RAAS/Autothrottle Problem

[rlowery 0]

I'm relatively new to PMDG and FSX and have an interesting problem that occurs on take-off. I have RAAS on and I have activated the MakeRwys program. Fuel load is light and payload is about 1/3. My dominant scenery for Australia is OBEX and I have the latest Navigraph database.  

I begin my take-off run on RWY 16R (3962m) at YSSY (Sydney, Australia) with A/T, RNAV and VNAV armed. I engage TOGA at about 50% N1, then the FO calls 80kts, then the RAAS calls "Short RWY, Short RWY" and the throttles are retarded to idle.

I can prevent all this by turning OFF RAAS and by setting "A/T manual Override" from "in HOLD Mode only" to "Never" but that is just a work around; it is not realistic!

Have any others experienced this or is anyone able to pinpoint my problem. TIA, Roger Lowery 

[jgoggi 65]

2 hours ago, rlowery said:

then the RAAS calls "Short RWY, Short RWY" and the throttles are retarded to idle.

You mean that, during HOLD mode (so A/T disengaged), after the RAAS "short rwy!", the throttles are AUTOMATICALLY retarded to idle, without pilot's intervention?

[scandinavian13 5,192]

15 hours ago, rlowery said:

I begin my take-off run on RWY 16R (3962m) at YSSY (Sydney, Australia) with A/T, RNAV and VNAV armed. I engage TOGA at about 50% N1, then the FO calls 80kts, then the RAAS calls "Short RWY, Short RWY" and the throttles are retarded to idle.

I can prevent all this by turning OFF RAAS and by setting "A/T manual Override" from "in HOLD Mode only" to "Never" but that is just a work around; it is not realistic!

No, it's not realistic, but it's also not how we programmed the aircraft. Something else is going on here, and I'm willing to bet it's because you left your throttles at 50% after engaging TO/GA. The "short runway" announcement was likely coincidental to the AT hitting HOLD mode, which "woke the sim up" to your throttles "reduced" to 50% (compared to where the AT had "moved" them).

Set your AT override mode back. Set 50%ish, then hit TOGA. After hitting TOGA place your hardware throttles fully forward (as soon as possible - you need to do it before the AT mode drops to HOLD). Once fully forward, the AT will ignore the throttles provided they're fully forward, and treat them like they're in the same spot that the AT placed them prior to dropping to HOLD. If you reduce them, it'll "wake" the AT up to your reduction and engage RTO.

[rlowery 0]

Thanks Scandinavian 13. You are correct. I was being distracted by the incorrect RAAS callout and was slow to move the hardware throttles fully forward.

But, why am I getting the RAAS "Short Runway" callout on such a long runway at such a low AUW.

Roger Lowery

[pete_auau 1,152]

14 minutes ago, rlowery said:

Thanks Scandinavian 13. You are correct. I was being distracted by the incorrect RAAS callout and was slow to move the hardware throttles fully forward.

But, why am I getting the RAAS "Short Runway" callout on such a long runway at such a low AUW.

Roger Lowery

In  the addon menu  click on it   click on the raas   go  to the runway section middle, make  sure its  set  to meters  and  you   select  what length  of  runway  so make  sure  its  set  to more  than 5000,  bet  your  is  set  to around  3000  or  lower

[byork 2,258]

Also run Make Runways again to update the scenery database that RAAS uses for its calculations.

 

 

[rlowery 0]

3 hours ago, pete_auau said:

In  the addon menu  click on it   click on the raas   go  to the runway section middle, make  sure its  set  to meters  and  you   select  what length  of  runway  so make  sure  its  set  to more  than 5000,  bet  your  is  set  to around  3000  or  lower

Thanks  pete_auau and byork. That solved the RAAS problem so all is now good. I was looking everywhere to find an editing input to RAAS - PMDG and RAASPRO folders, but to no avail. I didn't think to look under the ADD-ONS tab in FSX!

Pete, I think your RWY length suggestions are the wrong way round. If I set metres and a min RWY length of 5000, the RWYs needed would be in excess of about 16,000 ft. Mine was set to 5000 which I reduced to 2200 (about 7000') and that worked fine.

Thanks to all, Roger Lowery

[pete_auau 1,152]

no worries main thing  its  working  for  you

[Sky Prince 10]

On Friday, March 31, 2017 at 7:44 PM, scandinavian13 said:

No, it's not realistic, but it's also not how we programmed the aircraft. Something else is going on here, and I'm willing to bet it's because you left your throttles at 50% after engaging TO/GA. The "short runway" announcement was likely coincidental to the AT hitting HOLD mode, which "woke the sim up" to your throttles "reduced" to 50% (compared to where the AT had "moved" them).

Set your AT override mode back. Set 50%ish, then hit TOGA. After hitting TOGA place your hardware throttles fully forward (as soon as possible - you need to do it before the AT mode drops to HOLD). Once fully forward, the AT will ignore the throttles provided they're fully forward, and treat them like they're in the same spot that the AT placed them prior to dropping to HOLD. If you reduce them, it'll "wake" the AT up to your reduction and engage RTO.

Hello Kyle, 

I was checking this post out. But, shouldn't the product already be programmed to operate realistically by default? 

[scandinavian13 5,192]

3 hours ago, Sky Prince said:

But, shouldn't the product already be programmed to operate realistically by default? 

You're misinterpreting my post.

My point was that what he's seeing isn't realistic, but his symptoms aren't caused by how we programmed the aircraft. It's a coincidence of the RAAS alert, and the fact that he didn't (properly) advance the throttles beyond 50% ish, so when the A/T mode drops to HOLD (a mode that specifically allows the crew to override the throttle position manually), and his hardware is still at 50%, it reacts to that position and reduces throttle, which also engages RTO.

It's already programmed to be as realistic as possible, and the default is as realistic as we can get it (override in HOLD mode only). The limitation is most of the users don't have servo-driven hardware, so you need to make sure you adjust your hardware manually twice:

1. After hitting TO/GA, manually set your hardware throttle to 100% - this is mentioned in the Intro and/or the tutorial; and
2. Prior to T/D, manually set your hardware throttle to 0%.

...otherwise, you will have to deal with the consequences of the sim suddenly thinking you're telling it to use the position you left your hardware at.