How do you guys do it?

[Paul_Smith 92]

Ryan,With this simple example, may I ask if following will be a possible code for the MD11."IF AP/FD mode = GO-AROUND, THENIF Flaps <31.5, skip GPWS 'TOO LOW FLAPS', ELSE IFIF Gear selected UP, skip GPWS 'TOO LOW GEAR', ELSE IFIF FLaps <31.5 AND Gear selected up, skip GPWS 'TOO LOW TERRAIN'END IF"This one is nested and not correct of course, I'm not a programmer, but any other possible code C++ or XML will do.Would be happy not to hear these warnings where not appropriate. :( Regards,Harry

Hi Harry,Can you describe any of the situations where you hear alarms that are not appropriate? If possible, can you state actual and set states for gear, flaps, throttles, rate of descent etc. (i.e. Gear lever up, three reds still showing). If there is a difference between the logic used by PMDG and the real aircraft, this is the only way we will find it. Can you post a screen shot with an inappropriate alarm sounding and tell us your sequence of events prior it? As for the coding, I know a lot more about software then I do the MD11 and it is not usually correct to use negative tests. Statements like "IF Flaps <31.5, skip GPWS 'TOO LOW FLAPS'" cause problems because they do not make clear when an action should happen, only when it should not. Reading the systems manual for GPWS modes 4A and 4B, it looks like the rules could be coded as: ...IF GEAR is not "Down and locked" then { /* Mode 4A */......IF spd < 190kts then {.........if Radar_alt < 500ft then {............sound GWPS "TOO LOW, GEAR" .........}......} else if Radar_alt < 1000 then { /* check this carefully */.........boundry = (Radar_alt - 500) multiplied by (60 divided by 500) .........if spd < (190+boundry) then { ............sound GPWS "TOO LOW TERRAIN".........}......} ...} else /* Gear is down and locked */ { /* Mode 4B */......if Radar_alt <=245 AND flaps <35 then {.........if spd < 159 then {............sound GPWS "TOO LOW FLAPS".........} else { /* boundry conditions not clear! */............sound GPWS "TOO LOW TERRAIN".........}......}...}

[KCA9304 0]

Hi Harry,Can you describe any of the situations where you hear alarms that are not appropriate? If possible, can you state actual and set states for gear, flaps, throttles, rate of descent etc. (i.e. Gear lever up, three reds still showing). If there is a difference between the logic used by PMDG and the real aircraft, this is the only way we will find it. Can you post a screen shot with an inappropriate alarm sounding and tell us your sequence of events prior it? As for the coding, I know a lot more about software then I do the MD11 and it is not usually correct to use negative tests. Statements like "IF Flaps <31.5, skip GPWS 'TOO LOW FLAPS'" cause problems because they do not make clear when an action should happen, only when it should not. Reading the systems manual for GPWS modes 4A and 4B, it looks like the rules could be coded as: ...IF GEAR is not "Down and locked" then { /* Mode 4A */......IF spd < 190kts then {.........if Radar_alt < 500ft then {............sound GWPS "TOO LOW, GEAR" .........}......} else if Radar_alt < 1000 then { /* check this carefully */.........boundry = (Radar_alt - 500) multiplied by (60 divided by 500) .........if spd < (190+boundry) then { ............sound GPWS "TOO LOW TERRAIN".........}......} ...} else /* Gear is down and locked */ { /* Mode 4B */......if Radar_alt <=245 AND flaps <35 then {.........if spd < 159 then {............sound GPWS "TOO LOW FLAPS".........} else { /* boundry conditions not clear! */............sound GPWS "TOO LOW TERRAIN".........}......}...}

Paul,Thanks for your digging into this subject and programming code.Before I continue, let me state this:It is in NO WAY my intention to reprogram any part of software made by PMDG.As I'm not a programmer myself (must be clear from my first post in this thread), I have also NO intention to trigger any other person to reprogram something.Beside of that, how would one be able to integrate this into the default software.As the titel of this thread is "How do you guys do it?", and some example of a code line is given, made me ask Ryan a question in a code-like way.In normal words: Why do I get the mentioned EGPWS calls if I do a normal go-around, in the hope that whenever there will be an update to the MD11, this would be brought in line with the real aircraft.That being said, some other info:Additional to the PMDG SYSTEM .pdf WARN 10.17/18, I also consulted my RW documentation on EGPWS which states it slightly different.There it states that:Mode 4A is applicable during cruise and approach when landing gear is not down.Mode 4B is applicable during cruise and approach when landing gear is down and flaps not in landing position.No big differences there.Mode 4C:( the calls TOO LOW GEAR, TOO LOW FLAPS, TOO LOW TERRAIN are part of the EGPWS system only, and in the older GPWS systems voiced by calling 'TERRAIN' only.)So in the SYS.pdf, yes, EGPWS is installed.For Mode 4C I find in the other documentation that it is applicable at Take-off OR Go-around with either gear up or flaps not in landing position.As I see it:During a Go-around, when the gear is retracted or when the flaps are put out of the landing position, the only call remaining is 'TOO LOW TERRAIN' , and then only when you enter the Mode 4C envelope.That's how I remember it from the real thing too.Hope it is possible to simulate this logic whenever an MD11 update is considered.Regards,Harry

[3-2-1-Now 126]

Harry,Didn't know you flew the real thing.Either way, by doing as I suggested in my post, I do not hear the calls (they do work though).Best regards,Robin.

[KCA9304 0]

Harry,Didn't know you flew the real thing.Either way, by doing as I suggested in my post, I do not hear the calls (they do work though).Best regards,Robin.

Robin,Will try your personal procedure as well some time.However, I prefer to do a go-around the way it is stated in manuals, even more where PMDG's and my realworld procedures are the same.Regards,Harry

[Paul_Smith 92]

Hi Harry, I should have known it was mode 4C you were interested in as it is the least clear cut. Would I be right in thinking that in a go-around situation, you move the gear lever to UP before confirming a positive rate of climb? That would cause an instant "TOO LOW TERRAIN" warning.

[KCA9304 0]

Hi Harry, I should have known it was mode 4C you were interested in as it is the least clear cut. Would I be right in thinking that in a go-around situation, you move the gear lever to UP before confirming a positive rate of climb? That would cause an instant "TOO LOW TERRAIN" warning.

Hi Paul,Digged a bit deeper into my books lastnight on EGPWS Modes. Hence my conclusions as written above.Regarding the moment of Gear-Up selection:NO, Gear-Up selection is ONLY done AFTER a positive rate of climb is confirmed.Even then I still get non-appropriate calls for this fase off flight.@ Robin,If you do the Go-around procedure NOT according the books and leave the landing flaps set and also the Gear down to altitudes above 2500ft RA, yes then you effectively discard any GPS warnings here.Your only next concern is to retract the flaps out of a landing setting, before retracting the gear, in order to miss the gear warning. But thats not the way it's supposed to be done.Try it as every MD11 jocky is supposed to do it.Regards,Harry

[Paul_Smith 92]

Hi Harry,I am still not clear about when you are getting the warning. Are you following the procedures detailed in FCOM PT.30.7 or do you use some other procedure?

[KCA9304 0]

Hi Harry,I am still not clear about when you are getting the warning. Are you following the procedures detailed in FCOM PT.30.7 or do you use some other procedure?

HI Paul,I'm following the GA procedure exactly as stated in the PMDG FCOM, which is exactly the same procedure that I used on the 11 in real live.When selecting Flaps28, I get the call 'TOO LOW TERRAIN' and 'TOO LOW FLAPS'When selecting Gear-Up (Yes,positive climb) the call 'TOO LOW GEAR'All with the Amber 'GROUND PROX' Warning on the FMA.Difference is that, the procedures being the same, these calls are NOT there in the real plane.(Hearing lots of Turboprops around now.. ;-))Regards,Harry

[Paul_Smith 92]

Hi Harry, I am wondering if there is a timing issue. I could generate the TOO LOW GEAR only by pulling the gear early. In other words, if I pulled the gear lever while below 190kts and under 500ft I got a GEAR warning, I only got the FLAPS warning once, and I was very low and slow at the time. The missed approach procedure I use is power, speed, heigth. I hit the throttle or the TOGA and wait until I see the engines respond. Then I level off and wait until my speed starts to climb, then I raise the nose, ensuring my speed doesn't fall, only when I am on my climbing and and accelerating do I clean up the aircraft. While cleaning up first helps gain speed more quickly, my instructor pointed out that if the engine choses to fail forcing you to abort the abort, you may not have time to get your wheels and flaps back down. This was in a light single and not a commercial multi so I am not sure how relevant that advice still is to the MD11.

[Big_Les 1]

Exactly, and one line of code isnt independant. Line 33,409 may have relation to 4,000 other lines of code. So you need to project relation before you ever get to that point. It can be very complex. Which is why developers usually only work on one project at a time. And those that can work on many at a time are few and indispensable assest to the company.

Copy paste and hack......thats the way we do things at *****...

[KCA9304 0]

Hi Harry, I am wondering if there is a timing issue. I could generate the TOO LOW GEAR only by pulling the gear early. In other words, if I pulled the gear lever while below 190kts and under 500ft I got a GEAR warning, I only got the FLAPS warning once, and I was very low and slow at the time.

Paul,When doing a standard go-around procedure as per FCOM for the MD11, then:Speed is well below 190 kts while raising the gear.You are also low and slow when retracting the flaps from the landing setting (35 or50) to 28.(reference: FCOM, Procedures and Techniques, PT.30.7)Regards,Harry

[thefsxflyer 1]

C++ (Visual Studio 2008 specifically) for most of the custom programmed stuff.Something like making a flap extend isn't all that difficult, it's the systems where we have to do a bunch of mathematical modeling that end up being crazy.If I recall correctly, the FMS in the MD-11 has something like 100,000 lines of code in it. The Autopilot/Flight Director System and the Engine modeling are also very complicated.

Any that is why I pay money for your(PMDG) amazing products!! Taylor Oldham

[Paul_Smith 92]

Paul,When doing a standard go-around procedure as per FCOM for the MD11, then:Speed is well below 190 kts while raising the gear.You are also low and slow when retracting the flaps from the landing setting (35 or50) to 28.(reference: FCOM, Procedures and Techniques, PT.30.7)Regards,Harry

Hmmm.... I hate when people make me stop and really think about what I am doing. It appears I may not have been completely compliant with the FCOM after all, and I could have sworn I was the one doing things correctly :( . I was applying my own procedure (power, speed, height) to the 'official procedure' so I was up to almost 190 before climbing, and that is NOT what the FCOM says to do... I have been reading WARN.10.17 carefully and I think you have identified a legitimate issue with the warnings (not that you needed me to tell you that) which would appear to be that GPWS modes 4A and/or 4B are not being disabled by a positive rate of climb. Perhaps one of the devs could have a look at this when they get a chance (Ryan? Vin?)

[KCA9304 0]

Hmmm.... I hate when people make me stop and really think about what I am doing. It appears I may not have been completely compliant with the FCOM after all, and I could have sworn I was the one doing things correctly :( . I was applying my own procedure (power, speed, height) to the 'official procedure' so I was up to almost 190 before climbing, and that is NOT what the FCOM says to do... I have been reading WARN.10.17 carefully and I think you have identified a legitimate issue with the warnings (not that you needed me to tell you that) which would appear to be that GPWS modes 4A and/or 4B are not being disabled by a positive rate of climb. Perhaps one of the devs could have a look at this when they get a chance (Ryan? Vin?)

Paul,Good thing is we now agree about the GA procedure and the GPWS calls that are in-appropriate to this fase of flight.Thank you for having a look into this as well.Next best thing would be for the developers to chime in on this and when possible correct this if there will be another update to the MD11 software.Best Regards,Harry

[3-2-1-Now 126]

I wrote:

As long as you have positive rate of climb, then pull the flaps up before the gear, you shouldn't hear anything at all.Remember:* TOGA* POSITIVE RATE* FLAPS - select 15