Things I've noticed with the NGX

[3mta3 14]

Back to the gear issue - RE: extending above 250 kts.  I did a test flight and the problem is related to the "Aircraft Stress Causes Damage" checkbox.

 

If the box is checked - the gear will not deploy until less than 250kts, regardless of when you throw the handle.  If you uncheck the box - the gear extends at any speed you choose to deploy it. 

 

As we know that aicraft limits are 270/.82 extend/ 320/.82 extended/ 235 retract.  Glad we figured that one out. 

 

And regarding the fuel flows in reverse - I misstated the fact that the numbers reverse or go negative.  At max reverse fuel flows decrease to 630lbs/hr/eng and coming out of reverse they quickly jump up to over 3000lbs/hr/eng.  So this is most likely a real bug in the NGX where fuel flow is tied to thrust in some way.

 

I tried again the manual pressurization and you cannot get the cabin to pressurize on the ground - in flight it works and you can pressurize up to the max diff relief valve and then it "bounces" on that pressure - but on the ground - it should have the same behavior.  Those of you that have flown the classic and forgotten to flip the air/ground switch will know what this feels like!  I used to crack my window and slowly bleed out the pressure before flipping it to ground (the one time I forgot it :blink:), to not pop everyone's ears when the main cabin door was opened!

 

Forgot to recheck the FMC prog page issue - but still think it doesn't jump from PROG 3-2-1, etc, instead jumps to other pages when previous page is hit.

 

jRock

[Guest JetFueler]

My quick two cents is that entering descent forecast data will make the commanded VNAV descent MUCH more accurate and stable.  If you're skipping this step, I highly recommend utilizing it. I don't know how many people don't use it, I suppose it depends on how far one delves into the sim, but I found that as I learned more about the aircraft and started inputting that data I've had a lot less problems with my descents.  I'm not trying to impune any of our real world or sim pilots here, just making a suggestion for those that may not have tried it yet.

[Kiwi Spitfire 1]

I tried again the manual pressurization and you cannot get the cabin to pressurize on the ground - in flight it works and you can pressurize up to the max diff relief valve and then it "bounces" on that pressure - but on the ground - it should have the same behavior.  Those of you that have flown the classic and forgotten to flip the air/ground switch will know what this feels like!  I used to crack my window and slowly bleed out the pressure before flipping it to ground (the one time I forgot it :blink:), to not pop everyone's ears when the main cabin door was opened!

 

 

jRock

 

As you stated the classic had an air/ground switch which enabled manually pressurising the cabin on the ground. I think you will find modern aircraft have this switch tied in to the weight on wheels switch, automating the procedure and subsequently the aircraft will not pressurise untill the aircraft leaves the ground, and will depresurise upon landing...(but it should have done that already before touching down).  These aircraft will require either pulling the air sense CB manually, or may have a specific test switch to enable pressurisation on the ground.  (We actually use this test switch in flight in the P-3 in a pressurisation emergency)

 

You may notice the Ram Door Full Open annunciator light on the NGX - this indicates the ram air doors are open and effectively behaving like wide open outflow valves, making pressurisation impossible. These should open automatically on the ground, and close upon liftoff allowing pressurisation.

 

Hope this helps a little - Also, you mentioned cracking your window when you pressurised the classic on the ground, are you unable to manually position the outflow valve on that model?

[EGLL77W 1,508]

At what height do you aim to be fully configured? 1.200 ft AGL, F15, 200 kts IAS and no L/G yet?

 

1500ft - very minimum 1000. 200 knots was due to a sudden increase in tailwind from 175 knots, so I selected F15 to see if that was enough drag to reduce the speed. However with the speed trend only increasing- only way to get the speed back was dropping the gear. If it didn't then I would have done a missed approach - knowing there was a tailwind on the glidepath, reduced earlier etc. 

 

(Ps- please quote me in your reply next time. I often forget which topics I'm having convo's in if not reminded by email)

[Alpha Floor 237]

Oddly enough, I've been reading today old stories of retired Trident pilots and how they flew their Gripper's,

 

One told a story where they found themselves so high and fast for a "normal" gear extension, that they used the emergency gear extension mechanism. They landed safely, but after taking off for the next flight found out they couldn't retract the gear... Quite of an interesting read, here it is: http://www.pprune.org/archive/index.php/t-434496.html

 

As a sidenote, the Trident was the first jet airliner to have a full autoland system, you should definitely watch how the Captain talks to the camera while the F/O monitors the plane, I found it really hilarious (Those magnificent 60's hahaha): 

 

 

Sorry for the offtopic, but I couldn't refrain myself from sharing this.

[Don t moderate me this way 882]

1500ft - very minimum 1000. 200 knots was due to a sudden increase in tailwind from 175 knots, so I selected F15 to see if that was enough drag to reduce the speed. However with the speed trend only increasing- only way to get the speed back was dropping the gear. If it didn't then I would have done a missed approach - knowing there was a tailwind on the glidepath, reduced earlier etc. 

 

(Ps- please quote me in your reply next time. I often forget which topics I'm having convo's in if not reminded by email)

 

 

Thanks for bothering, Luke. I'll try to remember using quotes for the really essential questions I'll be having in the future. (Like "When will it be released?", "Will it feature a weather radar?" and, of course, "What's the meaning of life?"  :lol: )

[Ralgh 43]

As you stated the classic had an air/ground switch which enabled manually pressurising the cabin on the ground. I think you will find modern aircraft have this switch tied in to the weight on wheels switch, automating the procedure and subsequently the aircraft will not pressurise untill the aircraft leaves the ground, and will depresurise upon landing...(but it should have done that already before touching down). These aircraft will require either pulling the air sense CB manually, or may have a specific test switch to enable pressurisation on the ground. (We actually use this test switch in flight in the P-3 in a pressurisation emergency)

 

You may notice the Ram Door Full Open annunciator light on the NGX - this indicates the ram air doors are open and effectively behaving like wide open outflow valves, making pressurisation impossible. These should open automatically on the ground, and close upon liftoff allowing pressurisation.

 

Hope this helps a little - Also, you mentioned cracking your window when you pressurised the classic on the ground, are you unable to manually position the outflow valve on that model?

Ram Air Doors have no effect on pressurization. They are the doors that control the airflow through the PACK heat exchangers. They are located right near the leading edge of the wing root. They will remain full open in flight during slow flight with the flaps extended and inflight if the system deems it necessary for cooling. The real plane absolutely can be pressurized on the ground.

[EGLL77W 1,508]

Thanks for bothering, Luke. I'll try to remember using quotes for the really essential questions I'll be having in the future. (Like "When will it be released?", "Will it feature a weather radar?" and, of course, "What's the meaning of life?"  :lol: )

 

Thanks dude. Yeah I'm sure they'll begin soon LOL!!

[Kiwi Spitfire 1]

Ralgh, on 24 Mar 2014 - 07:39 AM, said:Ralgh, on 24 Mar 2014 - 07:39 AM, said:Ralgh, on 24 Mar 2014 - 07:39 AM, said:

Ram Air Doors have no effect on pressurization. They are the doors that control the airflow through the PACK heat exchangers. They are located right near the leading edge of the wing root. They will remain full open in flight during slow flight with the flaps extended and inflight if the system deems it necessary for cooling. The real plane absolutely can be pressurized on the ground.

 

Thanks for that Ralgh, always good to learn a little something about different aircraft, couldn't be bothered wading through the systems manual to find out myself, was just mentioining similar systems on aircraft I have worked on/flown. On the P-3 Orion we have a ram air aux vent valve that precluded pressurising on the ground and our outflow valve works a little differently, and I only worked on 747/767/A320 at AirNZ when I was a AMEL so they might have slightly different systems but the pack doors definately ring a bell now thanks for that, been flying the P-3 for too long :unsure:

 

Also I never said you 'couldn't' pressurise on the ground, just that you would have to manually carry this out, obviously every aircraft pressurises a little on the ground when you close the door, (to the point it is hard to open the door again with aircon on in the P-3), and I believe pax jets such as the 73 etc pressurise a little more at higher power settings to smooth out the change once airborne. I was asuming we were talking about down to say -5,000'+ etc so replicating in-flight diff levels. Aircraft don't just do this all by themselves sitting on the tarmac... 

 

Being a military aircraft we don't get too 'carebear' about peoples ears or if it is a little uncomfortable when we close the door etc haha so don't worry about little pressure changes, we open and close the main door in flight all the time to chuck stuff out, and also have a pack of tubes we deploy out of the belly of the aircraft for launching buoys - you definately feel that if the taco doesn't check you have depressurised first before opening the door to lower the package :blush:.  Some of our pilots are more 'military' than others so to keep ahead of the aircraft we have to sometimes increase the cabin depress rate to over 1,200ft/min...which you feel, but isn't as bad as the aircraft catching up with the cabin alt and then depressurising at 4,000ft/min!

 

Interesting in the PMDG NGX by manually closing the outflow valve all the way with aircon on the cabin doesn't pressurise - is this how you do it in the 'real' thing?

[willywonka 36]

 

 

I tried again the manual pressurization and you cannot get the cabin to pressurize on the ground

 

Interesting in the PMDG NGX by manually closing the outflow valve all the way with aircon on the cabin doesn't pressurise - is this how you do it in the 'real' thing?

Hope it's not too late to add to this thread. I tested this yesterday and I was able to pressurize the plane on the ground up to about 8.5psi delta P (didn't dare to go any higher). So it seems to work as intended.

[kstjohn 2]

Regarding your first point - why would you want to put the gear down at 270-250 knots in the first place, as long as you are not doing any sort of steep approach? As long as you always stay ahead of the plane and plan your descent you'll never have to deal with excessive speed.

 

I'll have to check out the reversed fuel flow on my system. Also keep in mind, like with any other software there will always be some bugs that only get noticed by a minority of users. However it's good that even those are being pointed out so they can get ironed out in a future update/SP.

Guess you've never flown RW in the NYC triangle.  We do it all the time.  It has nothing to do with planning and everything to do with ATC.

[scandinavian13 5,192]

Guess you've never flown RW in the NYC triangle.  We do it all the time.  It has nothing to do with planning and everything to do with ATC.

 

Gotta love N90.

...this is what happens when you stuff 3 (arguably 4, with TEB) major airports within 20nm of each other.

 

One thing I can never stress enough to the simmer group is that, when you go into N90, all bets are off (and the following "aviation isn't as rigid as you think!")

[E6BAV8R 88]

Anyway guys. Love the discussion. Very reasoned responses. But yeah, real live airline pilots use the gear when they need to - and don't "save" it to be extended at the last possible second.

 

Not to the extent you are referring to.  Sure, we may use the gear if we receive a last minute change due to ATC or weather and we have to immediately rush re-configuration to satisfy a new altitude change (to where changing prop settings or speed brakes won't be enough), but if you are having those issues when are in the middle of descent from cruise and brushing up against a 250/270 Knot limit, than something has gone rather wrong.  I don't know anyone that has ever had to get as drastic for drag as extending the landing gear all the way out on a STAR.

 

On another note, the landing gear is allowed to be extended into high mach speeds because it is used as a sole and last resort for drag in high overspeed situations, as you obviously can't be extending flaps or speed brakes at high mach - landing gear is the only option for drag at those speeds (and yes, you'll blow the gear doors off).

[Spin737 102]

you obviously can't be extending flaps or speed brakes at high mach - landing gear is the only option for drag at those speeds (and yes, you'll blow the gear doors off).

What? Forgive me, but are you typed in a 737? I disagree with this regarding speed brakes.

[E6BAV8R 88]

What? Forgive me, but are you typed in a 737? I disagree with this regarding speed brakes.

 

No, but I wasn't specifically referring to a 737.  There are jets where you either 1) aren't able to do so in overspeed or 2) don't have speed brakes.