Cessna 180 Primary CHT Gauge Replacement

[Steve Pierce]

So, if you install a Electronics International UBG16 engine monitor in a Cessna 180 (serial umber in the 3000s), can you remove the factory CHT gauge?

To: Electronics International
Looking at installing a UBG16 in a 1953 Cessna 180 (no dash letter). Can it be used as the primary CHT gauge eliminating the original CHT?


Thanks

Hello, Steve

Thank you for your email. While it is legal to install the UBG-16 in your aircraft, the UBG-16 is NOT a primary CHT instrument; therefore, you would not be able to remove your existing CHT instrument, even with the installation of the UBG-16.

Please don't hesitate to contact me if you need anything else!

Thank you,

Tyler Speed
Electronics International
63296 Powell Butte Hwy
Bend, OR 97701
541-318-6060

From the Type Certificate Data Sheet:

Certification basis
Models 180, 180A and 180B: Part 3 of the Civil Air Regulations dated
November 1, 1949, as amended by 3-1 through 3-8 except Paragraphs 3.265
and 3.668 of 3-7.

Equipment: The basic required equipment as prescribed in the applicable airworthiness regulations (see Certification Basis)
must be installed in the aircraft for certification. This equipment must include a current Airplane Flight Manual
effective S/N 18052490, 18053001 and on. In addition, the following item of equipment is required.
1. Stall Warning Indicator, Cessna Dwg. 0511062 through S/N 18051823.
2. Stall Warning Indicator, Cessna Dwg. 0700185 effective S/N 18051824 and on.
The equipment portion of Aircraft Specification 5A6, Revision 34, or Cessna Publication TS2000-12
should be used for equipment references on all aircraft prior to the Model 180G. Refer to the applicable
Equipment List for the Model 180G and subsequent models.

NOTE 4. The cylinder head temperature probe location is No. 2 cylinder through S/N 18051445, No. 1
cylinder S/N 18051446 through S/N 18052500, No. 3 cylinder S/N 18052501 and up.

Part 3 of the Civil Air Regulations Cylinder Head Temperature

§ 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 § 3.581 is
demonstrated at a speed in excess of the speed of best rate of climb.

Looks like I am in trouble.

 

[sierra bravo]

The same is true with the standard JPI EDM-700. The EDM 711 is certified for primary replacement and includes factory set high temp limit and panel mounted idiot light overtemp indicator.

 

[Charlie Longley]

I ordered an EI EC1 and had to send it back for an EC1P (Primary) to get rid of my old CHT. Very easy install. I put in a OPT as well. Basically replaced 4 instruments with 2. Lots of empty holes in my panel now!

 

[mike mcs repair]

Hmmm..part Field approval....???

installed per stc xxxxx deviated from stc by removing original mechanical gauge.....

heck we install car parts alternators & motorcycle batteries by field approval.....

 

[mike mcs repair]

Part 3 of the Civil Air Regulations Cylinder Head Temperature

§ 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 § 3.581 is
demonstrated at a speed in excess of the speed of best rate of climb.

Looks like I am in trouble.

oh, and is that part 3 or the earlier part 03 of the CARs?? just learned that last time I was at burls... 03 might be a little more lenient?? http://www.stacheair.com/data/At Work 9B Repair Station CD/Data Info/CAR's/cars.html

 

[mike mcs repair]

Hmmm..part Field approval....???

i mean, I even get experimental NON-TSO/PMA/STC gauges field approved in a panel with a single line "installed new CO detector Aero 553"

 

[soyAnarchisto]

I'll go you one further.... I'm installing a new EI CGR-30P, which can technically replace 7 primary instruments plus 5 non-primary instruments. I guess I'm a little unsure what exactly a primary and non-primary instrument is. I called EI and talked to Dave - but I'm still not sure if I can say remove/replace the suction gauge with a non-primary sensor in the CGR-30P. The old gauge in my panel doesn't have markings - only a green arc - and nothing in my POH really says what the values/limits should be. So do I burn one of my precious primary slots for that "required" suction gauge, or can I put put fuel flow on the primary page and relegate suction to a non-primary function (and still pull the old suction gauge out of my panel). Similar question about my ammeter. Is it really a "required" instrument? Can I replace it with a non-primary function of the CGR-30P? My POH of my CAR3 1956 Cessna 180 doesn't even really list minimum required instruments.

My way of thinking is that the following are the only "required" instruments, according to 91.205: MP, Tach, oil pressure, oil temp. As far as I can tell, even for IFR, a vacuum and voltmeter/ammeter are not really required. I am not really arguing to remove these things - I merely want to put them on the secondary screen. I should be okay doing this right?

Thoughts?

Here's my thinking about the "primary" functions:
1) manifold pressure
2) Tach
3) CHT/EGT
4) Fuel Flow
5) Oil Pressure
6) Oil Temp
7)Vacuum

And my 5 non-primary functions (on a secondary page - no limits specifed):
1) Flight Timer
2) Tach time
3) Volts
4) Carb temp.
5)Amps

 

[wireweinie]

'Primary' has to do with what's required by the TCDS. For example, the airspeed is required by the TCDS but a VSI is usually not. Therefore the airspeed needs to be a certified/TSO'd/STC'd gauge. If you want to add the VSI, it does not need to be 'certified'. That's why you see high dollar Mid Continent airspeeds but $150 Falcon VSI's.
Some of the older JPI 'all in one' gauges caused problems, because not all systems in the gauge were 'certified' for primary use. The usual engine systems like tach, oil press, and oil temp, were certified for primary use but CHT's were not. That meant that you could, legally, remove the old tach, oil press gauge, and oil temp gauge and replace them with that particular JPI. BUT, to be completely legal, you would have to keep your factory CHT gauge if the TCDS required it.

You can add non certified gauges to a panel, but you cannot REPLACE certified gauges with non certified.

The newer JPI's like the EDM 900's have most all systems certified for primary use, so it's generally safe to use them after you do a little home work. Most of the systems in a CGR 30P are certified for primary use, also.

Make sure you check the TCDS for required instrument and make sure that the system you install is certified for primary use for each of those functions. If so, remove the old instruments and install the new system. If a part of the new system is NOT certified for primary use, you'll need to keep the old gauge in place to be completely legal.

Web

 

[cubscout]

Yo, Soy, the other wrinkle is that Cessna used the spark plug washer probe on most of the earlier C-180's and C-182's, don't know when they wised up and went with bayonet probes. One legal kluge I've seen is to run something like the CGR-30-P (A GREAT way to go, in my opinion), with all six CHT probes in the proper Bayonet well, and tuck the original gauge fed by its spark plug washer probe off in some far corner of the panel where it won't be a distraction.

Thanks. cubscout

 

[stewartb]

My 180's TCDS doesn't list or address primary instruments and gauges. CAR 3 and FAR 91.205 do. My TCDS does list additional required equipment like a stall indicator. While a CHT instrument is required by regulation the location of a single probe is defined in the TCDS or supplemental TC. I believe one of the problems with digital instruments is compliance with range marking. There are no green or red arcs on digital instruments. JPI's CHT STC requires a warning light for redline (redline is defined in the TCDS). Other manufacturers may find other ways to comply with the markings requirement.

On soy's list fuel flow is not required. As I understand it a volt or amp gauge is required if an electrical system is installed. The suction indicator is only required if gyros are installed. EGT is not required.

 

[Steve Pierce]

There is a warning light on the primary CGR30P screen for low voltage. That would work for me.

 

[wireweinie]

My 180's TCDS doesn't list or address primary instruments and gauges. CAR 3 and FAR 91.205 do. My TCDS does list additional required equipment like a stall indicator. While a CHT instrument is required by regulation the location of a single probe is defined in the TCDS or supplemental TC. I believe one of the problems with digital instruments is compliance with range marking. There are no green or red arcs on digital instruments. JPI's CHT STC requires a warning light for redline (redline is defined in the TCDS). Other manufacturers may find other ways to comply with the markings requirement.

On soy's list fuel flow is not required. As I understand it a volt or amp gauge is required if an electrical system is installed. The suction indicator is only required if gyros are installed. EGT is not required.

The TCDS for the engine addresses the engine gauges. The O-470 TCDS (I'm assuming O-470) states the requirement for the CHT and location according to specific model. As the CHT system on the CGR-30P is a six place and is 'certified' you can remove the old one and install the new. CGR's are also programmed with the red, yellow, green arcs or bars in order to match the requirements.

Web

 

[stewartb]

FYI, here are Data Pertinent to All Models notes 4 and 5 from the 180 TCDS 5A6 that refer to CHT probes. Engine upgrade STCs may supercede this info and relocate the probe. My Pponk STC does.

The cylinder head temperature probe location is No. 2 cylinder through S/N 18051445, No. 1cylinder S/N 18051446 through S/N 18052500, No. 3 cylinder S/N 18052501 and up.


The installation of the O-470-S engine in Model 180J (1973 and 1974) will require a changeof the oil temperature gauge and the cylinder head temperature probe location. ReferenceCessna Service Letter 75-2 for information and instructions for this change.

When I bought my JPI EDM711 I had to send the airplane serial number and Pponk STC paperwork to JPI so they could program the STC'd CHT instrument for airplane specific redline and high limit cylinder probe location. My warning light is placarded 460* and anyone who flies my airplane can easily identify the high CHT limit. That would not be the case with a generic EDM700 or other similar non-specific monitor instruments. I assume the CGR is programmed for specific installations, too?

 

[hotrod180]

Just a reminder, besides the probe location as called out by the C180 TCDS,
the O-470 engine TCDS note one calls out the CHT redline at 525 with a spark-plug-gasket type probe,
but only 450 (A & J engines) or 460 (K, L, R, S, or U engines) using a bayonette type probe.

 

[soyAnarchisto]

There are green, yellow and red arcs on the CGR-30P. This thing is certified, by STC to replace a bunch of stuff. My question centrally was whether I can replace the ammeter with the ammeter function on the secondary page instead of primary. And I was looking to confirm this. I don't see anything in the 180 TCDS about it, or the suction gauge being required gauge. But since this plane will be very light IFR and I do have a vacuum pump (for now) I'm going to keep that on the primary page.

Again, I called EI - but Dave wasn't really any help. I'm not looking to get rid of the functionality -I just would rather have the fuel flow on always available on the primary page rather than having to click a button to see what the fuel flow is. I don't really need the ammeter visible all the time. My understanding about the "primary" with the CGR-30P is that it has "limits" - meaning redline arc values. Ammeter has no markings whatsoever - just a green arc.

I'm going to replace 7 instruments out of my panel with this thing. Awesome...

My 180's TCDS doesn't list or address primary instruments and gauges. CAR 3 and FAR 91.205 do. My TCDS does list additional required equipment like a stall indicator. While a CHT instrument is required by regulation the location of a single probe is defined in the TCDS or supplemental TC. I believe one of the problems with digital instruments is compliance with range marking. There are no green or red arcs on digital instruments. JPI's CHT STC requires a warning light for redline (redline is defined in the TCDS). Other manufacturers may find other ways to comply with the markings requirement.

On soy's list fuel flow is not required. As I understand it a volt or amp gauge is required if an electrical system is installed. The suction indicator is only required if gyros are installed. EGT is not required.

 

[soyAnarchisto]

Yes, it is programmed for specific installations. Thank you all for pointing out the change in thermocouple type and different rating. I was going off of what was in my POH - and was about to put in the (incorrect) limit of 500. That would have been a big mistake.

FYI, here are Data Pertinent to All Models notes 4 and 5 from the 180 TCDS 5A6 that refer to CHT probes. Engine upgrade STCs may supercede this info and relocate the probe. My Pponk STC does.



When I bought my JPI EDM711 I had to send the airplane serial number and Pponk STC paperwork to JPI so they could program the STC'd CHT instrument for airplane specific redline and high limit cylinder probe location. My warning light is placarded 460* and anyone who flies my airplane can easily identify the high CHT limit. That would not be the case with a generic EDM700 or other similar non-specific monitor instruments. I assume the CGR is programmed for specific installations, too?

 

[hotrod180]

FYI, here are Data Pertinent to All Models notes 4 and 5 from the 180 TCDS 5A6 that refer to CHT probes. Engine upgrade STCs may supercede this info and relocate the probe. My Pponk STC does.

Note 4: The cylinder head temperature probe location is No. 2 cylinder through S/N 18051445, No. 1cylinder S/N 18051446 through S/N 18052500, No. 3 cylinder S/N 18052501 and up.

Re note 4: the second change (s/n 18052501, 1975 C180J) coincides with the first use of the 470-S engine, but the first change (s/n 18051446, 1965 C180H) doesn't coincide with any model-year changes (engine, cowl, etc) that would seem to indicate a need to change the probe location. Wonder why they did it?