How come AIM-120 on the tips?

Now that we have the official F-16 forum, Ill pop my cherry with this question:

What is the reason behind AIM-120's on the wingtips, and usually AIM-9's on a wing station?

Id imagine the opposite was preferred, since all other air frames do so?

to keep wings alive longer.

Having 120's on the tips serves two purposes in that it increases the F-16's already impressive roll rate and having the weight of the 120's on the tips reduces wing tip flutter and reduces stress from flutter vibration.

The typical response is to help with wing oscillation that happens at certain speeds and AOA on the F-16. I never seen an official explanation. Meaning I never seen a manual break it down.

Interesting enough, Any missile on the wing tips (AIM9 or 120) is consider a no drag penalty. Also the launcher have to be installed that is why even the USAF Thunderbird still carry the launcher.

Much obliged :thumbup:

to keep wings alive longer.

May have been the intended reasoning way back when. However, not entirely true anymore, the added weight (vs AIM9 or nothing) is causing some issues.

That being said, I haven't seen any photo of F-16 carrying both AIM-120 and AIM-9, where Sidewinders would be on the tips.

Panther, I was about to say the same thing. It’s been adding more stress to the wings and causing problems for sure. Can’t tell you how many times I had to grab a C-1 stand and tighten screws to stop a fuel leak on a go.

AMEDooley there are reports of cracking out there too, but I’ve tighten the horizontal bolts more times than I dare to count.

What kind of damage does flutter create vs the increased stress? i.e. which is worse to deal with?

Structural fatigue which leads to leaking fuel tank, potential for cracking and complete structural failure.

So its probably better to have something heavy on the tips then not, to cut down on that.

In Flacon4 the pylon for the 120 caused more drag than the pylon for the AIM9 so I always put the 120 on the wingtips.

I'm not sure of the validity of this.

So its probably better to have something heavy on the tips then not, to cut down on that.

Problem is the weight is causing the same problems.

Having 120's on the tips serves two purposes in that it increases the F-16's already impressive roll rate.....

You'll have to explain this one to me. I just assume that the -120's weigh a considerable bit more than the -9's. If that assumption is true, I don't understand how you can come up with the notion that having more weight out on the wing tips will give you a higher roll rate. Being an old helicopter pilot, I have grown up with the example of the figure skater speeding up their rate of spin by bringing their arms into the center of rotation and slowing the spin down by extending them. what am I missing with the case of the AIM-120's??

What kind of damage does flutter create vs the increased stress?

I can tell you about what happens if you load the A-2000 (IRIS-T) missiles to the wingtips..: flutter forces will brake missile's wings. So A-2000 is certified to load only on stations 2/8 and 3/7.

Not 100% sure but I believe there is a similar limit for AIM-9X on the wigntips.

There are a couple only public photos of these loads in the wingtips, these are old and before newer tests and documented limitations.

Just for visual reference, here's the "flutter" everyone is talking about:

1DK-zGLK6GQ

AMEDooley there are reports of cracking out there too, but I’ve tighten the horizontal bolts more times than I dare to count.

Yeah, that makes us weapons troops have to pull the -129 off cuz the fuel eats thru stuff!

Just for visual reference, here's the "flutter" everyone is talking about:

 

1DK-zGLK6GQ

Wow, I had never seen nor heard of this issue with the F-16. I always assumed they carried 9s on the wingtips like everyone else. Quite an interesting little flaw there.

YO PANTHER! Hope all is well with you and yours girl!

The answer to your question is here. ( by a real fighterpilot )

YO PANTHER! Hope all is well with you and yours girl!

What's up Wicked? All is well here, excited to see the Viper is happening. :pilotfly:

Panther, I was about to say the same thing. It’s been adding more stress to the wings and causing problems for sure. Can’t tell you how many times I had to grab a C-1 stand and tighten screws to stop a fuel leak on a go.

AMEDooley there are reports of cracking out there too, but I’ve tighten the horizontal bolts more times than I dare to count.

It was doing that before they carried the -120 on station 1 and 9. I did that once a week on Luke in the late 90 with a impact driver and a hammer. Until we dip the screws, I think we use B1/2.

Thanks neutchain, very informative. I hope ED takes that into account and won't allow the AIM-120 to be loaded on stations 1 and 9.

Why would they do that when -120s on stations 1 and 9 are operationally approved and used?