Hawker 800XP/API winglets range question

[BoilerUP]

Pretty sure the difference in useful consciousness between an explosive decompression at FL410 and FL510 would be fairly imperceptible - if you're not already on a mask or proficient at the whole "quick don" concept you're going to be just as dead.

How many explosive and/or rapid Ds happen every year, though?

 

[400A]

Pretty sure the difference in useful consciousness between an explosive decompression at FL410 and FL510 would be fairly imperceptible - if you're not already on a mask or proficient at the whole "quick don" concept you're going to be just as dead.

How many explosive and/or rapid Ds happen every year, though?

These times are cut in 1/2 by explosive decompression.

Suit yourself. Still twice the reaction time at 410.


Altitude in Flight level Time of Useful Consciousness Altitude in meters Altitude in feet FL 150 30 min or more 4,572 m 15,000 FL 180 20 to 30 min 5,486 m 18,000 FL 220 5-10 min 6,705 m 22,000 FL 250 3 to 6 min 7,620 m 25,000 FL 280 2.5 to 3 mins 8,534 m 28,000 FL 300 1 to 3 mins 9,144 m 30,000 FL 350 30 sec to 60 sec 10,668 m 35,000 FL 400 15 to 20 sec 12,192 m 40,000 FL 430 9 to 15 sec 13,106 m 43,000 FL 500 and above 6 to 9 sec 15,240 m 50,000

 

[Gulfstream 200]

All joking aside, I'm with 400a 100%.

There is no performance reason to be at FL510 in any business jet. Its a sales gimmick that all the OEMs have jumped on.

Also, no departments I know fly up there, and if you did you would be called on to explain your reasoning. Good Luck with that.....and BTW, wanting to take goofy pictures of your PFD or Airshow showing FL510 just really isn't a good explanation.

 

[NCherches]

You get better AM reception up there and Rush has a lot to say lately...

 

[BoilerUP]

All joking aside, I'm with 400a 100%.

There is no performance reason to be at FL510 in any business jet. Its a sales gimmick that all the OEMs have jumped on.

Also, no departments I know fly up there, and if you did you would be called on to explain your reasoning.

All joking aside....why are you hesitant to operate the airplane to the full extent of its operating envelope?

Is it a risk managment/mitigation decision? Or one based on the fact that many swept-wing airframes simply don't gain much above the mid 40s?

Again, no flame or joke...just trying to learn.

 

[aa73]

Still don't quite understand why you corporate types love the high FLs... I have issues going higher than 350, not for performance but for solar radiation. Can't count the number of times we're at 350 and I see some high contrail, flick the TCAS to Above and find someone up at 450 or above... just plain craziness. Do you guys realize the amount of radiation you are subjecting yourselves to?

 

[Gulfstream 200]

All joking aside....why are you hesitant to operate the airplane to the full extent of its operating envelope?

Is it a risk managment/mitigation decision? Or one based on the fact that many swept-wing airframes simply don't gain much above the mid 40s?

Again, no flame or joke...just trying to learn.

Of course, no problem...its all just opinions here anyhow..

Whats a single advantage of operating at FL510? - not one thing.

If you ever have to stretch a leg to its limit by getting up there after hour 10-12 (no way before) you shouldn't be doing that leg...run a Da900ex at LRC of mach .72 and the last 2 hrs at FL510?? - nah...Im going to run .80+ and stop. Run a GLEX the same to try and get 13+45 instead of 13+15?...nah..just too many variables involved - real winds? weather? alternates? landing permits? customs? etc..

My current airplane can stay in its envelope at FL510 and mach .90....should I just operate there because its OK by the book?

Most planes I have flown in the last 10 yrs are capable of FL510 - and not once have I ever had to operate it over FL450...including 13hr+ legs. Nobody has ever shown me a leg that can be stretched by going higher than FL450, maybe FL470..the burn to get up there is the same as staying lower.

We would also have issues with pilots operating up there just to "do it" and take goofy pictures for their websites (seen it on some other sites, facebook etc!) I mean - why would you operate a G5 on a 3hr domestic leg at FL510?....not impressive (to me)

Im sure people have their reasons, and I dont care how others operate their departments, just saying that I see no reason to do such a thing..nor has anyone I have ever flown with. The military guys are usually the first to make it clear that we dont operate at FL510 - no need. Maybe it was their previous training...I dont know. If someone chooses to fly their capable plane at FL510 thats great, I wont tell them how to fly. Not my business.

The only remote reasoning I could see is an inexperienced guy digging through charts coming up with some hair brain plan that FL510 at hour 12 will make his trip almost possible....and again, in every operation I ever worked at common sense or experience would take over and tell him just to stop at a good tech stop and be 100% sure of making destination.

Just my .02 on "FL510 it dude"......its worth what u paid for it!

 

[Gulfstream 200]

Still don't quite understand why you corporate types love the high FLs... I have issues going higher than 350, not for performance but for solar radiation. Can't count the number of times we're at 350 and I see some high contrail, flick the TCAS to Above and find someone up at 450 or above... just plain craziness. Do you guys realize the amount of radiation you are subjecting yourselves to?

Gulfstreams have special anti-radiation deflectors. Not an issue.

 

[400A]

All joking aside....why are you hesitant to operate the airplane to the full extent of its operating envelope?

Is it a risk managment/mitigation decision? Or one based on the fact that many swept-wing airframes simply don't gain much above the mid 40s?

Again, no flame or joke...just trying to learn.

The safety reasons for me are endless. I am not willing to lay my life on the line to save a few bucks or maximize range. As G-200 says, the sales / marketing game of range predicated on these operations are insane. Not to mention the regulations. Above 410 SOMEBODY is supposed to have a mask on, and based on the 3-5 second reaction time, you are not gonna make it if you are not wearing it. A very small percentage actually wear the mask. If they were, they would be having the o2 serviced after every flight. I have never subscribed to the "it never happens philosophy". I want to consider " What if it does". If you lose pressure at FL 510, there is a very good chance you killed everyone in the back. Remember, they do not have a positive pressure mask, nor are they going to get it on in 3 seconds.

I have gone to 43, and 45 to clear weather. I put the mask on, cleared the weather and came back down.

Having to operate to the extent of the certified envelope? Remember, those numbers were computed in ideal conditions by test pilots. In the real world we rarely have those conditions, and most pilots do not even pay attention to the requirements. Example... My last flight was ISA+19 at FL350.

People make fun of the Hawker, but I can make it do everything the salesman promised the boss it would do. The Beechjet..... Not so much.

 

[BoilerUP]

Still don't quite understand why you corporate types love the high FLs...

Stretching range, topping weather, finding smoother rides, and fuel efficiency.

Our plane burns about 12% more fuel at FL410 than it does at FL450, and about 40% more fuel at FL350 - with true airspeed only about 3% higher at that altitude. For us, it makes operational sense to fly high when segment length allows (typically 1+30 or longer flights).

Do you guys realize the amount of radiation you are subjecting yourselves to?

According to the info at http://www.swpc.noaa.gov/info/RadHaz.html for operating at 35°N latitude...about 64% more radiation at FL450 than FL350.

Considering your average corporate pilot flies substantially fewer hours per year than your average airline pilot, I'd say our overall exposure is equal to or even slightly lower than airline pilots.

 

[BoilerUP]

Having to operate to the extent of the certified envelope? Remember, those numbers were computed in ideal conditions by test pilots. In the real world we rarely have those conditions, and most pilots do not even pay attention to the requirements. Example... My last flight was ISA+19 at FL350.

If a pilot doesn't know where to find & how to read a 1.3G and/or altitude capability chart, and doesn't understand basic high-altitude aerodynamics as it relates to their wing and their engines, then yeah they shouldn't be flying those altitudes. Good thing learning either isn't exactly rocket science...

I've seen as high as ISA+23 from the mid-20s through the mid-30s the last week...of course it dropped off sharply around FL400 and was ISA-6 at FL450.

 

[Box-Hauler]

Boiler, do you use a mask above 410? Not flaming just asking because that is my biggest reason not to go above 410, mask is not comfortable at all. I don't care if it saved 50% on the gas bill that mask is a killer.

As for wearing a mask, you could run the mask in "normal" and not 100% that would save on the oxygen fill ups, and then if there ever was a decompression the mask would auto go to 100% pressure feed.

 

[NCherches]

Of coarse he uses a mask up there... thats the rules right...

 

[Stryker]

Why can't you just answer the guys question, he didn't ask about the Gulfstream. Yes the API numbers are very accurate on both the 800A and the XP. You should get very close to the published fuel burns if not better.

 

[Livin' Life]

Why can't you just answer the guys question, he didn't ask about the Gulfstream. Yes the API numbers are very accurate on both the 800A and the XP. You should get very close to the published fuel burns if not better.

Agreed. The data they provided ARINC (which in turn is used in their flight planning) is very accurate. We're almost always within 100lbs of flight plan fuel.

We did however have a situation between a city pair that we fly often where we were consistently burning 200-300lbs more than flight plan. I called ARINC to find out why and after putting our heads together we realized that they weren't accounting for a crossing restriction on the arrival that puts us at a low altitude a good distance from the airport. They were able to put that in and the numbers began to match again.