Best clock to install in 2025

[rbmaze]

I have a '69 M20E and it currently lacks a panel-mounted clock. An IR checkride is my near future, so I want to get this properly sorted out.

I've thought about some options and I'm not sure what to go with. Planning to install this during my annual early this summer. My current panel has dual G5s and I have a GSB 15 for USB power. I am lacking a voltmeter so the AV-20 or other clocks with such a feature are a plus. Also I am very interested in installing an EDM900, so this will negate the voltmeter need, but I am going to hold off until after the annual since it will be my first. Or maybe I should skip the clock for now and just install the engine monitor right away.

What I am considering:

SC-5 Superclock

I like the look and functions, such as indicators for expired timers. Seems to have an intuitive interface. Lower cost. Dislike that the battery only lasts 10 years and is not field serviceable. Dated design.

AV-20-S

Looks like a great setup, but there are redundant features. I am planning to install an OAT probe on my G5. Is there any sense installing an AV-20 with another probe? I don't really need a backup AI with dual G5s as far as I know. The AoA indicator seems hit or miss in usefulness. Most expensive option, but nice display and interface.

CH93 series w/ USB

More modern than SC-5, but interface looks bare bones. I already have dual USB ports, but a backup would not be horrible to have.

The clock will go under the vacuum gauge on the left. EDM 900 will eventually mount vertically where the white card is to the left of the 530W. At that time I will remove the FS-450 and move the CDI to its position.

What would you install here?

[PeteMc]

My preference is a sweep second hand.  Not sure if I have a Mitchell aircraft clock or not, but it sure looks like one of their very basic analog clocks.  

Problem with the digital is that there are more "digits" to remember.  With the sweep hand you just mentally picture the clock and you know where 1 minute is for your Holds, etc.  For an actual approach, I used a kitchen timer clipped to my Lapboard during training.  Now days I have a timer in ForeFlight.

Another advantage of a clock with hands is for fuel balance.  I look at the minute hand and if it pointing to the right side of the clock, I should be on the right tank, left should be left tank.  So if I was talking to ATC or just contemplating my navel, if I'm unsure if I switched tanks, I just look at the clock.  

And then there's your Engine Monitor...  the cheaper the clock the less reason not to add the EDM900.  Talk to the mechanic and let them know you want to add an EDM and as they are looking at the plane, keep that in mind for work that can be deferred.  There may be some things that can wait a year that will let you get the EDM.  There also may not be and may be some other big ticket items, but if the shop knows the big picture going into the Annual it can only help. 

 

[DCarlton]

I installed an SC-5 years ago.  It's OK.  It's a clock.  The uptimer starts when I turn on my Alternator.  It's a good reminder.  

[N201MKTurbo]

I have a Waltham A-13A-1. I think it is the finest aviation clock ever made.

http://walthamclocks.com/a-13a-1.html

 

[DCarlton]

5 minutes ago, N201MKTurbo said:

I have a Waltham A13A. I think it is the finest aviation clock ever made.

Was that the OEM clock?  Fits in your yoke?  Their web site is not responding; very slow.  

[N201MKTurbo]

No it is in the panel. 
 

When I had my M20F I had an LC2 in the yoke. I had to modify it to fit.

[EricJ]

Another alternative, although maybe not practical before you need your check ride, is to slide-in upgrade your 530 to an Avidyne 540.    This allows a digital time display on the top (mine is configured that way) with seconds that qualifies as the clock.

I also have an LC-2 that has proven to be a maintenance hog, enough so that I'm no longer interested in trying to figure out what it's problem du jour might happen to be.   The UI is not great on those, anyway.

There's a comparatively inexpensive FDS GT50 that might work, 

https://www.aircraftspruce.com/catalog/inpages/flightdatafc50.php

 

 

[Ragsf15e]

3 hours ago, DCarlton said:

Was that the OEM clock?  Fits in your yoke?  Their web site is not responding; very slow.  

My ‘68F had a Waltham in the yoke. They were great!  They even overhauled it for me a couple years ago when it finally quit after 50 years.

[Glenn]

3 hours ago, N201MKTurbo said:

I have a Waltham A-13A-1. I think it is the finest aviation clock ever made.

http://walthamclocks.com/a-13a-1.html

 

I agree.  If my navigation ever depends on just clock and compass, I would rather have a clock that was not dependent on electricity.

Edited March 31, 2025 by Glenn
left out a word

[N201MKTurbo]

I bought mine on EBay about 25 years ago. I got a service manual for it and completely disassembled it, cleaned it and put it back together. It was the most complicated mechanical assembly I have ever done. The barrel grease was some strange mil spec that ended up crossing to Aeroshell #6. I needed a tiny dab of it. I used Möbius watch oil for everything else. The specified oil is nowhere to be found. I made a barrel winder out of a tap handle and a piece of copper pipe with a slot in it. It worked great. I got real good at sharpening tiny screwdrivers.

[N201MKTurbo]

41 minutes ago, bluehighwayflyer said:

I have a Waltham on my yoke and it is thing of mechanical beauty that just works.  I doubt I would install one ab initio today, however.

I had a LC-2 in my previous M20J and what a cheap piece of junk that thing was   Pretty much the antithesis of the Waltham.

I have an AV-30-C installed and am very fond of it.  So much so that just purchased an AV-20-S that I’ll be installing soon.  On the panel.  Not on the yoke to replace the Waltham.  It might cost the most but it does so much more that I think it represents the greatest value   I’m going to go ahead and install another OAT probe for it.  If I ever install a tailBeaconX in the future I will repurpose the AV-20-S to control it, assuming that will eventually be approved like it currently is for the AV-20-E. 

 

 

You probably had an A-11. It will fit on the yoke. I have enough parts to build one. I’ll have to put it together one of these days.

[hais]

A feature I wanted are two separate buttons. The stopping one just stops it. The reset one starts a new count. 

Some work in sequence like start-stop-reset-run. Too many clicks while in the hold. One press too many and now you have to click like 7 times to get in the correct mode...

[rbmaze]

17 hours ago, PeteMc said:

My preference is a sweep second hand.  Not sure if I have a Mitchell aircraft clock or not, but it sure looks like one of their very basic analog clocks.  

Interesting info. I can see the benefits of that. I like to run an hour before switching tanks, but your strategy seems useful.

 

17 hours ago, PeteMc said:

And then there's your Engine Monitor...  the cheaper the clock the less reason not to add the EDM900.  Talk to the mechanic and let them know you want to add an EDM and as they are looking at the plane, keep that in mind for work that can be deferred. 

Thanks for this advice. That makes a lot of sense. I already let a potential mechanic know I want to install an EDM900 and was quoted 50 hours. Didn't think of being able to defer work to combine with the install. I'm thinking I'll avoid doing it with the annual since I really have no idea what to expect as far as unknown issues that will pop up when I'm in the shop.

[rbmaze]

17 hours ago, DCarlton said:

I installed an SC-5 years ago.  It's OK.  It's a clock.  The uptimer starts when I turn on my Alternator.  It's a good reminder.  

Do you remember how long the install took? A shop asked me what options I want setup before providing a quote. I'm guessing things like LED dimmer and Engine Time (hobbs meter) are optional wires to connect.

Uptimer is a good reminder of your flight time?

[DCarlton]

13 hours ago, Ragsf15e said:

My ‘68F had a Waltham in the yoke. They were great!  They even overhauled it for me a couple years ago when it finally quit after 50 years.

I have my original mechanical yoke clock in a box in the garage.  I've gotta go find it now and check it out.  

[Utah20Gflyer]

I get my time from the clock in the gps (Garmin 355) which has hours and minutes and then use the timer on my Garmin 327 transponder for seconds - timing holds, etc.  I used to have a LC2 but found it to be very user unfriendly and got rid of it.  
 

So essentially I’m splitting the requirement over two devices.  I feel like this works because the GPS is what you use for release times and ATC reporting and they don’t want to hear about seconds.  The timer on the transponder is really simple and user friendly.   Until someone convinces me otherwise I think this fulfills the legal requirement.  
 

 

[DCarlton]

4 minutes ago, rbmaze said:

Do you remember how long the install took? A shop asked me what options I want setup before providing a quote. I'm guessing things like LED dimmer and Engine Time (hobbs meter) are optional wires to connect.

Uptimer is a good reminder of your flight time?

It's been a long time; don't remember how long it took but I could look it up.  It's a relatively easy install.  Probably best to download the install manual and read it to make sure you're getting what you want.  Seems like I remember wiring the backlighting had options (dimmed or not dimmed, etc).  I use the timer on the clock for flight times.  You can download the install manual on the EI web site.  

[rbmaze]

17 hours ago, EricJ said:

Another alternative, although maybe not practical before you need your check ride, is to slide-in upgrade your 530 to an Avidyne 540.

Unfortunately this is out of budget for me, but a great option to have a drop-in replacement. My 530W is mostly solid (I do receive some interference sometimes on the comm so I use it as my secondary). I'll probably run it until it dies and see if I can save the funds for a GFC500 one day.

 

17 hours ago, EricJ said:

There's a comparatively inexpensive FDS GT50 that might work

Thanks for the recommendation. I haven't seen this one and it's a lower price point than others.

[rbmaze]

21 minutes ago, Utah20Gflyer said:

I get my time from the clock in the gps (Garmin 355) which has hours and minutes and then use the timer on my Garmin 327 transponder for seconds - timing holds, etc.  I used to have a LC2 but found it to be very user unfriendly and got rid of it. 

I have definitely heard of others doing this and perhaps I should get on board and just save the money for my engine monitor. I have a 330 ES so I believe it has a timer. Just not sure how to "vet" a DPE to be sure they will accept this as legal which is one of the hurdles in my head.

[rbmaze]

17 hours ago, N201MKTurbo said:

I have a Waltham A-13A-1. I think it is the finest aviation clock ever made.

http://walthamclocks.com/a-13a-1.html

 

Is this the 8-Day Clock? Are these still made? The description is written in the present tense as if it's for sale, but I'm guessing only parts are available. I see one available on ebay.

[N201MKTurbo]

1 minute ago, rbmaze said:

Is this the 8-Day Clock? Are these still made? The description is written in the present tense as if it's for sale, but I'm guessing only parts are available. I see one available on ebay.

Waltham has been out of business since the 70s. A company bought their name and services the A13A and may produce new ones.

if you want one of their old clocks you have to buy a used one. 

[rbmaze]

Wow. Gone since the 70s. Thanks for the info.

[Utah20Gflyer]

1 hour ago, rbmaze said:

I have definitely heard of others doing this and perhaps I should get on board and just save the money for my engine monitor. I have a 330 ES so I believe it has a timer. Just not sure how to "vet" a DPE to be sure they will accept this as legal which is one of the hurdles in my head.

I’m sure the 330 has the same timer as the 327.   It really is the best aviation timer I’ve ever used.   Try it out next time you get up in the air and see what you think.  
 

I’ve tried using the timer on the GPS and my I pad but it just takes too long to get to it and set it up.  Also it takes those two devices away from how I want to be using them.  The timer on the Transponder is basically stand alone and takes maybe two button touches to get it ready.  Starts with one touch, stops with one touch, resets with one touch.  It’s perfect! 

[EricJ]

1 hour ago, rbmaze said:

 Just not sure how to "vet" a DPE to be sure they will accept this as legal which is one of the hurdles in my head.

If the DPE has been identified just ask them.   It's not an unusual issue so they may have dealt with it before, or they may just quote the reg.

[Pinecone]

If anyone needs a clock, I have the MidContinent digital with dual USB ports (you have never have too many) that came out of my panel.