F-15E, what's going on with the top of the wing?

[mrvark]

What is going on with the top of the wing of this F-15E? If I was building a model and let too much liquid cement pool something like this might result! It looks like the surface is uneven, but I guess it could just be a really bad paint job. I had to degrade the picture a lot to stay within the submission constraints, if you want to see a MUCH better picture, check here.

[ST0RM]

Looks like accumulated dirt/oil from being at Bagram.

[A-10 LOADER]

13 minutes ago, ST0RM said:

Looks like accumulated dirt/oil from being at Bagram.

Exactly.

 

Steve

[airmechaja]

Looks like a reflection coming off of the canopy. The canopy looks like it's lit up from aft. Very weird...........

[mrvark]

Is there something in that area that results in a lot of foot traffic?

[ST0RM]

More likely the flap and aileron actuators leaking hydraulic fluid, which catches the blowing dirt/sand and accumulates.

[shion]

Already saw this discussion in the past.

 

A F-15E mechanic explained it:

 

Quote

My guess is that is a "wet wing "with sealant which covers each rivet and fastener inside the wing.

these rivets are seeping jet fuel.

Like any kerosene burner, tanks are pressurized with bleed air to reduce foaming in the fuel and ensuring positive pressure against the low presure pumps.

 

examples:

 

 

 

 

[USAFsparkchaser]

Something else I see cool with this top picture is asymmetrical missile loads. Is that a AIM-9X outboard 120 inboard on right wing and 9L inboard and 120 outboard on left wing. First I ever seen this. Yes I believe it is fuel leaks we are seeing. I just weather one of my E’s in this same area with browns to simulate sand blowing over the leaking.

[Falconxlvi]

Haha, that’s nothing- you should’ve seen some of our 389th jets after a dust storm hit Bagram back in the day.  They were absolutely filthy!   Anyways, leaky fluids mixing with dirt sure make for some interesting looking wings.   Here’s yours truly in the fall of 2011 over Afghanistan 

 

 

Edited January 12, 2019 by Falconxlvi

[pminer]

Hmmm.....I'm thinking initial ice formations...? Seems like dirt would impact lift and would be cleaned off before flight...especially on top of the wing. Ice may be a better explanation...

Or maybe a funky looking frost formation in the area of the fuel tanks.....

Edited January 12, 2019 by pminer

[bdt13]

9 minutes ago, pminer said:

Hmmm.....I'm thinking initial ice formations...?

That makes some sense. MD-80s has wing icing after landing on occasion from cold fuel condensing and freezing on the wings where the fuel had cold soaked during the flight. The "stuff," whatever it is, is at the outboard aft end of the tanks, which appears to be the lowest end of the wing tanks, so where the fuel would be the longest and most often. 

[Falconxlvi]

49 minutes ago, pminer said:

Hmmm.....I'm thinking initial ice formations...? Seems like dirt would impact lift and would be cleaned off before flight...especially on top of the wing. Ice may be a better explanation...

Or maybe a funky looking frost formation in the area of the fuel tanks.....

Dirt and dust weren’t cleaned off- it would usually just be a fine film at most anyways.  The jets would occasionally get a bath flying through a cloud or when it rained at Base X.  As for the pic in the OP,  It’s just leaky fuel- not frost or ice. 

[habu2]

You can see the sun reflections off the wet fuel streaming out of leaks in the wing tanks, it is following the airflow patterns.

[Falconxlvi]

Just now, habu2 said:

You can see the sun reflections off the wet fuel streaming out of leaks in the wing tanks, it is following the airflow patterns.

Yep 👍🏻 

[BoeingDriver]

F-15's leak fuel from the top of the wings when the wings are full.  I made the mistake of pulling a screw out one day from one that was leaking.

[BoeingDriver]

5 hours ago, pminer said:

Hmmm.....I'm thinking initial ice formations...? Seems like dirt would impact lift and would be cleaned off before flight...especially on top of the wing. Ice may be a better explanation...

Or maybe a funky looking frost formation in the area of the fuel tanks.....

It's not ice.

[11bee]

8 hours ago, USAFsparkchaser said:

Something else I see cool with this top picture is asymmetrical missile loads. Is that a AIM-9X outboard 120 inboard on right wing and 9L inboard and 120 outboard on left wing. First I ever seen this. Yes I believe it is fuel leaks we are seeing. I just weather one of my E’s in this same area with browns to simulate sand blowing over the leaking.

That's the third pic I've seen of recent jets deployed over there that are now toting AIM-9M’s.    Very unusual....  Never saw them mixed with 9X's prior to this. 

Edited January 13, 2019 by 11bee

[GW8345]

Just a note;

 

The AIM-9L has not been used by the US for about 20 years, that is a AIM-9M.

[Finn]

Here is another one but on the ground:

 

 

Jari

[11bee]

9 minutes ago, GW8345 said:

Just a note;

 

The AIM-9L has not been used by the US for about 20 years, that is a AIM-9M.

My observation remains though.  For quite some time, only saw X’s carried. Starting at some point last year, began to see mixed loads of mikes and xrays. Seems strange that in a potential combat zone, they would all of a sudden be using a supposedly less capable missile alongside the weapon that was to have replaced it.  

Edited January 13, 2019 by 11bee

[GW8345]

1 minute ago, 11bee said:

My bad..   my observation remains though.  For quite some time, only saw X’s carried. Starting at some point last year, began to see mixed loads of mikes and xrays. Seems strange that in a potential combat zone, they would all of a sudden be using a supposedly less capable missile alongside the weapon that was to have replaced it.  

One possible reason for carrying a -9M is why pop a costly -9X at a low value target such as a drone or a helo.

[shion]

4 hours ago, 11bee said:

My observation remains though.  For quite some time, only saw X’s carried. Starting at some point last year, began to see mixed loads of mikes and xrays. Seems strange that in a potential combat zone, they would all of a sudden be using a supposedly less capable missile alongside the weapon that was to have replaced it.  

IR missiles have a shelf life time and are surely a number of flights-limited, it seems wise to use old missiles before the others.

 

[11bee]

3 hours ago, shion said:

IR missiles have a shelf life time and are surely a number of flights-limited, it seems wise to use old missiles before the others.

 

Why would we use these old missiles In a theater (Iraq / Syria)  where there is always the very really chance of having to fight against a high end opponent?  If it's because we don't want to burn up limited flght time hours for the new missiles,  why not reserve all these old 9M's for 2nd line duties like US air defense missions?   Wasn't the AIM-9M replaced because it was found to be a big disadvantage compared to current Russian short range AAM's?  And now we are all of a sudden redeploying them in a combat zone where there is actually a chance of fighting against a top-line adversary?   You may very well be correct but it's worth inquiring about.....     

 

The 9X has been in service for over 15 years.   If anyone can find pics from earlier in it's service life that shows USAF aircraft on combat deployments carrying mixed loads of M's and X's on the same aircraft please let me know.   I've looked a bit and it seemed like this is a relatively recent phenomena which means something recently changed.   

 

Of course this is now where Finn shows up with 50 pics to prove me wrong!  :) 

Edited January 13, 2019 by 11bee

[11bee]

3 hours ago, shion said:

IR missiles have a shelf life time and are surely a number of flights-limited, it seems wise to use old missiles before the others.

 

So we tell Mr Eagle Driver that we want you to fly a mission over Syria where there is a demonstrated chance that you might be engaged in A2A combat but we're going to reduce your inventory of current generation short range A2A missiles by half because of cost considerations?     My god, if things are at that point, we need to get some more money to our cash-starved military.

[shion]

17 minutes ago, 11bee said:

Why would we use these old missiles In a theater (Iraq / Syria)  where there is always the very really chance of having to fight against a high end opponent?  If it's because we don't want to burn up limited flght time hours for the new missiles,  why not reserve all these old 9M's for 2nd line duties like US air defense missions?   Wasn't the AIM-9M replaced because it was found to be a big disadvantage compared to current Russian short range AAM's?  And now we are all of a sudden redeploying them in a combat zone where there is actually a chance of fighting against a top-line adversary?   You may very well be correct but it's worth inquiring about.....     

 

The 9X has been in service for over 15 years.   If anyone can find pics from earlier in it's service life that shows USAF aircraft on combat deployments carrying mixed loads of M's and X's on the same aircraft please let me know.   I've looked a bit and it seemed like this is a relatively recent phenomena which means something recently changed.   

 

Of course this is now where Finn shows up with 50 pics to prove me wrong!  :) 

 

I think you miss something.

Some F-15E Sq like 366th, just received AIM-9X shooting upgrade last year: https://www.mountainhome.af.mil/News/Article-Display/Article/1479980/366th-fighter-wing-receives-new-weapon-for-f-15e/

 

So, no, it's not surprising they still have a stockpile of the previous version.

It's not surprising too, they still use AIM-9M for op missions.

 

And in Syria and Iraq, I don't think they fight against a high end opponent, i.e Russian last jets.

Missiles are here for self-defense.