New Photo of the F-22 shows something weird...

Im not sure that is even green fluid. It looks more like the aircraft material, which has been in contact with jet fuel, leaving behind a shimmering type effect.

I was trying to kind of figure out what was being looked at. If the shimmering effect you're talking about is between the two engine humps, it's because some of the LO is missing. It's a pretty common area that this happens, pretty high temperatures around there.

Question: Does anyone know if JP8 or the new synth fuels have any kind of corrosive effect on outer stealth coatings?
With the green being just aft of the refuel receptacle, I wonder if that area gets blasted by residual fuel after boom disconnect and it's starting to wear the top coating thin a bit.

originally posted by: Sammamishman
Question: Does anyone know if JP8 or the new synth fuels have any kind of corrosive effect on outer stealth coatings?
With the green being just aft of the refuel receptacle, I wonder if that area gets blasted by residual fuel after boom disconnect and it's starting to wear the top coating thin a bit.

The LO holds up pretty well, but it does weaken from JP8 and other fluids on the AC. Green could be a number of reasons, but not with the LO material and JP8 or other aircraft fluids.

originally posted by: 5GenNext
There isn't a copper nano particle added to the fuel.

Yes it's the APU exhaust panel. It isn't open. It is closed. There is material missing from near the exhaust door and only looks open.

Years of experience. The pilot will know if that door is open even a little bit. It doesn't open without the intake door.

Maybe not nanoparticle in particular but there is Copper in jet fuel . That green is probably just oxidized sediment that collected when the disconnect happened during fueling. www.astm.org...

pubs.acs.org...

It is possible that's what it is. But I haven't seen it after jets have gone through a tanker.

It looks as if some work has been done in that section (LO work) if you notice how it's reflective to a point behind the primary heat exchanger and then is back to a more LO grey where the green is.

originally posted by: Sammamishman
Question: Does anyone know if JP8 or the new synth fuels have any kind of corrosive effect on outer stealth coatings?
With the green being just aft of the refuel receptacle, I wonder if that area gets blasted by residual fuel after boom disconnect and it's starting to wear the top coating thin a bit.

actually the refueling receptacle is further up on the jet. The door that is leaking the green fluid is a different door.

originally posted by: boomer135

originally posted by: Sammamishman
Question: Does anyone know if JP8 or the new synth fuels have any kind of corrosive effect on outer stealth coatings?
With the green being just aft of the refuel receptacle, I wonder if that area gets blasted by residual fuel after boom disconnect and it's starting to wear the top coating thin a bit.

actually the refueling receptacle is further up on the jet. The door that is leaking the green fluid is a different door.

Are you talking about the green on the aft end between the motors? If so there is no door there. If somewhere else, help me to figure out where.

originally posted by: boomer135

originally posted by: Sammamishman
Question: Does anyone know if JP8 or the new synth fuels have any kind of corrosive effect on outer stealth coatings?
With the green being just aft of the refuel receptacle, I wonder if that area gets blasted by residual fuel after boom disconnect and it's starting to wear the top coating thin a bit.

actually the refueling receptacle is further up on the jet. The door that is leaking the green fluid is a different door.

What's the diamond shape component? it seems to have some of that green substance too.


Talking about this pic in particular.

The diamond shaped panel on the right side of the aircraft, that in the picture is above the IFRR and a little behind is where the gun is. The dark diamond is just a vent.

originally posted by: 5GenNext
The diamond shaped panel on the right side of the aircraft, that in the picture is above the IFRR and a little behind is where the gun is. The dark diamond is just a vent.

That vent has that residue too just not nearly as much as the other.

originally posted by: PlasticWizard

originally posted by: 5GenNext
The diamond shaped panel on the right side of the aircraft, that in the picture is above the IFRR and a little behind is where the gun is. The dark diamond is just a vent.

That vent has that residue too just not nearly as much as the other.

The only doors in that picture are the left and right engine loovers, IFRR, apu intake and exhaust. There is a vent located in the apu exhaust door. Vent for the primary heat exchanger, small vent for the OBIGGS system forward of that panel and the vent on the right side for the gun area.

originally posted by: boomer135

The only thing that could leak from there really would be PAO. But it is more of a yellow then anything. I think the green isn't a really anything except for a sloppy / failing paint job essentially.

The shiny in the middle of the two humps for the motors is common. The high temps that are there, the LO can't stay on very well and exposes the metal underneath.

There is a green primer (aero) that goes on and would give a similar look if the LO was applied not very well above that layer.

a reply to: 5GenNext

Could be primer. Primer is used to help the paint adhere to whatever surface is being painted. If the paint was coming off of the craft it would be due to the primer not being properly applied or something eating it from the top down. not the paint, not sticking to the primer. Paint always sticks to primer. Primer doesn't always stick to the surface(due to improper surface prep) . The enamel (aero, marine etc same stuff different name) paint they use on tanks, subs, planes guns, etc doesn't just come off exposing the primer coat.

If it is the green primer , it's because something is eating away at the hardened enamel top coat exposing the primer. The patterning suggests it's from something being exhausted from that port or possibly fuel blow off from the receptacle, hitting a subtle dead spot in that area as it rolls off the plane. jet fuel could eat that top coat off over time, if it kept stalling in that area as it went over the back of the craft during disconnect. Even if it only sits there for half a second, over time it could cause the top coat to erode off.

The LO material doesn't always adhere very well. Jet fuel, fluids, weather and poor maintenance all go into how easy it is to wreck havoc on the paint.

The metal showing through behind the primary heat exchanger is normal just die to heat. The material is different than other sections on the jet.

There is nothing that could be liquid there. There isn't liquid like that, it wouldn't stay in that spot, it would be streaked all over the jet. It's a common area for missing LO.

originally posted by: thebozeian
a reply to: EasyPleaseMe
Yes Skydrol tends to eat a lot of standard materials used in more mundane hydraulic systems. That's why I tend to double glove when playing around with it as after 5-10mins the standard disposable gloves simply fall apart. I didn't realize that military aircraft don't use it though. It was designed in the early 50's because of its fire retarding properties so it seems odd that it isn't in military use where fire risk is probably far greater.
LEE.

It is useful if military vehicles burn easily after a crash to lower the chance of technology recovery by your targets. I'm sure the pilots would prefer Skydrol though!

Hydraulic fluid is green.