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Over filling during flight?

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larry(at)macsmachine.com
Guest

Posted: Tue Jul 15, 2008 5:26 pm Post subject: Over filling during flight?

Hi Guys,



July 14 Monday was perfect. I walked Toby our cat, then packed the 

flight bag and went to the airport. After a lengthy preflight, the plane 

was pulled from the hangar and I did a secondary walk around. All good, 

the tower cleared my request for runway 5. I lifted off in a soft 

downwind, but still short enough for traffic. I set course for Clinton 

and climbed to 3000 ft. On the formerly flooded Mississippi, one could 

see the river traffic moving again and a few recreational boaters. 

Clinton airport was also visible 8-miles out. I passed over the airport 

and entered downwind for 32. Good pattern work, but I flared a foot high 

and just bounced the touchdown. I taxied in and parked to check 

wheel-pants for damage. None was found, so after visiting with the FBO, 

I taxied to 32 and took off, departed west. The header tank was less 

than ¼ full so the left wing pump was turned on. Engine temps were good 

for an 85-degrees ambient. EGTs 1370, oil 220, coolant 198, CHT 210 and 

oil pressure was 48 psi. On turning south for the return, I called Quad 

Cities approach, collected traffic and guidance and nearly forgot to 

track the refill. The header was completely full when I turned off the 

wing pump and centered the selector valve. I felt a chill down my spine, 

because I didn't want to “overfill”. I worried that fumes from spilled 

fuel could trace across the 601’s non-laminar wing to the exhaust pipe's 

back draft and turn the plane into a “roman candle”. I couldn't smell 

any fuel within the cabin. On landing, I taxied back and shut down. 

Inside the header, fuel was 3-inches from the cap and the overflow tube 

was dry. This is the tank's max fill limit. Very relieved, I put the 601 

back in the hangar and drove home with this tidbit chewing on my mind. 

Nice flight, but the wrong kind of adrenaline rush!



The question would be, is it possible to use the EIS to read the full 

point of a common rheostat type tank sensor to set an alarm point?



Or, should one consider a blinking light that constantly runs when 

either of the wing pumps is running.



Or, does anyone have a good "reminder" that the pump is running or the 

tank is nearly full?



Thanks again,



Larry McFarland 601HDS at www.macsmachine.com

craig(at)craigandjean.com
Guest

Posted: Tue Jul 15, 2008 6:01 pm Post subject: Over filling during flight?

Pillar Point Avionics offers an optical in-tank sensor that you could use.

Normally this is used to sense when a tank is emptying and the sensor

uncovered. But there is no reason why you couldn't use it to sense when it

becomes covered.



http://www.ppavionics.com/UFSTUFSAN.htm



Or you could just set a kitchen timer.



-- Craig



PS - I thought the advantage of a cat over a dog was that it didn't need

walking?



--

tjs22t(at)verizon.net
Guest

Posted: Wed Jul 16, 2008 1:34 am Post subject: Over filling during flight?

Go back in the archives and use "Pillar Point  & Bill Morelli" as he uses one...do not archive

  

 Pillar Point Avionics offers an optical in-tank sensor that you could  use.

Normally this is used to sense when a tank is emptying and the  sensor

uncovered. But there is no reason why you couldn't use it to sense  when it

becomes covered.



http://www.ppavionics.com/UFSTUFSAN.htm

   [quote][b]

psm(at)att.net
Guest

Posted: Wed Jul 16, 2008 3:04 am Post subject: Over filling during flight?

Hi Larry,



I've been mulling over your question about filling the header 

tank.  I didn't want to say anything because I really don't have a 

complete solution to the problem.  However, I have a different way of 

looking at it that might help you.



My thought is to design some electronic control that allows the fuel 

pump to operate only when the header tank has room for fuel.  This 

would allow you to automatically keep the header tank loaded without 

any conscious effort on your part.



Such a circuit would need "Hysterisis"  (sp?) which means it would 

use different levels of fuel in the tank to turn off and turn 

on.  For example it might turn on when the tank is 1/4 full and turn 

off when it is 9/10 full.



While such a control circuit is relatively simple to design, I'm 

afraid my own experience is not up to the task.  The problems are the 

harsh environment of being in an airplane and the high power needed 

to drive the fuel pump.  My own experience was limited to circuits 

working in the more benign electrical environment of the innerds of a 

computer.  That means I am not volunteering to do the design but just 

suggesting the idea.



Good luck,



Paul

XL almost there.



At 06:23 PM 7/15/2008, you wrote:

 	  Quote: 	
		  The question would be, is it possible to use the EIS to read the 

full point of a common rheostat type tank sensor to set an alarm point?



Or, should one consider a blinking light that constantly runs when 

either of the wing pumps is running.



Or, does anyone have a good "reminder" that the pump is running or 

the tank is nearly full?



Thanks again,



Larry McFarland 601HDS at www.macsmachine.com

raymondj(at)frontiernet.n
Guest

Posted: Wed Jul 16, 2008 2:57 pm Post subject: Over filling during flight?

Would it be practical to run the header tank vent back into the top of wing 

tank so if the header gets full the excess is pumped back into the wing 

tank.



Raymond Julian

Kettle River, MN



"Hope for the best,

but prepare for the worst."



---

klaus(at)utdallas.edu
Guest

Posted: Thu Jul 17, 2008 10:45 am Post subject: Over filling during flight?

Hi Larry,



In the original configuration of my 601HDS, two on/off switches

controlled the pumping from the wing tanks into the header tank.

During the first 10 hours I found out that this was a terrible arrangement.

I overfilled the header tank in flight, something you have avoided so far.

This produced a very dangerous situation.



There are many ways to fix the problem,

as you can see from the suggestions by others. I opted for

a very simple solution. I replaced the on/off switches by

spring loaded switches that when released always snap back

to the off position, where according to convention

the switches point down. This arrangement forces me to hold

the switches up while pumping. Sensing the pressure of

the switches keeps my attention on the filling process.

If I have to attend to something else, I let go of the switches, and

the pumping stops right there. In 1100+ hours of flying,

this has worked well. During a cross country flight, I

typically pump up the header tank every 30 min or so,

which is done rather quickly. Actually, it gives me something

to do and reminds me to think about the fuel supply.



Happy flying,



Klaus

larry(at)macsmachine.com
Guest

Posted: Thu Jul 17, 2008 11:19 am Post subject: Over filling during flight?

Hi Klaus,

That's the simplest and most direct thing I've seen so far.  Certainly 

the easiest change to make

at this moment.  Excellent idea! 

Thanks,



Larry McFarland 601HDS at www.macsmachine.com

do not archive

 



Klaus Truemper wrote:

 	  Quote: 	
		   



 Hi Larry,



 In the original configuration of my 601HDS, two on/off switches

 controlled the pumping from the wing tanks into the header tank.

 During the first 10 hours I found out that this was a terrible 

 arrangement.

 I overfilled the header tank in flight, something you have avoided so 

 far.

 This produced a very dangerous situation.



 There are many ways to fix the problem,

 as you can see from the suggestions by others. I opted for

 a very simple solution. I replaced the on/off switches by

 spring loaded switches that when released always snap back

 to the off position, where according to convention

 the switches point down. This arrangement forces me to hold

 the switches up while pumping. Sensing the pressure of

 the switches keeps my attention on the filling process.

 If I have to attend to something else, I let go of the switches, and

 the pumping stops right there. In 1100+ hours of flying,

 this has worked well. During a cross country flight, I

 typically pump up the header tank every 30 min or so,

 which is done rather quickly. Actually, it gives me something

 to do and reminds me to think about the fuel supply.



 Happy flying,



 Klaus

grs-pms(at)comcast.net
Guest

Posted: Thu Jul 17, 2008 2:27 pm Post subject: Over filling during flight?

A big second to Larry's comment, re Klaus' solution to over-filling the 

header tank. This is what one of my engineering profs would have called "an 

elegant solution".  No added weight, no added complexity, and if you do it 

from the beginning, no added cost.  I'm going to modify my still incomplete 

601HD accordingly.  Thanks, Klaus!



George Swinford



do not archive.



---

raymondj(at)frontiernet.n
Guest

Posted: Thu Jul 17, 2008 2:44 pm Post subject: Over filling during flight?

Greetings Klaus,



    How have you integrated fuel management into your emergency restart 

checklist?



Raymond Julian

Kettle River, MN



"Hope for the best,

but prepare for the worst."



---

klaus(at)utdallas.edu
Guest

Posted: Fri Jul 18, 2008 12:36 pm Post subject: Over filling during flight?

Hi Raymond,



You ask:

How have you integrated fuel management into your emergency

restart checklist?



The checklist depends on the engine and the tank system.



In case of complete engine failure:



1. Trim plane for best glide speed. Unless there an is unusual situation,

the propeller of the Rotax 912, 912S, or 914 will stop

due to the high compression ratio

of the engine and the fact that the propeller is geared. For direct

drive engines, the propeller likely will be windmilling.



2. Pick out a landing site. Fly toward the landing site at optimal glide 

speed.



3. If there is time for a restart atttempt:

3.1 (Here comes a controversial part) If this is a Rotax engine,

turn off the avionics since otherwise

the radios may be blown by surge voltages during the starting. (This nasty

aspect of the Rotax engine is not exhibited by direct-drive engines

that would be windmilling. In that case, the generator continues charging

and the starter is not needed in the restart attempt, a definite plus. 

On the other hand,

a windmilling propeller has more drag than a stopped propeller, a definite

minus as far as the glide ratio is concerned. )

To prevent starting of the Rotax engine with avionics turned on, we have

it set up that the starter can be activated only if the avionics are off

(another controversial part).



3.2 In the case of a direct

drive engine with windmilling propeller, check the oil pressure. If it is

zero, the engine is cooked and it's best to focus on everything

else. (The Rotax engine does not provide that

clue since it will be stopped and will have zero oil pressure regardless

of the condition of the engine.)

3.3 Turn on the boost pump.

3.4  601s with centertank and wing tanks:

If fuel level in the main tank is low, activate and hold the transfer

switches (here is a disadvantage that they are spring loaded and must be 

held.

On the other hand, if the switches are on/off, then forgetting later 

that they have

been turned on may overfill the center tank and create an extremely

dangerous situation during an emergency landing.)

601s with two leading edge tanks: Switch tanks.

3.4 Open throttle halfway.

3.5 Crank engine.



4. If engine does not restart and there is time left:

turn off fuel supply to engine, turn on avionics again

if turned off before,  and make emergency call on 121.5.



5. When over the emergency landing site, begin circling.

When about 1000 ft AGL, go for the landing. If this is an HDS, dive for 

the landing area

and do not try to fly an approach pattern, since likely the attempt will end

short of the landing area (The message for HDS pilots to remember is

"Dive for the landing"). For HD and XL, the glide ratio is better and 

one must

make sure not to come in too high. But if this is actually an airport, then

nevertheless dive for the runway and dissipate any remaining altitute by 

forward slip.)



Here is one more thought. We take off from a familiar airport so many times

that we become quite sure that this will always be successful. Next time 

you take

off and begin the climb, you may ask yourself repeatedly, as you

gain altitude,  the question "If the engine quits right now,

where should I land?" It may be that you will have

think about this. Well, doing it now is be better that when the real thing

happens.



Happy flying,



Klaus

*

*

*

*

raymondj(at)frontiernet.n
Guest

Posted: Fri Jul 18, 2008 1:50 pm Post subject: Over filling during flight?

Klaus,



    Thanks for the detailed reply.  You bring up several things about a 

geared engine I had not given any thought to.



    I was curious where you put the pumping fuel to the header in the list. 

I assume you hold the switches while you are cranking the engine, or perhaps 

I should say I think I would.  It makes sense to me now.



Thanks again for taking the time to reply.



Raymond Julian

Kettle River, MN



"Hope for the best,

but prepare for the worst."



do not archive



---

klaus(at)utdallas.edu
Guest

Posted: Mon Jul 21, 2008 10:35 am Post subject: Over filling during flight?

Hi Raymond,



Yes, the fuel transfer switches are activated while the engine is cranking.



A point I forgot in the previous list for engine restarting:



The most important steps should be taken before the engine has fully quit.

Here is a list that seems reasonable when the engine does run okay,

say is losing rpm or runs rough or stutters.



1. If there is manual mixture control, go to full rich.



2. Turn on auxiliary fuel pump.



3. Switch tanks if fuel is alternately taken from two tanks.

If there are a main tank and auxiliary tanks: check fuel level in main 

tank and

begin transfer if not at max level.



4. If there is carburetor heat and there is even a remote possibility

of carburetor ice: Pull carburetor heat. It will take a bit of time

for the ice to melt and the engine to speed up again.

The ideal temperature for carburetor ice is 68 degF OAT since the

air temperature drops by 36 degF in the carb venturi. But this is

by no means a rule. I have had carb ice with a Lycoming engine

that is not very susceptible to that problem, on a clear day with

good visibility at  32 degF OAT. Make sure that this action

is taken without delay, since otherwise preheat

may no longer work.



5. Check the oil temperature. If the temperature is unusually low or

unusually high, then most likely the engine is cooked. This is the

best tool for diagnosing a failed engine. (I did not learn this as

a student pilot, but was told about this later by experienced pilots.)



6. Check the engine oil pressure. If it is very low or zero, again

the engine is cooked.



7. (Rotax) Check coolant temperature. If excessive, engine will

fail shortly. Reduce power as much as possible while working

on landing site.



Happy flying,



Klaus



-- 

Klaus Truemper

Professor Emeritus of Computer Science

University of Texas at Dallas

Erik Jonsson School of Engineering and

  Computer Science EC31

P.O. Box 830688

Richardson, TX 75083-0688

(972) 883-2712

klaus(at)utdallas.edu

www.utdallas.edu/~klaus

raymondj(at)frontiernet.n
Guest

Posted: Tue Jul 22, 2008 7:44 pm Post subject: Over filling during flight?

Thanks for  the added info and suggestions.



Raymond Julian

Kettle River, MN



"Hope for the best,

but prepare for the worst."



do not archive



---

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