Separate jettison of external tanks

Hey guys,

A little problem and hopefully someone can help me.

Is it possible, and if yes, how, to jettison the centerline and the two wing tanks separately?

Yesterday we flew a short mission in our squadron and I accidently dropped all my fuel tanks - thankfully there was still enough fuel to reach the next airbase :D

Thanks!

kreisch

Officially, No.

I don't think you can. You were suppose to bring them back as they are expensive and in case of emergency/dogfight you drop them all.

Also they are pretty aerodynamically so you have no problem with flying with them empty. The big ones under the wings look badass also... like boosters... too bad they eat two big missiles.

Officially, No.

 

:D

I doubt you'd be able to do that with empty underwing tanks ...

I doubt you'd be able to do that with empty underwing tanks ...

Why not, manual states that as long as you got A-G weaponry, full centerline fuel tank, or wing fuel tanks (full or empty), you need to be in Reduced gain FBW. Apparently they are heavy enough (even empty) for the pylon locks to drop them off in case of over G.

Not that one should ever do this. Talking about abuse!

Why not, manual states that as long as you got A-G weaponry, full centerline fuel tank, or wing fuel tanks (full or empty), you need to be in Reduced gain FBW. Apparently they are heavy enough (even empty) for the pylon locks to drop them off in case of over G.

I haven't been able to drop an empty centerline tank with FBW set to AA just by pulling high G's...

haven't tried it with empty wingtanks though

I have got a mirage with all tanks currently on autopilot burning fuel and dumping it, when the wingtanks are empty I will test it again. Should be about 12 minutes.

Would be interesting to see if it reacts the same. Although it wouldn't matter much. since the centertank is drained before the wingtanks, so there would not be any point in dropping the (empty) wingtanks and keeping the center tank, that is already drained.

*edit*

I don't think you can. You were suppose to bring them back as they are expensive and in case of emergency/dogfight you drop them all.

 

Also they are pretty aerodynamically so you have no problem with flying with them empty. The big ones under the wings look badass also... like boosters... too bad they eat two big missiles.

Okay, thanks!

Here's how I drop the centreline tank.

I haven't been able to drop an empty centerline tank with FBW set to AA just by pulling high G's...

haven't tried it with empty wingtanks though

Yes, empty centerline fuel tank is permitted for A-A, so that is correct. But empty/full wing tanks is another story.

MiG-21Bis has the same ordnung with respect to what fuel tanks are permitted for up to and above 9G. Most fighter jets (if not all) do it this way.

In short: (A-G FBW = read reduced gain in FBW)

Full centerline tank -> A-G FBW (6.5G max)

Empty centerline tank -> A-A FBW (9G+)

===========================

Full wing tanks -> A-G FBW (6.5G max)

Empty wing tanks -> A-G FBW (6.5G max)

edit*

. Same result as with full ones.

And that is in accordance to the manual specifications.

Specifications are one thing, operations another. If the tanks don't break the plane I'm sure the mechanics will break your legs. And if they don't... you will be grounded anyway. :D

Many things can go wrong while jettisoning stuff normally. Trying to make things break off the wings by violence when you can simply push a button is madness.

If your life depends on the 9g turns you can do without the wing fuel tanks your life doesn't depend on the fuel you still got in the center one. Press the big round black/yellow striped button because that's its role. It keeps the IR missiles for this purpose only. Dispatch the threat with internal fuel then either refuel with the tanker or go towards friendlies and eject as close as possible to a safe zone if making to the base is not possible.

Anything else is just GTA stunts.

Specifications are one thing, operations another. If the tanks don't break the plane I'm sure the mechanics will break your legs. And if they don't... you will be grounded anyway. :D

 

Many things can go wrong while jettisoning stuff normally. Trying to make things break off the wings by violence when you can simply push a button is madness.

 

If your life depends on the 9g turns you can do without the wing fuel tanks your life doesn't depend on the fuel you still got in the center one. Press the big round black/yellow striped button because that's its role. It keeps the IR missiles for this purpose only. Dispatch the threat with internal fuel then either refuel with the tanker or go towards friendlies and eject as close as possible to a safe zone if making to the base is not possible.

 

Anything else is just GTA stunts.

It will never break your plane, there is a mechanism that is supposed to drop the load in the event of too much weight on the pylon (read too high G with given weapon on that pylon) as to prevent any aircraft damage. I`m not saying that is how you should do it, but the system is there for a reason. If you were "sleeping" while searching for the bandit, and he suddenly pops up on your mirror lining up for a shot, you would be clever to manoeuvre first, then drop things later, instead of remaining a straight flying target for just that second longer ;)

Talking realism all the way, stunts are for hollywood guys.

Even in DCS as we can see in the first movie posted in second post the tanks are not separating instantly, always nor both at the same time.

The mess you would be with just one tank under one of your wings would be far greater than the one you describe above with sudden enemy in your close six ready to gun you WW2 style. Just wait until the physics of max performance 9G turn with one single tank under a wing will be simulated in DCS M2K and we can discuss that scenario again :D .

Even in DCS as we can see in the first movie posted in second post the tanks are not separating instantly, always nor both at the same time.

The mess you would be with just one tank under one of your wings would be far greater than the one you describe above with sudden enemy in your close six ready to gun you WW2 style. Just wait until the physics of max performance 9G turn with one single tank under a wing will be simulated in DCS M2K and we can discuss that scenario again :D .

Imbalance sure, but certainly not until the point of damaging it. Same as with uneven load. The only reason it`s not recommended on some aircraft (like MiG-21) is that it demands much stick work to make the aircraft do what you want. You lose much manoeuvrability as well as landing, potentially having to drop load out before landing. Nevertheless, auto drop is there to prevent plane damage. On too much pylon weight, it will detach. I really cannot find anything "more" stressful on the airframe about it, than flying with uneven armament... :)

If you were "sleeping" while searching for the bandit, and he suddenly pops up on your mirror lining up for a shot, you would be clever to manoeuvre first, then drop things later, instead of remaining a straight flying target for just that second longer ;)

Indeed. And as you would have used the "Charges" mode of the FBW, you'd be limited to a load factor of +5.5g, thus keeping your tanks attached :)

The ability to select which tank to jettison (i.e. centre one or wing ones) was introduced on the 2000-5. It is not available on the C.

The "break point" of the pylons (certainly NOT an auto-drop feature per se) is a last resort thing, not to be used intentionnally.

Indeed. And as you would have used the "Charges" mode of the FBW, you'd be limited to a load factor of +5.5g, thus keeping your tanks attached :)

 

The ability to select which tank to jettison (i.e. centre one or wing ones) was introduced on the 2000-5. It is not available on the C.

 

The "break point" of the pylons (certainly NOT an auto-drop feature per se) is a last resort thing, not to be used intentionnally.

Oh I agree with that, certainly nothing to use intentionally ;)

TBH I`m not sure if it`s braking the pylon, or the locking mechanism just let`s go due to high G? Any clue on this?

Oh I agree with that, certainly nothing to use intentionally ;)

 

TBH I`m not sure if it`s braking the pylon, or the locking mechanism just let`s go due to high G? Any clue on this?

So you disagree with the fact you would be able to pull only 5.5G? :D

The switch is just near that big jettison all button... For your safety... after flipping the switch... while jinxing graciously, sure... press that button. Real physics is not limited to few aspects like a simulation.

look:

As I told you. One tank left on one wing or stuck on only one lock while turning and destroying your plane is a far worse situation you've put yourself in than the fact you let one bandit sneak behind you for a sneaky gunkill.

So you disagree with the fact you would be able to pull only 5.5G? :D

 

The switch is just near that big jettison all button... For your safety... after flipping the switch... while jinxing graciously, sure... press that button. Real physics is not limited to few aspects like a simulation.

 

look:

 

 

As I told you. One tank left on one wing or stuck on only one lock while turning and destroying your plane is a far worse situation you've put yourself in than the fact you let one bandit sneak behind you for a sneaky gunkill.

Well, I would agree that you would be able to pull only 6.5G, as that is the absolute max that A-G FBW let`s you pull :lol:

But on a serious side of things, remember that if you lose the tank by pulling hard (A-A FBW), then such collision cannot happen, as you are pulling away from the tank at all the time. If you release the tank at any instance, it will depart in a different direction. Again, this is more a safety measure by producers of all aircraft, rather than a "how-to-do-it" procedure.

Interesting video, it seems to be showing some older type of fuel tanks, and if I interpret it right, design phase (otherwise why would there be chase aircraft filming it?). Seems like they got problems with the hinges though, in all of these cases the tank is left locked on one hinge. Interesting how a detached tank can dive a bit, then back up and hit the aircraft (barely losing airspeed) :joystick:

Yes the video shows older type of fuel tanks or ordnance but the idea is simple. The test pilots test the envelope of the aircraft for all operations. Then the real life experience adds and rules for operating the aircraft are written and amended.

But, if we already have a lot of experience about bad separation from aircraft of payloads in normal situations... why would we risk our life in an abnormal situation?

If we are limited to 5.5G with tanks, flipping the limiter to A/A mode just to be able to pull maximum Gs and not pressing the nearby Jettison All button makes little sense.

I don't know exactly how they are locked to the wing but imagine it has more than one locking system and the tank ruptures one lock and remains attached to the other and because of the turn it twists and hits the wing. Just one tank. Now you have a dangling tank, a damage/bent wing and asymmetric load. Imagine how hard the guy in the back that is trying to shoot you down is laughing :D .

Yes the video shows older type of fuel tanks or ordnance but the idea is simple. The test pilots test the envelope of the aircraft for all operations. Then the real life experience adds and rules for operating the aircraft are written and amended.

 

But, if we already have a lot of experience about bad separation from aircraft of payloads in normal situations... why would we risk our life in an abnormal situation?

 

If we are limited to 5.5G with tanks, flipping the limiter to A/A mode just to be able to pull maximum Gs and not pressing the nearby Jettison All button makes little sense.

 

I don't know exactly how they are locked to the wing but imagine it has more than one locking system and the tank ruptures one lock and remains attached to the other and because of the turn it twists and hits the wing. Just one tank. Now you have a dangling tank, a damage/bent wing and asymmetric load. Imagine how hard the guy in the back that is trying to shoot you down is laughing :D .

Well at the end of the day, we are talking about pilot getting stressed, or whatever it takes to forget this hehe. I wouldn`t do this at all tbh. But sure, I would agree with you to reduce risks to a minimum wherever possible.