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A smidge of good news

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kkinney

Joined: 11 Jan 2006
Posts: 42

Posted: Wed Dec 09, 2009 5:29 pm Post subject: A smidge of good news

I've debated whether or not to post this. In the end, I figured it could help others, even if it does my ego no good.



My 601XL took to the air on 11/21 and she flew like an airsick angel. Yes, airsick, although it shouldn't reflect on either the airframe or engine.  Only on the pilot & builder.



On takeoff I bobbled the rotation (a merciful interpretation) and flew in ground effect to pick up speed. Near the end of the runway, the RPM dropped. I had previously studied the satellite photos and knew turning left would give me more options.



A left turn brought me in line with a long field. At 50-100 feet, you don't have time to run an emergency checklist. I wasn't able to flip the comm over to the standby freq; 121.5. I didn't have time to flip the transponder over to the standby code; 7700. I think I called a pan-pan and committed to an off-field landing. 



After avoiding a tree line, I pulled back the throttle to land.  RPM's picked up.  I didn't think it was supposed to work like that, but that was something for later. I maintained altitude but was running out of field and made another left turn to a shorter field.



I continued the left hand turn and (maybe) climbed above the tree line.  Soon I saw my first field and maneuvered for this.  If necessary, I could land there or continue back to the pavement.



RPMâ€™s held steady and I headed back to the runway.  The landing was far better than the take off and I taxied back to the FBO.



The culprit was a partially clogged fuel filter.  As I figure it, full throttle resulted in a too lean mixture and reducing throttle balanced the mixture.

In preparation for first flight, I made about 8 full power taxi run-ups to avoid fuel problems like this.  I didn't want to get above stall speed, so this limited me to about 10 seconds of full power.  This wasnâ€™t enough time to deplete the carb reservoir.



In hind sight, there were a couple things I could have done to detect this problem.  I could have either stood on the brakes and run up the engine for over 30 seconds.  This would have done bad things to the cylinder temps.  Alternately, I could have prepped for first flight and held full power for 30 seconds regardless of the speed.



Iâ€™d like to thank Dave Gallagher and Dennis Hardison.  Both are better pilots than I and did a great job at hiding their concern.  My wife & two boys didn't know anything was unusual until after I shut down the engine.

Dave provided a great deal of support in diagnosing the problem and suggesting how to avoid the problem in the future.

My tech counselors were Gary Collins and the late Howard Wells.  (We miss you, old man.) Neil Hulin provided support and inspiration early in the build process.

And finally Iâ€™d like to thank my wife for her support.  Without her, it wouldn't have been necessary to spend so much time in the garage.



Regards,

Kevin Kinney



P.S. After changing the fuel filter and more testing, we flew a traditional rectangular pattern.  Let flight testing proceed!!

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Wed Dec 09, 2009 5:47 pm Post subject: A smidge of good news

Is your fuel filter upstream or downstream from your fuel pump?



 	  Quote: 	
		   

 

 I've debated whether or not to post this. In the end, I figured it could help others, even if it does my ego no good.

 

 My 601XL took to the air on 11/21 and she flew like an airsick angel. Yes, airsick, although it shouldn't reflect on either the airframe or engine.  Only on the pilot & builder.

 

 

 The culprit was a partially clogged fuel filter.  As I figure it, full throttle resulted in a too lean mixture and reducing throttle balanced the mixture.

 In preparation for first flight, I made about 8 full power taxi run-ups to avoid fuel problems like this.  I didn't want to get above stall speed, so this limited me to about 10 seconds of full power.  This wasnâ€™t enough time to deplete the carb reservoir.


	


-- 

Bryan Martin

N61BM, CH 601 XL,

RAM Subaru, Stratus redrive.

do not archive.

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

craig(at)craigandjean.com
Guest

Posted: Wed Dec 09, 2009 5:57 pm Post subject: A smidge of good news

I'm glad this ended well and thanks for posting. I'm not trying to second guess you, just curious: did you do a fuel flow test of the final complete fuel system?



-- Craig 



--

carlossa52(at)gmail.com
Guest

Posted: Wed Dec 09, 2009 6:01 pm Post subject: A smidge of good news

Kevin, congratulations on your first flight!!



Carlos

CH601-HD, plans

Riveting centre wing

(do not archive)



2009/12/9 kkinney <kkinney(at)fuse.net (kkinney(at)fuse.net)>

 [quote]--> Zenith-List message posted by: "kkinney" <kkinney(at)fuse.net (kkinney(at)fuse.net)>

  

 I've debated whether or not to post this. In the end, I figured it could help others, even if it does my ego no good.

 

 My 601XL took to the air on 11/21 and she flew like an airsick angel. Yes, airsick, although it shouldn't reflect on either the airframe or engine.  Only on the pilot & builder.

 ..[b]

pchap(at)primus.ca
Guest

Posted: Wed Dec 09, 2009 6:14 pm Post subject: A smidge of good news

A smidge of good news?



I can probably speak for a few:   Not losing the aircraft and being 

alive is pretty damn good.



Good example for us all about how partial power or short full power 

run-ups may not always be enough.

Also, demonstrating the case where reducing throttle can improve 

engine performance if the problem is a limitation on fuel flow.



While pilots have to talk with their families at some point about the 

real risks, it was maybe not a bad thing that not everyone understood 

what was happening.



I didn't have much fun one time while watching my dad get a plane 

around a low circuit with a sick engine. Even though he had plenty of 

glider time and understood stalls, there's little latitude for 

mistakes. I've also lost two friends in crashes with sick engines, 

spinning in while trying to get back. If the engine in either case 

had just plain quit, their chances dropping it into a field would 

have been much better.

DO NOT ARCHIVE



Peter Chapman

Toronto, ON           601 HDS  /  912  /  C-GZDC

Ron Lendon

Joined: 10 Jan 2006
Posts: 685
Location: Clinton Twp., MI

Posted: Wed Dec 09, 2009 6:58 pm Post subject: Re: A smidge of good news

Kevin,



That's way better than a Smidge. Thank you for letting out the details, it has helped me and I'm sure others will also benefit from this post.



Again, Thank You,

_________________
Ron Lendon
WW Corvair with Roy's Garage 5th bearing
CH 601 XLB
N601LT - Flying
http://www.mykitlog.com/rlendon
Corvair Engine Prints:
https://sites.google.com/site/corvairenginedata/

kkinney

Joined: 11 Jan 2006
Posts: 42

Posted: Wed Dec 09, 2009 7:06 pm Post subject: Re: A smidge of good news

I knew fuel difficulties are the main causes of first flight problems so I did a lot of fuel testing.  



Early last summer, I did a full fuel flow test at level and climb attitudes.  Both came out at 300% of max fuel flow.  

To flush the system, I circulated fuel through the filters and back into the tanks.  I checked both gascolators and found them clean.  The final filter was enclosed so I couldn't examine that.



What I did wrong - 

1) My fuel pressure sender is in the wrong spot.  It's before the final fuel filter.  I'm considering moving it between the mechanical pump & carb.

2) A fuel flow test 6 months ago wasn't good enough.  I should have done one before the first flight.



Either of these would have avoided the situation.  I'm kicking myself for not realizing before my first flight.



If you take one thing away from my experience, make sure you do a fuel flow test in the days before your first flight.  



Keep learning, 

Kevin Kinney

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Wed Dec 09, 2009 7:41 pm Post subject: A smidge of good news

It's a whole lot easier to push fuel through a partially clogged filter than to suck fuel through one. The final fuel filter should be downstream of the fuel pump. You have a finger screen in the tank and probably a gascolator upstream of the pump, that should be plenty. Even in automobiles, the filter is downstream of the pump.



The fuel pressure sender should definitely be just upstream of the carburetor, that's the only place where fuel pressure matters. Any fitting, sharp bend or filter will cause a pressure drop in the fuel flow.



 	  Quote: 	
		   

 

 I knew fuel difficulties are the main causes of first flight problems so I did a lot of fuel testing.  

 

 Early last summer, I did a full fuel flow test at level and climb attitudes.  Both came out at 300% of max fuel flow.  

 To flush the system, I circulated fuel through the filters and back into the tanks.  I checked both gascolators and found them clean.  The final filter was enclosed so I couldn't examine that.

 

 What I did wrong - 

 1) My fuel pressure sender is in the wrong spot.  It's before the final fuel filter.  I'm considering moving it between the mechanical pump & carb.

 2) A fuel flow test 6 months ago wasn't good enough.  I should have done one before the first flight.

 

 Either of these would have avoided the situation.  I'm kicking myself for not realizing before my first flight.

 

 If you take one thing away from my experience, make sure you do a fuel flow test in the days before your first flight.  


	


-- 

Bryan Martin

N61BM, CH 601 XL, 

RAM Subaru, Stratus redrive.

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

sdthatcher

Joined: 13 Mar 2008
Posts: 91
Location: Port Saint Lucie

Posted: Thu Dec 10, 2009 6:03 am Post subject: Re: A smidge of good news

Great job Kevin keeping your options open and the plane in the air!  It doesn't always work out that way.



Scott Thatcher

N601EL w/WW Corvair 40+ hours

http://placestofly.com



 	  kkinney wrote: 	
		  I've debated whether or not to post this. In the end, I figured it could help others, even if it does my ego no good.



My 601XL took to the air on 11/21 and she flew like an airsick angel. Yes, airsick, although it shouldn't reflect on either the airframe or engine.  Only on the pilot & builder.



On takeoff I bobbled the rotation (a merciful interpretation) and flew in ground effect to pick up speed. Near the end of the runway, the RPM dropped. I had previously studied the satellite photos and knew turning left would give me more options.

Regards,

Kevin Kinney



P.S. After changing the fuel filter and more testing, we flew a traditional rectangular pattern.  Let flight testing proceed!!

sonar1@cox.net

Joined: 02 Oct 2007
Posts: 55
Location: Santa Barbara, Ca

Posted: Thu Dec 10, 2009 8:11 am Post subject: Re: A smidge of good news

Good job Kevin! I had a forced landing in a disked field in my 701 because of a clogged fuel filter. I used the little filter 05-01031  from Aircraft Spruce - cute, small, transparent, and rated for more than enough fuel flow. Over 20 hours, it got clogged with little transparent threads - I suppose from the airport fuel supply. I would warn everyone to avoid these, and go for a larger filter.

Fred Sanford  N9701

craig(at)craigandjean.com
Guest

Posted: Thu Dec 10, 2009 9:34 am Post subject: A smidge of good news

Are you sure about the 05-01031 p/n? Spruce shows that as "In-tank type.

Brass construction with fine-mesh screen. Has standard 1/4" barb inlet and

outlet tubes.". This picture shows an in-tank part made entirely of metal.



-- Craig



--

aussiech650

Joined: 04 Oct 2009
Posts: 25
Location: Sydney, Australia

Posted: Thu Dec 10, 2009 10:33 am Post subject: Re: A smidge of good news

Thats great advise Fred, the ability of the fuel filter to prevent clogging is directly proportional to the surface area of the filtration media. At all times, when it comes to fuel filters, the bigger the better and always on the pressure side between the pump and the fuel metering device (carby or injector)

wjones(at)brazoriainet.co
Guest

Posted: Thu Dec 10, 2009 11:52 am Post subject: A smidge of good news

Good job Kevin ,Anytime you can save yourself and your machine you have 

performed well .I have been flying these planes for over 50 years and have 

never had additional fuel filters other than the ones inside the tanks and 

gascolater screens .If you need additional filters you should maybe consider 

buying your fuel someplace else . I have seen too many planes go down from 

plugged fuel filters .I know some will say what does he know ,I can only say 

it has worked for the last 50 years .Wade Jones AP/IA

---

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