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freded

737NGX will not climb or achieve FMC settings

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B737-800NG will not exceed 200 KIAS or climb to altitude set in FMC during initial stages of Tutorial 1 flight from EGKK to EHAM.

 

FMC & MCP setup as per Tutorial 1...

Both F/Ds: 'ON'

AP CMD A: 'ON'

A/T: 'ARM'

LNAV: 'ON'

VNAV: 'ON'

N1 'ON'

 

 

Tried turningg A/T off and advancing throttles to full: Speed does not increase above about 208 Knots.

 

Tried using LVL CHG to increase altitude to height-setting in FMC for present leg: A/C climbs but as soon as VNAV is turned on, climb ceases.

 

Now approaching DAGGA where speed should be 257 KIAS and height FL101 (according to FMC), but speed is 200 and alt 6500.

 

Checked that Gear and Flaps are retracted and that Speed Brakes are 'Down'.

 

What is wrong?

 

I have tried this flight three times now with same or similar problems.

 

Mark

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What's the TAT say? Could be a weather issue.

 

How about a screen cap?

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Are you getting the flaps up indicators on the tape and setting flaps-up speed after T/O? Is your IAS speed set accordingly?

 

Is anything disengaging after T/O either through human error or a conflict of key bindings? Using FSUIPC?

 

By speedbrakes 'down' I hope you mean disarmed.

 

As suggested, a screenie would probably help.

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Well, it won't be weather (the 737 can easily overcome any temperature/density altitude issues you'll find on this planet unless you are horribly over gross) and if you can get it in the air, it should climb. It sounds to me like something is interfering with your thrust levers, pulling the power back on you. I know you pushed the thrust levers up, but what are your N1's actually saying during the climb? Did you somehow build a speed/altitude restriction into your programmed flight path? As the others have said, a screen shot or 3 would really help.

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Thanks, lads.

 

I'll answer your comments:-

 

Spin737: Not weather. I selected scattered clouds, no wind & no precip, as suggested in Tutorial 1.

 

fencer: Aircraft is not overloaded: Fuel 1/3; Pax Full; Cargo 2 x 1500 lbs - all as instructed in Tutorial 1.

 

tazisdylan: Flaps are UP according to gauge and lever-position. IAS set to 250 and AT set.

Yes, I use FSUIPC but no previous problema attributable to this.

Speedbrakes are disarmed.

 

BeaverDriver: After I pushed the thrust levers up, I checked and N1 was well over 90%.

FMC was set up according to Tutorial 1 and agreed with the images shown at each stage. No other speed restrictions were added, apart from those included in the mTutorial.

 

I'll send a screen shot or two if the same errors occur next time I fly the NGX.

 

Mark

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TAT, as in Total Air Temp?

 

Didn't know it was shown on panel...

 

Probably quite low - the flight is out of Gatwick in May.

 

Mark

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Mark,

 

They are asking about TAT because a high TAT can interfere with the climb performance. Consequently, if you are using FSINN and have not selected "Disable Weather by Default", your climb issue may well be the result of higher than expected TAT. Next time you are on climbout, have a look in the upper left corner of the upper display unit. Check your TAT.

 

JW

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yea it shown on top left hand side of your right hand side pfd if its very high you will have trouble climbing to your assigned altitude

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Well, it won't be weather (the 737 can easily overcome any temperature/density altitude issues you'll find on this planet unless you are horribly over gross

[Emphasis Mine]

 

That's all well and good, but certain programs that adjust the weather do not do so in an on-this-planet like fashion. FSINN, as an example, has a weather bug that increases temperature as altitude increases. So, while weather might not be a normal assumption on a real aircraft exhibiting these behaviors, it is in the sim for the above reason.

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Fair enough, but bugs notwithstanding, it's not at all unusual to see temperature inversions that can be quite significant in real life. It would take an extremely wild swing of temperatures to cause a 737 to not be able to climb pretty much normally. These airplanes are built to overcome pretty much anything that can be thrown at them, and in the 737 class, it's highly unusual to even have to step climb as you do in the 747 when loaded. The power to weight ratio is just too great. Now, if you are getting a temperature of +50C or higher at 10,000 ft, then maybe you have an issue (and I'd be telling the developer he either fixes a bug of that colossal a magnitude or you'll spread the word that this program should be avoided at all costs), and certainly if you do get very high rises in temperatures your climb rate will suffer, but no way down low should you see what the OP is seeing due to weather. I'm quite certain that you can see 737's, A320's, 747's, etc., etc. taking off at all the tropical airports those planes routinely go into at any time of the day or night and in extremely hot weather. In fact, in the tropics it's unusual NOT to have a pretty good inversion early in the morning and late in the evening (more often the former). If they can do it there, then surely you can get out of Gatwick and climb to cruising altitude at the weights the OP is at without having the 737 even breathing hard, even with unusually high temperatures and a hefty inversion. Something else is going on there, but it ain't weather, again, unless FSINN is really horribly out to lunch, but with temps that you again wouldn't find on this planet. If that IS the case, you can't blame it on the airplane, although I don't think anyone necessarily is at this point.

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Glenn,

 

Definitely. Most of the time, when people bring up the weather issue, it's brought up in defense of the plane. It's also normally associated with not being able to reach a reasonable cruise level, not so much speed and low alts as is the case here.

 

I forget how the tutorial is written in terms of settings, but the flight is supposed to be flown with the values pounds, right? If so, and the plane is configured to expect KG values, it will assume that it's very much over weight and act oddly. Same goes for the inverse.

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in the 737 class, it's highly unusual to even have to step climb as you do in the 747 when loaded. The power to weight ratio is just too great.

I had to step a few days ago coming out of KPHX to KSEA. Too heavy for our filed FL380, so we stopped at FL360 for a bit. Happens on the Hawaii flights, too, quite often.

 

It's not every flight, but it's not highly unusual, either.

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What are you flying (not doubting you - just interested)? I know my friend who flies 757's has had to step out of Guyana before but I guess he doesn't do it all that often. But that's a 75, not one of the heavies. But for a 737 I would be surprised to hear it happens very frequently, but I'm not a 73 captain :smile:.

 

That all said, my point though was that there's no way temperature (if they are even close to realistic) would cause the 737 to perform like that down that low in Britain. I'm wondering if maybe a door got left open or something like that. Not likely though. I've done that before and it was 10K before I started to get the aural warning and it didn't take me all that long to get there. Sounds like it might be a gremlin of some kind.

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What are you flying (not doubting you - just interested)? I know my friend who flies 757's has had to step out of Guyana before but I guess he doesn't do it all that often. But that's a 75, not one of the heavies. But for a 737 I would be surprised to hear it happens very frequently, but I'm not a 73 captain :smile:.

 

That all said, my point though was that there's no way temperature (if they are even close to realistic) would cause the 737 to perform like that down that low in Britain. I'm wondering if maybe a door got left open or something like that. Not likely though. I've done that before and it was 10K before I started to get the aural warning and it didn't take me all that long to get there. Sounds like it might be a gremlin of some kind.

It was a 737. I think it was an -800. I think it was just very warm at altitude, since we weren't too heavy. 150k or so, for takeoff, IIRC.

 

It's probably the weather engine he's working with, not a realistic problem.

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Oh really! Interesting. I've heard the 800's have a bit less giddy-up than the 700 relatively speaking (the charts say they need quite a bit more runway). Is that the case? Also, do you know what the short field kit consists of for the newer 737's? I know they are an option for the 600 and 700, but heard they are standard on the 900ER's.

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I've heard the 800's have a bit less giddy-up than the 700 relatively speaking (the charts say they need quite a bit more runway).

-700 can usually go up to FL400 or FL410 directly. Yesterday from KONT the optimum was FL398 passing about 10,000, so we went straight up.

 

The -800 and -900 don't do that well. FL370 or FL380 for a final and you can go up for a 2-2.5 hour flight. Any longer and you might be too heavy with fuel to go up without a step. They don't go past FL390 very often in my experience.

 

RE:SFP, I believe they are standard on the ER, but I don't know if that is any different from the -800SFP. Companies can select what parts of the SFP they want, too.

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Interesting! Still the "little" 737 has really grown, eh?

 

What makes up the SFP, do you know? Is it a wing mod or engine mod?

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Mostly aerodynamics - some wing optimization, different flap schedule regarding LE devices, then you have bigger ground spoiler deployment angle, and a two-position tailskid.

 

I suppose an airline will also want the 27K bump option and carbon brakes, if they need SFP.

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Hello Guys,

 

Wow! I seem to have started a very interesting and informative discussion between people who appear to know what they're talking about. Am I right to conclude that 'BeaverDriver' and 'Spin737' are real-world commercial aviation pilots? I've flown in a few DHC2 Beavers (and DHC3 Turbo Otters), sitting in the 'FO's' seat as a paying passenger, but don't even have a PPL. :-(

 

To return to my problem ;-), I don't use FSINN - in fact I'd never heard of it!

Googling it shows that it's similar to SquawkBox and used to communicate with VATSIM. Never tried that.

 

I do have REX2 installed on this machine but am not activating it for the PMDG 737NGX, as it eats into my few remaining frame rates. So the weather is set from the FSX World/Weather options.

 

As for leaving a door open, I'll have to do a proper checklist in future! I have to say that hadn't occurred to me as a possible cause but it's easy enough to open doors inadvertently with Shift-E...

 

Re "I forget how the tutorial is written in terms of settings, but the flight is supposed to be flown with the values pounds, right? If so, and the plane is configured to expect KG values, it will assume that it's very much over weight and act oddly..." (by scandinavian13). Yes, pounds are the default tutorial settings but it does tell you how to convert to Kgs if you need/want to. I didn't.

 

"SFP" - Short Field Program?

 

I'm about to start the Tut 1 flight again, so will report back on what happens this time!

 

Mark

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I have found a problem (whether it's THE problem is a different matter!).

 

Here are the values I get by closely following Tut 1.

 

In 'FS ACTIONS':-

 

FUEL set to: 1/3

PAYLOAD to: FULL

CARGO to: 1500 FWD & AFT

 

 

The above gives on 'FUEL':-

 

TOTAL LBS: 15198

TOTAL LEVEL: 33.0%

TANK 1: 7599

TANK 2: 7599

CENTER TANK: 0

GW: 167.9/MTW 174.7

ZFW: 121.8/CG: 19.1%

 

 

On PERF INIT:-

 

GW/CRZ CG: 168.1/19.1%

PLAN/FUEL: -/46.3

ZFW: 121.8

RESERVES: 5.0

TRIP/CRUISE ALT: FL240/FL250

 

 

BUT - Screenshot of PERF INIT in Tut 1 shows:-

 

GW/CRZ CG: 138.0/25.7%

PLAN/FUEL: -/15.3

ZFW: 122.7

RESERVES: 5.0

TRIP/CRUISE ALT: FL301/FL250

 

So there is a discrepancy between the GW/CRZ CG & PLAN/FUEL values for the PERF INIT that I get and the values shown in Tut 1.

 

Is this enough to prevent FMC selected speed and Altitude from being followed?

 

Mark

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Am I right to conclude that 'BeaverDriver' and 'Spin737' are real-world commercial aviation pilots? I've flown in a few DHC2 Beavers (and DHC3 Turbo Otters), sitting in the 'FO's' seat as a paying passenger,

 

You would be correct sir. However, my time is almost all in 185's, Beavers and Otters (all on floats or skis - not sure what a wheel actually looks like :lol:). In this instance, I'd be taking what 'Spin737' is saying over my comments. While the effects of density altitude are more pronounced on the machines I flew (especially the DH products - very high lift wing but no speed, and piston pounders), it wasn't very often I couldn't get out of a lake if it was long enough, and climb to a reasonable altitude. The 737 is waaaaay more capable of that than any of the machines I flew so that's why I don't think it's weather related. My friend who flies 757's (see below) has come out of Guyana (did I already mention this?) in a 57 with the temp +33C and almost no wind and not that long a runway and still got to altitude without too much grief, so that too makes me think the 737 shouldn't be having a problem like you are due to weather. Now, 'Spin737's' RW experience is far more relevant to this discussion and he does have experience on type (obviously) so I'd be listening to him over me as I say in this situation.

 

"SPF" does refer to the Short Field kit for the 737 NG's, but I'm not sure what the "P" refers to. My jumpseat time with the 737 was all on 200's mostly with gravel kits installed which was just about all we saw up north (along with 727-100's and the odd 200, again with gravel kits) and they were almost by definition, "short field capable" (they used to fly 737-200's into Dutch Harbor, Alaska with a 3990 ft runway, albeit at a reduced load, so that machine can work miracles for its class). This stuff with the NG is all fairly new to me, although a good friend of my is a 757/767 (he's co-rated) driver so he gives me a lot of info on things like the FMC.

 

I don't think the difference you see in the screenie is anything that should cause the problem. Your weights are very light either way. If the FMC is programmed for FL300 vs. 250, the airplane will still try to get there the same. There's no chance you had SPEED selected or LVL CHNG instead of just VNAV and LNAV is there? I think you said you double checked that. Insofar as the door being open, that's a bit of a shot in the dark by me and I doubt it would cause your issue either now that I think about it. Have you reflown the flight more than once and do you get the same issue each time? If not, it was probably just something overlooked (easy to do, even with a full checklist - I know :rolleyes: ). If it's repeatable, somehow try to get a few screenies on departure of as much of the panel as possible so we can see. We're kind of going blind on this. In a 172 that's a little easier than in this machine :smile:.

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"SPF" does refer to the Short Field kit for the 737 NG's, but I'm not sure what the "P" refers to.

 

I think it went either as "Short Field Package" or "Short Field Performance" as in SFP Package. Not sure though.

 

Anyway regarding OPs problem, I would really need to see what was going on there. This is why I like when an add-on has DFDR implemented, as an example Aerosofts Adv. Airbus is going to have what looks like a great one. An idea for future PMDG products, maybe?

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I had to step a few days ago coming out of KPHX to KSEA. Too heavy for our filed FL380, so we stopped at FL360 for a bit. Happens on the Hawaii flights, too, quite often.

 

It's not every flight, but it's not highly unusual, either.

 

Hi Matt,

I thought you were flying for a far east company (but I have been away from this forum for a while)

Cheers,

Bruno

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