Riddle me this Batman...

[Echo]

So again, tell me with a straight face Why the SHITE OEM single "Primary" cylinder temp probe is superior in ANY way to a four probe "Non-Primary" monitor.  Just a bunch of ridiculous.  NOT putting a primary $$$ monitor in my plane.  Spell it out for me keyboard warriors.  How is this single probe 60 year old analog indicator "the bible"...(cue Charley Heston with his staff).  The absolute peak of idiocy...#stop the stupid...

[MikeOH]

It is all about certification/qualification to a known standard: proof that the device is trustworthy, if you will.

The factory gauge system went through certification testing and was part of the Type Certificate issued for the aircraft.  An aftermarket device monitoring all cylinders may well be a more accurate and better device but without proper testing and documentation the FAA says "no bueno". So, naturally, those companies that go through all the certification testing can advertise as "primary" and charge a hefty premium.  Those that don't...well, you do get a better price!  IOW, the FAA doesn't want you, the owner, to get to decide what is 'good enough' and I can't say I blame them.  Welcome to aviation

[PeteMc]

Following up on what @MikeOH said.  The non certified units may be accurate to the 1/100th of a degree or even better out of the box.

But what happens after a year or two of sitting on the ramp or in you hangar as the temperature fluctuates greatly.  And what about that hard landing you had last week, and the one because of the crosswinds 8 months ago and then the one a year ago....  And that 1 cent part they put in instead of the 2 cent part... 

Sort of makes sense why the FAA doesn't just give them a blank approval because they are super accurate in a temperature controlled lab.

 

Edited June 2 by PeteMc

[Joshua Blackh4t]

You said ANY 4 probe non-primary guage. I got one here made of fencing wire and cable ties that I can sell you really cheap..... do you think that it is better than the OEM one?

A bit of an 'ad absurdum', but the point is that sure there are plenty that are probably good enough, but who should be the person to make the decision.

Also, not only is the primary one paying for the certification, its also paying for warranty/insurance. When your primary fails and you have an issue in your commercial operation, the lawyers come out. 

 

So it kind of makes sense?

Now, if you were talking autopilots......

[bcg]

Short answer, FAA.

Sent from my Pixel 6a using Tapatalk

[Echo]

No where in the M20E TC is there a requirement for a Cylinder Temp gauge.

[Echo]

The type certificate says butkus about a cylinder temp gauge being required equipment in the M20E...

[PT20J]

CAR 3.675 Cylinder head temperature indicating system for air-cooled engines. A cylinder head temperature indicator shall be provided for each engine on airplanes equipped with cowl flaps. In the case of airplanes which do not have cowl flaps, an indicator shall be provided if compliance with the provisions of CAR 3.581 is demonstrated at a speed in excess of the speed of best rate of climb.

[EricJ]

1 hour ago, Echo said:

No where in the M20E TC is there a requirement for a Cylinder Temp gauge.

It's a type certificate, not an inventory of every legal requirement.   The TC doesn't mention an altimeter or compass, either.

[Hank]

8 hours ago, Echo said:

The type certificate says butkus about a cylinder temp gauge being required equipment in the M20E...

 

7 hours ago, EricJ said:

It's a type certificate, not an inventory of every legal requirement.   The TC doesn't mention an altimeter or compass, either.

The list of required equipment is in the Owners Manual, and in the FARs.

Yours should look something like this:

There's another couple of pages that cover Night and Instrument flight, each of which includes everything listed above plus a few more.

[midlifeflyer]

Pretty much the same reason we can't use an iPad or other handheld GPS for primary IFR navigation.

[Echo]

Thanks everyone.  I agree 100% that the primary cylinder temp gauge is required equipment.  My avionics installer disagreed after he threw out my functioning OEM temp probe with a supplemental EDM830 install.  He also installed the crush temp probe I purchased for the EDM on the old gauge thinking it would read.He stated that if it is not in the TC it wasn't required.  Said "there is a lot of WRONG information on forums".  Now I have to fix his error to have a functioning cylinder temp indicator that is primary.

Thanks again for replys.  Hopefully they will help someone else someday.  Scott

[Shadrach]

On 6/1/2024 at 10:52 PM, MikeOH said:

It is all about certification/qualification to a known standard: proof that the device is trustworthy, if you will.

The factory gauge system went through certification testing and was part of the Type Certificate issued for the aircraft.  An aftermarket device monitoring all cylinders may well be a more accurate and better device but without proper testing and documentation the FAA says "no bueno". So, naturally, those companies that go through all the certification testing can advertise as "primary" and charge a hefty premium.  Those that don't...well, you do get a better price!  IOW, the FAA doesn't want you, the owner, to get to decide what is 'good enough' and I can't say I blame them.  Welcome to aviation

I totally agree with everything you’ve said.
However (), you know all too well that technological advancement far outpaces regulatory evolution.  We live in a day and age when one can buy inexpensive instruments and be assured they will deliver precise, reliable information that is easy to read, download and share.  I think there is probably room for a lighter regulatory touch here (as well as in other areas). If the goal of the regulatory body is to maximize safety, then regulators should be seeking to create a regulatory environment that facilitates maximal adoption of any well understood, reliable technology that contributes to safety of flight.  I am not so sure that they’re doing the best job of keeping the end goal in mind.

Experimental aviation provides a means to analyze and showcase areas where the certified, regulatory, framework increases safety and to also showcase areas where it generates almost no statistical difference in safety.  If an area of the regulatory framework isn’t increasing safety…what is it doing?  It certainly isn’t increasing availability and decreasing costs. 
The fatal accident rate in experimental aviation is much higher than certified. The precise stats might be fuzzy but the delta is large enough to be undeniable. More freedom granted and less regulatory oversight increases risk/decreases safety.  However, I’ve not found a single instance where an experimental operator’s uncertified nav lights, strobe system, landing light or engine monitor contributed to their or anyone else’s demise.
Regulators should be seeking to maximize the safety ROI from regulatory activities, yet there seems to be little interest in analyzing the areas where the FAA/PMA/TSO certification has no statistical effect on safety.  
I applaud the FAA for loosening the regs around AOA indicators. I would like to see that type of consideration more broadly applied. It would also be nice to see data on how many AOA equipped aircraft have been involved in stall spin accidents since the regs were relaxed. 

 

[PT20J]

5 hours ago, Echo said:

 Said "there is a lot of WRONG information on forums"

He was absolutely correct in this statement. However, he should have also pointed out that there is a lot of WRONG information from maintainers. That's why we have to verify what anyone tells us. Good for you to delve into this.