
By the way, from all these pictures, C-802 missiles is larger and longer than fuel tanks, C-802's tail has passed the wings, and from my pictures, It seems that JF-17's flaps had touch missiles. I don't know, it maybe the problem of angle.......
 

SinoSoldier

Colonel
By the way, from all these pictures, C-802 missiles is larger and longer than fuel tanks, C-802's tail has passed the wings, and from my pictures, It seems that JF-17's flaps had touch missiles. I don't know, it maybe the problem of angle.......
If you take a planar view of the JF-17, it's quite apparent that the hardpoints hold the fuel tank and missiles well below the airfoils as to allow the flaps to move.
 

Air Force Brat

Brigadier
Super Moderator
I really don't get that part. Max flap extension will, I'm quiet certain, only happen during final approach & landing. And post #2042 shows flaps deployed with these missiles loaded in what appears to me to be an approach set-up.
The "Maneuver" setting of slats/flaps normally sees them least extended of all the possible settings anyway. And with most of the external load attached to the wings, a theoretical high lift situation produced by a full flap extension will not make the wings rip off. Since all the forces act on the wing directly, and do not go through the wing / fuselage joint. If at all, the weapon mounts holdeng the missiles will fail structurally.
That is why heavy loads are normalle better placed under the wings. If placed under the fuselge, then all the stress of high wing lift vs. heavy fuselage momentum will go through the wing mounts.
Wolfie and Master Scratch, what are you talking about, you are both propagating inaccurate data gentlemen, and master scratch, I am quite tickled to find you really are human, and not some all knowing alien droid???

Trailing edge flaps are not deployed during ACM, any time an aircraft is subject to Gs those are stowed in their fully retracted position. They might possibly be deployed in very low speed or post stall maneuvering by the FCS, but not to enhance the maneuverability of an aircraft in a high speed, high energy furball??? Leading edge slats on the other hand are designed to automatically deploy when needed.

On a more serious note master Scratch, all loads carried by the wings are passed through to the wing attach and carry through spar to which both right and left wings are attached. This is the primary carry through structure that "carries" those loads to the fuselage, spreading them throughout the aircraft structure. In fact all loads "carried" by the wing are concentrated there at the wing attach point. The horizontal stabs, stabilators or ruddervators are also subject to similar loads at their attach points.

As an illustration, C-130s used in SEA and flown into and out of "assault strips" were subject to a lot of "wing box" failures, in fact we lost an aircraft and crew at LRAFB due to catastrophic failure of the wing box and separation in flight. They were practicing "stalls", and likely did have the flaps deployed, which in fact does increase the load on the wing box.

as to your theory on why aircraft carry external load on wings rather than the fuselage, that too is in error, in fact loads on the wings subject the wing attach point to significantly increased loads due to the longer moment arm carried to the attach point by the wing spar and structure acting as a lever. Stores carried under the belly do not subject the wing attach points to those significantly increased loads only the normal load.

That's why the "legendary A-10 was in the process of being re-winged with heavier wing skins and a heavier wing box carry through structure, those stores exert a tremendous bending moment on the "wing box" with any maneuvering.
 

[email protected]

Junior Member
Registered Member
Hi
The Chinese in this picture said :"As a light fighter, Anti-ground and anti-ship missiles are always too big for JF-17, it's flaps cannot down completely when it is carrying C-802AKG" (sorry my English is not so good, but the meaning of sentence is kind of like that...)

As far as I know, this "出鞘 Chuqiao" program is written by a famous and trustworthy Chinese military fan, his conclusions and intelligence are usually correct.
below pic show completely down flap with C-802 on-board, hope this will clear your doubts ....

regards,
KkgnN.jpg
 

delft

Brigadier
Wolfie and Master Scratch, what are you talking about, you are both propagating inaccurate data gentlemen, and master scratch, I am quite tickled to find you really are human, and not some all knowing alien droid???

Trailing edge flaps are not deployed during ACM, any time an aircraft is subject to Gs those are stowed in their fully retracted position. They might possibly be deployed in very low speed or post stall maneuvering by the FCS, but not to enhance the maneuverability of an aircraft in a high speed, high energy furball??? Leading edge slats on the other hand are designed to automatically deploy when needed.

On a more serious note master Scratch, all loads carried by the wings are passed through to the wing attach and carry through spar to which both right and left wings are attached. This is the primary carry through structure that "carries" those loads to the fuselage, spreading them throughout the aircraft structure. In fact all loads "carried" by the wing are concentrated there at the wing attach point. The horizontal stabs, stabilators or ruddervators are also subject to similar loads at their attach points.

As an illustration, C-130s used in SEA and flown into and out of "assault strips" were subject to a lot of "wing box" failures, in fact we lost an aircraft and crew at LRAFB due to catastrophic failure of the wing box and separation in flight. They were practicing "stalls", and likely did have the flaps deployed, which in fact does increase the load on the wing box.

as to your theory on why aircraft carry external load on wings rather than the fuselage, that too is in error, in fact loads on the wings subject the wing attach point to significantly increased loads due to the longer moment arm carried to the attach point by the wing spar and structure acting as a lever. Stores carried under the belly do not subject the wing attach points to those significantly increased loads only the normal load.

That's why the "legendary A-10 was in the process of being re-winged with heavier wing skins and a heavier wing box carry through structure, those stores exert a tremendous bending moment on the "wing box" with any maneuvering.
Additional information:
The wing box is often called the torsion box as a wing often experiences torsion and the wing box is the construction part that is particularly suited to carry such loads. You can easily see that at the same aircraft weight and during a similar maneuver the load on the wing moves aft when you deploy flaps and you increase thus the torsion load on the wing box.
In most aircraft most of the weight is carried by the wing. Engines hung on the wing, fuel in the wing and stores on the wing reduce the bending load at the wing root compared with aircraft were all the things are carried in the fuselage. ( Engines hung in front of the wing box, as in very many transport type aircraft, reduce the torsion in the wing box, which is also very valuable ). But with combat aircraft during manoevres things can be much more complicated. And such aircraft as J-20 generate a large part of the lift force with the fuselage.
 

Scratch

Captain
Trailing edge flaps are not deployed during ACM, any time an aircraft is subject to Gs those are stowed in their fully retracted position. They might possibly be deployed in very low speed or post stall maneuvering by the FCS, but not to enhance the maneuverability of an aircraft in a high speed, high energy furball??? Leading edge slats on the other hand are designed to automatically deploy when needed.
I will have to admit that I made a rather narrow sighted statement here, but can still say that I wasn't wrong per se. I was simply again sitting in a PANAVIA TORNADO then, were there is a "maneuver flap setting", in which slats and flaps deploy just partially. Less then in the "mid" of "full" setting.
Of course deploying flaps during high speed will subject the wing / jet to very high loads, nose pitch down and what not. However, a TORNADO is pretty much anything but an energy fighter, and in a tight turn will bleed speed really fast. As such you'll need to bring the wings full forward when decelerating through a certain speed, and then deploy maneuver flaps to continue turing min circle at rather low speeds.

It is the same with the F-14 that could extent slats 7° and flaps 10° in a maneuver setting when under a certain speed (that varried with altitude).
And perhaps also on MiG-23 (type) aircraft, with a very similar wing config.

On other types with all the different delta or maybe diamond setups, that may be or is a different story.

On a more serious note master Scratch, all loads carried by the wings are passed through to the wing attach and carry through spar to which both right and left wings are attached. This is the primary carry through structure that "carries" those loads to the fuselage, spreading them throughout the aircraft structure. In fact all loads "carried" by the wing are concentrated there at the wing attach point. The horizontal stabs, stabilators or ruddervators are also subject to similar loads at their attach points.

as to your theory on why aircraft carry external load on wings rather than the fuselage, that too is in error, in fact loads on the wings subject the wing attach point to significantly increased loads due to the longer moment arm carried to the attach point by the wing spar and structure acting as a lever. Stores carried under the belly do not subject the wing attach points to those significantly increased loads only the normal load.

That's why the "legendary A-10 was in the process of being re-winged with heavier wing skins and a heavier wing box carry through structure, those stores exert a tremendous bending moment on the "wing box" with any maneuvering.
I think here you're missing my point a little with your rebuttle.

Of course all the loads acting on the wing will eventually go throug the wing attach. But for wing carried stores there's going to be less. Let me state my point differently:
On a wing, the resultant force is lift, pulling up. On the fuselage, the resultant force is weight, pulling down.
In a very much simplified configuration, the wing creates the lift, the fuselage adds the weight. Generally, they need to be in equilibrium. The weigh (centered in the fuselage) pulls down with, say, 10t. Therefore wing lift needs to pull up with 10t. These opposing forces "meet" at the attach, creating a repsective stress here. If 2t are taken from the fuselage and moved to the wing, there's still 10t of lift, but also 2t of weight. The resultant force on the wing are 8t of lift. That is opposed by now only 8t of weight in the fuselage. Now the stress on the attach by the opposing forces, according to the forces diagram, is less.



Modern fighters indeed do produce a lot of lift on the fuselage, allevating that stress on the wing mount. Then again, with internal weapon bays, they also carry more weight there.
On the other hand, there's examples of civillian jets having wingtip mouted fuel tanks to ease the issue described above.

The thing is, for an airplane, the standart condition is flight, were the wings are bent up by lift. And not bent down when sitting on the ground.
 

Air Force Brat

Brigadier
Super Moderator
I will have to admit that I made a rather narrow sighted statement here, but can still say that I wasn't wrong per se. I was simply again sitting in a PANAVIA TORNADO then, were there is a "maneuver flap setting", in which slats and flaps deploy just partially. Less then in the "mid" of "full" setting.
Of course deploying flaps during high speed will subject the wing / jet to very high loads, nose pitch down and what not. However, a TORNADO is pretty much anything but an energy fighter, and in a tight turn will bleed speed really fast. As such you'll need to bring the wings full forward when decelerating through a certain speed, and then deploy maneuver flaps to continue turing min circle at rather low speeds.

It is the same with the F-14 that could extent slats 7° and flaps 10° in a maneuver setting when under a certain speed (that varried with altitude).
And perhaps also on MiG-23 (type) aircraft, with a very similar wing config.

On other types with all the different delta or maybe diamond setups, that may be or is a different story.



I think here you're missing my point a little with your rebuttle.

Of course all the loads acting on the wing will eventually go throug the wing attach. But for wing carried stores there's going to be less. Let me state my point differently:
On a wing, the resultant force is lift, pulling up. On the fuselage, the resultant force is weight, pulling down.
In a very much simplified configuration, the wing creates the lift, the fuselage adds the weight. Generally, they need to be in equilibrium. The weigh (centered in the fuselage) pulls down with, say, 10t. Therefore wing lift needs to pull up with 10t. These opposing forces "meet" at the attach, creating a repsective stress here. If 2t are taken from the fuselage and moved to the wing, there's still 10t of lift, but also 2t of weight. The resultant force on the wing are 8t of lift. That is opposed by now only 8t of weight in the fuselage. Now the stress on the attach by the opposing forces, according to the forces diagram, is less.



Modern fighters indeed do produce a lot of lift on the fuselage, allevating that stress on the wing mount. Then again, with internal weapon bays, they also carry more weight there.
On the other hand, there's examples of civillian jets having wingtip mouted fuel tanks to ease the issue described above.

The thing is, for an airplane, the standart condition is flight, were the wings are bent up by lift. And not bent down when sitting on the ground.
Heh, Heh, Heh!, now that was FUN, (for me, college boy), I couldn't resist the opportunity to ding you a little, (let me say, I really missed you bruda, and I am so happy that you and bd popeye are back aboard the good ship Lolli-Pop), where you both belong.

Master Delft helps your case considerably, (yes, he is a real engineer), when he makes a very similar point, and your own military experience gives you some bonus points as well, however, of course as a pilot, I have been there and done that, (yes, I am just a private pilot), and I have to look at the big picture. I have also removed/replaced/trimmed a few wings on GA aircraft, (on high wing Cessna's there is an off camber bolt at the front/main spar, and also one at the rear/secondary spar, between those two off camber bolts one is able to adjust each wings incidence, both left and right.) They are used to achieve primary trim of the aircraft in flight, secondary or fine tuning may be accomplished with rigging the flaps and ailerons, I only add these details to illustrate that I have some very real world experience/practical knowledge both as a pilot and mechanic, and also few hours in a Mitsubishi Mu-2k, where if I'm not mistaken, the tip tanks function as the Mains? I love the looks of tip tanks, hate what they do to the flying qualities, particularly if fuel flows leave one heavy, and the other light, they are used when there is not sufficient room in the wing for internal tanks, fuel is much safer in the wing than in the cabin in the event of a forced landing/crash, and aside from safety, it frees the cabin up or passengers/cargo.

In any respect external loads whether tips, engines, landing gear or ordinance increase the load/bending moments applied at the wing root junction to the fuselage, ie attach points, the wingbox/torsion box/torque box, whatever you choose to call it, distributes those loads to the primary structure of the aircraft.

As to maneuvering flaps you are of course correct, but as I pointed out, they are ONLY used at relatively low airspeeds, and they most certainly induce very high loads on the wing/root juncture. I would point to two heartbreaking videos, one of a C-130A used as an airtanker, two of a Partenavia used as an airshow aircraft, both aircraft, loose both wings at the root due to high g loads as the aircraft are being pitched up, the wings fail upward as the fuselage continues to travel forward, resisting the upward pitching moment.
 

Victor1985

New Member
Registered Member
i have a simple question, suppose we have a radar antenna any kind you want and we have 3 radar waves that are hitting the antenna each at different angles, waves may have or not same frenquency, question being those 3 waves will give in the antenna 3 different signals (phase difference) because of the different angles of hit?
 

Top