Getting up in the Flight Levels

[Mike A]

231QZ is currently at Sarasota Avionics getting a major avionics upgrade which includes a JPI 730 engine monitor.  Until now, I have been hesitant to take her up above about 13k' and push her very hard without knowing exactly what is going on in the engine.  Once this work is all complete I will be a lot more willing to take her up high and give her some gas. 

 

My question for the high flyers is:

What is the minimum trip (distance or time) that you are willing to take the time to climb up into the flight levels?  I have a hard time imagining that I would be willing to do >25 minutes of climb (18,000' at +/-700 fpm) for anything less than 2.5 or 3 hours of cruise, but would be interested in hearing what other use for their flight planning.

[Danb]

Mine like 13-15000 which is a nice safe quite area, most decisions are based on Wx, winds, and distance.even through it may take a little extra to climb into the levels it is also nice to derive the benefits of a long easy descent hoping they allow it. Mike I'll bet once you get used to flying up there your level of appreciation will increase..good luck and happy safe flying..watch out for ice!

[carqwik]

Simplest thing to do is to use a flight planner like DUATS and plug in a bunch of different altitudes for the trip assuming you have correct profiles for different altitudes (e.g., turbo planes get a bit faster in terms of TAS at higher altitudes) and engine power/fuel flows.  And of course winds aloft can have a major role in altitude selection as well.  The goal of course is choosing an altitude that minimizes flight time or fuel use....or both!

 

In the end, it usually doesn't pay off to climb into the flight levels unless the trip is getting towards 3 hours in duration....or the wind component is a big deal higher rather than lower and going the direction of your travels.  I usually do what figures out to be the fastest trip...subject to wx, geography (big rocks out west), etc. 

[BobAustin]

I suggest you use Fltplan.com for your planning various altitudes. Best site out there and FREE.

[David Brown]

My only advice for this is OXYGEN. When you spend even 2-3 hours at anything above 10'000 without O2 you arrive in a very suboptimal state.

 

Any flight over 10,000' and any flight at night over 5000' is O2 time. In fact I have used O2 by day below 10,000' when tired and to print further fatigue as much as possible.

 

Mountain High O2 is your friend if you are not kited out already.

 

As for time at a FL, I would say as a rough rule of thumb, if the flight is less than an hour at the FL, so 15 min climb and 15-20 descent, plus an hour or more in the cruise it might be worth doing, especially if the winds or the ride is worth it. I will take a hit on speed or climb just for comfort escaping thermals and weather.

[WardHolbrook]

As others have mentioned, optimal cruise altitude depends upon a lot of factors - one of the chief ones is the wind. I love FltPlan.com and use it for nearly every flight.

 

When you start playing around in the FLs, you need to make sure that your 02 system is up to snuff and working properly. I would also suggest that you take a hard look as one of these: http://www.skyox.com/product/SK12-6-CV They're not expensive and in the event of a problem with your built-in system  a small emergency back-up bottle like one of these would be worth its weight in gold.

 

Finally, you're spending a lot of money on upgrades to get your airplane up to speed, but you haven't said anything about yourself. I would highly recommend that you spend a little time and money getting some altitude chamber training. It's guaranteed to be an eye opener. (Bad things can happen to you even in the lower flight levels.) There are various course around the country and the price for the training is very reasonable.         

[phecksel]

Is there any value in an O2 sensor to actively monitor your oxygen levels?

[WardHolbrook]

Is there any value in an O2 sensor to actively monitor your oxygen levels?

Yes. They're called pulseoxyimeters and if you're up playing around in the FL's in a nonpressurized airplane you ought to have one in your flight bag. They are readily available and fairly inexpensive.

[M016576]

My only advice for this is OXYGEN. When you spend even 2-3 hours at anything above 10'000 without O2 you arrive in a very suboptimal state.

Any flight over 10,000' and any flight at night over 5000' is O2 time. In fact I have used O2 by day below 10,000' when tired and to print further fatigue as much as possible.

Mountain High O2 is your friend if you are not kited out already.

As for time at a FL, I would say as a rough rule of thumb, if the flight is less than an hour at the FL, so 15 min climb and 15-20 descent, plus an hour or more in the cruise it might be worth doing, especially if the winds or the ride is worth it. I will take a hit on speed or climb just for comfort escaping thermals and weather.

That's true... But... Some of that depends on what you're acclimated to and how young/good of shape you're in. If you're based at 7000', and run/lift often, you might be fully capable up at 12000'. If you're based at sea level and smoke regularly, 6000' msl could be a challenge for you. Hydration and rest also play a factor.

I'm not a doctor, so I won't go any further: source of info comes from annual / recurrent military physiology training / chamber training.

[carusoam]

Pulse oxymeters are a low cost means of measuring what you are experiencing. Get one, use it...it will make sense.

Trying to use an iPad in a hyperbaric chamber must be a challenge.

Best regards,

-a-

[aviatoreb]

231QZ is currently at Sarasota Avionics getting a major avionics upgrade which includes a JPI 730 engine monitor.  Until now, I have been hesitant to take her up above about 13k' and push her very hard without knowing exactly what is going on in the engine.  Once this work is all complete I will be a lot more willing to take her up high and give her some gas. 

 

My question for the high flyers is:

What is the minimum trip (distance or time) that you are willing to take the time to climb up into the flight levels?  I have a hard time imagining that I would be willing to do >25 minutes of climb (18,000' at +/-700 fpm) for anything less than 2.5 or 3 hours of cruise, but would be interested in hearing what other use for their flight planning.

 

It depends.  Sometimes there is an aeronautical safety reason to go higher even if it is not efficient.  For example, when crossing the adirondacks, esp in the winter, I will go higher just to maintain gliding distance at all times to a safe landing spot.  So even if flying 45-60 min I will still go to 12-15k - even if it might be into a head wind.  I can get to 15k in 12 min, or 11min in the winter.

 

Otherwise, I just fly the predicted winds, and I use software to predict efficient altitudes, and consider where that puts me relative to the tops.  I use weathermeister that predicts the winds aloft, with my own airplane climb and speed profiles to choose an efficient altitude, and I compare that to the expected weather conditions to make my choice. I would rather fly 9k below clouds if the efficient 11k is in the clouds. 

[rainman]

+1 on the O2. Get a pulse oximeter and start checking your oxygenation levels at various altitudes. You may be surprised at what you find. Waiting until you "feel" bad can get you killed. Consider 90-93% as an indication to start oxygen. Lots of threads on this subject.

[Marauder]

I carry one all the time and check my O2 level even though I don't fly that high.

Sent from my iPad using Tapatalk

[Jerry 5TJ]

As a rule of thumb for turbo/turbine cruise altitude some use 1000' for every 10 miles. That suggests FL250 for 250 mile trip. Rule works OK if you can maintain >1000 FPM all the way up.

Wind is the big factor - unless headwind component rises less than about 2 kts per 1000 feet it is not worth climbing higher for speed alone in a turbocharged piston plane.

[David Brown]

That's true... But... Some of that depends on what you're acclimated to and how young/good of shape you're in. If you're based at 7000', and run/lift often, you might be fully capable up at 12000'. If you're based at sea level and smoke regularly, 6000' msl could be a challenge for you. Hydration and rest also play a factor.

I'm not a doctor, so I won't go any further: source of info comes from annual / recurrent military physiology training / chamber training.

Indeed 

 

Having said that, everyone will benefit from O2 at FL's some will just not need as much.

[chrisk]

For me, the deciding factor is the wind.   My last long trip was Austin to Ocala Fl.   ~850 miles in 4.5 hours.  I was at FL 21.  It was well worth the climb, as I had a 30 kt tail wind.   At 8000ft, there was a bit of a head wind component.   I would suggest looking at something like skyvector.com   You can display winds aloft and change the altitude to get a good visual.  Also the AOPA flight planner will select the "best" altitude for your. -Unfortunately, it doesn't seem to take into account the faster speeds as you go up.  For my last short trip, it was advantageous to stay low and ride the tail wind.

 

Also, it really is worth a pulsoximeter.   The are cheap, $60 or less, some around $20.  On my long flight I got up to around 14,000 and started feeling like crap "more like stupid"  Looked at the meter and the O2 levels were low (low 80's).  WTF?  Decided to look around a bit before calling ATC for a change.  After a bit more investigation, the hose on my mask was dis-connected at a coupler.  I probably sat on part of it. ... Plugged it back in and felt better almost instantly.  Fortunately I caught this before I got too stupid.  I suggest checking often.

 

I didn't push my plane when I was at FL21.  I was well ROP and was getting a true air speed of around 165kts, and a ground speed of ~205 kts.   CHTs were very low.  I'm sure I could have pushed it more, maybe 35Kts, but with more fuel burn and higher CHTs.  --And with the tail wind, why bother.  It would only make things go 15% faster.  Next time, I will probably go LOP.

[JohnB]

Ok, now that we're talking about oxygen, does anyone know where I can purchase a mooney specific oxygen filler adapter? Usually when I go into an unfamiliar FBO and ask for an O2 refill, they don't have the adapter that fits as it's too small. I'm hoping that I could purchase one that fits on my bravo that could couple with something most oxygen filling stations have, so I can refill at most places that have O2. Any solutions?

[DonMuncy]

If all else fails, I think Aerox has them.

[FlyDave]

Ok, now that we're talking about oxygen, does anyone know where I can purchase a mooney specific oxygen filler adapter? Usually when I go into an unfamiliar FBO and ask for an O2 refill, they don't have the adapter that fits as it's too small. I'm hoping that I could purchase one that fits on my bravo that could couple with something most oxygen filling stations have, so I can refill at most places that have O2. Any solutions?

John,

The fitting on your plane is a "Scott" fitting. The other side is a CGA-540. I just ordered one from mountain high oxygen. It's a TA-916-S:

http://www.mhoxygen.com/index.php/ground-support-equip/adapters/193-transfill-adapters6

But if you're thinking of getting your own tanks and transfilling equipment some of the systems come with this adapter.

Dave

[WardHolbrook]

If you use O2 in any quantity, it's best just to get your own gear and fill your own tanks. Anymore, oxygen is oxygen - it all come's from the same tank.   

[M016576]

+1 on the O2. Get a pulse oximeter and start checking your oxygenation levels at various altitudes. You may be surprised at what you find. Waiting until you "feel" bad can get you killed. Consider 90-93% as an indication to start oxygen. Lots of threads on this subject.

You might never recognize that you feel bad. One of the side effects of hypoxia is a Euphoric state. Another side effect is loss of color Vision. The symtoms manifest in different ways for different people, which is why chamber or physiology training is a good idea for those that head up into the FLs. Thats also Great advice to wear the pulse oximeter and to pay attention to it.

Unlike some of the other aircraft I fly, a mooney, even with speedbrakes, won't be able to descend fast enough to extend your useful consciousness up at / above FL250. Probably not a bad idea to have a small second bottle as an emergency O2 bottle if you wander up there as well. At 250, your useful consciousness is measured in a few minutes without O2.

[jlunseth]

About 2 hrs. is my minimum flight length to go to the flight levels, but it really "depends."  I don't do an aggressive climb, I climb generally at 500 fpm once ATC releases me to climb to my intended altitude.  That can mean 40 minutes or so in a climb at 500 fpm.  The "depends" part is what are the winds aloft doing?  Sometimes you need to get quite high to catch a strong wind.  Sometimes it starts not far off the ground.  So a climb speed of 105 kts. true quickly can translate into a good ground speed if you have the right wind.  I might go up right away even on a shorter flight if it means catching a strong wind. 

 

It is a lot like sailing, you use the winds to your best advantage.  With a turbo you can do that.  On the way home you might be down with the NA's at 2500 AGL, but you have cut your total trip time quite a bit.

 

There is one decided advantage of a turbo (among others) that often is not mentioned.  In the summer in the Midwest where I live, the popcorn cumulus usually occupies the air column up to somewhere between 12 and 16k.  Below that it is bumpy.  If you are a pilot and by yourself you probably don't care, you are used to it, but nonpilot passengers do care.  Not fun to get jostled around for 4 hours.  It also gets old having to fly through cumulus, or constantly be dodging around it making your 200 nm trip more like 220.  In a turbo you can top the turbulence and clouds (except for the Tstorms), and you will find it is always glass smooth up there.

 

A whole page on O2.  Frankly, in the various discussions I have heard and read on nonpressurized turbo flight, it is the NA pilots who never use O2 that make a big deal out of O2.  O2 is simple.  Follow the regs.  Get on O2 at anything over 12k.  Get a pulse oxymeter, they are cheap.  Keep your percent O2 above 92%.  You will find after a few flights with the oxymeter that you rarely use it anymore, you know how the system works and how you feel if your levels are low, and you will know what flow produces the O2 level that you need.  Best to have a built in system rather than tubes and tanks moving everywhere.  Use a miked mask if you are going into the flight levels, your O2 usage will go down and the flow is more even than cannulas.  Using O2 is as easy as, well, breathing. 

 

In a 231 it is not uncommon for us to make around 240 kts. GS on 13 gph.  The engine is perfectly happy and the CHT's are around 380.  Climb out should be at 100% power, FULL RICH, to altitude.  Read that again.  FULL RICH.  That keeps the CHT's in the 380 range all the way up in my aircraft, except one cyl. which is about 20 degrees hotter, I need to have my mechanic check the cooling on that one at annual this year.

 

You will find you need to rethink descents if you are coming west to east to your intended airport in the flight levels.  More art than math.  It depends a great deal on how strong the winds aloft are going to remain as you descend down the air column.  You will need to start the descent anywhere from 125 nm out to 75 nm depending on whether the wind will be keeping your GS up.  Just tip the nose over, pull off about an inch of MP to make up for the ram air effect, and enjoy the speed.

 

Fastest trip ever, Peoria to Fredricksburg in 1:45.  275 kts. GS

[JohnB]

John,

The fitting on your plane is a "Scott" fitting. The other side is a CGA-540. I just ordered one from mountain high oxygen. It's a TA-916-S:http://www.mhoxygen.com/index.php/ground-support-equip/adapters/193-transfill-adapters6

But if you're thinking of getting your own tanks and transfilling equipment some of the systems come with this adapter.

Dave

Perfect, thanks Dave!

[aviatoreb]

You might never recognize that you feel bad. One of the side effects of hypoxia is a Euphoric state. Another side effect is loss of color Vision. The symtoms manifest in different ways for different people, which is why chamber or physiology training is a good idea for those that head up into the FLs. Thats also Great advice to wear the pulse oximeter and to pay attention to it.

Unlike some of the other aircraft I fly, a mooney, even with speedbrakes, won't be able to descend fast enough to extend your useful consciousness up at / above FL250. Probably not a bad idea to have a small second bottle as an emergency O2 bottle if you wander up there as well. At 250, your useful consciousness is measured in a few minutes without O2.

 

I keep this thing at the ready when I fly high - I wanted something that would supply O2 without any fuss to get it ready.  With this device you twist the mask part onto the bottle and turn, and you are on O2:

http://www.mhoxygen.com/index.php/portable-constant-flow/emergency-systems/165-ntg-co-pilo2t-portable-o2

 

JoB what do you need to do to get chamber training as a civilian?  I was wanting to shadow a F16 pilot who recently did his currency chamber training, who has a Mooney here on the field, but it didn't work out.

[Shadrach]

The Army says there is no physiological degradation from SL to 4000ft.

http://phc.amedd.army.mil/topics/discond/ai/Pages/AltitudeEffects.aspx

I have found that fitness level helps when comparing same individual performance. But is not always an indicator of how well an individual will do against others. I slept on vogelsang pass after submitting the moderate peak 11,516. We had a marathon runner in our group, at the time, I was a smoker, but ran weekly and cycled often. Our marathon runner was doubled over puking be midnight with a pounding headache, a cyclist in the group was suffering from a pounding headache and could not sleep because of it. I being the portrait of bad behavior was sitting around the fire with a flask of Maker's and hand rolling cigarettes.

At sea level, either of those guys would have eaten my lunch. At altitude they were really suffering. We all lived in the Bay Area at around the same altitude. The effect that altitude has on an individual can be a fickle thing...