Engine Misfire at Altitude.

[basloane]

I would not be too concerned with the FAA swat team crashing your door down for flying above FL200 ( unless they are dressed in bunny rabbit suits ).
I have known of P337s that have flown as high as FL240 for a short periods, and I have done a couple of long flights at FL210 and FL220.
I have been told that the skymaster is probably good for about FL260, but have not tried it. I am guessing that performance begins to drop off significantly at those levels.
The biggest risk is the cabin altitude... When I was a 30-40s something person in reasonable physical condition, non smoker with no health issues I could regularly fly my non-pressurized T-Arrow daytime at 15,000 with no ill effects. When I reached my early 50s, I tried a flight at 15,000 in a Bonanza and ended up with a pounding headache.
In any case, best to have Oxygen standing by......
As for ADS-B, we installed a GTX345. For most flights, 978 UAT is probably sufficient, but one day you are going to want to fly over weather at FL200......
Does anybody know what happens with 978 UAT above FL180....?

[mshac]

Well I found out I do have an STC for the pressurized mags - ACD Corp STC SE4303NM 4/25/1988 if anyone is interested.

Thanks basloane for your info on flying above FL200. Seems logical that with pressurized mags, the P337 should be good for FL240 at least. I would carry a pony bottle with me in case of cabin pressure loss. The original owner pulled the factory chemical emergency O2 system. I wouldn't mind having it back in service if they still sell the 02 charges.

Pressurized A/C with a ceiling above FL250 require the pilot to have a high altitude endorsement, I wonder if that played into Cessna's thinking.

If I can get up and play in the low 20's, I may have to upgrade my ADS-B.

And that begs the question - What happens when you fly a 978 UAT aircraft above FL180??? Do your wings immediately turn into fireballs? Do controllers screens start flashing red with your tail number??? Curious minds want to know!

[JimC]

Originally Posted by mshac

Pressurized A/C with a ceiling above FL250 require the pilot to have a high altitude endorsement, I wonder if that played into Cessna's thinking.

ALL aircraft with a ceiling above FL250 require the endorsement. The FARs define a "pressurized aircraft" as an aircraft with a ceiling higher than 25,000 ft. That means all T337s, period.

I'm still getting the misfiring...haven't fixed it yet. Kim, do you still have all that pressurize mag hardware?

[mshac]

Originally Posted by JimC

ALL aircraft with a ceiling above FL250 require the endorsement. The FARs define a "pressurized aircraft" as an aircraft with a ceiling higher than 25,000 ft. That means all T337s, period.

I'm still getting the misfiring...haven't fixed it yet. Kim, do you still have all that pressurize mag hardware?

Nope, that's wrong. From the FAA's own Advisory Circular: "As required by 14 CFR § 61.31, pilots who fly at altitudes at or above FL250 in a pressurized aircraft must receive training in the critical factors relating to safe flight operations under those circumstances."

Link: https://www.faa.gov/documentLibrary/...AC_61-107B.pdf

[JimC]

I'm not saying this makes sense - it's a poorly written regulation - but it's clear. The "problem" is the FAR's definition of "pressurized aircraft" - it's any aircraft that can fly over 25,000 ft. So according to 61.31(g) a T337 is a pressurized aircraft, and a P337 is not. There are many recently developed aircraft that you and I would call pressurized that have maximum operating altitudes of 25,000 ft, even though the engine and airframe can go higher. 61.31(g) does not apply to them.

The regulations make much more sense if you replace the word "pressurized" with "high altitude" all through 61.31(g) - but they're written with the word "pressurized."

The FAR is pretty straightforward and clear in the way it defines "pressurized aircraft":

61.31(g)(1): "no person may act as pilot in command of a pressurized aircraft (an aircraft that has a service ceiling or maximum operating altitude, whichever is lower, above 25,000 feet MSL), unless that person has received and logged ground training from an authorized instructor and obtained an endorsement in the person's logbook"

A T337 has a service ceiling over 25,000 ft.
Therefore it is a "pressurized aircraft" according to the FARs. (Hey, I didn't say they made sense.)
Therefore all of 61.31(g) applies.
61.31(g) *never* talks about how high you are actually flying. It only talks about whether or not you're acting PIC.

BTW, the AC doesn't say that you can skip the training if you're operating below 25,000 ft. If the aircraft can go that high, you need the training.

[n86121]

In PCA above 18k ft, the world is all 090Mhz. radar, tcas, etc

That said, the heavies up there all have TCAS and can see your basic Mode AC transponder just fine.

As can FAA if within radar coverage as well.

Just remember, your 978 mhz UAT will not see any 1090 transponders directly.

You will onl see 1090 targets when both your UAT and their 1090 are observed by and within range of an ADS B ground station.

if you have dual mode 1090/978 ads B in, you will see any 1090 ads-b out aircraft, 978/1090, but not any basic 1090. mode a/c.

D

[mshac]

That's good info about UAT above 18k, but if you're that high anyway, you'll be IFR and under normal traffic separation rules, so I wouldn't be too concerned about not seeing 1090 equipped traffic. Many of us use a portable 1090/978 in unit for weather and traffic to display on our tablets, so at least there's that. I'm not familiar with "basic 1090" - I guess that would be a 1090 equipped aircraft without ADS-B? I wouldn't imagine there would be many of those around.

Fun fact - Class A airspace used to be called "Positive Control" airspace (IIRC), and it started at 24k, not 18k. So for the longest time you could fly VFR right up to 23.5k.

[n86121]

That’s right

Basic mode a/c a mode A/c transponder without ads b out.

Mode S can be selectively interrogated by radar.
Rather than just interrogating everything in sight.
But even mode S doesn’t have ads b out.

Only mode S extended squitter (ES) replaces w ads vector info.

What I’m hearing is once you get away from major metropolitan airspace,
a lot of smaller aircraft not equipping w ads b

If they don’t go into the airspace that requires it,
they don’t have to get it.

It’s a mixed blessing. Great where everyone has it,
but no guarantee one is seeing everyone else.

[mshac]

My old Bonanza had some sort of a "Transponder sniffer" traffic device that was probably from the 1980's - whenever it sensed a transponder nearby a red light flashed and there was a warning tone. It had HI-LOW sensitivity, you kept it on HI, then if you got an alert switched it to LOW. If you got another alert, you knew the other plane was closing on you. It sure did keep your head on swivel when it alerted - Good times...