Loose Fuel Line Fittings, a very close call !!!

[TS Flightlines]

I hate to be a pain, but a 302* high temp nylon tie wrap wasnt exactly what I had in mind. We all have seen firesleeve secured by safety wire, which is better than nothing. Fastenal makes a stainless pinch band that can work too, for those doing a one time assembly.

[Jerry Fischer]

I had to off field a Commanche 260 on 10/2/1992 in Aliceville AL (N8548P)
for NTSB reference for EXACTLY the same reason. Luckily the three of us walked away thanks to good primary off field emergency proceedure training during my primary flight training (thanks Don Lindsay).

[JonJay]

The truly amazing thing for me is how well designed our aircraft fittings are. There should have been lots of warning that this fitting was leaking.
I am surprised that the smell of fuel, or a stain did not get noticed early on, before the leak became so gross. No disrespect intended.
I recently had a pin hole leak in a hard fuel line on the Bucker caused by some internal corrossion due to a poorly fabricated part. The amount of fuel leaking was barely enought to cause a drip, yet I could smell the fuel immediatly when I flew it, and this is an open cockpit.

[Wayne Gillispie]

Originally Posted by LettersFromFlyoverCountry

Man, there's a fair amount of thread drift here. Bottom line for me: How the heck does some of this stuff pass inspection?

I would think someone using a nylon tie as a firesleeve clamp would scream., "stop whatever else you're doing and take a good LONG look at everything on this engine."

It is all related, we are learning and being nice.

As far as passing inspection...the builder has to make the signoff before first flight, so he is ultimately responsible. It depends on who you get to look at your plane. DAR/A&P's may notice. The FSDO inspector may not. I would think neither check torques on all hardware/fittings and they won't be with you on your test flights.

[Wayne Gillispie]

Originally Posted by JonJay

The truly amazing thing for me is how well designed our aircraft fittings are. There should have been lots of warning that this fitting was leaking.
I am surprised that the smell of fuel, or a stain did not get noticed early on, before the leak became so gross. No disrespect intended.
I recently had a pin hole leak in a hard fuel line on the Bucker caused by some internal corrossion due to a poorly fabricated part. The amount of fuel leaking was barely enought to cause a drip, yet I could smell the fuel immediatly when I flew it, and this is an open cockpit.

The only time pressure is on that line on the ground is with the boost pump on, throttle and mixture forward(priming). Only about an ounce of fuel at low pressure flows through. At this point in the start procedure one may just think they overprimed. We don't leak test this during our before test flight checks. I only tested to fuel servo outlet while doing my 42 gph fuel flow test.

After start up and in flight there is alot of heat and airflow to dilute the 2 oz of fuel leaking every minute. Depending on firewall sealing, eyeball vent
open/closed position and your sense of smell it may not be noticed. These lines can stay snug enough to not leak measureably for hours, but once they
do turn it can turn in to a gusher in a short amount of time depending on line position/tension/pressure and vibration frequency.

I had a one drip leak every five minutes during pre-test flight checks just after fuel filter in tunnel with boost pump running. I thought it was my neighbors leaky Mooney. I finally pinpointed it with an electronic combustible gas detector.

[johnny stick]

I am thinking all these critical B-nuts, especially on the fuel system, should be safety wired. may be a pain in the but, but this pain is better than a fire. JMHO

[TS Flightlines]

Johnny---there are alot of place that you would have to be a magician to safety the nuts. Safetying isnt the answer, but checking the connections is.

[Danger Will Robinson]

Here is an accident where a loose B nut cost a pilot his life. Not a pretty way to go.
http://aviation-safety.net/wikibase/wiki.php?id=40302