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ideoplastic

What gives?

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First of all let me tell you that I have already read almost if not all posts in this forum concerning throttle issues and have read both tutorials that came with the package,

as well as doing 2 clean reinstalls of the software. This is the issue:

 

 

After preparing the aircraft for flight (start up from cold, FMC configuration, loading fuel calculated by TOPCAT, & setting correct trim), I am on the runway ready to go.

initial altitude setting set on MCP which matches the waypoint on the SID in the FMC with corresponding speed restriction. Flaps correctly set, Parking break released,

Throttle to 40%, selection of TOGA done. Aircraft rolls down the runway and take-off takes place with LNAV/VNAV selected. After take off aircraft climbs and the continues

to the waypoint mentioned above but totally disregards the speed restriction on the FMC and then continues increasing speed to 350+ knots. LNAV/VNAV are still active

and N1 throttle setting on MCP still lit and allegedly active. The autothrottle has not been touched at all during this time and the FMC has been set so that autothrottle

cannot be manually overridden.

 

I appreciate that many people don't seem to have this problem, so why is the above happening to me? - Is there some hidden setting among the hundreds of pages in

the manuals and tutorials that I have missed? - This has happened to me in all flights I have done so far, having to use manual throttle control instead. The speed

MCP button doesn't seem to work either when activated, well let's say sometimes it decides to work.

 

Any feedback would be appreciated.

 

 

Thanks

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My first thought was A/P not engaged or disengaging, but I note that you have it on. So scrub that. FD on? On PF side? Command A on (assuming the Captain is the PF)?

 

I take it you are doing all the necessary stages of the FMC programming? Did you have any similar issues with the tutorials when you flew them?

 

What indicators are you getting on the annunciator when this happens?

 

Are you running FSx as adminstrator and not in a default directory as both these can cause all sorts of issues?

 

Could you give us a flight plan so we can give it a test?

 

I personally have never experienced this, if someone else has they may be able to offer you some more definitive thoughts, but with resepect, it will be something simple that has been overlooked or a basic setting somewhere.

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Off the top of my head....

 

Do you have the 250/10000 speed restriction on your CLB page? What are your FMA's showing? It should read N1, LNAV, & VNAV SPD in green after crossing your thrust reduction alt. The engine display should switch from TO to CLB.

 

Also, to rule out any possible conflicts, I would retard your throttle to idle to ensure it's not commanding max thrust or interfering with the A/T logic.

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Hello Joaquin, I agree with Jay who pointed out that A/P was not engaged in your Post. However, if it is and you failed to mention this, it may be due to the Alt restrictions in the Perf. page bottom right, by default 18000ft (USA). If flying in the UK Alt restrictions are usually 6000ft. so change the 18000 to 6000ft. and this should work, all other things being equal. Richard Welsh.

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CMD has nothing to do with the A/T logic.

 

If it's on you're flying on autopilot. If it's off, with LNAV and VNAV engaged, you're flying the FD the same way CMD would. It's the same information derived from the same source.

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However, if it is and you failed to mention this, it may be due to the Alt restrictions in the Perf. page bottom right, by default 18000ft (USA). If flying in the UK Alt restrictions are usually 6000ft. so change the 18000 to 6000ft. and this should work, all other things being equal. Richard Welsh.

 

Nothing to do with this.

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First of all thanks to everyone for all the replies. I've been flying 737s for a number of years, the PMDG in FS9 and the iFly and later the PMDG in FSX. Autopilot was definitely on. I think the best thing to do

is make a video of the whole procedure so that everyone can see what I'm talking about. It is difficult to include everything in a post without turning it into a book. So I'm going to get back to you guys

as soon as it's done and uploaded to a site.

 

Regards

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Yeah sorry guys in my first post I said AP when what I was actually referring too was A/T. Back to typing school I go....

 

***Hangs head in shame***

 

Any vids/pics for us yet?

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The autothrottle has not been touched at all during this time

 

Haven't flown for a while so I may have missed something, but the autothrottle should be on, but then I think it must be active for the TOGA to be working?

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Ok everyone, sorry for the delay. There will be no need for me to make a video. Spent a couple of hours going again through the tutorials, specifically Tutorial No.2 - Realized that my problem

had been all along not understanding the way the LNAV/VNAV system works in the NGX which seems to be slightly different from that on the FS9 737.

 

However there are a couple of things I'm still a bit uncertain about and would really appreciate some feedback on them.

 

Let's say I'm on Vatsim flying at 250kts and the controller just wants me to reduce speed to say 220kts - What would be the correct way of doing this while still following the VNAV/LNAV path.

I've noticed that pressing the SPEED button on the MCP doesn't seem to control the auto throttle very well and often causes the speed to drop or increase wildly.

 

Also if I'm at the gate and start the flight in the default mode (engines running), the aircraft starts moving forward even though throttle at that point is in Neutral. Any way of stopping this from happening?

 

Thanks once again to al for taking the trouble to follow this thread. I think I'm getting there.

 

Regards

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Hi Joaquin,

 

In that scenario you are better of going FLC CH and set speed 220kts. This will leave you a little high on the Vnav path, but the distance you will have to slow at the DECEL point is lower too.

 

Just remmember to monitor your 3x rule.

 

Kind regards,

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Let's say I'm on Vatsim flying at 250kts and the controller just wants me to reduce speed to say 220kts - What would be the correct way of doing this while still following the VNAV/LNAV path.

I've noticed that pressing the SPEED button on the MCP doesn't seem to control the auto throttle very well and often causes the speed to drop or increase wildly.

 

Have you tried the Speed INV button? It works the same as the Altitude one - just press it and it brings up your current speed, and then you can set it at what you need.

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Let's say I'm on Vatsim flying at 250kts and the controller just wants me to reduce speed to say 220kts - What would be the correct way of doing this while still following the VNAV/LNAV path.

 

At this point you are done with all the science, smoke & mirrors that VNAV & ECONnomy flying provides - VNAV is a wonderful & strategic tool but by the time ATC starts barking specific ALTitudes & SPeeDs at you its time for your grey matter to shift up a gear into a more 'tactical' mode.

 

With the AP engaged you'll find direct interaction with the MCP easier to handle than "heads down button punching" on the CDU...it also helps to maintain your Situational Awareness.

 

FLCH is the tool - get the Speedbrake out too (if necessary) because you cannot go down & slow down (very easily) at the same time.

 

V/S is useful to get the throttles away from the Idle Stop towards the last 1000ft of a FLCH descent & can create a nice smooth transition from an FLCH idle descent into a 'power on' level flight segment (if that is what ATC require) or a nice subtle CDA onto the glideslope.

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Just wanted to let you know that have now understood how to fly the aircraft and have had a few flights with no issues whatsoever. Thanks to all for the great info and help provided.

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