50 minutes ago, rsrandazzo said:

I love when someone stumbles into something non-normal that shows off the depth of the simulation value

Robert. now i think you know that i do get the value of your product and i really appreciate your nice job on making everything simulated even in many aspects of maintenance side aswell. Hope you read my reply to his post as well since i tried to give him the best info from the real Doc ( actually UAL airline's doc  ). 

On 2/24/2018 at 6:36 AM, Samany69 said:

and where is the Reference or the document which you are taking this info from ?? ... I am looking straightly at the Original document and can't find anything about 50 seconds of Fault or Disagree Detection ! and hey , In flight , 50 seconds of delay in an approach procedure could lead the plane to somewhere really bad .... Fortunately Boeing is not doing anything wrong haahaa .... Trust me my friend. I wont give out info in this Forum until they are official or 100% correct , otherwise i will Straightly mention that what I have said is according to my own experience or is just my opinion . yet as you see I just said according to the maintenance manual . so i'm not going to change your mind about what I have said . neither Boeing company does convince the operators that something in the airplane works this or that way. this is a fact to be honest.

Saman,

When I replied to your original post on Friday about this I never said you were completely wrong, just that what you said was not strictly correct.  No offence was meant, because all of my observations are based on the B747-400 type (i.e. aircraft and simulator) with which I am very, very familiar and, like you, I also check my technical facts before making any posts on Avsim.  However, there may be other failures or switch positions involved with this particular scenario which we will never know about (e.g. what STATUS message(s) are there on the lower screen?). 

Since you ask, my Boeing 747-400 Pilot's Technical Reference for the standard 2 ADP and 2 EDP configuration clearly states "... it takes approximately 50 seconds to detect that a leading edge flap group has failed and during this period the opposite group will have moved to their commanded position  .....etc, etc"  From an operational point of view, a 50 seconds delay shouldn't cause the pilots a major headache on any approach.  In any event, a leading edge flap fault would become apparent very early on during the approach when the flaps are being extended from Flaps Up to Flaps 5.  Even if carrying out the QRH non-normal procedure became a problem for them, they could always ask ATC for an extra mile or two before committing themselves onto the final approach.  As I have already mentioned, the same cannot be said with a FLAPS PRIMARY EICAS Caution message when approximately 6 additional minutes is needed to extend the trailing edge flaps from Flaps UP to Flaps 30 - and this will need careful planning if a missed approach is to be avoided as well as thorough Briefing for the actions to follow if the final approach is discontinued whilst in the landing configuration.

It seems we have both inadvertently fallen into the trap of not qualifying what we said, because RSR is quite right in what he says here about the different B744 equipment configurations.  Boeing has made many modifications to the B744 during its operational life and some of them have been quite significant - not least being the three different engine types or the different Demand and Aux pumps fitted to them. Some of my more cynical pilot colleagues used to call these differences and improvements  'Starving Seattle Mods', because they seemed to proliferate during economic downturns in the aviation industry! 

I hope we can agree on being grateful to PMDG for taking the time and effort to faithfully reproduce many of these differences in the various QOTS liveries they have available in their Ops Center.  It isn't easy trying to please every pilot or mechanic, is it?!  :-)

Bertie

Edited February 25, 20188 yr by berts
correction

14 minutes ago, berts said:

I hope we can agree on being grateful to PMDG for taking the time and effort to faithfully reproduce many of these differences in the various QOTS liveries they have available in their Ops Center.  It isn't easy trying to please every pilot or mechanic, is it?!  :-)

aye , Agreed . Also I meant no offence too . Just happy that you understand that i did mean no offence . also happy to see that you are also falling deep in to the system's and their Actions.  nice to meet you . glad to call you a friend of mine now ;) . Please let me know if we can share more info in private messaging in anyway you prefer cuz i do LOVE to learn . my ears are all open to learn anything new .

Regards.

On 24/02/2018 at 4:52 PM, Samany69 said:

Dear Friend. It is fine that you don't accept it . I don't mind it at all . you are not standing against my words. your actually standing actually against what boeing company has Said about their own airplane in the official documents.

With all Boeing documents, you have to look at grammar which is used. The words "may" and "can" are used when there is any likelihood of something happening. e.g. The Boeing manuals say that during a Standby Power check, the EICAS BAT DISCH messages may take several minutes to appear. I've only seen long delays in one or two tests out of hundreds of tests. Through real world experience, you establish norms (norms may or may not be programmed into big sims).

 

On 24/02/2018 at 5:36 PM, Samany69 said:

I am looking straightly at the Original document and can't find anything about 50 seconds of Fault or Disagree Detection !

During gear operation, disagreements between TE flap drive and flap motion cause transfer to Primary Electric operation within a certain time frame. A 42 second delay is quoted in my 747-400 Avionics Engineering Training manuals when gear is in operation. What is 8 seconds between friends? Flap operation is especially unpredictable when pressure is low or non-existent.

Never take any manual as gospel. I can't count the number of times I've requested amendments to our Boeing-issued Maintenance Manuals because of disagreements between different manuals or for things which don't match up with what I see in real life. And some of these requested amendments have taken a year to filter back down into the airline manuals.

Regards

JHW

6 hours ago, Qavion2 said:

And some of these requested amendments have taken a year to filter back down into the airline manuals.

John . Your are right Sir . Well , at least for some people here ( i mean in simming world ) it is much more than good to read extra manuals .... instead of Auto flying the whole world and calling them selves Pilots :D. but yet i admit you are right.

On 24/02/2018 at 7:57 AM, rsrandazzo said:

Gents,

Another important consideration for you all to ponder:  Some 747-400s (mostly UAL airplanes) have 4 pneumatically driven hydraulic demand pumps.  (Called ADPs.)  instead of the standard 2 ADP and 2 EDP configuration.  In this case, if the load on the bleed system is extremely high and there is a deficit in production, you **could** conceivably trigger a flaps primary condition because the leading edge devices use pneumatic pressure as their normal motive power.  (I would have to go back and sniff around some schematics to see if you would get it in the situation Robert created...  Please forgive me for not doing so tonight...)

And to those of you who immediately suspected a problem in the hydraulic system, remember that this would give you a problem on the trailing edge, not the leading edge.  Not exactly germane to this discussion- but worth pointing out since a number of you immediately went for hydraulics as the source of motive power for the LEDs.

Also- points to everyone for the engagement in the discussion.  I love when someone stumbles into something non-normal that shows off the depth of the simulation value.  Most users don't touch even 10% of the simulation value in this product- and if I constantly pointed things out- you guys would grow bored of my constant lectures. 

 

To EVERYONE:  When you get EICAS messages- make sure you read them.  Then go to the QRH and look at the trouble shooting process.  You will learn some REALLY interesting things about your airplane!

 

 

Hi Robert,

Actually this is true in all 747-400 as the flaps are driven by systems 1 and 4 which always have air driven demand pumps. However in the PMDG QOTS II hydraulic demand does not affect hydraulic pressure. It never varies from 3000 psi. If the EDPs are running the demand pumps are never needed, unlike the aircraft.

Edited February 26, 20188 yr by kevinh

7 hours ago, kevinh said:

It never varies from 3000 psi.

Don't forget that ADPs are triggered by both configuration and system low pressure. Depending on the aircraft, as soon as the flaps start moving or, in some cases, whenever the TE flaps are not zero, the ADPs cut in to keep up the pressure and, importantly, the flow. Pressure is not always a good indication of hydraulic power.

2 hours ago, Qavion2 said:

Don't forget that ADPs are triggered by both configuration and system low pressure. Depending on the aircraft, as soon as the flaps start moving or, in some cases, whenever the TE flaps are not zero, the ADPs cut in to keep up the pressure and, importantly, the flow. Pressure is not always a good indication of hydraulic power.

Yes but it’s low pressure and configuration that triggers the ADPs. In the PMDG 747 they never get triggered by flap movement or position. Pressure remains at 3000. Flow from the pump due to an actuator moving should reduce system pressure somewhat as the pump increases flow to compensate until the pump output reaches maximum flow then the pressure drop increases rapidly as flow increases further. Pressure low enough to get the ADP running. 

If you open the EICAS HYD page and operate the flaps you see the demand pumps never run. 

 

On 27/02/2018 at 1:54 PM, kevinh said:

If you open the EICAS HYD page and operate the flaps you see the demand pumps never run. 

Ticket submitted?

19 hours ago, Qavion2 said:

 

Ticket submitted?

I think it's less of a bug than a missing feature, maybe we can suggest for the new PMDG 748 to add this in?

30 minutes ago, Robert3512 said:

I think it's less of a bug than a missing feature, maybe we can suggest for the new PMDG 748 to add this in?

Have you checked with Hardy to see if this is a problem with his sim?

I certainly don't remember this being a problem on the 707, put the 3,000 psi does sound vaguely familiar.  

blaustern

On 3/1/2018 at 10:20 AM, Bluestar said:

Have you checked with Hardy to see if this is a problem with his sim?

I certainly don't remember this being a problem on the 707, put the 3,000 psi does sound vaguely familiar.  

blaustern

Err......what? PMDG doesn't make a Boeing 707, how is this relevant...?

13 hours ago, Robert3512 said:

Err......what? PMDG doesn't make a Boeing 707, how is this relevant...?

Are you sure that PMDG doesn't have a B707?

It is certainly as relevant as the slow slats issue that has taken up three pages. ROFL

On 01/03/2018 at 1:20 PM, Bluestar said:

Have you checked with Hardy to see if this is a problem with his sim?

No problems last time I checked. There is even an option to modify the flap logic for #1 & #4 ADP activation.

Note that the logic is based on inboard TE flap transmitter position signals. If you can't get the inboard flaps to extend, this can create a few problems for other systems. However, since the inboard TE flaps are functioning normally, then we have to look elsewhere for a cause.

Cheers

JHW

Edited March 4, 20188 yr by Qavion2

20 hours ago, Qavion2 said:

However, since the inboard TE flaps are functioning normally, then we have to look elsewhere for a cause.

Cheers

JHW

John,

Maybe there was an electrical problem of some sort?  The left wing trailing edge flap position sensors are not powered from the standby bus, so you will get an expanded flap indication if it is not powered.  However, if this was the cause I believe you would also see an amber x on the left outboard and inboard TE Flap indications.

Bertie