N55E008

[Confirmed] XP10 Climb Performance

8 posts in this topic

Hello.

To me, the climb performance appears a bit implausible.

Took off from EDDL to LGKR today under following conditions:

- ISA conditions ( 15°C / Q1013 )

- zero wind ( ground & aloft )

- TOW 58039kg

- CLB rating ( ca. 93% N1 )

- climb schedule 250/280/0.74

- no Anti Ice required

- RFL 330

According to Simbrief, a total distance of 117NM was expected for the Climb to FL330.

Actually it took 170NM ( 53NM more than predicted ).

Vertical speed was less than 1000ft/min after passing FL240...

With Mach0.74 vertical speed was 500ft/min after passing FL305.

Average rate of climb from 150ft to FL330 was 1130ft/min. ( 29 Minutes )

 

This performance does’nt appear very convincing to me.

Is this a problem with the XPlane 10 Flightmodel in general or with the IXEG internal modeling?

Thanks and best regards

 

EDIT: I‘ve got the impression, that other Add on Aircraft are facing the same problem, such as the FF A320.

So probably an xPlane 10 inherent issue...?

 

 

 

 

Edited by Morten
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Used to work fine in XP10, although been a year since I tried.  Sounds a bit on the low side yes, at that weight you should drop below 1000fpm around FL300.  You have off course checked you do not have any ekstra drag out, like accidentally extended the gear, flap or spoilers.

Lately we have also seen examples of 3rd party plugins that are somehow messing with flight model (should be a law against that:angry:)   So try disabling all other plugins and try again.

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Hello Morten,

thank's for your reply.

"You have off course checked you do not have any ekstra drag out, like accidentally extended the gear, flap or spoilers."

You bet! ;)

I'll try to disable some plugins, although ( apart from Sky Maxx, RWC and better Pushback ) I do not have a namable number of plugins installed...

Best regards

 

Edited by N55E008
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So Morten, I've disabled all plugins exept for the Gizmo64.

 

Conditions were:

- GW 58.000kg

- ISA 

- wind calm

- no Anti-Ice

- CLB Rating

- climb schedule 250/280/0.74

 

Climb rate:

below 2.000ft/min after passing FL150

below 1.500ft/min after passing FL190

below 1.000ft/min after passing FL240

 

Would be glad if you could examine the issue.

Best regards!

 

IMG_8817.JPG

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Hi,

I have run this performance test on X-Plane 11 (I don´t even have XP10 installed anymore), but I don´t think anything should have changed with regard to the performance.

I have used my official flight planning data for the 737-300 I used to fly. These are the test parameters:

Airport at sea level

Temperature ISA +10 (25C).

Brake release weight 58.000kgs.

No wind.

Climb schedule: V2+15 to 1500 feet. Then 250kts to 10.000 feet. Then 290kts until Mach is 0.74. Then 0.74. Full climb power.

Watch for the IAS/MACH changeover, if you are on FL CHG it will automatically change from 290 to 0.71 at ca. 26.000 feet. That is too early, you need to revert manually to IAS and switch over when the speed reaches M.74 (c/o button).

Here are the values I get (first the flight test values with IXEG 1.21, then the values from the book):

Altitude           Distance(IXEG)    Distance (Real aircraft)       Time (IXEG)     Time (Real aircraft)

6.000                    11.2                          10                                   3:25                       3

10.000                   18.2                         17                                   4:54                       5

14.000                  29.8                          29                                   6:59                       7

20.000                   48.3                         47                                   9:59                      10

24.000                   64.9                         65                                  12:29                     12

28.000                   86.4                         89                                  15:33                     16

31.000                   102.3                       104                                 17:46                     18

33.000                   117.0                       125                                  19:50                    20

Climb rate just before reaching 33.000 feet was 800 feet per minute.

Cheers, Jan

 

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Ok everyone,

I have worked a bit more with N55E008 and he has been very helpful in identifying and isolation the problem in XP10.

Indeed it turns out that in our move to support XP11 I have made a mistake in changing the script for the fuselage drag. This will indeed result in a drag in XP10 that is too high. This error is most prevalent at higher speeds (of course), so you will notice mostly during speeds in excess of 250 kts (climb and descent). Cruise and lower altitude operations should still be ok, although technically the drag is a bit too high as well, naturally.

I have fixed the script, we will run it through some internal testing (I would like to avoid another embarrassment!) and then we will distribute it to those interested (= still on XP10).

I expect this to happen very short-term.

Thanks for everyone´s patience and especially N55E008´s help!

Cheers, Jan

 

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Dear Jan,

you're very welcome, glad I've been helpful.

Keep up your excellent work!

Best regards,

Toto

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