SR22 Down - Gulf of Mexico

[Kritchlow]

All the ADM I've seen will take you to 15,000 ft because that's a safe altitude anywhere in the CONUS

Problem with most ADM systems is they don’t reduce power. Now I can’t speak for the Cirrus, but we had ADM systems in many of the Citations I have flown. It will descend, but not encroach barber pole. So, if you have the power set at barberpole speed.....

Newer citations have auto throttles. Not sure if that’s now accounted for.
There’s really no reason it couldn’t be in the older airplanes. Power automatically reduced to idle if a TR deployed in flight. Same could be done for ADM.

 

[Tarheelpilot]

You sure about that?
The reports don't say anything about passengers, not even a dog. And the plane was an unpressurized Cirrus registered in an private corporation, which suggests there's no air carrier certificate involved. Just a guy the same as me, (hopefully) sucking on oxygen.

Nope... I was wrong. Got this thread mixed up with another one. Please disregard.

 

[NJP_MAN]

Problem with most ADM systems is they don’t reduce power. Now I can’t speak for the Cirrus, but we had ADM systems in many of the Citations I have flown. It will descend, but not encroach barber pole. So, if you have the power set at barberpole speed.....

Newer citations have auto throttles. Not sure if that’s now accounted for.
There’s really no reason it couldn’t be in the older airplanes. Power automatically reduced to idle if a TR deployed in flight. Same could be done for ADM.

I hear you. It's my understanding that originally the 750 was intended to have AT. The 7X I fly and just about every new airplane I can think of that has ADM also had AT. Expect power reduction a turn off course and a descent to level at 15,000. Without reading the book I think the turn is 90° but it could be 45°. Not sure if it uses the oceanic emergency descent protocol.

 

[Everskyward]

The Sovereign also had the automatic emergency descent feature, but as @Kritchlow notes, you had to be able to reduce power and extend the speedbrakes yourself.

 

[EvilEagle]

I see you guys scrambled 2 F16's and then later 2 F15's. What would be the procedure trying to wake him up?

...No idea if that would have helped - just curious if something like that would ever be purposefully tried? (As a last resort).

We don't have any plans in place to wake people up. If the guy is out due to hypoxia, it wouldn't help wake him up. If we purposefully kicked his autopilot off and he never woke up there would be no end to the arm chair quarterbacking and potential suits from the family. As crazy as it sounds, that's the way it seems our country works these days.

I'd think short of trying to reach him via radio, the only audible option short of explosive ordinance would be close passes or use of afterburner to try and wake him.

Radio for sure, fast/loud passes - maybe. (see above)

I did do some of that when my wingman fell asleep crossing the Atlantic one time. Tried flying close, AB passes, yelling on the radio - was thinking about trying to give him turbulence but didn't because he was just asleep and I didn't want to kill him if he didn't wake up. In the end he just woke up for no apparent reason; thankfully we didn't have to cross that bridge.

Too bad about this guy in the Cirrus; sometimes bad things just happen.

 

[RudyP]

I only know a couple of pilots that own SR-22s with turbochargers, but they both fly them up pretty high most of the time. The MEAs going westbound from where I live are all in the oxygen levels. That's why they own 22Ts. What's the point of having a turbocharged Cirrus and flying it down low?

I have my O2 on above 8000 ft at night and above 10,000 ft in the daytime. I am thinking about making it 8000 ft all the time, just because of my age.
And I use a pulse-oximeter, with a second one in the plane for passengers (I rarely have more than one other person in the plane when O2 is in use though). Cannot understand why anybody wouldn't.

Once again I find it ironic that we have concerns about the reliability and use of O2 systems and their attendant accessories, such as pulse oximeters, and in the same thread commentary about the Cirrus autopilot automatically descending the airplane - a system that must be magnitudes of order more complex as a viable solution.

Everyone is different but in my experience there are 3 camps of SR22Turbo drivers.
1) People like me (the majority, btw) who fly in the high teens but don't routinely go up to the mid 20s. We get 200KTAS at 17,000-18,000 ft and it generally isn't a horrible human environment if a small glitch in the O2 system happens. Thats pretty much how I fly and my average GS over 3 years and 100,000+ miles is ~180 KTS- which when you factor headwinds more often than tailwinds, climbs, patterns, etc... isn't all that bad since that is wheels up to wheels down time.
2) those who bought a turbo but don't like canulas and fly in the 8000-12,000 ft range. There are a surprising number of these folks who dont like oxygen but bought a turbo 22 because everyone else does and they dont care about the extra $60K or whatever it is. Their true airspeed isn't much faster than a naturally aspirated STR22. Remember that a fully loaded new SR22T is $930K
3) A handful of pilots who routinely fly in the low flight levels. The airplane is certified to FL250 and it is perfectly legal to be there. I have done it on occasion and under the right circumstances, it is very cool to be doing 220KTAS + a big tailwind but it takes a lot of caution (or balls) to do that routinely (IMO) in an unpressurized plane. Also the full face mask sucks...

In my anecdotal (but more like 30-40 owner/pilots experience, the vast majority of SR22T/TN pilots are in camp 1, then 2 and a small minority in 3..

When you do get the right time, place and go high, it's pretty cool how fast you can go though. This is 352 Kts over the ground (up high, with a honking tailwind and in a slight descent)!

 

[Kritchlow]

Why the high teens? Is the aircraft most efficient there, or “just because it can?”


Many airplanes can fly higher than they do, but it may not be the most efficient altitude.
Do you have a system for checking that?

 

[Tantalum]

I only know a couple of pilots that own SR-22s with turbochargers, but they both fly them up pretty high most of the time.

My CFI is the CSIP at an SR22T club here and I was asking him about where they typically fly it.. IE, are they really going up into 22-25K range? He told me the plane "flies the best" in the 14K-18K range and that's where most of the club members hang out at.. he had the same note about unpressurization and O2.. at 16K you're not totally screwed immediately if you have an O2 glitch. at 25K it's much lonelier..

 

[TCABM]

... note about unpressurization and O2.. at 16K you're not totally screwed immediately if you have an O2 glitch. at 25K it's much lonelier..

Here’s a quick look at time of useful consciousness (TUC) at various altitudes. Notice the steep drop above FL200.

TUC is essentially the amount of time you have between interruption of normal O2 and when you start to become useless, not total unconsciousness.

 

[FastEddieB]

One time in my NA SR22 I chose to fly home from an Angel Flight with a trip to 17,500’, the plane’s Maximum Operating Altitude. It was a short trip, and I did it just for fun. I spent maybe 10 minutes straight-and-level at 17,500’.

A fair amount of the time spent in the cruise climb is regained in the long descent. So, my total trip time was not far different from flying it at a lower altitude.

I mention this to say there was nothing inherently “crazy” about this pilot choosing to climb into the Flight Levels for this relatively short flight. Not to say there’s not a significant difference between 17,500’ and the low 20’s.

edited to add:

I think this was taken at the top of this flight. Note 163 KTAS at 9.3 gph!

 

[Tantalum]

Here’s a quick look at time of useful consciousness (TUC) at various altitudes. Notice the steep drop above FL200.

That is indeed quite dramatic! And supports the point my CFI and Rudy mentioned about having a lot more options in the 16K neighborhood
**one thing I never understood with these charts, how is useful consciousness 6 seconds at 50K. This could potentially be a stupid question, but I can hold my breath realistically for about 40 seconds.. maybe a minute if I absolutely had to. So if I suddenly lost my O2 at 50K feet how is that in 6 seconds I'd be a vegetable?
**did the Concorde ever have any recorded cases of decompression? I believe it was designed to stay pressurized with two cabin windows missing??

One time in my NA SR22

*were you hand flying up that high?

I really learned to appreciate the altitude effects on the powerplant with the man press and % power when I transitioned to the Cirrus. Really makes you appreciate it better. The Warrior and old Skyhawk POH give you some rudimentary chart (that looks like it has been faxed, scanned, and copies a dozen times) showing RPM and percent power at various altitudes, but until you see the man press and % power drop you don't really appreciate it

 

[FastEddieB]

*were you hand flying up that high?

Probably not.

In any case, there seemed to be plenty of performance available at 17,500’, at least when light. But that is an Operating Limitation. Probably an artificial limit due to difficulties in certifying for altitudes higher than that. Or maybe anticipated problems with unpressurized mags or something like that.

 

[Ted]

I only know a couple of pilots that own SR-22s with turbochargers, but they both fly them up pretty high most of the time. The MEAs going westbound from where I live are all in the oxygen levels. That's why they own 22Ts. What's the point of having a turbocharged Cirrus and flying it down low?

I have my O2 on above 8000 ft at night and above 10,000 ft in the daytime. I am thinking about making it 8000 ft all the time, just because of my age.
And I use a pulse-oximeter, with a second one in the plane for passengers (I rarely have more than one other person in the plane when O2 is in use though). Cannot understand why anybody wouldn't.

Once again I find it ironic that we have concerns about the reliability and use of O2 systems and their attendant accessories, such as pulse oximeters, and in the same thread commentary about the Cirrus autopilot automatically descending the airplane - a system that must be magnitudes of order more complex as a viable solution.

I don't think anyone's saying not to fly in oxygen levels, but there's a big difference between flying in the mid teens and in the flight levels in terms of time of useful consciousness when you have a problem with your O2. There's also a big difference between flying single pilot and two pilot. If you look at the regs regarding oxygen masks starting in the 30s, they do change for single vs. two pilot, basically because the thought is that one pilot will probably stay awake.

As to the avionics solutions for hypoxia, I think they end up being very good ideas in addition to the PulseOx. Obviously the PulseOx is the first line of defense, but it has issues. For one, I don't see most pilots actually keeping the things on them for extended periods of time during flying, just doing spot checks. A finger-based PulseOx isn't convenient to wear. So you check it, you see you're fine, take it back off again since it's annoying to you. Then you start to feel happy (first sign of hypoxia) and think "Oh, I don't need that stupid thing." Your SpO2 drops off, and the story continues.

Everyone is different but in my experience there are 3 camps of SR22Turbo drivers.
1) People like me (the majority, btw) who fly in the high teens but don't routinely go up to the mid 20s. We get 200KTAS at 17,000-18,000 ft and it generally isn't a horrible human environment if a small glitch in the O2 system happens. Thats pretty much how I fly and my average GS over 3 years and 100,000+ miles is ~180 KTS- which when you factor headwinds more often than tailwinds, climbs, patterns, etc... isn't all that bad since that is wheels up to wheels down time.
2) those who bought a turbo but don't like canulas and fly in the 8000-12,000 ft range. There are a surprising number of these folks who dont like oxygen but bought a turbo 22 because everyone else does and they dont care about the extra $60K or whatever it is. Their true airspeed isn't much faster than a naturally aspirated STR22. Remember that a fully loaded new SR22T is $930K
3) A handful of pilots who routinely fly in the low flight levels. The airplane is certified to FL250 and it is perfectly legal to be there. I have done it on occasion and under the right circumstances, it is very cool to be doing 220KTAS + a big tailwind but it takes a lot of caution (or balls) to do that routinely (IMO) in an unpressurized plane. Also the full face mask sucks...

In my anecdotal (but more like 30-40 owner/pilots experience, the vast majority of SR22T/TN pilots are in camp 1, then 2 and a small minority in 3..

When you do get the right time, place and go high, it's pretty cool how fast you can go though. This is 352 Kts over the ground (up high, with a honking tailwind and in a slight descent)!
View attachment 59020

Exactly. Just because a plane is certified to a particular altitude doesn't mean that's its optimal altitude. The 414 has a service ceiling of FL300. RVSM aside, that's a ridiculous altitude for the plane to fly at. Cabin altitude will be way too high, the engines will be unhappy, just lots of reasons why you wouldn't want to be there. I imagine it would fly like crap at that altitude. FL180-200 in the 414 is much happier. I expect that an SR22T would do better at its service ceiling than the 414, but I'd fully expect the "happy" altitude to be in the mid to upper teens.

 

[Tantalum]

A finger-based PulseOx isn't convenient to wear

I don't recall seeing any such app for our fitbit, but do any of the smartwatches have an integrated O2 sensor? That would seem the easiest solution since you're already wearing it...

 

[Clark1961]

**one thing I never understood with these charts, how is useful consciousness 6 seconds at 50K. This could potentially be a stupid question, but I can hold my breath realistically for about 40 seconds.. maybe a minute if I absolutely had to. So if I suddenly lost my O2 at 50K feet how is that in 6 seconds I'd be a vegetable?

If you tried to hold your breath during decompression at 50k feet the day would not end well for you. The lungs are rather poor pressure vessels.

 

[Ted]

I don't recall seeing any such app for our fitbit, but do any of the smartwatches have an integrated O2 sensor? That would seem the easiest solution since you're already wearing it...

None do currently.

 

[FastEddieB]

I had a pulse oximeter Velcro’d to the panel, along with a reminder on my 430 to check it periodically.

 

[Tantalum]

If you tried to hold your breath during decompression at 50k feet the day would not end well for you.

Yeah that might hurt. But it's crazy to think that you only have 6 seconds of oxygen reserve in your blood. Sobering

 

[RudyP]

Why the high teens? Is the aircraft most efficient there, or “just because it can?”


Many airplanes can fly higher than they do, but it may not be the most efficient altitude.
Do you have a system for checking that?

Mostly because the human is most efficient there. My TN gains 2 knots of true airspeed for every 1000 ft of altitude on the same fuel flow so it is more efficient at FL250 than at 18,000 but I am more comfortable at 18 than 25. The human response curve to altitude is not linear. FL250 is a very harsh environment for a human if anything happens to the oxygen flow. It’s just a lot more risk exposure in an unpressurized plane. Besides, it’s also uncomfortable (have to wear full face mask, very dry air, feel bloated, etc)

 

[Everskyward]

I don't recall seeing any such app for our fitbit, but do any of the smartwatches have an integrated O2 sensor? That would seem the easiest solution since you're already wearing it...

I believe the finger device measures the redness of your blood, or some such thing, to determine the O2 saturation, so it wouldn't work well on your wrist. They would need to come up with another way to measure.

 

[deonb]

I don't recall seeing any such app for our fitbit, but do any of the smartwatches have an integrated O2 sensor? That would seem the easiest solution since you're already wearing it...

The Fitbit Ionic has a sensor, but I don't think the software for that is enabled yet. (And it might never be).

 

[TCABM]

**one thing I never understood with these charts, how is useful consciousness 6 seconds at 50K. This could potentially be a stupid question, but I can hold my breath realistically for about 40 seconds.. maybe a minute if I absolutely had to. So if I suddenly lost my O2 at 50K feet how is that in 6 seconds I'd be a

First, it’s onset of the LOSS of useful consciousness, not incapacitation. However, the higher you go, the quicker that happens, too.

Here’s a really good, quick (3-5 min) read about the effects and outcomes as observed in real time.

http://avstop.com/medical/anencountewithhypoxia.htm

 

[StanN45]

If you ever have the opportunity to come to OKC, this is an excellent, one day training on the affects of hypoxia. It is, to say the least, an eye opener. Getting to take a ride in the altitude chamber is quite an experience.

https://www.faa.gov/pilots/training/airman_education/aerospace_physiology/

 

[TCABM]

If you ever have the opportunity to come to OKC, this is an excellent, one day training on the affects of hypoxia. It is, to say the least, an eye opener. Getting to take a ride in the altitude chamber is quite an experience.

https://www.faa.gov/pilots/training/airman_education/aerospace_physiology/

There’s a traveling version (PROTE), too. I think it’s been to the Mooney summit recently.

 

[StanN45]

There’s a traveling version (PROTE), too. I think it’s been to the Mooney summit recently.

I believe that is correct. I've heard they go to Oshkosh as well. The chamber ride is still worth the trip.

 

[Everskyward]

I never understood the allure of flying high, but maybe that's because I spent a lot of time doing it in both pressurized and unpressurized airplanes (way too much time in these). If I had the choice, and the weather was cooperating, I would fly at 1,000' AGL. Unfortunately I didn't have the choice, except when flying the mapping planes. No jet flying at 1,000' AGL.

That said I know others feel differently.

 

[Hank S]

There’s a traveling version (PROTE), too. I think it’s been to the Mooney summit recently.

It was supposed to be there, but "they" had scheduling issues and sadly did not bring it.

 

[tawood]

Yeah that might hurt. But it's crazy to think that you only have 6 seconds of oxygen reserve in your blood. Sobering

I don't think that you have 6 seconds left if you hold your breath...I think the problem is, you can't predict to hold your breath, THEN have your oxygen fail. You would be breathing, then your oxygen fails, and you've already continued breathing...holding your breath at sea level (or while your oxygen is working) starts you with lungs full of oxygen. How long can you hold your breath if you first exhale completely? (at least that's my uneducated guess)

 

[TCABM]

I don't think that you have 6 seconds left if you hold your breath...I think the problem is, you can't predict to hold your breath, THEN have your oxygen fail. You would be breathing, then your oxygen fails, and you've already continued breathing...holding your breath at sea level (or while your oxygen is working) starts you with lungs full of oxygen. How long can you hold your breath if you first exhale completely? (at least that's my uneducated guess)

Depends on the failure mode. Rapid decompression reduces your TUC by 1/2 or more and is easily identifiable, but by the time you recognize the event it’s too late to be able to ‘hold your breath’.

A Kink in your hose that subtly decreases the O2 delivery may not even be noticeable. Or worse, your AvOx bottle is filled with breathing air.

 

[jkaduk]

2) those who bought a turbo but don't like canulas and fly in the 8000-12,000 ft range. There are a surprising number of these folks who dont like oxygen but bought a turbo 22 because everyone else does and they dont care about the extra $60K or whatever it is. Their true airspeed isn't much faster than a naturally aspirated STR22. Remember that a fully loaded new SR22T is $930K

Maybe a lot of them want the turbo for Tahoe, Aspen, Telluride etc. But otherwise don't want to go high.

 

[Tantalum]

^maybe "holding your breath" was a poor way of putting it, does our body really have that little reserve oxygen in the bloodstream that breathing "oxygen free" air will affect you within 6 seconds? Must be true, that's what the charts show, just surprising!

 

[Tantalum]

Maybe a lot of them want the turbo for

I mean.. if you can afford it, then why not? At $900K having that power from the turbo is just good, and nice, and fun to have in general. You see people buy supercharged range rovers and Cayenne turbo S models for no other reason than it's fun. Ultimately, isn't that why most of fly, just for the fun?

If I had the means to actually afford a turbo version of something I'd opt for it too

PS, I still need to do that great lakes checkout at some point!

 

[denverpilot]

^maybe "holding your breath" was a poor way of putting it, does our body really have that little reserve oxygen in the bloodstream that breathing "oxygen free" air will affect you within 6 seconds? Must be true, that's what the charts show, just surprising!

There’s always O2 transfer going on inside the body when you’re “holding your breath”. As it’s been described to me, the issue is that under lower pressure all that transfer stops.

And, nobody’s mentioned that in a rapid decompression, everyone’s gonna fart, too. LOL. Might as well add that, since it is PoA after all.

 

[Ted]

I never understood the allure of flying high, but maybe that's because I spent a lot of time doing it in both pressurized and unpressurized airplanes (way too much time in these). If I had the choice, and the weather was cooperating, I would fly at 1,000' AGL. Unfortunately I didn't have the choice, except when flying the mapping planes. No jet flying at 1,000' AGL.

That said I know others feel differently.

Having spent time between 500 AGL and FL270, I tend to agree with you. It's a lot more fun to fly low. That said, I tend to fly at the best altitude to complete the mission. That generally means a combination of what altitude will get me the best TAS, efficiency, tailwinds, around weather (icing, storms, etc.) and also taking into account human factors. So I'm rarely flying at 1,000 AGL, although I last winter I did fly from NYC back home to KS at 2,500 MSL (which was <2,000 AGL for most of the trip) because of winds. It was a lot of fun, way more fun than flying at FL180-190. But the 414 is 40 KTAS faster at FL180-190, so guess where I spend more time given my typical 600+ nm legs...

You really have to be going a long ways to get a benefit from being up that high in a piston bird, though. Not like a turbine bird where you get way better speed and efficiency up high.

 

[Tantalum]

I tend to feel more comfortable with a few thousand feet between me and terra firma. At less than 2K AGL if you have an engine problem you have very limited options..

 

[Ted]

I tend to feel more comfortable with a few thousand feet between me and terra firma. At less than 2K AGL if you have an engine problem you have very limited options..

That's part of the decision matrix when picking an altitude. Keep in mind I'm flying in a twin so as long as I have an OEI climb >0 then I'm fine. In a single, yes, there are additional considerations there.

There's no one size fits all answer. My guess is in this case he wanted to go up high for the sake of going up high and because he could. We all make similar decisions at one point or another.

 

[Tantalum]

Keep in mind I'm flying in a twin

That makes sense. At the same token, I tend to not like going much higher than 10K.. albeit the planes I am flying ceiling out in the mid teens, but at that altitude if you have to get down suddenly you are much further from home. An engine out gives you plenty of time, but something else, like a fire, and it can take a while to get a distressed Skyhawk down. The Cirrus with the power out and a strong slip will have a tremendous vs

 

[tawood]

I tend to feel more comfortable with a few thousand feet between me and terra firma. At less than 2K AGL if you have an engine problem you have very limited options..

Although I agree, I would add that it depends on where I'm flying...in Michigan's thumb or nearly anywhere over Indiana (both of which are full of plowed farmland) or nearly anywhere in Michigan during a normal winter (the lakes freeze solid) I can be comfortable flying at 1000 AGL, due to all the landing choices. But get me over most of Michigan's upper peninsula, and 5,000 seems too low.

 

[Ted]

That makes sense. At the same token, I tend to not like going much higher than 10K.. albeit the planes I am flying ceiling out in the mid teens, but at that altitude if you have to get down suddenly you are much further from home. An engine out gives you plenty of time, but something else, like a fire, and it can take a while to get a distressed Skyhawk down. The Cirrus with the power out and a strong slip will have a tremendous vs

In the 414 in emergency descent I'll be able to do 6,000+ FPM down. In the sim it was around 7,000, and I think that with the MT props I could get down faster (with engines windmilling those things are major barn doors). So even from FL190, I can get down really fast. So that aspect makes sense.

In the 172/PA28, I'd go up to 12,500 max but there was no point in going any higher. Really your chance of a fire in those things is also pretty low. I worry about it more in the 414 with the turbos.

 

[Zeldman]

And, nobody’s mentioned that in a rapid decompression, everyone’s gonna fart, too. LOL. Might as well add that, since it is PoA after all.

That was the first thing I learned in the altitude chamber.....