Twin Commander

General Category => Fuel Systems => Topic started by: ghancock on November 06, 2015, 07:18:43 am

Title: Fuel Leaks
Post by: ghancock on November 06, 2015, 07:18:43 am
As most of you know I have a 680FP.  The shop pulled the 4 inboard bladders in the wings and sent them off for recertification.  They ended up patching a good number of small holes due to the previous shop that installed them not putting proper insulation inside the wing area and instead used a few strips of duct tape.  The shop has reinstalled the bladders and put gas in the plane but upon my arrival last Friday, they had sprung leaks in what appeared to be both wings. 

I found out later that morning that they had just taken it to the pump prior to my arrival and finished filling it up and that it had not been totally full all week.  So I'm assuming my leak is in the forward bladders but not 100%.  The only reason I'm thinking it was in the wing bladders is that both wings had fuel running out of them albeit very slowly.  The main fuel was coming into the baggage area where main fuel sump is.  But it wasn't coming directly from it, it seemed to be coming from the small holes around it, like it was leaking from above somewhere and just running out at that point due to gravity.

We didn't have long to look for where the leak was coming from because it was filling the fuselage and baggage compartment with gas and we had to get it drained out quickly to stop the leaks.  I wasn't there during all the fill ups so have no way to confirm when what qty of gas was inserted nor for how long.  They told me the tanks were full except for about 20 gallons that morning and that no leaks were found, however, I know they were also very busy on another plane so not sure how much attention was paid to the plane in the days it sat there.  Would assume they were paying attention but just not big on assumptions.

They have since removed the bladders again to inspect for problems but they say everything looks fine and they have reinstalled them into the wings.  They are supposed to fill them up again today to see if they leak again but the way things are going I'm not very confident.  I have also spoken to Morris about the situation and he thinks they didn't get all the valves and hoses connected properly but they insist they were all tight and on when they took them back out.

Anyone know of anything else I might want to check before having to send all the bladders back out again for inspection?

Thanks,

Glenn

Title: Re: Fuel Leaks
Post by: Mike Floyd on November 10, 2015, 01:28:51 pm
Glenn, The clamps on the tank interconnects have bad threads on them. They will feel as if they have tightened up but they are not truly tight. Look at the clamp band threads and you will see distorted slots. Kind of like a bolt being cross threaded. Replace them with new
Title: Re: Fuel Leaks
Post by: ghancock on November 11, 2015, 06:37:17 am
Thanks,  According to the shop they replaced all of the clamps with new ones already.  I've been waiting for 2 days now to hear if it still leaks after they removed all of the bladders and reinstalled them.  Hope to hear today.

Glenn