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Crosswind - The First Step Toward the Next Flight

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z4t143(at)hotmail.com
Guest

Posted: Wed Feb 15, 2006 8:39 pm Post subject: Crosswind - The First Step Toward the Next Flight

Thanks to all of you listers who have offered public and private support and much needed words of encouragement following Crosswind's forced landing and substantial damage on 18 January.



Today marks the first day in a long "pre-flight" period as my family and I begin our "return to flight" program.  Specifically, today we completed the settlement process with our insurance company and are now cleared to begin repairing/rebuilding Crosswind!



First, let me say that the experience we had with Falcon AIG Aviation insurance was wonderful.   From the time I contacted them for a quote until we received our settlement check, the customer service and considerations given to our special circumstances were outstanding.  I highly recommend the following agent:

Jim Stewart, Falcon Insurance Agency- Kerrville, TX, EAA Division, 866-647-4322, jstewart(at)falconinsurance.com



Next, let me address some of the questions some of you have raised and some lessons learned.



1) The 801 does NOT glide well at engine out.  Although I was at 4000 MSL (~3500 AGL) when I lost power, I covered only 1 mile in distance before I met the tree line.  My lesson learned is that if I ever again need to execute an engine out forced landing, I will begin my search for an acceptable field BELOW me and not out in front of me.



2) The cabin structure seems to be very "crash worthy".  Although I still consider it divine intervention and a modern miracle that I walked away without a scratch, the engineer in me has to look at the wreckage and assess what failed and what held.  The cabin structure did well despite the fact that both wings absorbed much of the energy and crushed the airframe behind the front seats.



3) Stay over the field when flight testing new conditions.  I became a bit overconfident during this flight test and strayed too far from the field when I inititated a new flight condition.  I had been up for just over an hour and all was well.  Although I was flying ovals over the field, I had drifted a bit farther East of the field during this pass and was just enjoying the scenery.  However, it was when I was at this farthest point from the field (about 2 miles off the end of the runway) that I set up a new, first time ever, flight condition.  I'll explain the new flight condition below, but the lesson learned here is to be over the field when you try a new combination of aero configuration and power setting.



4) The flight condition and analysis:  As stated earlier, I had been up for over an hour doing engine performance checks. The aircraft had 22 gal of 100LL fuel at take-off and an estimated 10-12 gal still on board when the flight was terminated.  This flight test mission was to assess engine performance.  Specifically, I was flying ovals around the field at different altitudes and power settings and recording all the available performance parameters.  I had been making radio calls to my ground crew who recorded all the readings, which included pressures and temperatures, even carburetor air tempurature.  The flight condition at which I lost fuel pressure and subsequently the engine, was low speed, high drag, and moderate to high power.  Specifically, I had dropped the flaps to 30 degs and increased power to hold altitude.  In this condition, I was slow (58MPH), with moderatly high power (2100 RPM), and probably reduced cooling through the cowl.  The outside air temperature was around 48 deg F and the Carb Air temp was 45 deg F.  Shortly after entering this flight condition, the fuel pressure dropped to below 2psi and the engine quit very shortly thereafter.  There was no indication of rough running such as would be the case with carb ice.  With the electric fuel pump on and following all the normal procedures, I was able to start the engine briefly, but it never did accelerate.  Finally, it stopped and would not start again.  The current working theory is that at this flight condition, the gacolator overheated, vaporized the fuel, and created a vapor lock in the system.  The fact that both the electric and mechanical fuel pumps are downstream of the gascolator created a condition wherein, the system could not expell the vapor and deliver fresh fuel to the engine.



Fuel System Changes for Crosswind II:  During this re-build I plan to do the following to minimize the chances of this happening again.



Move electric fuel pump upstream of gascolator



Move gascolator farther away from exhaust pipes



Wrap exhaust pipes with insulation wrap to minimize radiant heating



Add cooling air blast tube from engine baffles to blow on gascolator



Add air vent lines to filler necks of 801 fuel tanks and route open vent line to wing lower surface



Hope this summary can help some of you as you begin your testing.



Check out our website for updates.  http://crosswind.myairplane.com/



Dave

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squiggles(at)yahoo.com
Guest

Posted: Sun Feb 19, 2006 10:59 am Post subject: Crosswind - The First Step Toward the Next Flight

Good Afternoon Dave...



It's good to hear you are in positive spirits after

the accident and armed with a game plan to get back in

the air.



I have been building my 801 powered by a Mazda Rx7

engine since the spring of 2002( who knew it would

take as long as putting the kit together to get the

fwf together ).  That background aside I would like to

agree with you on several points:



- The ZAC fuel caps require supplemental vents.  On a

ground test of 20gph on a tank the tank sucked itself

inwards.  Subsequent tests of the remaining 3 fuel

caps in my kit revealed the same behaviors.  Brazing

in a bung at the neck was a simple affair.  Have a

look at the hts2000 brazing rods(

http://www.aluminumrepair.com/aluminum_repair.htm ) if

you wish to do it yourself.



- Radiant heat in a engine compartment is not fuels

friend.  Simply creating a barrier between the source

and the destination is sufficient.  It can be as

simple as a piece of .025 aluminum with a piece of

Fiberfrax.  Or similar boiler or kiln insulation.  Of

course wrapping the exhaust tubes will be more than

sufficient and by keeping the exhaust gas temps up you

could increase the velocity in the tubes and possibly

gain some benefits there as well.



- With our gravity feed systems there is always head

pressure.  As such for vapor lock to have occurred in

the environmental conditions you describe with a stock

ZAC 801 o360 FWF layout would seem possible, but not

necessarily at the top of the list.  Though, Sherlock

Holmes said on many an occasion, "When you have

eliminated all which is possible, then whatever

remains, however improbable, must be the truth."



You mention you only traveled 1 mile, did you by

chance notice you vertical speed descent rate?  Was

the propeller windmilling?



Good Luck on your return to flight program 



-Scott

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JERICKSON03E(at)aol.com
Guest

Posted: Tue Feb 21, 2006 12:47 pm Post subject: Crosswind - The First Step Toward the Next Flight

In a message dated 2/19/2006 12:59:52 PM Central Standard Time, 

squiggles(at)yahoo.com writes:



- The ZAC fuel caps require supplemental vents.  On a

ground test of 20gph on a tank the tank sucked itself

inwards.  Subsequent tests of the remaining 3 fuel

caps in my kit revealed the same behaviors



What configurations of fuel caps are being used on completed 701 & 801 

aircraft?

The ZAC kit caps I have are vented, four places at the edges.

Cap's seen at the factory have ram air tubes attached. Several older designs 

also have used ram tubes on the caps.



Question is one of having at least free gravity flow while in flight, so the 

cap's need to at least be freely vented. Which leads to, what is the air 

pressure on the wing upper surface, where the caps live? Has anyone ever checked to 

understand what the effect is of venting the caps close to the wing upper 

surface?



Searching for a good solution for fuel flow in flight.

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Johann G. Johannsson

Joined: 10 Jan 2006
Posts: 18
Location: Iceland

Posted: Tue Feb 21, 2006 2:04 pm Post subject: Crosswind - The First Step Toward the Next Flight

Hello All.



I am using one old fuel tank and one newer fuel tank in the wings. Both 

have the vented caps, but the caps are different.

I do not have the fowrard facing tube in the caps. To prevent the 

possibility of gravity not doing its work in my wing tanks, I installed 

one facet 105 fuel pump behind the seats which feeds the header tank. 

When I turn the pump on and it has been running for a few sec. fuel 

seems to flow freely without the pump.

So the conclusion in my setup is,  you need to get the flow started and 

then it will flow on its own with gravity.



Regards,

Johann G.

Iceland.

Z 701

 



JERICKSON03E(at)aol.com wrote:



 	  Quote: 	
		  



In a message dated 2/19/2006 12:59:52 PM Central Standard Time, 

squiggles(at)yahoo.com writes:



- The ZAC fuel caps require supplemental vents.  On a

ground test of 20gph on a tank the tank sucked itself

inwards.  Subsequent tests of the remaining 3 fuel

caps in my kit revealed the same behaviors



What configurations of fuel caps are being used on completed 701 & 801 

aircraft?

The ZAC kit caps I have are vented, four places at the edges.

Cap's seen at the factory have ram air tubes attached. Several older designs 

also have used ram tubes on the caps.



Question is one of having at least free gravity flow while in flight, so the 

cap's need to at least be freely vented. Which leads to, what is the air 

pressure on the wing upper surface, where the caps live? Has anyone ever checked to 

understand what the effect is of venting the caps close to the wing upper 

surface?



Searching for a good solution for fuel flow in flight.

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_________________
Johann G.
Iceland.
Flying Zenith 701.

frank.hinde(at)hp.com
Guest

Posted: Tue Feb 21, 2006 2:31 pm Post subject: Crosswind - The First Step Toward the Next Flight

This is not ideal but probably workable because the wing tanks are

feeding the header.



What is happening here is the vacuum in the tank (vented to a low

pressure area above the wing) is preventing the fuel from flowing

downhill.



You then turn on the pump and suck on the bottom of the fuel to get it

moving.



"Vacuum" and "suck" are not good terms for a fuel system....If this was

a high altitude plane I can guarantee you would be boiling fuel in the

tank and potentially vapour locking a pump.



Not an ideal setup but workable because 701 won't normally go that high

and you are not feeding the engine directly from the wing tanks.



If this was a direct feed I would want a better venting system.



Farnk



--

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n801bh(at)netzero.com
Guest

Posted: Tue Feb 21, 2006 5:27 pm Post subject: Crosswind - The First Step Toward the Next Flight

What configurations of fuel caps are being used on completed 701 & 801 

aircraft?

The ZAC kit caps I have are vented, four places at the edges.

Cap's seen at the factory have ram air tubes attached. Several older designs 

also have used ram tubes on the caps.



Question is one of having at least free gravity flow while in flight, so the 

cap's need to at least be freely vented. Which leads to, what is the air 

pressure on the wing upper surface, where the caps live? Has anyone ever checked 

to 

understand what the effect is of venting the caps close to the wing upper 

surface?



Searching for a good solution for fuel flow in flight. 

//////////////////////////////////////////////////////////////////////////////////////////////////////

 

I can tell you guys what happens on my 801. I built 17 gal  aux tanks that sit outboard of the stock tanks and are plumbed together at the rear. The inner tanks fill the outer tanks through the transfer line. I kept it VERY simple because most experimental planes go down because of poor fuel systems. There are a few things my 801 does that most other ones do too.  In the beginning I ran the stock ZAC caps on my inner tanks. The low pressure created on the top surface of the thick STOL wings that Chris Heinz designed is alot more then most of us can realize. If I fill my tanks even close to the top, the suction will draw out fuel and it runs down the top of the wing, This happens through the vent openings that are in the cap. I painted my plane with Dupont Imron and believe it or not the paint is now stained with blue dye that's in 100LL. Ya I am pissed but I don't loose sleep over it. When I built my aux tanks I welded a bung on the top outer end panel of the tanks just like ZAC provides with their stock ones. I ran a 3/16" tube from there  down  and protruding through the lower skin to vent the tanks. This uses the high pressure thats on the underside of the wing. To fix the fuel from being drawn through the vent openings in the cap I expoxied the holes closed and use my other vents to breath the fuel system. I also tied both wings together using the ports that are on the inner  top end surfaces of the stock tanks that ZAC provide. This port is for the return line if one is running a fuel injection setup that needs a  fuel return to the tank. My main concern was two fold. The first was the 801 that crashed in Texas because of poor tank venting in it first few flights. It was clear that caused the downing of that plane. My other concern was most 801's are known to empty the left tank twice as fast as the right tank if they are used together, ie, fuel valve on both. Well, guess what. I thought I had the solution to that problem and mine STILL uses more fuel from the left tank when I have my fuel valves se!

 t to bot

h. All I can figure is that the circular flow of the prop hits both wings in different ways and that causes the uneven flows. I have resigned to that fact and manage my fuel by using my left/right fuel valves as needed. I can say my setup does work and shows no sign of vent problems and I am at the stage of testing my firebreathing monster that I have removed most of the HP limiting devices, IE, restrictor plates, ignition RPM chips,etc I initially installed on my plane to prevent it from breaking in half during full power climbs. Currently I am burning 16+ gph during takeoff and throttle it back to 5.8-6.2 gph for cruise. I have never had a moment where the tanks didn't vent properly at climb power settings. FWIW....

 

do not archive



Ben Haas

N801BH

www.haaspowerair.com



What configurations of fuel caps are being used on completed 701  801 

aircraft?

The ZAC kit caps I have are vented, four places at the edges.

Cap's seen at the factory have ram air tubes attached. Several older designs 

also have used ram tubes on the caps.



Question is one of having at least free gravity flow while in flight, so the 

cap's need to at least be freely vented. Which leads to, what is the air 

pressure on the wing upper surface, where the caps live? Has anyone ever checked 

to 

understand what the effect is of venting the caps close to the wing upper 

surface?



Searching for a good solution for fuel flow in flight. 

//////////////////////////////////////////////////////////////////////////////////////////////////////



I cantell you guys what happens on my 801. I built 17 gal aux tanks that sit outboard of the stock tanks and are plumbed together at the rear. The inner tanks fill the outer tanks through the transfer line. I kept it VERY simple because most experimental planes go down because of poor fuel systems. There are a few things my 801 does that most other ones do too. In the beginning I ran the stock ZAC caps on my inner tanks. The low pressure createdon the top surface of the thick STOLwings that Chris Heinz designedis alot more then most of us can realize. If I fill my tanks even close to the top, the suction will draw out fuel and it runs down the top of the wing, This happens through the vent openings that are in the cap. I painted my plane with Dupont Imron and believe it or not the paint is now stained with blue dye that's in 100LL. Ya I am pissed but I don't loose sleep over it. WhenI built my aux tanks I welded a bung on the top outer end panel of the tanks just like ZAC provides with their stock ones. I ran a 3/16" tube from there down and protruding through the lower skin to vent the tanks. This uses the high pressure thats on the underside of the wing. To fix the fuel from being drawn through the vent openings in the cap I expoxied the holes closed and use my other vents to breath the fuel system. I also tiedboth wings together using the ports that are on the inner top end surfaces of the stock tanks that ZAC provide. This port is for the return line if one is running a fuel injection setup that needs a fuel return to the tank. My main concern was two fold. The first was the 801 that crashed in Texas because of poor tank venting in it first few flights. It was clear that caused the downing of that plane. My other concern was most 801's are known to empty the left tank twice as fast as the right tank if they areused together, ie, fuel valve on both.Well, guess what. I thought I had the solution to that problem and mine STILL uses more fuel from the left tank when I have my fuel valves set to both. All!

  I can f

igure is that the circular flow of the prop hits both wings in different ways and that causes the uneven flows. I have resigned to that fact and manage my fuel by usingmy left/right fuel valvesas needed. I can say my setup does work and shows no sign of vent problemsand I am at the stage of testing my firebreathing monster that I have removed most of the HP limiting devices,IE, restrictor plates, ignition RPM chips,etcI initially installed on my plane to prevent it from breaking in half during full power climbs. Currently I am burning 16+ gph during takeoff and throttle it back to 5.8-6.2 gph for cruise. I have never had a moment where the tanks didn't vent properly at climb power settings. FWIW....



do not archive



BenHaas

N801BH

www.haaspowerair.com

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Johann G. Johannsson

Joined: 10 Jan 2006
Posts: 18
Location: Iceland

Posted: Wed Feb 22, 2006 10:18 am Post subject: Crosswind - The First Step Toward the Next Flight

Hello Frank.

Thank you for the advice. If I would have known what I know today, when 

I closed up the wings, I would have done things differently, a correct 

venting and bigger wing tanks, no header tank. Fuel pump in each wing root.

This setup seems to work OK so I will just keep it this way for now. I 

may get a different fuel tank caps later if the fuel transfere method 

will cause a problem, but that is a project for later.

The header tank is only filled through the wing tanks.I do have a fuel 

sensor in  the header tank and when the wing tanks are empty,  I have 

approx 1,5 hours of endurance in the header tank. Also have the fuel 

flow sensor to give me the estimated endurance based on RPM. I really 

like the Stratomaster E2 EMS.



Regards,

Johann G.

Iceland.

Joeing 701

do not archive

Hinde, Frank George (Corvallis) wrote:



[quote]



This is not ideal but probably workable because the wing tanks are

feeding the header.



What is happening here is the vacuum in the tank (vented to a low

pressure area above the wing) is preventing the fuel from flowing

downhill.



You then turn on the pump and suck on the bottom of the fuel to get it

moving.



"Vacuum" and "suck" are not good terms for a fuel system....If this was

a high altitude plane I can guarantee you would be boiling fuel in the

tank and potentially vapour locking a pump.



Not an ideal setup but workable because 701 won't normally go that high

and you are not feeding the engine directly from the wing tanks.



If this was a direct feed I would want a better venting system.



Farnk



--

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_________________
Johann G.
Iceland.
Flying Zenith 701.

frank.hinde(at)hp.com
Guest

Posted: Wed Feb 22, 2006 11:15 am Post subject: Crosswind - The First Step Toward the Next Flight

Your welcome.



I too have a JPI fuelscan (or is that floscan) and can tell you it is

prbably the most useful cross country instrument I have. Deadly

accurate.



Of course this is for a wing tank plane only. If you have a header tank

an even more reliable and accurate fuel burn meter is the simple sight

tube.



Cheers



Frank 



Do not aarchive



--

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