BarracudaHockey

My Feedback: (11)

If you're in the US or coming to the US and flying under AMA rules/insurance, the fuel bag situation is resolved and they are now approved for use.

Here's the relevant change to 501-A
510-A.pdf

5. The fuel tanks shall be of rigid construction with consideration given to burst and puncture resistance. Consideration shall be given that non-metallic fuel lines may not be able to contact hot parts of the engine as installed. Bag style fuel cells are permitted under the following conditions:

a. is a multi-layer fuel cell that is purpose built for the application and designed to be resistant to rips, tears, hardening and cracking from kerosene/jet fuel exposure.

b. is mounted in such a way as to ensure no contact with rough surfaces capable of causing abrasion between the tank and any aircraft surface.

c. is mounted away from or protected from heat exposure from the engine(s) and pipe(s).

d. is filled with a pressure sensing fueling system to ensure the cell isn't over pressurized during fueling.

e. NO plasma/IV bags are permitted.

qcsteve

Glad they are updating the rules. Not familiar with fuel bags. Is a uat needed with a fuel bag?

AEROSHELDON

My Feedback: (99)

Thanks for the hard work Cuda!!

BarracudaHockey

My Feedback: (11)

No, used properly they are completely bubble free.

Halcyon66

https://www.fuelbag.de/

Use google translate and you can get information and ideas.

Regards,

AEROSHELDON

My Feedback: (99)

Which fueling system is allowed? I think jetcat fuel pump senses pressure but not sure. Plus it is always out of stock it seems.

rgburrill

I am not a jet person so I may be off base here, but doesn't subparagraph a. above describe a non-rigid fuel tank which goes against paragraph 5?

grbaker

My Feedback: (29)

paragraph 5 reads:

causeitflies

Well that took a while but glad it's done.

mongo

My Feedback: (15)

probably not an overly bad idea to have a UAT anyway,

just in case there is a suction leak somewhere in the system, pulling air you don't know about, until it is already too late.

CobraJet

My Feedback: (4)

Finally! Can't believe it took AMA this many years to approve the fuel bags!

enricoSu30

no, you do not need a uat, just the fuelbag

BarracudaHockey

My Feedback: (11)

Here's some abuse testing done by Martin Pickering

acw

My Feedback: (1)

Probably a noob question but one thing I wonder with bags is whether the bag fuel pressure is affecting how hard the fuel pump has to work. I would expect the pump voltage at say full power to be lower when the bag is full vs when the bag is 50% full with less pressure.

I wonder if all ECUs properly adjust for varying fuel pressure going into the pump as it appears that some of them calibrate during the first full throttle...

AEROSHELDON

My Feedback: (99)

Unless it’s over-full as a tick the bag really isn’t under pressure at all.

mongo

My Feedback: (15)

yeah,
the bags do NOT expand like a balloon. they are a fixed volume and that is all they will hold or give out.

picture a heavy duty IV bag...

Dansy

My Feedback: (53)

‘The only thing about this video, is that pump is not in accordance with AMA rule….since it doesn’t sense pressure….

jetcat and Vspeak are the only 2 I know that sense pressure….any others???

BarracudaHockey

My Feedback: (11)

Yes I'm aware of the fuel filler issue and they are addressing that particular pump to bring it to compliance.

The point of posting the video was showing the bags take abuse. I'm still dealing with folks that think they are less safe but they have been using them in European models and commercial uav's for years and in full-scale aviation for decades.

Zeeb

My Feedback: (41)

Hey Andy, I know you are in the northern part of Florida, but are you making out okay with the flooding situations in Florida now?

BarracudaHockey

My Feedback: (11)

Thanks for asking, my lawn is crispy, I'd love some of that. Not my car floating down the road but something would be nice.