Fuel strainer under pilot's knees--curtis drain valve replacement??

[Dcflyn]

Ok, so our fuel strainer (the one controlled from the pilot floor) is frozen shut. It is evidently not rebuildable. Has anyone replaced the valve with a curtis drain valve and gotten a field approved 337? Help!

[KSMooniac]

Call LASAR in CA.  

[Dcflyn]

Call LASAR in CA.  

 

Did that. They said good luck.

[KSMooniac]

wow, that sucks!  If they don't have a solution, that ain't good.  I'd be surprised if you can get a field approval for anything different but you might ask your IA.

 

I'm not sure if the one in my '77 J is the same part or not, but I might have it available in another month or so.  I'm debating about converting my plane to the later configuration with the selector in front of the center console vs. under the pilot's knees.

[Mooneymite]

Can you post a picture?

 

From what I remember of mine, it is lead-pipe simple.  Seems like owner fabricated parts are possible?

[Dcflyn]

No doubt that we could fabricate a curtis drain valve, but at next annual we'd have to get it signed off. Mooney has a replacement kit. Not in stock, 90 day turnaround and $970. Not if I can help it! I need to find a 337 already done. I'm having trouble posting photos here--please scroll to the bottom of the page here for a close up of the part: http://n2690w.blogspot.com/2014/03/back-on-her-feet-again.html

[Guest]

A while ago I was at the Quality Aircraft auction in Florida. A few vintage Mooney fuel selectors were bought by Dave from Airmods in New Jersey if my memory is right.

Failing that I would remove the unit and soak it in an ultrasonic cleaner with LPS 1 or kerosine, for a few days. You may be able to get it apart.

Clarence

[rangermb]

Hey Scott...I have a 77J as well and am interested in someday moving the selector to the center as I am not built like either an NBA star of Chinese contortionist. Is there any info and/or drawings available for the move? Any guesses on the overall cost?

 

Thanks

 

Mike

[Andy95W]

Dcflyn,

My first M20C had a Curtis valve replacement. I bought that airplane in 1992. Since I was new to Mooneys at the time, I never thought anything of it and figured that all of them were like that. My POH had been modified to note that the drain was now manipulated outside the airplane rather than inside. There was no 337 associated. I was not an IA at the time, but I never had a problem with my annuals being signed off. I guarantee that airplane is still flying with the same Curtis valve and without a 337.

As for modification, it is really a tough call from an IA viewpoint. On one hand, the valve is simply a drain that is actuated by hand and uses a spring to return the valve to a closed position - exactly the same description as the Curtis valve. The Curtis valve, in fact, is preferable because it allows the use of a sampler cup to see sediment or water in the catch sample. As such, that would not constitute a major alteration, it would be a minor alteration, which would not required a 337, as long as the part had some form of approval such as MIL-SPEC.

But on the other hand, one FAA checklist I have from my FSDO notes "Changes to or relocation of exterior fuel vents, fuel drains, or battery vents. (Applicable to components not attached to the basic engine.)" as requiring an "evaluation" to determine if the Field Approval process would even apply. I have known some inspectors who would agree that you are not changing the design of the system, only parts, and therefore it is a minor alteration. And there are others who would freak out and accuse you of single-handedly trying to bring down general aviation.

Bottom line? I would try for a field approval based upon lack of availability of original parts, to increase safety in order to be able to use a sample cup to observe the drained fuel, and show how other aircraft manufacturers use the exact same setup. (I believe the Piper Arrow does, I am positive the Piper Aztec does.)

If not that, then I would consider finding an old-school A&P, give him the Curtis valve as an owner supplied part, and ask him to replace the existing drain valve with the Curtis and do a logbook entry.

Good Luck,

Andy

[KSMooniac]

Hey Scott...I have a 77J as well and am interested in someday moving the selector to the center as I am not built like either an NBA star of Chinese contortionist. Is there any info and/or drawings available for the move? Any guesses on the overall cost?

 

Thanks

 

Mike

 

Hi Mike,

 

I'm sure there are drawings in/at Mooney, but not needed in my opinion for this switch.  I have an '81 salvage J, and I'm going to transplant the center console and engine controls into my '77 and get rid of the ****ing throttle quadrant.  I'm debating about going ahead and moving the fuel selector as well.  In my opinion (and that of my mechanic friend) this can be done with a logbook entry since we're just moving Mooney parts from one M20J to another M20J.  The parts manual of course shows/confirms what is used as well.  I'm getting new engine controls for this switch too.

 

Cost for me is pretty much just my labor, which is worth $0/hr for this Mooney addiction/hobby.  I try not to think about lost OT pay.    I don't even have an estimate of how long it will take yet since I haven't pulled those parts from the salvage cabin yet, but should do it this weekend.  I don't know the cost of used parts from somebody like LASAR or Jerry Pressley, but those are the two sources I'd contact first.  Fuel selectors are expensive, though.  Some of the cost could be offset by selling your current selector after the fact since the pre-J birds use the same one.

 

Not sure if all that effort will be worth it to you or not.  I think I'll do it "while I'm in there" since it is a nicer configuration.  I don't have any trouble using the current selector.  I've seen folks make a helper tool out of PVC by notching the end to grab the lever, and that way they don't have to reach all the way to the floor.  You might try that if it is a problem for you.

 

Scott

[KSMooniac]

If not that, then I would consider finding an old-school A&P, give him the Curtis valve as an owner supplied part, and ask him to replace the existing drain valve with the Curtis and do a logbook entry.

Good Luck,

Andy

 

I would do exactly this if I were in your shoes.  I can't imagine any FSDO inspector recognizing such a change in the first place, and certainly not giving you grief about it.

[jetdriven]

the issue is how can you make the curtis drain valve actuate from the pull ring inside?

[M20F-1968]

I have a fuel drain/sump and fuel selector from an Ovation.  As Mooney parts you should be able to use the drain/sump in a Lycoming set-up without many issues. Pictures are attached.  I also have a fuel selector/drain unit which is a copy of the H&E.  It was built in Ohio but not sure which aircraft it was used on but it is a certified aircraft part as it came from Wentworth.  Picture also attached.

 

You can reach me at johnabreda@yahoo.com or call at (617) 877-0025.

 

John Breda

[Andy95W]

the issue is how can you make the curtis drain valve actuate from the pull ring inside?

You would no longer use the pull ring on the inside. You would use a sampler cup directly on the curtis valve just like you do the fuel drains on the wing tanks. The curtis valve would stick out of the fairing in the same place the current drain sits.

[cliffy]

I'm willing to bet that if you present the curtis valve idea to the local FSDO Maint guy telling him you'd like to do it as a minor alteration he'll go along with it. Have pictures or something to support your idea. Tell him also that it is an improvement in the design because NOW you will be able to see if there is any water in the gascolator instead of it just draining on the ground where you can't see it. Also include a comment about installing a placard or POH revision sheet to tell pilots of the change, I've done this before and had good results on other ideas.