PMDG 777 should work exactly the same. For example, at 5000 on approach - set 0 in the MCP alt, hit FLCH with the FD's on and AP off, level the aircraft or reduce the descent rate. Thrust remains in HOLD and airspeed will continue to bleed with no protections.

 

 

I haven't followed Asiana recently, but I do remember reading shortly after the accident that autothrottle does not work in this situation, either in VNAV or FLCH, can't remember which.  Any idea what the logic behind dropping airspeed protection and going into HOLD in this situation?  HOLD makes sense on the takeoff roll so the pilot can intervene easily either to max thrust or minimal/reverse thrust in a rejected takeoff, but why on descent, especially on final approach?

 

I will give this a try in the PMDG.

 

Thanks,

Mike

HOLD in FLCH with large level changes Is completely normal and can be quite handy at times, you also have it on the 744 & IDLE clamp on the MD11.

 

Thrust will go to HOLD because it will remain at idle for a prolonged period, whilst in HOLD you can make fine adjustments to the amount of thrust required which in turn will affect your descent rate.

 

Another example, 37000ft you have just passed TOD set 12000 in the MCP and hit FLCH, thrust goes to IDLE and then HOLD and you will have the maximum descent rate available, if whatever reason you require a different descent rate you can manually adjust thrust.

 

Not a good idea to use FLCH at low altitude for a number of reasons

 

Here's the link http://forum.avsim.net/topic/425478-flch-trap/

 

 

HOLD in FLCH with large level changes Is completely normal and can be quite handy at times, you also have it on the 744 & IDLE clamp on the MD11.

Thrust will go to HOLD because it will remain at idle for a prolonged period, whilst in HOLD you can make fine adjustments to the amount of thrust required which in turn will affect your descent rate.

Another example, 37000ft you have just passed TOD set 12000 in the MCP and hit FLCH, thrust goes to IDLE and then HOLD and you will have the maximum descent rate available, if whatever reason you require a different descent rate you can manually adjust thrust.

Here's the link http://forum.avsim.n...5478-flch-trap/

 

Thanks, Rob.  This makes sense.

 

Just found an article from October where the pilots were claiming the autothrottle malfunctioned. 

 

http://www.huffingtonpost.com/2013/10/09/asiana-crash-cause_n_4074196.html

 

Looks like they needed to RTFM a bit more carefully.

 

Mike

hehe, true! Well the final report is not out so anything is possible, however it does look increasingly likely that they were majorly out of the loop.

Going to take a look at the fsx weight pages might record what the trim does. I also take the hint regarding the controls, I too have had the problem where my controls are lost randomly so I have to put them through fsuipc, I will ensure there are no duplicates in the control settings.

 

Answer to your questions mike, I generally use the LONG panel state for long hauls and don't start with a dark cockpit, always load fuel, pax and cargo with the pmdg cdu loader, and yes auto throttle is active on approach (that takes some getting used to, generally I prefer manual throttles for the 747 on approach as I can be far smoother).

 

Cheers

 

Craig Read

Ok... Test Flight Alpha!.. Here are the details:

 

No weather application running.. weather in FSX set to sunny day.. outside temp is +14C

 

PAYLOAD PAGE (LBs .. I know I know.. I'm British as well!)

 

Payload = 0 (LOAD LEVEL 0%)

 

TOCG 25.2%

ZFW 344.2

GW / MTW    376.1 / 768.0

 

FUEL PAGE

TOTAL ILBS 31821 (9.9%)  I just stuck in 10% I can't see this being a problem she's light as a feather.

Further fuel info... Lower EICAS FUEL PAGE indicates 15.9 and L MAIN and R MAIN tanks, centre is empty.

 

Fuel and Payload page for Boeing 777-200LRX in FSX reads:

 

Empty Weight 344224 Pounds

Payload 0 Pounds

Fuel 4730.99 Gallons

Gross Weight 375921 Pounds

Max Gross Weight 768000 Pounds

Max Allowable Fuel 53515.00 Gallons

 

If I click Change Fuel the distribution I get is

 

23.0% or 2369 (15872lbs) Gallons in Left and Right tanks, Center and Center 2 are empty.

 

For Change Payload, I get all 0's

 

So... that's all out the way I'm gonna go a slap dash loop round EGSS, take off is:

 

Flaps 5

25%CG

TRIM 3.0 (set)

V1 137, VR 137, V2 153 (set +5 on MCP)

 

Thrust limits at TO and CLB, 100.4 TO N1  shown OAT at 14C no SEL set.

 

After takeoff I am flying nose down with 5 degrees down.  Speed isn't increasing and stuck around 200 knots

 

MS FSX payload and fuel pages remain pretty much the same..

 

My TRIM is set to 3.0 still... pitch down is now 8 degrees, FCL page shows no elevators down, STAB moves from 2.6 to around 4.2 in turns pretty ordinary.. I can't get to Flaps UP speed.  she flys the LNAV course with no problems at all...

 

Thoughts? It's clear to me the autopilot is trying, because even with a manual intervention I can't climb any better.. if I try to my speed just bleeds off rapidly..  Descent is 10 degrees no down which is pretty crazy. I am getting deceleration with 2450 fpm descent rate.. engines idle and 10 degrees nose down!  HOW!?

 

Reference speed selected for landing 30 FLAPS, with 137 knots... seems reasonable to me!   STAB about 2.2 at this time.. I am at 2500 feet.. Engines are a CRZ power.. 89.5% to maintain a level flight at 2500.. this seems excessive to me.. and obviously compensating for something..    

 

Aircraft at FLAPS 5.. very unstable.. can't maintain an altitude target at all.. keeps busting it.. trying to catch it.. STAB at 3.87 speed is 180..

 

FLAPS 15 GEAR DOWN.. down to 160.. nose is level with hoizon..  7 miles to go.. G/S capture..

FLAPS 30.. set MCP to 145..  (VREF is 137 so a bit for luck).

 

Tracks G/S and LOC well..

 

Nose is down at about 2.5 degrees.. now stable descent.. 800 fpm.. STAB 5.42

 

Minimums everything seems normal. (apart from pitch etc)

 

A/T is in SPD by the way.. stab now 5.9 at 100 feet

 

Landed ok.. but pitch was way off.. 

 

 

 

 

FINALLY, my specs for you..

 

i7 Haswell at 4.5Ghz

780 Nvidia

Z87 board

8GB RAM

 

Here is the bit where people may start pointing (and I know technically not supported but!)

 

Windows 8.1

FSX

Active Sky 2012

Bunch of sceneries but not loads..

PMDG MD-11

PMDG 747X

PMDG 737NGX

PMDG 777

 

Considering dual booting with Windows 7 now......

 

Thoughts on spec?

 

Cheers

 

Craig Read

Hey Craig,

 

I got your Pm! Seriously mate, I've mentioned this a few times, if the aircraft is flying nose down then something is corrupt, doing test flights and trying different weights etc is likely not going to help.

 

Take look at your windows setup, permisions, security, how you are installing the aircraft and if you have any aggressive anti virus/firewalls affecting the install.

 

EDIT- just been doing a little research on your issue, do you have any hardware for setting the flaps?

 

Regards

I use Saitek Cessna Yoke and an additional throttle to go with the one with the yoke, I also have Saitek rudder pedals too...

 

I've had the dreaded loss of controls through windows 8 but running everything through FSUIPC I think I have bottomed that out.. I've also made sure that all controls from the yoke, rudder pedals and additional throttle go through FSUIPC too

 

Config I have for Yoke and throttle is Cessna throttle does spoilers, throttle 1 and throttle 2... extra throttle does throttle 3.. throttle 4.. and flaps..

 

Does that help?

 

Cheers

 

Craig Read

Damn, I found a post with a similar issue to yours. Unfortunately I closed it on my browser about an hour ago!

 

basically it was an NGX user, the aircraft was flying nose down and behaving strangely. It turned out he had an axis on his hardware mapped to the flaps in fsuipc, even though it showed as flaps up on the aircraft the sim was actually seeing full flaps and behaving accordingly.

 

 

Will see if I can find the post again.

 

 

I've had the dreaded loss of controls through windows 8 but running everything through FSUIPC I think I have bottomed that out.. I've also made sure that all controls from the yoke, rudder pedals and additional throttle go through FSUIPC too

 

Sorry to have to suggest this, but lots of people seem to be having FSUIPC related issues.  In particular, routing the throttles through FSUIPC is not recommended by PMDG.  So, try moving the FSUIPC.ini file out of the modules folder (instead of deleting it), unplugging all your add-on hardware, and flying with the mouse, just to eliminate all possible sources of interference.  If things work right then, add one piece of hardware back at a time. 

 

Someone else fixed his (different) problem by doing a separate profile for the T7 and having the controls connected through FSX instead of FSUIPC direct, and I believe the FSUIPC web site may have some fixes as well, but since I personally haven't had a problem with FSUIPC I am not up to date on that discussion. 

 

But before you do anything else, disconnect the hardware, let FSUIPC create a new ini file, and see if it works OK just flying with the mouse.

 

Mike

I would disconnect all flight control hardware.

Delete (or cut it away and back it up) the FSUIPC.INI file.

 

Install the latest FSUIPC version.

 

Now try to fly the 777 with keyboard only.

 

If all is fine then you can start adding hardware back in (one piece at the time).

If possible do not use FSUIPC for your controllers.

Just use the FSX interface for basic things like elevator, aileron, thrust initially.

Just try that initially. Without FSUIPC (works fine for my CHPro yoke and rudders plus SAITEK throttles)

 

If all that works...THEN....you can read up in one of the FSUIPC threads on how to use it for your hardware.

If things stop working again, you know it is FSUIPC causing your problems.

 

Ps I know you are an experienced FSX user so you might think FSUIPC has nothing to do with it since it works fine with all other addons.

The 777 is different!

The above suggestion has helped solve peoples problems several times with the 777.

(it is not my invention, it is in the PMDG intro guide!)

Reporting back, I found the posts before your reply FLEX and have already removed the flaps from FSUIPC.. seems I am not flying nose down anymore!  Just doing a quick flight now to determine if my landing performance is as I expect it to be..

 

Just completed first run and everything completely normal now on approach too!

 

Cheers

 

Craig Read

A video will help  

Possible cause: How do you change your flaps? Is it with some hardware? If so, try using F7 to extend the flaps. I vaguely remember reading something where changing flaps with hardware can sometimes make the flaps appear to work on the plane, but not actually have any aerodynamic effect.

Reporting back, I found the posts before your reply FLEX and have already removed the flaps from FSUIPC.. seems I am not flying nose down anymore!  Just doing a quick flight now to determine if my landing performance is as I expect it to be..

 

Just completed first run and everything completely normal now on approach too!

 

Cheers

 

Craig Read

look at post 41 if you still have problems.