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antonio4231

fuel sump on a long ez?

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Ok, I've been trying to get started building an open-ez for a couple of years now but life keeps getting in the way. So instead of starting on the fuselage, I've spent what time I have had available in building metal and wood parts and research. I want to build a pretty standard long, with only a long nose mod and maybe a forward opening spit canopy and a rollbar to replace the ugly head rest. My question is during all my reading and research, I came across a person building a long with a fuel sump in the back and no fuel selector in the cockpit. I think that the verieze was built with a sump in the back. What are the pro's and con's of removing the fuel selector from betwixt your thighs? It seems to me that it would increase safety by removing a potential point of failure from a sticking valve/switched to wrong tank in a crisis? Also it removes the potential for being showered in fuel in case of a catastrophic failure involving rupture of a fuel line/valve in the event of a hard landing? I don't know enough about this to form an opinion, so please share your thoughts. Thanks Anthony

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Ok, I've been trying to get started building an open-ez for a couple of years now but life keeps getting in the way. So instead of starting on the fuselage, I've spent what time I have had available in building metal and wood parts and research. I want to build a pretty standard long, with only a long nose mod and maybe a forward opening spit canopy and a rollbar to replace the ugly head rest. My question is during all my reading and research, I came across a person building a long with a fuel sump in the back and no fuel selector in the cockpit. I think that the verieze was built with a sump in the back. What are the pro's and con's of removing the fuel selector from betwixt your thighs? It seems to me that it would increase safety by removing a potential point of failure from a sticking valve/switched to wrong tank in a crisis? Also it removes the potential for being showered in fuel in case of a catastrophic failure involving rupture of a fuel line/valve in the event of a hard landing? I don't know enough about this to form an opinion, so please share your thoughts. Thanks Anthony

i think the builder of johns plane was changed for the that resin, and to this date i don't think the valve ever leaked in the cabin all thou it did kill him.

there is lots of pros and cons for that move, read for a day and you'll go with the plans way :P


Steve M. Parkins

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The potential for not having the fuel valve in the wrong position is greater than any of the other points of failure you mentioned.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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The argument of not having fuel in the cockpit is not valid. The only thing that keeps fuel from the cockipit are one fiberglass bulkhead (Strake and fuselage side)

 

Also, if you follow the plans sump blister configuration, then you already have the fuel lines in the cockpit. Running that aluminum tube up to the front seat and putting in a valve adds insignificant risk.

 

Putting the valve on the firewall then adding linkages to operate the valve from the cockpit adds additional failure modes (Ask John Denver about this)

 

If your landings (impact) are hard enough to break the fuel line (aluminum tube) or cause the valve body to rupture, I'd be willing to bet that the strakes are no longer on the plane, so its a mute point. :sad: :sad:

 

Stick with the plans and use a good quality valve. A good source, check with aircraft grave yards and get a real fuel valve. put new O-rings in it and you'll be good to go.

 

Waiter


F16 performance on a Piper Cub budget

LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract

visit: www.iflyez.com

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It seems to me that it would increase safety by removing a potential point of failure from a sticking valve/switched to wrong tank in a crisis?

The stock valve does not stick if you put a dab of Fuel Lube on it every few years. Or install one of the high-buck valves.

 

Yeah, maybe in a crash/hard landing a fuel line could break but aluminum fuel lines are pretty flexible. . . OTOH, the landing gear bow could get shoved up into your more-brittle fiberglass sump tank. Sort of a toss-up, I'd say.

 

I think the plans system is OK and the build goes a lot faster if you follow the plans. Not to discourage experimentation. :)


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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My longez had the fuel valve mounted in the hell hole. It was actuated with a torque tube (as opposed to the little rod that the Varieze used/uses). Actuation was very solid feeling. Mounting location near my right shoulder/elbow was not a problem.

 

My Cozy has the standard valve mounting location (right elbow). However, I do have a both selection that I run mostly---and do have the ability to run right or left in the event that I need to tank isolate.

 

John Denver's biggest 2 problems were:

1. Failure to realize he was too low on gas during preflight---even though he looked at and acknowledged the tank amounts.

 

2. Failure to realize that he was not going to restart the engine, failure to suck up his fate, and failure to execute a nice landing in the water. AFAIK, 100% of EZ water landings (pilots executing a good landing in the water as opposed to an uncontrolled crash) have had 0 deaths.

 

The fuel valve set up, the extra cusions behind his back, and rudder pedals that were that were not yet adjusted for him---were all contributing factors for not restarting the engine. But if number 1 (above) was taken care of, there would have been no reason for number 2. And if he executed a good landing----he would be out a Longez---but he would have survived.

 

The John Denver story is not a Longez story----it is a pilot headwork story. Pilots running out of gas is one of the worst headwork items. At almost every fly-in/airshow, people ask if my airplane is the kind that John Denver died in----and then they more or less want to know how I feel flying an airplane that has those kind of problems. Of course, I reset their thinking----any pilot can run any plane out of gas---and he could have survived it.

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I have a Cozy with a sump under the right rear thigh support.

Both tanks feed to it.

The only valve I have is a shut off valve at the fire wall.

The only time it is actuated is for maintenance.

It has a spring to hold it in the open position.

I have a cable (bowden) from the front seat to close (pull against the spring tension) it should I need to.

Its a simple setup, if I have fuel in the tanks, the engine will run.

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Howdy Anthony-

I also have a rear seat tank similar to Chris’s description above. I consider it one of the primary safety elements on the plane. The only fuel discipline is to “have some.” Passengers don’t notice it unless I mention it. This wasn’t undertaken lightly, but 15 years between buying the plans and starting building allowed time to think about it.

I built the 5 gallon thigh support tank in my VariEze in 1991 after viewing Vance Atkinson's installation in his Cozy. Vance's operational experience and suggestions for improvement, along with the opinions and advice from several others familiar with his system were of significant benefit in my design.

The system is more than just the two ½ inch ID tubes that drain fuel freely from the strakes into the sump. Additional lines allow fuel to drain from the strakes into the sump in climb, cruise, descent and start attitudes, and for air to vent from the sump tank high point if fuel is used out of it. Two of the vent lines go forward and include short lengths of clear tubing for sight gauges at the instrument panel. Fuel balance between the strakes is accomplished by moving the exterior vent lines (in front of the main gear legs) slightly in or out from the fuselage.

The lines were flox sealed and stainless filter screens were easily installed by reaching into the strakes and into the rear seat sump through temporary 12 inch access panels during building. Hope life keeps getting in there in the mix :)

Good building-


Bill James, Fort Worth VariEze

Downdraft Plenums

Quickcowls

There was supposed to be Anhedral???

http://www.ezchronicles.com/blogger.html

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Thats exactly what I have been thinking of:

 

Both tanks drain into a sump from the strakes with no valves.

 

No screens on the strake drain tubes, and large enough diameter tubing to allow any contaminants/water to pass directly into the sump.

(How would you clean a screen inside the strake tank, anyway?)

 

A drain on the sump to remove any contaminants and water that ends up in there. Maybe a bunghole for a cleanout too.

 

In-tank fuel pumps submerged in the sump to eliminate vapor lock.

 

Dual fuel filters incorporated in there somehow, with ability to run on either.


Marc Oppelt

Olympia, WA

http://picasaweb.google.com/oh.u8it2

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I have a small sump just below the main spar. The tank is V shaped with both tanks feeding it via 3.5 square inch holes. The sump is plumbed through the firewall so lines should be short. It is like a tunnel that connects the tanks with the lowest point in the center.

 

Joe Berki

 

Limo EZ

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I still have the screens in the tanks over the outlet holes, in fact I still have the small plans sumps. Maybe its not necessary to still have thes sumps but I am pleased I still have the screens. My main tank screens are raised in a dome shaape and have a very large surface area, probably 10 square inches.

I have a finger screen (removable) on the sump under the seat. This is about 1 1/2 inches up from the bottom of the sump so a lot of crap can sit in the bottom of the sump before going to the engine. The sump is removeable. Its drain outlet (water sampling) is accessable from underneath the fuselage. No pumps in the sump but an Airflow performance pump/filter combo sits under the other thigh support to feed the injected 360. I still have a gascolator on the engine side of the firewall. I probably do not need it as the fuel has already passed through 2 sumps (water collection) and three filters before it gets to the gascolator. I may well remove it. The Airflow performace filter is very good, it has a large area and is very fine.

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