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Noel

How to control climb rate after TO w/ VNAV enabled

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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!

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Sam issue here but I started pitching to 10 degrees stable before hitting AP. Also to stop the horn its control shift Z

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when I hit the autopilot she shoots up to a climb rate of 5500+.
If the pane has a light to medium load with fuel for a 4-6 hour flight, 5500+FPM is in the ballpark.

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Any ideas what I may be doing wrong?

 

Yes.

 

To be blunt, you're bending your flying to a product that isn't coded to be realistic. FSCaptain might add a feeling that things are more realistic because you have to follow procedures, but many add-ons that watch your vertical speed (to include FS2Crew) are hopelessly incorrect when it comes to penalizing or warning you for it.

 

People do not feel rate, they feel acceleration. The same way you feel natural going 450 knots through the air in a 777, you feel natural in a 5500 feet per minute climb/descent. The issue, however, is the rate at which you go from 0 to 5500. That's what people feel, as that's acceleration.

 

So, my advice would be to either disable that metric, or ignore it. The add-on is unrealistically flagging you for normal operation. It would be like flagging you for putting the flaps down.

 

All that said, if you'd like to tame the climb, use a takeoff and climb de-rate. In order to calculate more realistic climb de-rates, though, you'll need a program like TOPCAT.

 

 

 

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.

 

This one is clearly explained in the into manual, but for your convenience, I made a video a while back because this one seems to stump people a lot:

 

What's happening is that you're hitting Z, which disables the autopilot, but starts the alarm. You're then hitting Z again, which re-enables the autopilot (Z is the default FSX AP ON/OFF toggle), but you're probably manipulating the controls at this point, which again, kicks the AP off and the alarm goes off.

 

As mentioned in the video, it would probably be best to set up a key command in the CDU menus for AP disconnect. This is a one-way switch: OFF. That way, hitting the button twice will: 1 - turn off the AP, and 2 - tell the automation that the action was intentional, and disable the alarm.

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I have a button assigned to my CH Yoke, click that twice for disengage. One of the red buttons, very convenient.

By the way, double-click works with all aircraft but with the iFly 747, click the button then reset the bar on the AP panel, gotta ask them one day.

What I like PMDG for, it is one developer where everything works like a mechanism in the swiss watch -))))

 

PS, Kyle can you please remind me, on PMDG 747, does the double-click disengage and silence the autopilot or you still have to reset it by pressing on the bar?

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PS, Kyle can you please remind me, on PMDG 747, does the double-click disengage and silence the autopilot or you still have to reset it by pressing on the bar?

 

To be honest, I've forgotten. For a plane that was my first PMDG purchase (the original FS9 release anyway), with a ton of hours in it, I didn't even bother re-installing it a few years ago when I reformatted my machine.

 

I thought you could set up an AP disconnect key command in the Options menu (up on the FSX menu bar). I could be wrong.

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Gr8, thank you all for these quality tips and suggestions.  I'll give it a whirl!

 

Noel

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Kyle can you please remind me, on PMDG 747, does the double-click disengage and silence the autopilot or you still have to reset it by pressing on the bar?

 

I'm nit Kyle, but I can confirm it does!

 

The A/T is a different matter, however -- there is no 'soft' disengage (at least not that I've found over the last three years) so the only way to disengage the A/T is to use the 'disarm switch on the MCP (twice to silence the alert/EICAS message -- so it ends up back in the 'armed' position and armed but disengaged).

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The A/T is a different matter, however -- there is no 'soft' disengage (at least not that I've found over the last three years) so the only way to disengage the A/T is to use the 'disarm switch on the MCP (twice to silence the alert/EICAS message -- so it ends up back in the 'armed' position and armed but disengaged).

 

There is a "soft" autothrottle disengage.

 

If you press CTRL-SHIFT-R then that presses the black button on the side of the throttle levers. Press it again the alarm will silence allowing full manual autothrottle control with no master caution message.

 

To engage the autothrottle again just press the A/T button on the MCP and you're good to go.

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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

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If you press CTRL-SHIFT-R then that presses the black button on the side of the throttle levers. Press it again the alarm will silence allowing full manual autothrottle control with no master caution message.
 
To engage the autothrottle again just press the A/T button on the MCP and you're good to go.

 

Is that for the 747? I will give it a go, thanks!

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Is that for the 747? I will give it a go, thanks!

 

Sorry I thought you were referring to the 777 but the same concept should apply in the 747. :) However I'm not sure if theres a button shortcut since I don't have the 747.

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Sorry I thought you were referring to the 777 but the same concept should apply in the 747. :) However I'm not sure if theres a button shortcut since I don't have the 747.

 

No worries Antoni -- we got diverted off on a little four-holer tangent when I answered Alex's question about the AP disengage on the Jumbo  ^_^. I will give it a go in any case -- I've not been able to find a 'soft' disengage option in the PMDG menu, but it may be that it's hidden elsewhere.

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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

Thanks, you'll note in my OP I have been using V/S and that works along w/ derating, but I didn't recall this behavior in FSX version, but perhaps I've forgotten.   I will check out the section on the FCTM for this too--thanks!   I think Kyle's idea to disable the penalty in FSC is probably a good idea too for me.   Such a great plane though every part of it!  And shockingly good performance, overall.

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There you go. From Page 4.3 on my FCTM (which might be different as its not PMDGs) I don't think I've busted any copyrights by posting it but let me know and ill delete if necessary. Sorry about the formatting.

On a side note, low level offs play havoc with your noise abatement so be ready to intervene the speed if you capture at 1000'.

Also, don't be afraid of speeding up. Deleting the speed restriction below 10000' on the VNAV CLB page saves gas, is more comfortable and does not strictly contravene the laws of aviation even in FAA controlled areas. Just look at minimum manoeuvre plus fifteen at max TOW on the -W.

 

High Takeoff Thrust - Low Gross Weight

When accomplishing a low altitude level off following a takeoff using high takeoff thrust and at a low gross weight, the crew should consider the following factors:

  • altitude capture can occur just after lift off due to the proximity of the level off altitude and the high climb rate of the airplane

  • the AFDS control laws limit F/D and autopilot pitch commands for passenger comfort

  • theremaynotbeenoughaltitudebelowtheintendedleveloffaltitudeto complete the normal capture profile and an overshoot may occur unless crew action is taken.

    To prevent an altitude and/or airspeed overshoot, the crew should consider doing one or more of the following:

  • usereducedthrustfortakeoffatlowweightswheneverpossible

  • reducefromtakeofftoclimbthrustearlierthannormal

  • disengagetheAFDSandcompletetheleveloffmanuallyifthereisa possibility of an overshoot

  • usemanualthrustcontrolasneededtomanagespeedandpreventflap overspeeds. 

Cheers

Matthew Knight

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Hi Matthew,

 


Deleting the speed restriction below 10000' on the VNAV CLB page saves gas, is more comfortable and does not strictly contravene the laws of aviation even in FAA controlled areas. Just look at minimum manoeuvre plus fifteen at max TOW on the -W.

 

I'm very happy to be corrected -- but I was of the impression that the 250KIAS below 10,000 was very much the law in FAA-land (within 12NM of the coast in any case).

 

 

 

§91.117   Aircraft speed.

(a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).

( B) Unless otherwise authorized or required by ATC, no person may operate an aircraft at or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D airspace area at an indicated airspeed of more than 200 knots (230 mph.). This paragraph ( B) does not apply to any operations within a Class B airspace area. Such operations shall comply with paragraph (a) of this section.

© No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport or in a VFR corridor designated through such a Class B airspace area, at an indicated airspeed of more than 200 knots (230 mph).

(d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

 

I was of the impression, from everything that I've read that ATC, in the US, is not the Administrator and cannot legally authorise >250KIAS (or min clean as outlined in (d)) below 10k except in specific circumstances where this has been pre-approved by the FAA (DFW springs to mind as somewhere where I believe the FAA has authorised high-speed departures).

 

Paragraph (d) takes care of the minimum clean speed issue with heavies.

 

In Europe, on the other hand, ATC is permitted to lift the restriction (and it does of course save time and fuel).

 

As I say, though -- very happy to be corrected -- always interesting to see how things differ between authorities!

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As I say, though -- very happy to be corrected -- always interesting to see how things differ between authorities!

 

Unless the plane (FMC) lifts the restriction by itself due to the min safe airspeed being higher than 250, here in the United States, you're busting a reg. The FMC, when at high gross weights, will command a speed higher than 250 when necessary. This is legal per 91.117(d).

 

Deleting it when the FMC leaves it in there and you're breaking a reg.

 

Granted, ATC probably won't even notice since the speed is usually only marginally above 250, but it's best not to go messing with things when you shouldn't be.

 

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I stand corrected with my generalisation especially regarding deleting the speed trans line and the direct mention of the FAA controlled areas.

I am aware of the regulation 91.117 but I think it is important to remember that the regs are black and white and aviation is seldom thus.

The phrase, minimum safe airspeed is totally judgemental and in no way implies -UP speed. Many 744 operators, for example, specify -UP +10 as minimum speed. For the T7 boeing refers to keeping minimum manoeuvre speed plus fifteen at all times (the behaviour of the MMS is another topic), no mention is made of non normal situations, windshear, turbulence etc.

Also in nearly all areas I am familiar with (excluding USA, The Bahamas, Bermuda, Transport Canada, Saudi?) the speed trans line can be deleted with approval to improve the mid level climb conditions so aside from the mention of FAA and T. Can the majority of the other 190 something countries stand by my reply, which, by the way, was intended to assist a generic (i.e. not land specific) question about passenger (albeit fictional / badly coded ones) comfort.

So in short i apologise for mentioning regs, the FAA, and I appreciate the correction for the benefit of both my future posts and others reading. I do sleep easily at night though, without fear of a fed in a grey suit coming after me next time I depart IAH on a heavily loaded T7 be it in RL or especially in a sim.

And finally it is I that is very happy to be corrected, If nothing else, one person is a little wiser today than yesterday, and that exemplifies the spirit of the forum and flight simulation in general.

Cheers

Matthew Knight

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To be blunt, you're bending your flying to a product that isn't coded to be realistic. FSCaptain might add a feeling that things are more realistic because you have to follow procedures, but many add-ons that watch your vertical speed (to include FS2Crew) are hopelessly incorrect when it comes to penalizing or warning you for it.

 

People do not feel rate, they feel acceleration. The same way you feel natural going 450 knots through the air in a 777, you feel natural in a 5500 feet per minute climb/descent.

I beg to differ. You are right that people feel acceleration rather than rate, but they also feel the direction of acceleration. If you are climbing at 5500 ft/min then the angle the plane makes with the ground is rather steep and people will feel uncomfortable.

 

I have done some digging through the web. From what appears to be comments from RW 777 pilots I got the impression that the plane is indeed capable of a 6000 ft/min climb, but that normal rates are more like 3000 ft/min.

 

Btw, FSCaptain does not penalize pilots for climbing at 5500 ft/min with this plane, for the simple reason that this is how PMDG programmed it. With any other plane it would.

 

Peter

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The phrase, minimum safe airspeed is totally judgemental and in no way implies -UP speed. Many 744 operators, for example, specify -UP +10 as minimum speed. For the T7 boeing refers to keeping minimum manoeuvre speed plus fifteen at all times (the behaviour of the MMS is another topic), no mention is made of non normal situations, windshear, turbulence etc.

 

Right, but this would be addressed by 91.117a. The operator's definitions of things would be in a Company OpSpec. This OpSpec gets approved by the FAA and becomes enforceable as though they were regs, but the approval by the FAA carries...? You guessed it: the authorization of the Administrator.

 

 

 


And finally it is I that is very happy to be corrected, If nothing else, one person is a little wiser today than yesterday, and that exemplifies the spirit of the forum and flight simulation in general.

 

Glad you look at it that way. I've never come across anything so contentious as the speed argument. I've had lots of people get very angry when I pull the regs out on them.

 

 

 


I beg to differ. You are right that people feel acceleration rather than rate, but they also feel the direction of acceleration. If you are climbing at 5500 ft/min then the angle the plane makes with the ground is rather steep and people will feel uncomfortable.

I have done some digging through the web. From what appears to be comments from RW 777 pilots I got the impression that the plane is indeed capable of a 6000 ft/min climb, but that normal rates are more like 3000 ft/min.

 

Yes and no. Sure, people feel the direction of the acceleration, but sensation is partially dependent on position reference. This is best referenced to turbulence. During turbulence, people often "sense" that they're dropping hundreds of feet, when in fact, they're only dropping a handful. With limited reference points, their sensations are distorted. While you're right that someone can feel the angle between them and the force of gravity, this is not a refined sense (unless the person were blind, where other senses become heightened to compensate). They'd certainly feel it, but the difference between "climb" and "steeper climb" is likely lost on all of them.

 

Moreover, you're referring to posts of "RW pilots." While I usually question those posts in general (because anyone can say "RW Pilot" and go appear knowledgeable by reading an FCOM), I'll assume they were correct in saying what they say. However, those were real pilots, flying the aircraft to real SOPs (which is not the case in this thread). These SOPs and dispatch numbers likely come down from highers up dictating a certain procedure, such as the utilization of climb derates, to tame the climb. It's going to depend on the company.

 

 

 


Btw, FSCaptain does not penalize pilots for climbing at 5500 ft/min with this plane, for the simple reason that this is how PMDG programmed it. With any other plane it would.

 

Again, it shouldn't - regardless of the plane. The concept of hawkeyeing V/S is misguided in its entirety. Some airports require some pretty steep departure profiles (LGA, EGLC, to name a couple common ones - and SNA is certainly one), which would require those kinds of climb rates from other types of aircraft. Having been in aircraft departing like this, the feeling is "new" and not "uncomfortable."

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Hi Kyle,

 

[About FSCaptain] The concept of hawkeyeing V/S is misguided in its entirety.

Well, the idea in FSCaptain is more like looking for the steepness of the angle. If you are climbing at 5500 ft/min at 250 Kts then the angle is approximately twice the one at 3000 ft/min. And of course there are individual ft/min rates in FSCaptain for each plane. I agree that the rate itself is meaningless, but if you combine it with the standard speed of a plane during climb, then you get something meaningful.

 

Your signature suggests that you have been on the development team, so you could perhaps enlighten us as to where the 5500 ft/min originate from. Surely you had a reason. I could imagine that this is the usual rate for the freighter, for instance.

 

Just to make this clear: I never had an issue with this climb rate, but it always stroke me as exceptional. Now that we're having this discussion it would be nice to learn more about it.

 

Best,

Peter

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Well, the idea in FSCaptain is more like looking for the steepness of the angle. If you are climbing at 5500 ft/min at 250 Kts then the angle is approximately twice the one at 3000 ft/min. And of course there are individual ft/min rates in FSCaptain for each plane. I agree that the rate itself is meaningless, but if you combine it with the standard speed of a plane during climb, then you get something meaningful.

 

That makes a little more sense, I guess. The pitch is more of what's being sensed, but still, unless you're been flying for years and years and years, the difference really isn't noticeable because most passengers don't have a frame of reference (even at a window seat). Moreover, they have no other experiences to compare it to outside of aviation. So, to those passengers, it's hard to say that this feeling is normal or abnormal in general. It's just sensory overload: the accel on the runway, the pitch up, the shaking of the airframe, the loud noises, and so on.

 

 

 


Your signature suggests that you have been on the development team, so you could perhaps enlighten us as to where the 5500 ft/min originate from. Surely you had a reason. I could imagine that this is the usual rate for the freighter, for instance.

 

Ah...I think I see the issue.

 

So, when it comes to departure (all the way up to cruise, in fact), your pitch mode is primarily a pitch-for-speed mode. This means that you set your engines at whatever setting you're going to set them, and then control your speed by adjusting pitch. If you're light, you're going to have to keep the pitch pretty high because of all of the excess thrust versus a very heavy departure. If you're heavy, you'll have a markedly lower V/S. In other words, you're using pitch to eliminate the excess thrust of the engine. For decreases in weight, you will have an increase in the pitch required to negate that thrust.

 

We didn't set the plane to look for a 5,500fpm climb rate. Rather, we set the plane to look for a way to hold the assigned speed (per the Boeing climb schedule, mind you) by modulating pitch. This is something that people do as far down as Cessnas, by the way.

 

This, of course, reflects my earlier point that RW pilots operate the aircraft to realistic procedures and numbers. A RW pilot and dispatcher would know that an aircraft at lighter weights should probably get a de-rate (or assumed temp) on takeoff to tame the pitch angle if they deemed it necessary. At light weight, the 777 will easily vault skyward with seemingly reckless abandon (try it: zero payload, 20,000lbs of fuel, no derate, fly it up via VNAV). You are correct, though, that freight carriers consider derates for comfort less than a passenger line would, but it's honestly not as much of a big deal as it's made out to be.

 

Seriously, the SNA departure is no joke (no derates and a standing run up used here):

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Thanks for the explanations, Kyle. This makes a lot of sense to me and is most appreciated :)

 

Peter

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Quick additional question to your last, informative answer. Regarding juristiction, do these approvals apply to us registered aircraft, us built aircraft or any aircraft operating over the us?

In the latter case, I imagine that the approval of domestic authorities would in most cases simply be ratified by the faa, leaving capacity for marginal authorities to be properly vetted.

The example that springs to mind is the case of the 744 leaving the west coast for London and having an engine failure. The faa were pressing that the airline was responsible for a regulation breach but the company's policy specifies to continue as the crew did. That policy must also have fallen under these criteria and been approved.

Similarly the us's argument that the eu has no juristiction over us registered aircraft's carbon output within eu airspace (that was always a ridiculous proposal on the part of fritz and his gang) is somewhat hypocritical if they are assuming juristiction for all operations within faa airspace, unless of course an incident or accident should occur.

Not really on topic but an interesting discussion.

Thanks again

Cheers

Matthew Knight

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