This is an area of what appears to be a mix of fuel staining and corrosion at one of the inspection panels in an '84 Piper Malibu. Looks troublesome to me, but thought I'd post it up here for looks and comments. Any thoughts and/or suggestions?

EDIT: i don't like the look of those little bubbles when I open up the image and zoom in at the fuel stain

If it were at Bonanza I would say It's just begging to have that inspection plate taken off to get a visual on the problem. I would grab an A&P and get that inspection plate off before further flight.

On a wet wing, the inspection plates might be part of the wet wing. Quote from MMOPA PDF p41 http://www.mmopa.com/gallery/magazines/7-1.pdf

"There were an abundance of rivets required and the wet sections' inspection plates had to be sealed. Then they had to be resealed when it was found that they leaked."

You may well have to defuel, take off the inspection plates, inspect and fix, reseal the inspection plates and refuel.

Maybe you ought to ask your question over at the MMOPA forums since they have lots of Malibu experts to give you a definite answer. Or call Kevin Mead who is all things Malibu / Mirage.

http://www.meadaircraft.com/about/meet_kevin.html

http://mmopa.com/

Thanks, guys. I am planning to post it over at MMOPA- it's just easier to do so here from my phone so I thought I'd give it a shot. I may give Kevin a call.

Can almost guarantee you have loose fittings on one of the hoses that you will see if you remove the access panel. Remove panel, tighten clamps and I bet you are good. Cold weather always made mine weep. Very common issue as most mechanics don't tighten check at annual.

Those fuel coupling hoses should be replaced, with age, sometimes tightening them just makes them leak more.

http://www.malibuaerospace.com/sitepages/pid80.php

A common problem on more than a few.