New Owner
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Re: New Owner
I had a local graphics shop make the vinyl decals for the yoke. I have the same decals only much larger for the tail. I gave them a picture and told them to scale it to 1'' high for the yokes and it turned out perfect. I also had them make a new baggage placard, 2'' N numbers for the tail, N number for the panel, and serial number decal for the aft left side of the fuselage. They did great work and It was only $50 for everything.
Re: New Owner
How did mount/route wiring for your push to talk? That's another project on the to do list.robw56 wrote:I just powdercoated my yokes and went with MS27039-4-23 screws with AN 960-416L washers and AN364-428A (low profile) nuts. The screws are the same diameter and thread as an AN4 bolt but I think look better for the application.
DEM
Re: New Owner
The push to talk button is mounted in a 1/4" hole drilled in the front and the wire comes in through a smaller 1/8" hole in the back. The wires are soddered(spelling?) to the switch. The wire is also held towards the center of the yoke with a small metal tab and a small screw. There's another like tab that holds the wire where it comes out of the panel. It was like this when I bought the plane.
Re: New Owner
Not meaning to hijack the thread, but as for the yoke mic-switch treatment.... horror stories abound about losing the yokes because someone did this to them without a basis of approval.
Now, I know that having a "basis of approval" can bring up an entirely-new argument ... but I'm not trying to do that. ((I, personally, cannot believe that installing a small switch like that will compromise the integrity of the yoke. I like the appearance too. But the authorities don't usually agree.)
What I'm trying to do is to WARN owners that unless you are willing to risk crossing paths with a picky inspector who will require you to throw away your very valuable original metal yokes because you don't have engineering approval for the modification... and subsequently be forced to run the gamut in a search for approval for installation of a completely different Cessna model aircraft's yokes...(yet another nightmare to those who've been caught in this trap) ... then I'd urge you to gain approval in writing before you alter your yokes by drilling them for a switch.
Now, I know that having a "basis of approval" can bring up an entirely-new argument ... but I'm not trying to do that. ((I, personally, cannot believe that installing a small switch like that will compromise the integrity of the yoke. I like the appearance too. But the authorities don't usually agree.)
What I'm trying to do is to WARN owners that unless you are willing to risk crossing paths with a picky inspector who will require you to throw away your very valuable original metal yokes because you don't have engineering approval for the modification... and subsequently be forced to run the gamut in a search for approval for installation of a completely different Cessna model aircraft's yokes...(yet another nightmare to those who've been caught in this trap) ... then I'd urge you to gain approval in writing before you alter your yokes by drilling them for a switch.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: New Owner
Suggestion: Have this switch installation inspected by an IA to determine it contains aviation quality materials that are installed in a safe manner. Make sure that any wire routing is protected from possible chaffing/fire hazard and does not interfere with flight control functions. Have IA prepare FAA Form 337 and submit to FSDO for a field approval. Include photo(s) or wiring diagram with description to verify proper installation and a statement to the effect: "discovered remote switch previously installed and undocumented. Inspected and verified for proper installation etc. etc." Take to your local FSDO and see if an Avionics Inspector will review and stamp.
It is very unlikely that an FAA Inspector would discover something like this walking around on an airport. The FAA can not compel you to throw away a yoke but they can and will write up a "Condition Notice" if they discover an unsafe condition. The notice will give you the opportunity to present information justifying it or the opportunity to correct before further flight. This is an example of why we should get an annual inspection done as a pre buy and to use a qualified IA who can identify things like this and protect the new owner from possible un airworthy conditions.
Speaking of which, a cheap automotive switch, installed by someone who does not know what he/she is doing can cause an inflight fire or interference with flight control functions in the case of a primary flight control which can lead to an accident. Pilots need to know about this stuff before they go fly particularly if they are taking innocent passengers who are trusting their skill and judgement. Don't assume. Beware of complacency. Have a great summer!!
It is very unlikely that an FAA Inspector would discover something like this walking around on an airport. The FAA can not compel you to throw away a yoke but they can and will write up a "Condition Notice" if they discover an unsafe condition. The notice will give you the opportunity to present information justifying it or the opportunity to correct before further flight. This is an example of why we should get an annual inspection done as a pre buy and to use a qualified IA who can identify things like this and protect the new owner from possible un airworthy conditions.
Speaking of which, a cheap automotive switch, installed by someone who does not know what he/she is doing can cause an inflight fire or interference with flight control functions in the case of a primary flight control which can lead to an accident. Pilots need to know about this stuff before they go fly particularly if they are taking innocent passengers who are trusting their skill and judgement. Don't assume. Beware of complacency. Have a great summer!!
Re: New Owner
Excellent point. I work in the engineering dept of an aircraft OEM with multiple Structures DER's. I think we can come up with some numbers for the feds if necessary.gahorn wrote:Not meaning to hijack the thread, but as for the yoke mic-switch treatment.... horror stories abound about losing the yokes because someone did this to them without a basis of approval.
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My yokes are plastic.
Actually, the yokes in my airplane are upright rams horn types that must have been installed at some point. This puts the controls really high. Hate 'em. So I bought a set of original style yokes off Ebay that I was gonna refurb and install. They are plastic, and not in very good shape. Thinking of just getting some leather steering wheel wrap and wrapping them. Then I won't have to worry about my gloves slipping on the controls in winter.DEM
Re: New Owner
The drilling of the yoke also involves weakening of the yoke. A picky inspector may require that documentation be provided that will support the premise that the hole drilled did not weaken the yoke in any significant way.
Plastic yokes are even worse. With age they weaken, and it is well-known that many plastic yokes have `disintegrated in flight (sometimes at the most inconvenient moment such as during landing).... there are plastic yokes which been condemned by Airworthiness Directive and must be replaced. The 170 airplanes left the factory with all-metal yokes. Some of them have been salvaged and installed in other models of aircraft....which is why they have become valuable. (It is not always a simple matter to take another model Cessna airplane's yokes and transfer them to a different model aircraft. This is why it might be considered risky to drill holes without prior approval.)
Voorhees comment regarding the quality of the electrical switch and the associated wiring is a different (valid) matter. (and I was not necessarily speaking of an FAA inspector who might demand the altered yokes be thrown in the trash.)
Plastic yokes are even worse. With age they weaken, and it is well-known that many plastic yokes have `disintegrated in flight (sometimes at the most inconvenient moment such as during landing).... there are plastic yokes which been condemned by Airworthiness Directive and must be replaced. The 170 airplanes left the factory with all-metal yokes. Some of them have been salvaged and installed in other models of aircraft....which is why they have become valuable. (It is not always a simple matter to take another model Cessna airplane's yokes and transfer them to a different model aircraft. This is why it might be considered risky to drill holes without prior approval.)
Voorhees comment regarding the quality of the electrical switch and the associated wiring is a different (valid) matter. (and I was not necessarily speaking of an FAA inspector who might demand the altered yokes be thrown in the trash.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: New Owner
This push to talk switch is an example of a very common practice in general aviation where well meaning pilots and mechanics make modifications and don't have them checked for airworthiness and then documented properly. It is my belief that many well meaning IAs will look at something like this and kind of shrug it off as being relatively harmless in the bigger scheme of things. If an FAA Inspector ever questions it and asks how it got through an annual, the IA will swear that it wasn't installed when I inspected the airplane. There are also very thorough IAs who will inspect something like this and give an owner good advice on whether or not to keep it. There is minimal guidance provided to understand an installation like this. I don't think it is addressed in 43-13 and I don't know of an STC available. Its one of those deals where there is nothing that says you can but there is also nothing that says you can't. Making sure it is done right is important because it establishes the level of safety you want in your airplane.
So my advice is to first not "assume" that it was done correctly and is something you want in your airplane. Get a good IA, preferably the one you trust to do your annual and ask him/her to evaluate it for a possible field approval. This will involve some disassembly to check materials, proper wiring/installation, evaluation of impact if any on the (I think its aluminum) yoke including the presence of dissimilar metals and, if so, proper corrosion prevention. If the installation is acceptable make out a 337 and submit. This will go to an avionics inspector and they (thankfully) have a reputation of being meticulous. I would bet that this inspector's first reaction will be appreciative for dealing with a general aviation pilot or mechanic who actually gives a damn. Im serious. And then, I think, if the inspector trusts the IA and the supporting data is valid, I believe it will be approved. My opinion only, but I do not believe this requires special engineering. A 1/4" hole that is filed in with a solid switch, properly secured should not weaken a pretty stout aluminum yoke. 1/8" hole on the back side that is reinforced, not a big deal. The forces on that yoke, while present during every flight, are minimal. I would be more concerned with improper wiring and corrosion. Years back, Cessna control yokes had serious corrosion problems in the lower assemblies and an improperly installed switch might start the same process. I agree that the plastic yokes were a big mistake.
When I got my 170 12 or 13 years ago it had numerous problems like this which I was able to work out with the help of a really good IA who provided me with an airplane that is fully documented and has been trouble free for a long time (tap on wood, of course). Of course the best advice for all of us (me included) is to resolve stuff like this before you buy.
So my advice is to first not "assume" that it was done correctly and is something you want in your airplane. Get a good IA, preferably the one you trust to do your annual and ask him/her to evaluate it for a possible field approval. This will involve some disassembly to check materials, proper wiring/installation, evaluation of impact if any on the (I think its aluminum) yoke including the presence of dissimilar metals and, if so, proper corrosion prevention. If the installation is acceptable make out a 337 and submit. This will go to an avionics inspector and they (thankfully) have a reputation of being meticulous. I would bet that this inspector's first reaction will be appreciative for dealing with a general aviation pilot or mechanic who actually gives a damn. Im serious. And then, I think, if the inspector trusts the IA and the supporting data is valid, I believe it will be approved. My opinion only, but I do not believe this requires special engineering. A 1/4" hole that is filed in with a solid switch, properly secured should not weaken a pretty stout aluminum yoke. 1/8" hole on the back side that is reinforced, not a big deal. The forces on that yoke, while present during every flight, are minimal. I would be more concerned with improper wiring and corrosion. Years back, Cessna control yokes had serious corrosion problems in the lower assemblies and an improperly installed switch might start the same process. I agree that the plastic yokes were a big mistake.
When I got my 170 12 or 13 years ago it had numerous problems like this which I was able to work out with the help of a really good IA who provided me with an airplane that is fully documented and has been trouble free for a long time (tap on wood, of course). Of course the best advice for all of us (me included) is to resolve stuff like this before you buy.