Well I had perfectly understood the matter regarding the difference between rate of climb and acceleration since the first post.
 
My concern was focussed on the pressurization and the effect of the rapid change of pressure on the organism and you clearly answered it on the second part of your post above.

 

Right - I just wanted to be sure a passerby got that side of it as well, just in case, since it's such a misconception (even one version of FS2Crew will fuss at you if you go over a certain V/S - I forget which one).

 

 

 

So the lesson to learn for me is that high rate of climb is not an issue on the pressurization side and there is no limitation or special recommendation on the rate of climb (in normal situation) neither on SOPs or anything else.

 

Correct - at least for modern aircraft. I'm not aware of any SOP restrictions, though I would say they're likely few and far between if there are any (and likely to do with some other issue other than passenger comfort at that).

 

 

 

The only think to avoid is the accelerations due to brutal changes of pitch during climb. So as I understand rate of climb above 3500fpm or 4000fpm may not be so uncommon for high-powered aircrafts at low weight such as B777 or B757.

 

Correct. Even I can make 1000 fpm seem like a whole lot in a little Cessna by shoving the nose over. Once you settle in on 1000 fpm though, the only discomfort at that point is the completely unpressurized cabin.

 

 

Even I can make 1000 fpm seem like a whole lot in a little Cessna by shoving the nose over.

 

He he true! I can remember my first flight lesson on a Robin DR400 when the instructor encouraged me to shake the stick a bit to get me feel more confident with the resistance of the aircraft... I was a bit worried by the fabric covered wing    and was a bit too shy with the controls.

 

I moved the sitck back and forth twice and my stomach played the yo-yo! Though most of experienced pilots would say that "arf that's nothing!" I still go easy with the controls. I'm not really keen on acrobatics feelings.

 

 

I still go easy with the controls. I'm not really keen on acrobatics feelings.

 

Especially with passengers, what they feel is ten times what you perceive. I pretty much stick to A/P when there are pax in the cabin.

 

I missed this point in the discussion:  It's getting very hard to find a flight today that is not at least 75-85% full. The airlines' are not in cahoots together (that anyone can prove) but their information systems are big investments in how to maximize yield and those will tend to work together even if not connected. Some beautiful mind came up with that a few decades ago.

He he true! I can remember my first flight lesson on a Robin DR400 when the instructor encouraged me to shake the stick a bit to get me feel more confident with the resistance of the aircraft... I was a bit worried by the fabric covered wing    and was a bit too shy with the controls.

 

I moved the sitck back and forth twice and my stomach played the yo-yo! Though most of experienced pilots would say that "arf that's nothing!" I still go easy with the controls. I'm not really keen on acrobatics feelings.

 

haha - yep. I always love flying in the back of a tubeliner with people who know you're a pilot (by that, I mean family/friends - I'm not the type to go off announcing it to FAs - yes, I've seen a couple people do that). Any time there's turbulence, I'll see them glance over at me to see if I'm fazed by what's happening. The fact that I'm still engrossed in a movie, or book, or sleeping (rare) is usually enough to tell them "that's nothing."

To me the feelings in a tubeliner are very different than the one in a GA. I would never be sick in a tubeliner even in strong turbulences while that first lesson was that close to make me throw up really.

But even if I'm not a real pilot per se (I still have to get my license but some other matters kept me away for a while from the lessons), amongst my family and friends I'm by far the most knowledged in aviation matters and my relatives also glance at me when there are turbulences or when they have a doubt about what's going on. 

They usually are reassured because - call me unaware - but I'm barely scared in an aircraft.

Noel

Try using Flap 20 for takeoff.

Aslo, select CLB2 when you enter the T/O perf data.

If all else fails, disconnect the A/T and reduce the N1 by a few.

The use of V/S is acceptable though as it effectively does the same thing as the line above by using thrust for speed.

There is a section in the FCTM about low initial level off altitudes to prevent the bird overshooting when its light, and although not quite the same thing, the techniques would apply equally here as its basically referencing high vertical speeds after liftoff.

Cheers

Matthew Knight

As a real-world airline pilot, if you're going for realism, this whole discussion is a bit silly, I would just throw away whatever this FSCaptain program is if it has a problem with climb rates. There's nothing unrealistic or even not smooth about a high climb rate.

Not sure what's up but the climb rate gets extreme and FSCaptain don't like it one bit!   I had initially used vertical speed set rather than VNAV and of course that works, but my sense from FSX days (using P3D now w/ T7) was that climb was exquisitely controlled w/ VNAV enabled.   Any ideas what I may be doing wrong?   I will spool up to 55% EPR, hit the TO/GA button and advance throttles, take off and control the climb rate w/ trim then when I hit the autopilot she shoots up to a climb rate of 5500+.

 

While I'm here, also when I have to do a manual/non-autoland, I can't figure out how to get the blooming horn to shut off after disengaging the autopilot to manually land.  I tried hitting the  Z key twice and it temporarily shuts off the horn but it will then come back on and stay on no matter what I do.

 

Thanks in advance!

 

 

You need to derate the engines if your light.   You take off and or climb at full power or near full power with a light load with the real plane you would have the same thing happen.   

Our company SOP require us to reduce rate of climb/descend to max 1500ft/min once within 1 min of reaching the assigned altitude.

 

Not for pax comfort or press reasons, but to avoid RA with other traffic.

 

So if climbing to 9000ft with 3000ft/min, then at 6000ft the PNF would call "approaching 9000" and the PF would engage VS +1000 to +1500ft/min.

 

So we are switching from VNAV to VS quite a lot during departure!

(4 times during our climb out of IAD yesterday if I recall correctly)

And then, once we are cleared for further climb we would engage Vnav again (or FLCH as Kyle said, because it is really nice for small altitude changes like 1000 to 3000ft)

 

The same is true for descends but less often since descend rates are often less extreme than climb rates below 10000ft with a light 777.

 

 

And then, once we are cleared for further climb we would engage Vnav again (or FLCH as Kyle said, because it is really nice for small altitude changes like 1000 to 3000ft)

 

A question regarding this... Let's say you you were first cleared to 6000ft after departure like London area and you are levelled at 6000ft and 250kt. Then ATC clears you to FL140.

With a T7 not fully loaded, if you engage VNAV (or leave it as it was already) and let the aircraft starts her climb in VNAV, at least in the sim it will overshoot 250kt as the engines spool up to THR REF by sometimes more that 10kt before pitching up enough to get back to 250kt.

 

In RW, would you select first V/S to get the aircraft in climb with speed managed by thrust or would you let the aircraft overshoot 250kt momentarely whil establishing in the climb?

I have not actually noticed that.....but those are them little kind of unaccuracies that come with an FSX addon versus a multimillion RW 777.

 

I dont worry about those kind of "cosmetic" problems in FSX.

 

But to answere your question, no, I would not start with VS to avoid that.

Just use VNAV and accept the few seconds that you will be 10kt too fast.

 

If it happens all the time though, and if it bothers you, you could submit a ticket to see if the PMDG team can smooth out the transition from level flight to climb a bit.

Thanks for the answer Rob.

 

I understand from your answer that this would not happen with the real aircraft.

However it does not bother me much as long as I don't get a warning from the online ATC (which has not occured yet).

 

If it is a"cosmetic" problem in fsx, I could get over it as well. It is just a matter of making the flight as real as it gets including compliance with regulations.

 

I must confess that I have so much faith in the PMDG's work that I tend to blindly believe their T7 absolutely reacts like the real one in any circumstances forgetting the limitations of fsx...  :wink:

 

That's why I ask that question because if this had to happen in RW, the question would be whether it is acceptable to exceed temporaly the 250kt limit, or everything should be done to avoid it (ie using V/S...)

 

I don't think it's really worth sending a ticket for that. If it is a behaviour of the addon, then I guess PMDG did already everything they could up to the limitations of fsx. If it is only on my system, then I would need to do more tests to get a full picture of the parameters involved (weather conditions, weight, thrust settings...) and it would take a long take for something that is not really a problem.

 

 

the question would be whether it is acceptable to exceed temporaly the 250kt limit,

 

Absolutely, and for two reasons.  First, ATC is not watching your speed like a traffic cop creating revenue. They are focused on separation and trends. Also, a 10 kt difference in IAS is negligible and often winds will have a larger impact on what ATC does see.  Secondly, any Heavy like the B777 is expected to have to exceed 250 KIAS to stay in the air when heavy.  It's normal.  In fact KIAH has NOTAM'ed their airspace to 280 KIAS up from 250 permanently.

yes, I can confirm that....for all practical purposes in real life you would follow an ATC instructed speed by +or- 10kt.

 

For example if you are instructed to fly 210kt and your clean maneuvering speed is 218kt you would fly 218kt so you dont have to extend flaps 1.

Good to now, thanks.

I knew already that the 250kt could be exceeded to the clean speed (if higher) but I didn't know what was the tolerance for the speed limits.

 

When you are not on the business, there are so many rules that you may think it is extremely strict and the lesser deviating wouldn't be tolerated.

 

 

When you are not on the business, there are so many rules that you may think it is extremely strict and the lesser deviating wouldn't be tolerated.

 

Yeah. When it comes to aviation, a lot of the rules are there for the Agency to smack you with if you mess up royally, but they aren't sitting there picking people off for slipping up as long as it didn't cause too much of an issue.

 

Even logbooks are primarily completed on an "on your honor" basis. ATC isn't the sky police (though, make no mistake, they'll hogtie you and drag you down by the empennage if you ruin their day by doing something stupid). The limits are usually slightly flexible (unless it's the ground), but it's usually best to avoid pressing your luck where you can. What's the best landing flap setting? Do you set up a standard takeoff flap setting, or do you make it dependent on the field? What is the max operating weight of a 747-400?

 

...and on and on.