First of all just wanted to say that after reading various manuals and doing a  couple of flights the aircraft is working very nicely. Did another 4 hour flight test last night and must congratulate PMDG for creating this beauty.

 

There is only one thing that has happened on all the flights I have done so far, and it has to do with the AT

no achieving the speed reductions when not in VNAV mode. Last night on level flight the Speed was set at 220kts but the aircraft would not reduce below 235kts and a couple of times speed increasing to even 240kts, similar situation in previous flights, forcing me to deploy air brakes. Would have thought that during level flight with no downward momentum the aircraft would attain what is on the Speed bug.

Is this behaviour normal? Any feddback much appreciated.

 

By the way and just in case this is my second try at posting, first time got message below.

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Thanks

I'm not sure how you are attempting to control speed, with speed constraints on LEGS pages or via MCP SPD? Big difference of many between 737 and 777 is speed control in VNAV. The 777 has to be flown with MCP SPD in the terminal area. Speed constraints must be accompanied with altitude constraints and they are always AT OR BELOW. The 777 doesn't slow down for an approach, that's up to the pilot.

You need to hit the speed restrictions well before you reach a fix, as I use MCP SPD and never use VNAV - had to deploy the "spoilers of shame" just to slown down to a specified speed 

 

 

had to deploy the "spoilers of shame" just to slown down to a specified speed

 

Intro manual - it's a lot more common on the 777.  I wouldn't call it a "shame" thing, really.

I have flown the T777 many many times as a passenger and I always see them get deployed.

The problem with the 777 is that unless you plan to do the slowest descent in history you will almost always have too much energy, 240kts is too much to begin your approach and careful planning is really important, I usually get my speed down to at least 220kts by around 6000ft. You'll find that best practice seems to be switching to FLCH below 10k. In most instances and in all the descents i've done with the T7 so far i've needed some spoiler at somepoint to get that speed down especially in the transition between descent and approach.

_{So as to make my query clearer.}

 

_{Aproach to KMIA - LNAV - SPD - AT - ALT - VSPEED - No VNAV} 

 

_{On downwind to RWY09 with some 15nm to go before turning right to intercept localiser/ILS my alt is 5000 and Vatsim Controller}

_{advises descent to 3000 and 220kts - with VS to -800, on reaching 3000 speed 235 kts, speed bug set to 220kts and level flight}

_{speed continues at 235 and 240 for a brief period then when lined up at 12DME need to reduce to 180kts, speed bug set but}

_{speed hardly affected, at this point speed brakes engaged to achieve the speed restriction.}

 

_{So is this behaviour normal for a 777 in real life  while AT-LNAV-SPD-ALT is engaged?}

 

_Thanks

 

 

Aproach to KMIA - LNAV - SPD - AT - ALT - VSPEED - No VNAV 

 

No VNAV is implied when you're in SPD and VSPEED modes...

 

 

 

220kts - with VS to -800, on reaching 3000 speed 235 kts, speed bug set to 220kts

 

If you want to be sure you're going to keep your speed, use FL CH.  Otherwise, your VS may be forcing you to descend at a higher rate than necessary to maintain speed.

 

 

 

level flight speed continues at 235 and 240 for a brief period then when lined up at 12DME need to reduce to 180kts, speed bug set but speed hardly affected, at this point speed brakes engaged to achieve the speed restriction.

 

Do me a favor and go to PMDG Setup > SIMULATION and let me know what mode you have for your AT override.  Additionally, are you calibrating your throttle via FSUIPC?

 

 

 

...also, what's with the weird line breaks in your posts?  Makes it difficult to read.

Thanks for your reply Kyle.

 

Point 1 - Only showed the settings to indicate what was active at different stages.

 

Point 2 - I never use FL CH on approach preferring manual speed adjustment and vertical speed, but will certainly try your recommendation during next flight.

 

Point 3 - AT set to NEVER - Throttle always calibrated via FSUIPC - Works very well with all my payware aircraft including the 737NGX.

 

Ahhhh....The line breaks! That's been doing my head in for a while. When I type a post and press return, it all looks OK on my screen but when I see the post  it shows this unusual line breaks. If you have some advice on this, greatly appreciated. Bit embarrassed to ask before about this issue. :blush:

 

 

Point 1 - Only showed the settings to indicate what was active at different stages.

 

Understood - I was just pointing out that it was redundant (and having it in there was confusing at first)

 

 

 

Point 2 - I never use FL CH on approach preferring manual speed adjustment and vertical speed, but will certainly try your recommendation during next flight.

 

There's no reason to avoid FL CH, really, particularly because it offers the speed control that V/S does not.  If you can't hold a speed in V/S, you need to manually adjust it.  Fact of life there.

 

 

 

Point 3 - AT set to NEVER - Throttle always calibrated via FSUIPC - Works very well with all my payware aircraft including the 737NGX.

 

Thanks.  There have been some issues where the hardware throttle is breaking through the NEVER setting, and there's some relation to FSUIPC.  Just curious to see if this was any different.

 

 

 

Ahhhh....The line breaks! That's been doing my head in for a while. When I type a post and press return, it all looks OK on my screen but when I see the post  it shows this unusual line breaks. If you have some advice on this, greatly appreciated. Bit embarrassed to ask before about this issue.

 

No idea.  Based on one of your earlier posts, it looks like you copied and pasted from another program, which could cause that.  The last post looks fine, though.

Cheers, will try out these suggestions and see how it goes.

 

All the best Kyle.

I have flown the T777 many many times as a passenger and I always see them get deployed.

Ditto - first time I flew on one I was amazed at how often they were being deployed. In fact, started to get worried we were not going to slow down until we hit the Tarmac

Hi,

 

I also have some problems when using the AT to maintain a selected speed. Today I was just flying around the NY area with a speed on the MCP of 159 kts. The AT did never manage to get to that speed, either it was stable at 170+ and sometimes it dropped down to about 140 and stayed there for a while, and the throttles did not advance to pick up the speed again. The wind was pre set and stable at indicated value on the ND.

 

I have Saitek Yoke and throttles configured internal in FSX, and my problem remained even when I disconnected the throttles from the computer.

 

 

What could be the problem here?

 

Simon Larsson