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Mango

don't be afraid of high vertical speeds! 1800fpm no!

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I see posts where people are limiting their climb rates to the default autopilot climb of 1800 fpm, like in a post down the line about flying the A321. Real jets, especially light weight, do climb like fighter jets!! Do not stop them from climbing rapidly at the initial 200 to 250 kias climb up to 10,000. And above that, up to the flight levels, climb thrust usually 88 - 94% or whatever keeps the other gauges from redlining.. is normal, and you take what the vs gives you! In real modeled jets, (the default don't have lvlchg), you climb at the IAS you want, 250 - 300 etc... at the vertical speed you get... often 4000 - 6000 fpm! Don't try to cut that part down.... unless you are having a hard time keeping up with it.... It will settle down to half that or more at FL300 and above.... A light weight 747-400 will easily go up at 6000fpm initially, as well as a 737NG, A321 etc.! I have seen brief 8000 fpm in the real beechjet I fly, and the default LR45 will realistically hit 10,000 fpm initially if light :)Peter / Beechjet Captain near Boston

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I remember seeing video of an A340 at some airshow climbing nearly vertically which made me marvel at the power of the thing, but wouldn't the pax loose their lunch climbing at this rate.Mike.

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Actually, and please correct me if I am wrong, I dont think there will be anyone feeling sick with a 6000fpm or any climb rate for that matter provided the climb rate is a constant or near constant. Infact at any constant climb rate you will experience a force of exactly 1g (as if you were not climbing at all)since there is no acceleration.Excessive but constant climb rate may be a problem if the pressurization system is unable to keep up, or if the attitude of the plane is soo steep that your food slips off your table.Kabs

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What about descend?Should't there be a poiint in FPS where I cannot exceed?What is the normal range for descend rate in a 747?Manny

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Only thing is, these high FPMs apply only if jet is lightweight. Try that with a near full 747, and lots of cargo, well, good luck...

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The passenger issue with FPM is the pressure change rate.How fast do people have to unblock / clear their ears and does a rapid pressure change cause other problems.This is usually more of a problem on descent than climb.There is also a preceptive issue with humans. We expect and are comfortable with attitudes which push us back into out seats.We are not comfortable with nose-down attitudes which pull our backs away from the seats.

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I think the biggest problem is there is still no true IAS hold in FSX. Dial up the desired IAS and altitude, and the AP pitches to maintain the desired IAS.How this has been ignored for so long is beyond me.

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>There is also a preceptive issue with humans. We expect and>are comfortable with attitudes which push us back into out>seats.>>We are not comfortable with nose-down attitudes which pull our>backs away from the seats.>>I completely agree. What FPM or nose-down angle do you suggest is a good limit as a rule of thumb for passenger comfort?

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>I think the biggest problem is there is still no true IAS>hold in FSX. Dial up the desired IAS and altitude, and the AP>pitches to maintain the desired IAS.>>How this has been ignored for so long is beyond me.The Wilco Citation X does it. And you'll get some steep climbs as well even with full tanks... ;-)Heiko

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It varies with aircraft, but most airlines choose less than 2000 FPM for descent.However, FPM has very little place in the real world for larger aircraft on descent and climb - it's is IAS and pitch.The Bombardier Challenger 604 and the Gulfstream 200 which I've been able to ride the jump seat do not use FPM.They set pitch angle and adjust it up or down to maintain IAS.More than 5 degrees nose down appears to be unpleasant to many people.Also remember that normal cruise for most jet aircraft is 2 to 5 degrees nose up, so five degrees nose down is 7-10 degrees nose down to the pax.

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It's also the direction of the acceleration. It's still 1 G when you stand on your head..

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I love this form, you end up learning so much more than what was proposed in the original questions :)

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Hi all,I've said something similar before on this forum and was quickly "put in my place" by someone who, curiously, didn't actually have any airliner flying experience.I completely agree with the original poster on this issue, it's very very rare to worry about fpm. The only 2 times I can think of is when close to the ground (sets the GPWS off) or when making relatively small climb/descents in a busy TMA (sets TCAS off). Either way, there is an element of protection from those two systems, you would have to be arrogant beyond belligerent to ignore them, not to mention fired.>It varies with aircraft, but most airlines choose less than>2000 FPM for descent.The only restriction in the airline I fly for is that we have to descend at less than 3000fpm when within (or below obviously) 3000ft of the MSA. Apart from that there are no restrictions to our climb/descent rates. The MSA restriction isn't for passenger comfort.The Airbus VSI goes orange when climbing or descending greater than 6000fpm but it won't stop you. I've seen a descent of around 7000fpm and a climb of about the same. Nobody noticed anything out of the ordinary down the back (and believe me they're quick to tell you if they think they do).Any modern pressurisation controller will be able to handle very large rates of climb and descent without any discomfort. Passengers don't really care what your fpm is, only that their beer is cold, their hosties attractive and they arrive on time.>However, FPM has very little place in the real world for>larger aircraft on descent and climb - it's is IAS and pitch.That is correct but we often don't worry too much about pitch, whatever is required to keep the aircraft safe and doing what you want it to do will be fine. The passengers will generally only notice large, quick changes of pitch, roll, slip, engine power (noise) and de/acceleration. Anything else will go unnoticed.I hope this helps,Ian

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>Hi all,>>I've said something similar before on this forum and was>quickly "put in my place" by someone who, curiously, didn't>actually have any airliner flying experience.>>I completely agree with the original poster on this issue,>it's very very rare to worry about fpm. The only 2 times I can>think of is when close to the ground (sets the GPWS off) or>when making relatively small climb/descents in a busy TMA>(sets TCAS off). Either way, there is an element of protection>from those two systems, you would have to be arrogant beyond>belligerent to ignore them, not to mention fired.>>>It varies with aircraft, but most airlines choose less than>>2000 FPM for descent.>>The only restriction in the airline I fly for is that we have>to descend at less than 3000fpm when within (or below>obviously) 3000ft of the MSA. Apart from that there are no>restrictions to our climb/descent rates. The MSA restriction>isn't for passenger comfort.>>The Airbus VSI goes orange when climbing or descending greater>than 6000fpm but it won't stop you. I've seen a descent of>around 7000fpm and a climb of about the same. Nobody noticed>anything out of the ordinary down the back (and believe me>they're quick to tell you if they think they do).>>Any modern pressurisation controller will be able to handle>very large rates of climb and descent without any discomfort.>Passengers don't really care what your fpm is, only that their>beer is cold, their hosties attractive and they arrive on>time.>>>However, FPM has very little place in the real world for>>larger aircraft on descent and climb - it's is IAS and>pitch.>>That is correct but we often don't worry too much about pitch,>whatever is required to keep the aircraft safe and doing what>you want it to do will be fine. The passengers will generally>only notice large, quick changes of pitch, roll, slip, engine>power (noise) and de/acceleration. Anything else will go>unnoticed.>>I hope this helps,>>Ian>>>>>Coming straight from the mouth of a real commercial pilot! Like others in this post, I was always concerned about this matter of FPM thing and when ever I would see the needle go beyond 2,000 FPM I would adjust, making flying big aircraft annoying and difficult.Great Post :)

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The problem in FS with high FPS in descent is most aircraft gain a lot of speed.While an AI aircraft will descend at 7000 FPM and slow down, very few user aircraft can avoid gaining speed at a very fast rate.

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>I think the biggest problem is there is still no true IAS>hold in FSX. Dial up the desired IAS and altitude, and the AP>pitches to maintain the desired IAS.>>How this has been ignored for so long is beyond me.Guess I don't really follow (yet). What do you mean... Doesn't the current AP/ATHR hold the IAS you want it to hold...? If I dial in some ALT and some IAS, engage the appropriate modes the AP will hold these values. Anything wrong with that, varying from reality? Just curious.Thanks,Etienne

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Right on.>I remember seeing video of an A340 at some airshow climbing>nearly vertically which made me marvel at the power of the>thing, but wouldn't the pax loose their lunch climbing at this>rate.>>Mike.Actually I believe the A340 is known for it's ridiculous climb rate after take-off, but then again I assume this is only true for a usual long-range fully loaded flight.Anyways, I can only agree with Peter regarding VS... Airlines will often just use FLCH modes and similar, resulting in 4000+ fpm rates easily with no one complaining. I assume the power is the only limiting factor.Still I do have a question to any real world airline guru who might read this. What would be typical *cruise* rates e. g. during a step climb, or what would be a typical rate of descend after having reached the TOD (initial descend from cruise)?Thanks a ton.Etienne

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True IAS hold is not an autothrottle. The AP will pitch the aircraft to hold the desired speed at whatever throttle setting you're giving it. So if you're climbing out, throttle at, say, 97%, to an altitude of , say, 10,000 feet, at a selected IAS of 250 KIAS, the AP will climb at whatever rate necessary to hold 250 KIAS. AFAIK, this is found on every passenger carrying jet aircraft.

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>The problem in FS with high FPS in descent is most aircraft>gain a lot of speed.>>While an AI aircraft will descend at 7000 FPM and slow down,>very few user aircraft can avoid gaining speed at a very fast>rate.>You are right, in FS, I found that when climbing and pitching to hold a desired air speed is easy but when it comes to decents I have to constantly use speed brakes and flaps to slow the plane down if going beyound 2,000 FPM. It barely holds 250.

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>Still I do have a question to any real world airline guru who>might read this. What would be typical *cruise* rates e. g.>during a step climb, or what would be a typical rate of>descend after having reached the TOD (initial descend from>cruise)?Climbs are difficult to generalise as they are dependant on weight, altitude and aircraft. I've only experience on the little Airbus' but once above FL300 climb rates can drop off markedly. I've seen as much as around 2000fpm and as low as about 300fpm, depending on weight. You put on climb power and see what you get. If you are up against an altitude restriction you could trade some speed for altitude but at those altitudes there's not much to play with and it's a very short term measure.Pulling open climb (or FLCH for you Boeing guys) to descend from TOD we usually get somewhere in the mid/high 2000s to low 3000fpm.As I said, only applies to little Airbus' but I can't imagine other aircraft being hugely different to this.Hope this helps,Ian

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>The problem in FS with high FPS in descent is most aircraft>gain a lot of speed.It's a problem in real life too. If we find ourselves high we often try and wind the speed up with the speedbrakes out to get the very high descent rates needed to get back on the profile. If your speed limit is low (250 kts or less) then you will really struggle to get much more than 1500 to 2000fpm, even with the speedbrakes. If you need to slow down as well, bad luck, choose one. I personally prefer to go down, then slow down.You can use flaps but only if you're below the maximum speed for them and in the Airbus the first flap selection (available from about 210kts) isn't very draggy. You really need to get Flap 2 out, 180kts Flap 2 Open descent buys you just over 1200fpm, should get you back on the glideslope if you are a *bit* high.When things get really bad you can drop the gear, that's a hugely effective speedbrake and it can be used at fairly high speeds (250kts Vlo in the little Airbus' - and 280 once they're out). The problem is that they generate a lot of cabin noise and once down can't really be taken up again without worrying everyone. I've seen guys drop the gear very early to rein in a hot and high approach, it works very nicely but we really shouldn't have been there in the first place.Hope this helps,Ian

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I like to take the FS aircraft out for a long test flight, especially when it's a new model. You'd be surprised at what you can learn about how your virtual airplane will handle at different phases of flight. Since this IS a simulator you can easily vary the airplane's weight, change altitudes, conditions of flight,etc. It will help you gain a much better understanding of what the airplane (even these virtual ones) is capable of and what it is not. We try to do this in real life too, ( in a sim of course ), I like to see just exactly what the limits of my airplane are, so that if the need ever arises I will know what I can and cannot do. Become a virtual test pilot and see what you can do. Ever try rolling a B-707 at about 1000' AGL?,....It's been done in real life.John M

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QuoteAny modern pressurisation controller will be able to handle very large rates of climb and descent without any discomfort. Passengers don't really care what your fpm is, only that their beer is cold, their hosties attractive and they arrive on time.UnQuotePoint taken about the capabilities of modern pressurization systems, that said high rates of ascent and the possability of a catastrophic pressurization system failure seems at least in principle an uncomfortable combination, also any pressure vessel will have its total life span reduced by rapid pressurization / rapid de-pressurization. Also all other things being equal, an aircraft in a rapid descent / ascent mode may lose a margin of safety should it suffer a mechanical failure or experience severe weather condtions.Best and Warm RegardsAdrian Wainer

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QuoteActually I believe the A340 is known for it's ridiculous climb rate after take-off, but then again I assume this is only true for a usual long-range fully loaded flight.Unquotehttp://www.cfm56.com/index.php?level2=engi...&level4=historyThe CFM-56 A340s have a reputation for being underpowered, the Rolls Royce engined variant is supposed to be much more satisfactory.http://en.wikipedia.org/wiki/Rolls-Royce_TrentBest and Warm RegardsAdrian Wainer

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