Ignition Switch Question

[AJ88V]

19 minutes ago, KSMooniac said:

False.  All of the Mooney models are approved:  AMLswitch2.pdf

I just installed this with my dual EIS kit in my J.  The switch panel is large, and I had to sacrifice one of the 2 1/4" instruments on my left sub-panel to make it fit.  I wish the toggles were more definite in their movement, and I wish the starter button was shielded.  But they work!

Awesome, Scott.  The sheet I found only had the one page which listed the M22 at the top of the page (hence my stupid comment!).  Thanks for posting the correction.

Did you file a 337 for your installation?

While we're at it, do you have shower-of-sparks ignition?  From my brief scan of the documentation, you need to only be on one mag for start if I read it correctly.  Thanks!

[KSMooniac]

My plane had the dual/siamese mag with an impulse coupler, not the SoS system.  I think you can replace/remove the SoS or an impulse coupled mag and install the EA ignition in its place and have a regular mag on the other side.  

And yes, there were a bunch of 337's for this upgrade.  1 each for EIS/Start switch panel, back-up battery panel, back-up battery installation, EIS (airframe and engine STC), plus we also did CiES fuel senders and an LED landing light.  7 337's and $100 worth of paper copies!  

Some STC's are silly IMO for truly minor mods (like the Rosen Visors that came with my plane) and some are needed, like the EIS installation.  I don't see why the switch panel needs an STC, but that is the way they did it so we must comply.  

[AJ88V]

52 minutes ago, KSMooniac said:

Some STC's are silly IMO for truly minor mods (like the Rosen Visors that came with my plane) and some are needed, like the EIS installation.  I don't see why the switch panel needs an STC, but that is the way they did it so we must comply.  

Yeah, I totally don't understand the Rosen sun visors.  Major mod?  That makes no sense at all.

More generally, I read that many mechanics are prophylactically filing 337s and letting the FAA decide major vs. minor mod.  The article stated this was exactly the wrong way to go about it, since it encroaches on the A&P's prerogative to decide and creates unnecessary work for the FSDO, but the regulations (NOT LAWS) are so vague and the (potential) penalties so severe that some mechanics just file to cover their azzes.

[outermarker]

one thing to consider is the original ignition switch has a push to start feature. The reason is because of the plastic overlay. The nut tightens on the overlay. So, you don't have to overtighten the nut if you have to push. The other type you have to overcome the tension of the internal springs to engage the start mode. If the nut isn't tight enough the switch will rotate. Then you have to open the radio panel and reach in to hold the switch. Then get channel lock plyers to over tighten the nut (which will cut into the plastic overlay) hopefully enough without stripping the threads and not bugger up the nut surface. Then every time you go to start you will be aware that a bit too much pressure and the switch might rotate again before you get into the start mode. If you still have a plastic overlay, it is not worth changing the push to start feature for a twist to start feature. I know this because when I bought my Mooney it had a turn to start switch and for a long time, I thought it was correct...and for a long time I had from time-to-time issues with the switch rotating.

[AJ88V]

22 minutes ago, outermarker said:

one thing to consider is the original ignition switch has a push to start feature. The reason is because of the plastic overlay. The nut tightens on the overlay. So, you don't have to overtighten the nut if you have to push. The other type you have to overcome the tension of the internal springs to engage the start mode. If the nut isn't tight enough the switch will rotate. Then you have to open the radio panel and reach in to hold the switch. Then get channel lock plyers to over tighten the nut (which will cut into the plastic overlay) hopefully enough without stripping the threads and not bugger up the nut surface. Then every time you go to start you will be aware that a bit too much pressure and the switch might rotate again before you get into the start mode. If you still have a plastic overlay, it is not worth changing the push to start feature for a twist to start feature. I know this because when I bought my Mooney it had a turn to start switch and for a long time, I thought it was correct...and for a long time I had from time-to-time issues with the switch rotating.

I would think riveting in an adapter plate for the smaller cylinder diameter of the ACS switch should be straightforward and uncomplicated.  Much better than clamping to the plastic overlay.  In fact, you could even machine a small washer to fit in the oversized hole (larger than the hole with a rim to center on the hole and then get a good clamp on the aluminum panel with a second flat washer.  Definitely within my skill as an owner-manufactured part.

[EricJ]

47 minutes ago, AJ88V said:

More generally, I read that many mechanics are prophylactically filing 337s and letting the FAA decide major vs. minor mod.  The article stated this was exactly the wrong way to go about it, since it encroaches on the A&P's prerogative to decide and creates unnecessary work for the FSDO, but the regulations (NOT LAWS) are so vague and the (potential) penalties so severe that some mechanics just file to cover their azzes.

Filing the 337 is the conservative way to go about anything, since there's no consequence to filing the 337 if it isn't needed, compared to any perceived risk of not filing it when it might be needed.   The FAA does zero with them other than stick them in the aircraft records, unless there's an incident where the records need to be reviewed.   Nobody at the FAA does any review or initial decision making with the 337, that's all done by the A&P filing it out and the IA approving it.   It's just a document that gets added to aircraft records, so it is useful that way to make a permanent, retrievable documentation of something that gets done to the airplane.    That can be useful during an ownership change if the original records are lost.

[Andy95W]

4 hours ago, outermarker said:

one thing to consider is the original ignition switch has a push to start feature. The reason is because of the plastic overlay. 

The reason the Mooney has the push to start is so that you can engage the shower of sparks without engaging the electric starter.  Without that feature, you would not be able to hand prop the engine.

[Pinecone]

18 hours ago, ProtoFly said:

Why not go with something like the Electroair Ignition Panel?

Gets rid of the AD...

https://www.aircraftspruce.com/catalog/pnpages/08-17142.php

Have you seen one in person.  It feels cheap.  The switches don't have much resistance to switch on or off.

I was going to put on in my airplane.  The avionics shop got and we both decided we did not want it in our airplane.  I went with locking toggle switches for mags and a spring loaded toggle for starter.  Love it.

[ProtoFly]

1 hour ago, Pinecone said:

Have you seen one in person.  It feels cheap.  The switches don't have much resistance to switch on or off.

I was going to put on in my airplane.  The avionics shop got and we both decided we did not want it in our airplane.  I went with locking toggle switches for mags and a spring loaded toggle for starter.  Love it.

No, I've not seen one in person.  Do you have pictures of your setup?  Did it require a field approval?  What parts?  (inquiring minds want to know...)

[PT20J]

16 hours ago, AJ88V said:

Yeah, I totally don't understand the Rosen sun visors.  Major mod?  That makes no sense at all.

It’s clearly not a major mod. But, the visors are not identical to the originals. So, my understanding is that the FSDO where Rosen is located required an STC for installation and the FAA expects 337s for STCs.

What’s interesting is that you are supposed to file a 337 to install something with an STC, but you can subsequently remove it with just a logbook entry. 

 

[Andy95W]

22 minutes ago, PT20J said:

What’s interesting is that you are supposed to file a 337 to install something with an STC, but you can subsequently remove it with just a logbook entry. 

That’s different from my FSDO’s guidance during IA seminars. Not a big deal, I bet a lot of guys don’t do it, but they said to do it because 337s are the only “eternal” record of the aircraft and it’s Type Certificate alterations. (ie., if the logbooks were destroyed or lost.)

[Pinecone]

2 hours ago, ProtoFly said:

No, I've not seen one in person.  Do you have pictures of your setup?  Did it require a field approval?  What parts?  (inquiring minds want to know...)

Avionics did the install and paperwork.  No 337 AFAIK.

The parts are just normal toggle switches from Aircraft Sprube.  The ones for the mags are the Pull to Move type.

[PT20J]

3 hours ago, Andy95W said:

That’s different from my FSDO’s guidance during IA seminars. Not a big deal, I bet a lot of guys don’t do it, but they said to do it because 337s are the only “eternal” record of the aircraft and it’s Type Certificate alterations. (ie., if the logbooks were destroyed or lost.)

Well, that interpretation certainly makes sense. And, my IA may have had it wrong. IAs do seem to disagree a lot.

When I was purchasing the airplane, Don Maxwell did the prepurchase inspection. He had done some work a while back on the plane replacing a wingtip, outboard wing skin and a rib due to a hangar door incident. I had another IA of about Don's years of experience review the logbooks. He said that the repair should have a 337. Don said it didn't need one because he just replaced some parts with new factory parts. I asked a third IA that is director of maintenance at a large Part 135 operation and he thought about it for a while and agreed with Don, but said he wouldn't find fault with someone who thought a 337 was warranted. I'm lucky to have two experienced IAs on my home base and if I don't like the answer I get from one, I go ask the other. Sometimes they agree; sometimes not.
But then all the FSDOs don't agree with each other either. That's why you get an STC for Rosen sun visors and don't need one for GLAP windows. From GLAP FAQ:

Q3: Why are your thicker side windows not STC'd?

A: Our regional FAA has determined where STC's are to be applied. Keep in mind that not requiring an STC keeps the paperwork down and a 337 form is not necessary. We have been told by our regional FAA office that STC's have been overused for minor changes, thicker side windows are considered to be a minor change by our regional FAA office (Chicago).

[McMooney]

I was going to get the electro aire switch panel, but now think i just want simple locking toggles.

look so much better and take up far less space.   I believe somewhere the FAA is pretty much ok, with standard  up to spec electrical parts.

as for the 337, i wouldn't think it necc but if my IA doesn't charge me a fortune, maybe i'll have him submit it just for recording purposes

[EricJ]

36 minutes ago, PT20J said:

FSDOs don't agree with each other either. That's why you get an STC for Rosen sun visors and don't need one for GLAP windows.

Yup.   I get that sense from our local IA seminars, where probably half of the presenters are from FAA offices of one type or another, including the FSDO, and you can get two different opinions in two different seminars from different presenters.   One was being adamant about STCs always requiring 337s because they're always major alterations.   Somebody asked about "what if it is isn't a major alteration?" and the response was that if it wasn't a major alteration it wouldn't need an STC.   So I asked about Rosen visors being a major alteration, and suddenly everything got very handwavy and he never answered the question. 

At one session there were a bunch of guys from the FSDO and they kept calling on each to answer questions because they knew who had worked a particular area, etc.    Somebody asked about whether ADs apply to experimental aircraft, and it got very quiet, and then they told on themselves that there really is not agreement about that.   I attended a FAASTeam meeting last week where they were opining that since a condition inspection is essentially a safety inspection and ADs are safety related it'd be difficult to justify signing off a condition inspection without compliance to ADs.  So, yeah.  I just take the position that if I'm comfortable standing in front of a judge explaining why I did something, that that's about as good as I can do.

[PT20J]

1 hour ago, McMooney said:

I was going to get the electro aire switch panel, but now think i just want simple locking toggles.

look so much better and take up far less space.   I believe somewhere the FAA is pretty much ok, with standard  up to spec electrical parts.

as for the 337, i wouldn't think it necc but if my IA doesn't charge me a fortune, maybe i'll have him submit it just for recording purposes

The Decathlon I used to fly just had toggles and they weren’t even locking.

[47U]

4 hours ago, PT20J said:

The Decathlon I used to fly just had toggles and they weren’t even locking.

It was Pilot Coyote (since sold his Mooney and left the forum) that inspired me to go to toggles after he said the Citabria he flew had toggles, as do some twin engine aircraft.  I found a paper online written by an RV builder and modified his schematic.  My IA called it a minor alteration.

I mounted them above the radio stack, where nothing else fits (the early M20s had the mag switch up there) and moved the Master switch up there, also.  It bought me some space on the pilot’s panel.  I thought it might be awkward during engine start, but it’s not at all.  Left hand on the switches, right hand on the throttle.  I did put a ‘cage’ around the Master, so as to not bump it if I am doing mag checks in flight (with turbulence).  I found the switch cage (guard) online, supposedly it’s design came from the space shuttle.  So, being easily swayed by nostalgia (and future telling of the history) that’s where I went.  (I’ve posted this before, so my apologies, but there’s new members all the time so… there you go.  That’s my excuse.)  

I also think the locking toggles are a good option if you’re going that direction.

 

[A64Pilot]

On 11/24/2024 at 4:13 PM, ArtVandelay said:

An oil filter is critical single point of failure component. Not only do we not need a 337 if we change brands, but owners are allowed to do the work.

Only because an oil filter is a standard part, and only then we are allowed to use the correct one by part number, we can’t just use one that fits.

Having said that a Mag switch is really isn’t a single point of failure in that if it fails it leaves the Mag hot when off, so it’s a ground safety issue, not a safety of flight issue. (in my opinion) Others will of course differ

In my opinion a 337 is required not because of 43.13, but because your changing the Type Design by using a switch that’s not called for in the drawings and that is a major.

Unless of course the STC for the electronic mag you have allows it.

Unfortunately the descriptions of minor vs major in 43.13 is only a guide, along with just about every other Pub from the FAA then yers ago the FAA made 43.13 acceptable, no longer approved further watering it down.

[jamesm]

11 hours ago, Pinecone said:

Have you seen one in person.  It feels cheap.  The switches don't have much resistance to switch on or off.

Yes, I have them installed and yes the magneto rocker switches are cheap however the push to start button switch is a MS (Mil Spec) quality push button switch .  The rocker switches are something along the lines  of  low end automotive quality grade but it had a STC'd and I didn't want to have deal with the headache at a later date. I really don't like the idea that push to start feature is not guarded very well. Could easily depending where mounted  could get bumped. If I recall correctly I heard this or similar topic that came up on "Ask the A&P's"  Podcast and  Mike Bush seemed a bit skeptical l about taking any switches and making into Magneto switch as to whether it was a  major or minor alteration/repair and a person brought up that ElectroAir switch solution had a STC . Either way I decide to get a 337 to avoid conflict in the future at least in theory.

James '67C

[jetdriven]

48 minutes ago, A64Pilot said:

 

In my opinion a 337 is required not because of 43.13, but because your changing the Type Design by using a switch that’s not called for in the drawings and that is a major.

How is changing a switch of one part number for another part number a major change in type design? And also aren’t we allowed to substitute parts and materials for vintage aircraft? (all mooneys are vintage aircraft) I mean they have to be equal or better right but I can’t see how any of this is major. 

[Justin Schmidt]

I do have the electroair switch panel. I do like it but I think there is a flaw. There needs to be a cover.

I have it bottom left, by my knee. I have knocked it in flight turning a mag off.

[ArtVandelay]

In my opinion a 337 is required not because of 43.13, but because your changing the Type Design by using a switch that’s not called for in the drawings and that is a major.

By that reasoning, replacing the rocker circuit breaker/switches would require a 337. You’ve effectively eliminated minor alterations, everything not in the parts manual would require a 337.
I can make a owner produce part, clearly not in the parts manual, and have it installed without a 337.
14 CFR Part 43 Appendix A lists examples of major alterations and the ignition switch is not included.

[EricJ]

Lot of airplanes have very basic toggle switches for magnetos.   The ancient supercub I did my tailwheel training in did, as do a lot of older airplanes, and as mentioned many twins do, too.   They're very common in experimental airplanes, warbirds, etc.  The AD-burdened Bendix switches are just an easy way to add a security layer (i.e., key) for a market where that is accepted as a Good Idea.   From a usability/reliability standpoint toggle switches are way better, but the security issue is important when you're marketing new airplanes that are a significant expense to the people who are buying them.

 

1 hour ago, 47U said:

It was Pilot Coyote (since sold his Mooney and left the forum) that inspired me to go to toggles after he said the Citabria he flew had toggles, as do some twin engine aircraft.  I found a paper online written by an RV builder and modified his schematic.  My IA called it a minor alteration.

I mounted them above the radio stack, where nothing else fits (the early M20s had the mag switch up there) and moved the Master switch up there, also.  It bought me some space on the pilot’s panel.  I thought it might be awkward during engine start, but it’s not at all.  Left hand on the switches, right hand on the throttle.  I did put a ‘cage’ around the Master, so as to not bump it if I am doing mag checks in flight (with turbulence).  I found the switch cage (guard) online, supposedly it’s design came from the space shuttle.  So, being easily swayed by nostalgia (and future telling of the history) that’s where I went.  (I’ve posted this before, so my apologies, but there’s new members all the time so… there you go.  That’s my excuse.)  

I also think the locking toggles are a good option if you’re going that direction.

 

I still think that's a really cool way to do it, and having a separate, maybe protected, start button is another very good option.   There are lots of ways to do this.   I don't personally see anything that makes this sort of thing a major alteration by the regs.

[A64Pilot]

15 hours ago, jetdriven said:

How is changing a switch of one part number for another part number a major change in type design? And also aren’t we allowed to substitute parts and materials for vintage aircraft? (all mooneys are vintage aircraft) I mean they have to be equal or better right but I can’t see how any of this is major. 

This is the SB your referring to, read through it and if using it you can get your mechanic to buy off go ahead, but this isn’t owner level maintenance.

I don’t have a dog in this, just in my opinion using a mag switch not specifically approved requires a 337. Apparently so do several manufacturers or they wouldn’t have an AML for the part.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_23-27.pdf

 

Ref the aircraft that has toggle switches installed by “Avionics” I almost guarantee you that a 337 was filed as they almost always are for Avionics installations, Why I can’t fathom why removing one brand of VHF radio and replacing with another requires a 337, but almost always one is filed, so add the toggles and Starter switch. In this instance I’m certain a 337 is required and the POH should be changed too as starting and run up procedures etc have changed, and that’s a major.

My FAA inspector joked that according to FAA records the average GA airplane is flying around with four or more radios as they file a 337 for installation, but don’t file one for removal.

Oh, and my 1946 C-140 came from the factory with toggle switches and a pull handle starter. I prefer the toggles myself, I think being completely independent is safer and don’t see the need for a cover myself.

It does however make the airplane easier to steal.

The Crop duster I used to manufacture had no keys of any kind, not even a door lock, after 911 Homeland Security had a hissy fit, but I think the FAA told them to pack sand 

Edited November 28, 2024 by A64Pilot

[ArtVandelay]

I don’t have a dog in this, just in my opinion using a mag switch not specifically approved requires a 337. Apparently so do several manufacturers or they wouldn’t have an AML for the part.

The AML only means this switch was used by the manufacturer. It has NOTHING to do with whether it’s a major modification.