Tank seats - Pros & Cons

Gyro28866

David McCutchen
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IMOP:
You have to have a seat and you have to have a fuel tank! Both of these items have weight.
1. Is the combined weight of both items more than a Seat/tank combined?
2. Obviously, you will have a seat, Then where would you put the fuel tank? and what extra parasitic drag are you introducing. and where is it and the changing weight in relation to the vertical CG.
3. To me, the seat/tank is a no brainer, just sayin.
 

Brian Jackson

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I would be quite interested in seeing data comparing the rates of post-crash fires with seat tanks vs. separate tanks. As I understand it, metal tanks are better than fiberglass because they deform instead of fracturing. But metal can still puncture. The seat tanks I'm familiar with are malleable polyethylene, so one might think this is a safer option, but I won't conclude that without data. Anyone know?
 

Tyger

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Just remember: no gyro is ever going to pass a crash test.

Fortunately there are a lot fewer things to hit (or be hit by) than in a car...

Anyway, in my gyro, it's the passenger that gets to sit atop all that gasoline. :giggle:
 

Georgi

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Just remember: no gyro is ever going to pass a crash test.

Fortunately there are a lot fewer things to hit (or be hit by) than in a car...

Anyway, in my gyro, it's the passenger that gets to sit atop all that gasoline. :giggle:
Tyger, then it is the time to start giving rides on your laps:)
 

Tyger

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I have had a few passengers ask where the gas tank is, and I've said "you're about to sit on it". This has produced some wan smiles, but no one has then refused to climb aboard (or asked to sit on my lap).
PS I have only had one passenger that I actually might have liked to have sit on my lap... after the gyro flight, ofc. :p:sneaky:
 

ultracruiser41

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I always explain that in a motorcycle…. The tank is between my legs….. in a Cessna…. It’s above my head….. and in my wife’s minivan….. my kids sit in it😁😂🤣
 

All_In

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My last choice for safety would be the IDEA of sitting with a gas tank wrapped around 1/2 of me.
However, I've flown sitting on them and didn't think about it. And I'll fly models that have them in the future as they serve dual purposes.
I do like Aviomania's solution. It's a composite with a kevlar layer fuel cell in the shape of the seat but not part of the seat there is a gap.

Also, in the frame support tubes, he only puts doublers tubes where the bolts go through and extents them to bend in a crash where he wants it to hit the ground supporting the fuel cell and pilot off the ground. He creates a weak spot with only one layer of tubing that will form a triangle from the keel/mast to the bent frame tubing below the keel on the ground now holding the tank and pilot off the ground and keel.
 
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Doug Riley

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Ken Brock's first seat tanks were fiberglass. They had a high gloss and were very pretty. I was disappointed when I ordered one and it arrived with a flat black finish. Ken had switched to polyethylene or some such molded plastic.

There was some talk of the 'glass delaminating in the presence of fuel (Ken denied this when I asked), and it was more brittle than the squishy poly. Making 'glass seats also involved a lot of expensive hand labor.

I don't know of any fuel fires in open gyros having poly seat-tanks. Home-made 'glass tanks often oozed fuel and saturated their pilots. Whether any of these dudes actually ignited after flight I don't know.

Old-time pickup trucks had the gas tank in the cab, just aft of the seat back. Small tube-n-rag airplanes often have tanks that are suspended by straps just above the knees of the crew/pilot.

There have been a few serious fuel fires in crashes of RAF gyros, in which the fuel seat-tank is inside the cabin.

A possible rule of thumb would be that (1) enclosed gyros must not have the fuel tank inside the enclosure, and (2) no fuel tank may be mounted above the level of the engine (where gas can spill onto hot parts in a survivable pancake landing).
 

gyrojake

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From my past experience, most gyro's catch fire because of the engine coolant.
After a crash the antifreeze hits the exhaust, it ignites and lights the leaking gas that is available.
Antifreeze “It doesn’t seem logical for a water based chemical to be flammable. However it is.
 

All_In

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Thank you, Doug and Jake.
I learned from both of your posts!!!
I love this forum!!!!!!!!!!!!!!!!!
 

Brian Jackson

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Thank you, Doug and Jake.
I learned from both of your posts!!!
I love this forum!!!!!!!!!!!!!!!!!
I was just about to reply the same thing to Doug & Jake. Always something valuable (and potentially life saving) to be learned from them. That's why this forum is so important.
 

Heron

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Coolant fluids are some kind of alchool I think!
As far as fire goes any tank can supply the means, doesn't matter where they are located and for someone who always had motorcycles that proximity was never an issue.
Maybe we should blame de seat belts lol . . .
Thanks for the inputs, forming a defitive opinion here!
 
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