Cessna flap relay

SPAJC

SPAJC

Pre-takeoff checklist
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Jeff
Well, here we go....after all of the responses to my thread about my flaps sticking, I believe I have found the culprit....thanks for all the help!!! Now that I know where the problem is, I can't figure out where to get the part from.

There is a relay or solenoid mounted to a rib about a foot in-board from the flap motor. It is small, rectangular, and has four wires that connect to it; one on each side. I believe it is flaky and needs to be replaced.

Can anyone tell me where to find one??? Not only is it not listed on the wiring diagram, I can't find anything even similar to it from any parts supplier. I saw where another 150 owner had the same problem and posted the same question on the Cessna Owner Forum, but, received no answers. Please help! It is a 1965 Cessna 150F. Thanks in advance for any advice!!!

61ec58e9e041620acec5e27b805c9dec.jpg



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I just went through my Cessna 150 parts catalog (admittedly for 1970-1977, but should be similar for electric flaps), and I couldn't find anything like that in the diagrams. Then I reread your description and looked at the picture again. Those crimp connections don't even look like factory stuff, and no part number on it?
Where do those wires go?
 
They are part of the harness that goes to the flap motor. Best I can say. I made the same observation about the automotive electrical connectors. The wiring diagram doesn't show a relay that I can tell. I'm no expert with wiring diagrams, but I do ok with them and don't see a relay. Apparently it is standard just from reading some stuff online. Why it has been at least seemingly re-wired like it has,I don't know. Maybe it hasn't, but I was under the impression that there are a specific type of connector required for aircraft applications. Maybe it doesn't matter....don't know. But, either way, I need to replace it and can't find it anywhere. All I find are solenoids similar to what would be under the hood of a 70's model truck.


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Yeah, those connectors look just like the stuff you get from O'Reilly Auto Parts. And the fact that they're open and near the airframe metal seems suspect.
I'm baffled.
There should be someone with far more knowledge along soon with better information.
 
Aeric said:
I just went through my Cessna 150 parts catalog (admittedly for 1970-1977, but should be similar for electric flaps), and I couldn't find anything like that in the diagrams. Then I reread your description and looked at the picture again. Those crimp connections don't even look like factory stuff, and no part number on it?
Where do those wires go?
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That's a good observation and question to follow up on. That's what good mechanics do! This thing was probably built in 1964-1965 and those could be factory terminals, easy to verify by looking throughout the airplane. The wires look factory and labeled.

Something to keep in mind when researching parts. When you can't find it in the books you have its quite possible they were installed via service bulletin or other and your books don't reflect that.
 
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The wires are clearly factory or at least somewhat official. The relay looks over built, overpriced, and obscure, so it is probably a legit aviation part. The connectors do appear to have been replaced by someone using off the shelf automotive connectors though.
 
The legit aviation part is probably a legit automotive part. Such was not uncommon in the era. After the big Navion fuel valve AD fiasco, I have a replacement valve, identical to the one that was there before except it now has a part and serial number stamped on it and a sheet of ICA's.
 
The wiring drawing looks like there are 4 diodes and two resistors.

Flag 1 says those terminal when installed on the relay are to be soldered to the relay. That relay sure looks like a replacement as the crimp terminal were cutoff to get the old one out. They don't appear to be soldered to the relay anymore.
 
bnt83 said:
I really hope your A&P could find this.



I see a relay p/n 0420017-2 on wiring diagram no. 0410011 revision A, which is page 575 of 784.



http://www.redskyventures.org/doc/c.../Cessna_100_Series_1962-1968_MM_D637-1-13.pdf
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Awesome info!!! Thanks for the info Brian! That is a different diagram than the one that I have. Mine doesn't show a relay. I'll get to looking for the part now!!!! BTW, three of the connectors pulled right off. There was only one that was soldered. This is actually why it was still in the airplane when I photo'd it. I couldn't get that wire off and didn't want to cut just yet. I probably should have mentioned that, but didn't think it was relative and it didn't occur to me to put it in there. I did remove it and look for a part number, it was just dangling from that one wire under the wing while I looked at it. My AP hasn't looked at it yet. He APs on the side. He is in the first responder field just like I am and as such his schedule sucks just as bad....thanks for the help all!!!! This really helps!!!!


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SPAJC said:
Awesome info!!! Thanks for the info Brian! That is a different diagram than the one that I have. Mine doesn't show a relay. I'll get to looking for the part now!!!! BTW, three of the connectors pulled right off. There was only one that was soldered. This is actually why it was still in the airplane when I photo'd it. I couldn't get that wire off and didn't want to cut just yet. I probably should have mentioned that, but didn't think it was relative and it didn't occur to me to put it in there. I did remove it and look for a part number, it was just dangling from that one wire under the wing while I looked at it. My AP hasn't looked at it yet. He APs on the side. He is in the first responder field just like I am and as such his schedule sucks just as bad....thanks for the help all!!!! This really helps!!!!


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FWIW that same service manual link says "A relay, mounted in the right wing near the flap motor is incorporated into flap circuits of 150 serial 15062291 thru 15063135, a service kit (SK150-16) is available to install on earlier models if desired." on page 185 of 784.

SK150-16 is mentioned in service letter SL65-098 titled "Flap System Change, to prevent blowing fuses".

Diodes on the drawing appear to be internal to the relay.
 
Lotta history there.


Factory Configuration --->

SK150-16 (October 18, 1965) relay install to prevent fuses blowing

SL68-01 (January 12, 1968) lubrication of jackscrews

AD72-03-03 Modify Flap Actuators (been revised several times including superseding AD 70-15-16

SK150-37 (March 3, 1972) hydraulic snubber install to prevent slippage (AD)

SE72-17 (May 19, 1972) Replacement of actuator components

SK150-41 (October 20, 1981) replaces actuator, snubber, and wiring.
 
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You could probably get one for a lot of dollars from Cessna, who bought it from GM as a horn relay OR you could go to the aforementioned "O'Reilly's" an tell them it was from a '65 Chevy/Olds/Pontiac/SomeGM and get the same part for nickels and dimes.

Your call.

Jim
 
8964b13e6cfe8bf5c12d1a2e51e6c7b0.jpg


I found one!!!! It has definitely been discontinued....looks like those connectors are original. $100 out the door....not as bad as I thought it would be.

Thanks for all the help!!!!!


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SPAJC said:
I found one!!!! It has definitely been discontinued....looks like those connectors are original. $100 out the door....not as bad as I thought it would be.

Thanks for all the help!!!!!


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Hope it solves your problems.
 
Fixed!!! Thanks for the help everyone!!!! It is greatly appreciated!!!!!! I've not gone wrong yet by posting my questions on this forum...a lot of knowledge and experience here that newbies like me are grateful for. Have a great day!


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Jim,

In the absence of a replacement part, such as in my case where the part has been discontinued, would it be legal to use an automotive replacement to repair? Otherwise how else would we repair it?? The shop that has the replacement said that it would not come with an 8130 because it was manufactured before the 8130s were in use...so, it wouldn't have one anyways. They just happened to have a new one sitting in the back of the shop, brand new in the package from Cessna. Apparently the last one in existence from my searching. Otherwise, i wasn't able to find anything anywhere else. I did find a reference to a part that it was replaced with, which is similarly unavailable. Thanks!


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It's a simple 12v horn relay, there is ability to come up with "owner produced parts" not all A&Ps are afraid of using a perfectly safe and useable low cost replacement part that operates at the same specifications. The relay itself didn't get discontinued, it was just replaced in industry with a different form.
 
SPAJC said:
I agree completely....i'm just wondering what the legalities would be


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Legal. Worst that can happen is that the FAA would somehow spot it and make you change it before you fly again, that's the worst.
 
SPAJC said:
Jim,

In the absence of a replacement part, such as in my case where the part has been discontinued, would it be legal to use an automotive replacement to repair? Sent from my iPhone using Tapatalk
Click to expand...

It is NOT legal to use an automotive replacement part directly without some sort of process to make it legal. Fortunately the Feds recognized this some years ago and said that it was legal for the owner/operator to MANUFACTURE their own part(s) for factory aircraft.

Then the FAA Chief Legal Beagle got into the mix and wrote one of the most magnificent opinions I've read in a very long time. And, it has been challenged and stood the test of the court.

Basically it is this ... MANUFACTURE takes many turns and twists and the opinion is about as wide open as I've ever seen anything come out of the FAA. If you take a stock part (like a relay) and materially modify it in any way, you have MANUFACTURED it. If you take your own drawings to a machine shop and they make the part you have MANUFACTURED it.

In the case of a horn relay, I do hope that there was a misdrilled hole or two in the case that you had to drill out to make it fit into the airplane. IF that is so, then you MANUFACTURED it because it is different from the part you bought at AutoZone. I'm SURE you had to drill a hole or two to make it fit the airplane, and therefore you have a perfectly legal 21.303 (b)(2) part.

The logbook entry goes something like this:

"Replaced flap actuator relay with owner-manufactured part per FAR 21.303 (b)(2). Checked operation and satisfactory. Signed John Owner, countersigned Jack Wrench A&P"

Did that help?

Jim
 
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weirdjim said:
It is NOT legal to use an automotive replacement part directly without some sort of process to make it legal. Fortunately the Feds recognized this some years ago and said that it was legal for the owner/operator to MANUFACTURE their own part(s) for factory aircraft.

Then the FAA Chief Legal Beagle got into the mix and wrote one of the most magnificent opinions I've read in a very long time. And, it has been challenged and stood the test of the court.

Basically it is this ... MANUFACTURE takes many turns and twists and the opinion is about as wide open as I've ever seen anything come out of the FAA. If you take a stock part (like a relay) and materially modify it in any way, you have MANUFACTURED it. If you take your own drawings to a machine shop and they make the part you have MANUFACTURED it.

In the case of a horn relay, I do hope that there was a misdrilled hole or two in the case that you had to drill out to make it fit into the airplane. IF that is so, then you MANUFACTURED it because it is different from the part you bought at AutoZone. I'm SURE you had to drill a hole or two to make it fit the airplane, and therefore you have a perfectly legal 21.303 (b)(2) part.

The logbook entry goes something like this:

"Replaced flap actuator relay with owner-manufactured part per FAR 21.303 (b(2). Checked operation and satisfactory. Signed John Owner, countersigned Jack Wrench A&P"

Did that help?

Jim
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It goes even further, you can be involved by providing the specification to the supplier. You don't have to modify it at all.
 
Henning said:
It goes even further, you can be involved by providing the specification to the supplier. You don't have to modify it at all.
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Yep. But I doubt providing FlyByNight Auto Parts Store with a specification that reads, "Horn Relay from a 1955 Pontiac" will pass even the loose muster of Chief Counsel :goofy:

Jim
 
weirdjim said:
Yep. But I doubt providing FlyByNight Auto Parts Store with a specification that reads, "Horn Relay from a 1955 Pontiac" will pass even the loose muster of Chief Counsel :goofy:

Jim
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"Normally open Relay that handles (state required amperage here) at (state required voltage here) found in AC/Delco part #" and the Delco Part probably has a MilSpec # that makes things even easier.
 
Well, I was apparently wrong. I thought they were fixed...went flying today. They worked fine on the first approach. Took off for another trip around the pattern and got to practice my no flap landings....going to check a couple of things when I get another chance. But, the motor is working fine when it works. Then it just stops....you can hear it clicking when you hit the switch, so I know theres power coming out of the switch. Other than checking for poor connection again, any ideas? Is this symptomatic of a failing flap motor even though it runs great when it runs? I ran the flaps up and down probably 20 times the other day and not a single hiccup. Worked great for the pre-flight and first approach today, then stopped on the second approach. Wouldn't budge a bit when I hit the switch. Thoughts on this appreciated as always!!!!


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SPAJC said:
Well, I was apparently wrong. I thought they were fixed...went flying today. They worked fine on the first approach. Took off for another trip around the pattern and got to practice my no flap landings....going to check a couple of things when I get another chance. But, the motor is working fine when it works. Then it just stops....you can hear it clicking when you hit the switch, so I know theres power coming out of the switch. Other than checking for poor connection again, any ideas? Is this symptomatic of a failing flap motor even though it runs great when it runs? I ran the flaps up and down probably 20 times the other day and not a single hiccup. Worked great for the pre-flight and first approach today, then stopped on the second approach. Wouldn't budge a bit when I hit the switch. Thoughts on this appreciated as always!!!!


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Did you clean the motor and check the brushes yet?
 
SPAJC said:
Well, I was apparently wrong. I thought they were fixed...went flying today. They worked fine on the first approach. Took off for another trip around the pattern and got to practice my no flap landings..../QUOTE]


You can run them up and down all day on the ground, but when you get an air load on them aloft, then "something" is jamming the system. It might be a brush problem. It might be a linkage problem that is jamming when forced by the sliipstream. Lots of stuff MIGHT be the culprit. Now you get to play Sherlock.

Good luck, and aren't you happy you didn't spend Cessna money on that part?

Jim
Click to expand...
 
Not yet. Getting ready to...went through checking connections and such and thought that I had located the problem in a loose wire connection and fried relay. Stopped there when I thought that it was fixed.


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SPAJC said:
Not yet. Getting ready to...went through checking connections and such and thought that I had located the problem in a loose wire connection and fried relay. Stopped there when I thought that it was fixed.


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Or there is a dead spot in the motor. You can find them all over ebay cheap.
 
SPAJC said:
Not yet. Getting ready to...went through checking connections and such and thought that I had located the problem in a loose wire connection and fried relay. Stopped there when I thought that it was fixed.


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You failed in the diagnostic order, you bought a part before completing all the 'service' items. You also didn't test or open the old relay to inspect it before replacing. Checking connections and securing them was good, but you should have held off on replacing the relay until you had cleaned and serviced the motor. Brushes for the motor are a couple of bucks. When you start pulling out 'The parts gun', you always start with the cheap parts first, but you only replace parts when they fail testing / inspection.
 
SPAJC said:
fried relay. Stopped there when I thought that it was fixed.
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Parts don't "fry" without a reason. Sorry you had to learn that lesson. Replacing "fried" parts without finding the frying pan is what we call in the business "shotgunning". That is, replacing parts that hit the shotgun blast without rhyme nor reason.

Troubleshooting is an art. You've just had your first lesson.


Jim
 
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bnt83 said:
Or there is a dead spot in the motor. You can find them all over ebay cheap.
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What the hell is a "dead spot in the motor"??? Motors don't have dead spots. Motors have rotors. Motors have stators. Motors have brushes. Motors have a lot of things, but "dead spots" aren't on the list.

Please go play in some other sandbox.

Thanks,

Jim
 
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