Fuel stains and bombs.
1. Big green stains on the 206 fuse side beneath the wing root. Leaking bag says the Lame. Swapped out the bag for a newie. Next day...big green stains on the 206 fuse side beneath the wing root. !! Oops.
On closer inspection where the fuel pipe entered the fuselage it was barely touching the skin and dew or rain a droplet could sit there...just like a micro battery?..and had corroded a hole in the pipe.
2. C 180 for skydiving. BIG red stains under the belly. Other pilots had complained of fumes in the cockpit. I shifted the seat and opened some inspection holes and had a visual look around. Lots of red but couldnt see anything of interest....then just as I was replacing a cover a saw a silver wiggly thing moving on the side wall. Que ?
With a careful look it was fuel washing the tin clean at that little spot...a microscopic thread of fuel was squirting out of a minute corrosion hole in the fuel line.
Just the luck of the light to spot it, and a kick in the bum from the owner for entering the defect into the MR.!
3. Turbo Baron - strong fuel smell in the cockpit. When checking the survey camera lens and filter under the fuse, green stains and fumes venting from the drain holes.
Lames called for a look see...and couldnt find anything. Just on taxi Lame asks for some tool...no can see. Must still be under the floor then, no ..couldnt be there. Shortly back at the shop because the gear wouldnt retract..yes that where the tool was.
Flight day is now lost so grabbed a bag and said I'll get back on the aircraft only when you have located that fuel leak.
With more thorough inspection and back under the floor pilots side, a small puddle of fuel was found that was fed from the tank selector cable that ran out of a tube from the
actual fuel cock up by the engine. A seal had failed, hence the dribble...and the fumes.
Moral of the story...and not many do it with the DI...have a good look underneath.
The scary part was before that we had flown at altitude, with oxygen and on descent before landing the captain used to light up a fag !!