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

[XWRed5 0]

OK, I'll bite....>Quite a bit of groupthink...e.g. the blind leading the>blind...in this thread.I'd be interested to hear from your years of experience flying commercial jet airliners, Bob.>The idea that you just accept whatever climb rate that rated>climb power might give you is...wrong. Especially for>jets capable of flying long legs with heavy fuel loads that>might happen to be flying a short, light one."just accept" agreed, usually use is more like it. Mr Boeing and Mr Airbus gave us FLCH and Open Climb /Descent for a reason. They are the most commonly used climb and descent modes (at least in the Airbus). The most efficient way to climb is to use climb power (that's why it's called climb power because it the best/most efficient power setting for the ... climb) and a speed commensurate with your weight (and cost index). The actual fpm you get is immaterial. I guess if you're a long haul aircraft doing a short hop you could limit the climb rate but that's a rare event.>A 6000 fpm climb in a transport category jet will produce a>deck angle that is absolutely uncomfortable for passengers.The girls pushing the trolleys from the back to the front won't like it but those 150 punters all sat in their seat sipping G and T's and reading the paper wouldn't notice, we tend to adopt the attitude smoothly. We're only taking about 10 to 12 degrees of pitch here, we're not going ballistic with Hollywood bits of luggage flying around the cabin and hosties screaming "WE'RE ALL GONNA DIE!!!". 6000fpm climb isn't maintainable for that long either, it'd soon die off and return to something more sensible, that doesn't mean we don't do it. >It's also very difficult to control smoothly when a controller>issues a late climb restriction close to your altitude...you>can end up doing a very uncomfortable nose-over to meet the>restriction. Agreed, there's a time and a place for those large rates of climb/descent and to get the 5/6/7000 fpm climbs we're talking about you have to be trying, you wouldn't get that in a managed speed, open climb/descent in the Airbus. You would have to be doing it deliberately.> Unless you're taking off from Kathmandu and>trying to get above the towering Himalayan cumulogranite>clouds nearby, there's no reasonable excuse for operating like>that.Managed speed, open climb (or even managed climb) will give you climb power and whatever climb rate you get to keep the speed. That's pretty standard I'm afraid.>In real world flying in the G-V, I generally use V/S mode with>a ~3000 fpm maximum climb rate when operating the G-V light,>for example. The G-V is capable of a 12-hour flight with>41000 lbs of gas...but is also typically used for flights of>just an hour or two with less than 10000 lbs of fuel, and left>to fly to its performance limits, it'll climb like a Saturn>rocket with full climb power at those weights.So you fly the airborne equivalent of a Lamborghini and you're trying to force your operating procedures on the airborne equivalent of a Greyhound bus. At what point did this seem like a good idea? >No experienced real pilot just lets the airplane go to its own>limits regardless of the impact is has on the paying customers>in back. In fact cargo operators even keep a lid on climb>rates when light (which isn't often).Climb power is an engine manufacturer specified limit that balances power, noise, fuel consumption and thrust with an aim to get the aircraft to it's cruise altitude quickly and efficiently. If you consider it a limit then you don't really understand what climb power is. Even in a little Airbus we struggle up to the high FL300's regularly, somewhere between 300 and 500fpm, clawing our way up, sometimes trading speed for altitude to get to the altitude we want. The aircraft is pretty much at it's performance limit ... so far I've yet to die or suffer any ill effects from this. >Also, the A340 is indeed renowned for its performance, all>right...as one of the true pigs of the sky. The thing can>barely get out of its own way at typical heavyweight loads for>overwater flying. Lightweight, sure it can climb fast, like>any other jet designed for heavy loads, but the 340 is>typically operated at considerably lower thrust-to-weight>margins than most, if not all, other airliners in this>category.Indeed, I see the A340 (particularly the older 200/300 series) often eating up the runway and becoming airborne much later than everyone else. It's no star performer.I can categorically state that it is normal for airliner climbs to be flown with climb power set and the pitch adjusted to maintain a set speed. The fpm/pitch angle is not an issue. Descents are usually flown with idle power and the pitch/fpm adjusted to maintain a set speed. VS is used to try and smooth out an expected step climb, avoid setting off TCAS or the EGPWS if approaching traffic or high ground or to try and maintain a constant descent approach (this list isn't exhaustive, the pilot can choose to use VS whenever he wants). Long haul aircraft that are particularly light may choose to limit their climb rates depending on the situation, that's called airmanship, the exact reason you limit them on your Gulfstream, Bob. That doesn't mean we're wrong. Just because we fly airliners differently to your pocket rocket does not mean we are not "experienced real pilot(s)". We're operating a different aircraft, accept that we'll use different procedures.If we choose to inform others, keen, educated and enthusiastic people who are genuinely interested in learning about this, please don't misguide them with your belligerence and arrogance, inform them of your operating procedures of course, it's always good to hear of the different ways of operating different aircraft ... but don't say we're wrong because we do it different. That's just stupid.Don't mean to rant Bob but you really can't go round spouting off misinformation and untruths like this and not expect to be corrected.Hope this helps,Ian

[XWRed5 0]

My apologies Adrian, I just reread my message and it comes across a bit sharper than I intended. It was written with a wry smile on my face, with the intention of being dry, mischievous wit. Perhaps I should have included a bunch of :-)'sI'm not sure I quite captured that though, my apologies if I offended you, it really was not my intention.Take care,Ian

[badderjet 181]

>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.Ok, I got that part now. So it's more like a IAS hold that affects pitch (and VS and ALT too). A/THR would be an IAS hold that does not affect pitch, correct? Guess the former would be a FLCH on a Boeing aircraft, anyone?Cheers, :-beerchugEtienne :-wave

[ryanbatc 12,859]

Intelligent and Interesting post here guys...I called up a friend up mine (US airline I'm not saying) that operates CRJ-200's and he wasn't there but I'm interested in their company policies etc with regards to ascents and descents. I told my friend we got some neat guys (you pilot dudes) talking about stuff on this forum and he'll get back to me with a voice mail or something soon I should hope. He's prolly flying right now lucky duck!Oh to fly again....it's so expensive when you're not being paid to fly LOL!