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TS-IOR
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Bizjet @ FL470!

Sun Apr 14, 2013 12:09 pm

Right now a Bombardier BD700 Global 5000 of Delia AS http://fr24.com/OYGVI is cruising FL470 ! Didn't know a bizjet could climb to such a higher level ! What about pressurisation and the view there ?!
 
EMBQA
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RE: Bizjet @ FL470!

Sun Apr 14, 2013 12:25 pm

Learjet's can go to FL51 if I remember correctly
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citationjet
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RE: Bizjet @ FL470!

Sun Apr 14, 2013 2:23 pm

Quoting TS-IOR (Thread starter):
Didn't know a bizjet could climb to such a higher level !

There are many biz jets that are certified to 51,000 ft max operating altitude, per the FAA TCDS. Some of the models include:
Cessna Citation 650, 750; Gulfstream GV-SP, GV; Lear 45, 24 E/F, 28, 29, 55, 31, 60, for examples. Many of these models were FAA certified in the early 1990s, and some of the Lears even earlier.

http://rgl.faa.gov/Regulatory_and_Gu.../rgMakeModel.nsf/Frameset?OpenPage
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tb727
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RE: Bizjet @ FL470!

Sun Apr 14, 2013 5:39 pm

Quoting CitationJet (Reply 2):
Many of these models were FAA certified in the early 1990s, and some of the Lears even earlier.
Quoting EMBQA (Reply 1):

Learjet's can go to FL51 if I remember correctly

I've flown 25D's that were certified for FL510, we could never get the pigs up there but I've been to 450 enough, really no good reason in a nearly 40 year old airplane to go so high. We routinely would take them up there or at least 430 and try and get the engine to compressor stall as a maintenance procedure. If it didn't the airplane was certified to go up as high as we could take it after that maintenance flight.

Once in a while you hear someone up there, it's more and more common and I am sure it's something brand new.
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26point2
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RE: Bizjet @ FL470!

Mon Apr 15, 2013 2:02 am

The BD700 Global Express/5000 is also certified to FL510. Normal cruise is at FL450 where the cabin is at 4500". Very nice.
 
PapaChuck
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RE: Bizjet @ FL470!

Mon Apr 15, 2013 2:43 am

While these aircraft may be certified up to FL510, it's actually quite rare for them to climb that high. As an enroute controller, I can count on one hand the aircraft I've worked at FL470. I can remember only one aircraft, a G-V, at FL 490. The range between the high 30's to the low 40's seems to be the butter zone between speed and efficiency for the biz jets.

I've worked aircraft higher than FL490, but I'm not at liberty to discuss it.   

PC
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TS-IOR
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RE: Bizjet @ FL470!

Mon Apr 15, 2013 11:40 am

And what about ATC ? Some UIRs ceiling is up to FL460 only  
 
CaptCufflinks
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RE: Bizjet @ FL470!

Mon Apr 15, 2013 1:38 pm

Quoting EMBQA (Reply 1):
FL51

I would imagine they could go a little higher than that  
Quoting TS-IOR (Reply 6):
And what about ATC ? Some UIRs ceiling is up to FL460 only

FL460 is only the boundary of their 3 dimensional 'block' of air - there's nothing stopping you monitoring a frequency that you are flying above/below/around, in fact it is good airmanship to do so. If the controller has the capacity to do so, he may even offer some sort of service to the aircraft.
 
DashTrash
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RE: Bizjet @ FL470!

Mon Apr 15, 2013 7:20 pm

I've been to 510 twice. You lose so much performance above 450 it's just not worth it.
 
KELPkid
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RE: Bizjet @ FL470!

Mon Apr 15, 2013 8:04 pm

Quoting PapaChuck (Reply 5):
I've worked aircraft higher than FL490, but I'm not at liberty to discuss it.

PC

IIRC, in the Contintental US, Class A airspace ends at FL600, and it's all Class E above that  
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foxxray
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RE: Bizjet @ FL470!

Tue Apr 16, 2013 10:45 am

Flying higher than FL450 is mostly just to say "i did"...  

Many biz are certified up to FL510 (7X, Glex, Gulfstream, Learjet, Citation X, ...) but you can only reach this level when you have burned a lot of fuel...
 
speedbird128
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RE: Bizjet @ FL470!

Wed Apr 17, 2013 9:56 am

Quoting tb727 (Reply 3):
Once in a while you hear someone up there, it's more and more common and I am sure it's something brand new.

Nah not that brand new... I've had plenty around F450 or F470 - at least several per week...

However, only a handful at F510, and those above I cannot discuss either...

When I worked down in africa, anything that could reach its max crz level to get over the CB's did so... Otherwise it could end up being several hundred NM (sometimes not so scenic) detour...

Quoting foxxray (Reply 10):
Flying higher than FL450 is mostly just to say "i did"...

I think that's quite accurate...
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26point2
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RE: Bizjet @ FL470!

Wed Apr 17, 2013 2:50 pm

As has been discussed in other threads there is no great operational advantage to climbing much above FL450. TAS is lower, margin above stall speed is lower, aircraft performance is lower. If trying to top weather a climb to FL470 or above can be done but one has to acknowledge the trade-off mentioned above. Topping a massive buildup with tops above FL450 will likely be met with strong up/downdraft and some turbulence. Would you want to be any where near the stall margin?

Some have mentioned ability to get a more direct route if above other traffic. OK, perhaps, might save 1 or 2 minutes. Also mentioned is the ability to climb above the strongest headwind. In my experience if the headwind at FL450 is troublesome then a higher climb might improve things a bit but you won't climb above all of it

Many folks I work with worry about explosive decompression at these altitudes...in which case you're likely toast.

I'm happy at FL450. Most guys are.
 
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Bruce
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RE: Bizjet @ FL470!

Thu Apr 18, 2013 3:30 am

I just did a random check ofn flightaware.com of one jet type: Citation X (C750) and about 5 or 6 of the 8 currently in the air are at 40,000 and up. N790XJ is at FL470 now enroute from TEB to VNY. They are doing a 5 hour coast to coast run and are in the last 40 minutes, so they've burned off much of the heavy fuel load they atarted with.

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flymia
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RE: Bizjet @ FL470!

Thu Apr 18, 2013 5:21 am

I have been up at about FL450 in a ciation Sovereign. I remember the pilots telling me to try to turn my cell phone and see if I got any service. I think I got some roaming. That was in 2007. Flew OPF-HPN-OPF my first and so far only private jet flight (hope that changes!) and what a way to fly! And 45,000ft is pretty awesome!
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KELPkid
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RE: Bizjet @ FL470!

Thu Apr 18, 2013 7:56 pm

Quoting 26point2 (Reply 12):
Many folks I work with worry about explosive decompression at these altitudes...in which case you're likely toast.

Wouldn't one flightdeck crewmember be wearing a positive pressure O2 mask at all times? The FAR's require it above FL420, IIRC...not sure what altitude the positive pressure requirement kicks in at  
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citationjet
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RE: Bizjet @ FL470!

Thu Apr 18, 2013 9:36 pm

Quoting flymia (Reply 14):
I have been up at about FL450 in a ciation Sovereign.

I have been at FL410 in a Citation Mustang. I was the only passenger in the 4 passenger jet. Amazing to be in such a small jet, looking down on the larger commercial aircraft flying below us.
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MD-90
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RE: Bizjet @ FL470!

Fri Apr 19, 2013 4:19 am

Quoting CitationJet (Reply 16):
I have been at FL410 in a Citation Mustang.

Sure it's "only" FL410 but how many bizjet passengers ever get to fly at their aircraft's service ceiling?
 
DashTrash
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RE: Bizjet @ FL470!

Fri Apr 19, 2013 2:28 pm

Quoting KELPkid (Reply 15):
Wouldn't one flightdeck crewmember be wearing a positive pressure O2 mask at all times? The FAR's require it above FL420, IIRC...not sure what altitude the positive pressure requirement kicks in at

I can't believe I don't remember the reg, but yes. The altitude is lower than that.

In the X the masks are only good below FL400, however. Best hope if you lost the cabin would be to smack the throttles to idle and let the EDM bring you down. It's not a memory item though, and I'm not sure how many pilots have that school of thought. I know it's would I would do if I had enough time before losing consciousness. EDM would HOPEFULLY get you down low enough to regain conciousness without the mask before you died.
 
MD-90
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RE: Bizjet @ FL470!

Fri Apr 19, 2013 8:35 pm

Quoting DashTrash (Reply 18):
In the X the masks are only good below FL400, however. Best hope if you lost the cabin would be to smack the throttles to idle and let the EDM bring you down.

So how does the FAA certify these jets to fly at FL510 without some sure way of safely descending to a lower altitude even after a catastrophic decompression event?
 
citationjet
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RE: Bizjet @ FL470!

Fri Apr 19, 2013 9:16 pm

Quoting MD-90 (Reply 19):
So how does the FAA certify these jets to fly at FL510 without some sure way of safely descending to a lower altitude even after a catastrophic decompression event?

The Citation X's FAA TCDS T00007WI, page 5 specifies Special Condition 25-ANM-80 was used to certify it to 51,000 ft.

To see TCDS T00007WI:
http://www.airweb.faa.gov/ >> Select Type Certificate Data Sheet >> Search for T00007WI.

To see Special Condition 25-ANM-80:
http://www.airweb.faa.gov/ >> Select Special Condition >> Search for 25-ANM-80.
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26point2
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RE: Bizjet @ FL470!

Sat Apr 20, 2013 12:40 am

Quoting KELPkid (Reply 15):
Wouldn't one flightdeck crewmember be wearing a positive pressure O2 mask at all times? The FAR's require it above FL420, IIRC...not sure what altitude the positive pressure requirement kicks in at

It's actually above FL410 for Part 91 ops and this has got to be the most often violated FAR in the book. Above FL410 one pilot must wear his quick donning mask. Anyone who has ever worn a quick donning mask will know that it's terribly uncomfortable and good luck if your claustrophobic. It's meant to be worn in an emergency so comfort was evidently not in the equation

I'm not condoning this behavior...of course I always wear mine...but judging by how often one hears a pilot transmit on the radio while wearing an O2 mask...and it's obvious because he sounds like his head is in a bucket...it doesn't happen as often as one would think.
 
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RE: Bizjet @ FL470!

Sat Apr 20, 2013 12:52 am

Quoting 26point2 (Reply 21):
I'm not condoning this behavior...of course I always wear mine...but judging by how often one hears a pilot transmit on the radio while wearing an O2 mask...and it's obvious because he sounds like his head is in a bucket...it doesn't happen as often as one would think.

To be fair, if I were wearing the mask, I wouldn't be talking on the radio at all - I'd have the other guy do that. You can barely move your mouth with the thing on.

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26point2
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RE: Bizjet @ FL470!

Sat Apr 20, 2013 10:02 am

Interesting side note about this O2 mask wearing business:

SAFA ramp checks can and do happen to unsuspecting biz jet crews in Europe, particularly if operating an N reg....in France. Authorities check for airman and aircraft regulatory compliance and they can be quite comprehensive. One of the "gotchas" it is said is a check of your O2 tank level after a North Atlantic crossing. If the tank is at or very near 100% full it is obvious the O2 mask requirement was ignored during the crossing and therefore subject to violation.

This could be an urban legend as I don't personally know of anyone who has been dinged for it but I can see an over-eager inspector making a case for it.
 
rwessel
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RE: Bizjet @ FL470!

Thu Apr 25, 2013 6:04 am

Quoting 26point2 (Reply 23):
Interesting side note about this O2 mask wearing business:

SAFA ramp checks can and do happen to unsuspecting biz jet crews in Europe, particularly if operating an N reg....in France. Authorities check for airman and aircraft regulatory compliance and they can be quite comprehensive. One of the "gotchas" it is said is a check of your O2 tank level after a North Atlantic crossing. If the tank is at or very near 100% full it is obvious the O2 mask requirement was ignored during the crossing and therefore subject to violation.

This could be an urban legend as I don't personally know of anyone who has been dinged for it but I can see an over-eager inspector making a case for it.

The better O2 systems on sailplanes I'm familiar with base the oxygen flow on the altitude (or more precisely, the local barometric pressure), and mix the required amount into air. So if you actually bothered putting a mask on at (say) 5000ft, you'd get zero O2 flow from the tank, and would be breathing 100% air. If you use a cannula, you'd just get zero flow through the tube at that point.

Obviously biz jets are pressurized, I would have assumed that a similar system would be in place to avoid wasting oxygen from the tanks until it's actually needed - perhaps with an override in case of smoke in the cockpit (which the sailplane systems have as well).
 
DashTrash
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RE: Bizjet @ FL470!

Thu Apr 25, 2013 1:36 pm

Quoting rwessel (Reply 24):
Obviously biz jets are pressurized, I would have assumed that a similar system would be in place to avoid wasting oxygen from the tanks until it's actually needed - perhaps with an override in case of smoke in the cockpit (which the sailplane systems have as well).

Demand flow system. When you breathe in, oxygen flows. When you're exhaling, no oxygen flow. Unless you're in emergency, then it's pressure breathing.
 
rwessel
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RE: Bizjet @ FL470!

Fri Apr 26, 2013 3:54 am

Quoting DashTrash (Reply 25):
Demand flow system. When you breathe in, oxygen flows. When you're exhaling, no oxygen flow. Unless you're in emergency, then it's pressure breathing.

Right, but doesn't it mix O2 and air based on the pressure?
 
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Starlionblue
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RE: Bizjet @ FL470!

Fri Apr 26, 2013 6:32 am

Quoting MD-90 (Reply 19):
Quoting DashTrash (Reply 18):
In the X the masks are only good below FL400, however. Best hope if you lost the cabin would be to smack the throttles to idle and let the EDM bring you down.

So how does the FAA certify these jets to fly at FL510 without some sure way of safely descending to a lower altitude even after a catastrophic decompression event?

I'll speculate here. If a window blows out the aircraft can still maintain pressurization (certainly true on an airliner). So you'd have time to get down. However I have no idea if you still need pressure breathing masks above FL400.

Quoting KELPkid (Reply 15):
Quoting 26point2 (Reply 12):
Many folks I work with worry about explosive decompression at these altitudes...in which case you're likely toast.

Wouldn't one flightdeck crewmember be wearing a positive pressure O2 mask at all times? The FAR's require it above FL420, IIRC...not sure what altitude the positive pressure requirement kicks in at

As 26point2 says, this is likely the most violated FAR in existence.
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DashTrash
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RE: Bizjet @ FL470!

Fri Apr 26, 2013 2:33 pm

Quoting rwessel (Reply 26):

Right, but doesn't it mix O2 and air based on the pressure?

It does unless you select 100%. Most of the time you wouldn't use that.
 
rwessel
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RE: Bizjet @ FL470!

Sat Apr 27, 2013 8:12 am

Quoting DashTrash (Reply 28):
It does unless you select 100%. Most of the time you wouldn't use that.

So wouldn't then the amount of O2 used be minimal (or zero) if the cabin remained pressurized? I'm asking in the context of the notion of busting a crew for non-compliance with the high altitude O2 mask regs based on the O2 tank contents after a flight.
 
DashTrash
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RE: Bizjet @ FL470!

Sun Apr 28, 2013 4:03 am

It wouldn't be nil, but will reduce consumption.
 
affirmative
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RE: Bizjet @ FL470!

Sun May 26, 2013 3:50 pm

From what I gather there are many good reasons to go above FL420. In most of the world its outside RVSM airspace and the commercial guys never get up there. If you get up to FL420+ you'd get "own navigation" by atc and fly the shortest route to your destination. Over the continental US and the atlantic this can be a big gain as I understand. I haven't had the opportunity to fly this high yet but hope to do so soon..  
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trnswrld
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RE: Bizjet @ FL470!

Sun May 26, 2013 6:26 pm

At work last week (enroute controller), I had if I remember correctly a G5 request block altitude FL490 through FL510 lol. Thats the first time in my career I have ever said FL510 to an aircraft. IO have had a few at 49, but thats only been a couple times. FL430 and FL450 are pretty common altitudes these days.
 
26point2
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RE: Bizjet @ FL470!

Mon May 27, 2013 12:38 am

Quoting affirmative (Reply 31):
If you get up to FL420+ you'd get "own navigation" by atc and fly the shortest route to your destination

I spend most of my time at FL430 or FL450 and although we get more direct routes it's never "own nav" to anywhere. There is other biz-jet traffic up there and military airspace to avoid and spacing and all the rest. Also, certainly don't get direct anywhere over the Atlantic as no matter the altitude there is no ATC radar and everyone must stay on designated tracks.
 
foxxray
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RE: Bizjet @ FL470!

Mon May 27, 2013 8:39 pm

Quoting affirmative (Reply 31):
From what I gather there are many good reasons to go above FL420. In most of the world its
outside RVSM airspace and the commercial guys never get up there. If you get up to FL420+ you'd get "own navigation" by atc and fly the shortest route to your destination. Over the continental US and the atlantic this can be a big gain as I understand. I haven't had the opportunity to fly this high yet but hope to do so soon..

Many good reasons ? You only said one, which is not really true... Above FL420 you can request more "direct" to farthest waypoints but in no way you are outside controlled airspace and can resume your own navigation... Then imagine, let's go, take off from LFPB go to KTEB... no routing, only go to   No way !
It can be usefull sometimes to fly really high, but the only true advantage is that you can be above weather in almost every parts of the world... No hundred Nm detours, the gain will be more interesting than the direct route you can get...

Quoting 26point2 (Reply 33):
I spend most of my time at FL430 or FL450 and although we get more direct routes it's never "own nav" to anywhere. There is other biz-jet traffic up there and military airspace to avoid and spacing and all the rest. Also, certainly don't get direct anywhere over the Atlantic as no matter the altitude there is no ATC radar and everyone must stay on designated tracks.

Fully agree   

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