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Climb performance over FL300


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I wasn't having this problem initially but now I am finding that the aircraft will not climb much above 30,000. Climbing in CLM mode at mach 0.68 or so, the aircraft slowly trims nose up and gradually loses speed. Maybe a weight and balance issue but I am light looking at the EFB performance page. Must be doing something wrong but I can't figure it out. Even when I go into ALT hold at FL270 the flight director is commanding 10 degrees nose up and can't develop any speed.

Microsoft Flight Simulator Screenshot 2021.04.01 - 16.31.33.07.png

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In this altitude with those outside temperature you would not need both AI on. CAI maybe used for precautions when flying in clouds, WAI should only be switched on when the ICE alarm comes on.

250 KIAS should be your minimum speed during climb.

if you fly with real weather, it may happen that incorrect atmospheric data are induced, but check your weather settings to assure that this is not any extreme.

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16 minutes ago, curben said:

Can you try with Anti-Ice off? At these temperatures you shouldn’t get icing (IRL that is, sim might be a different story)

Will try that. I bet you're right.

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17 minutes ago, metzgergva said:

In this altitude with those outside temperature you would not need both AI on. CAI maybe used for precautions when flying in clouds, WAI should only be switched on when the ICE alarm comes on.

250 KIAS should be your minimum speed during climb.

if you fly with real weather, it may happen that incorrect atmospheric data are induced, but check your weather settings to assure that this is not any extreme.

Ok. Thanks. I guess I forgot to switch the anti-ice off.

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16 minutes ago, curben said:

You may also want to pitch down to gain speed first and then attempt to climb again 

Tried that but the autopilot trimmed up again when I engaged it.

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8 minutes ago, John2 said:

Tried that but the autopilot trimmed up again when I engaged it.

I’d would lower ALTS and VS down until you gain speed (e.g. 290/M0.74) and then set ALTS to your original FL and engage speed mode and set thrust to CLB. That usually works for me?

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The CRJ—like most jets—is happiest when moving through the air between 250-290 knots. So when you're climbing, you should NEVER be less than 250 knots. Above 10,000ft 290 knots in the climb is normal. As you climb, somewhere between 29,000ft and 32,000ft 290 knots will equal roughly M0.74. When you see M0.74 at the top of the speed tape, click the speed knob and the plane will climb at M0.74. Doing this you shouldn't have any issues getting to altitude. 

 

Anti-Ice does unfortunately rob a significant amount of power from the engines so keep that in mind. If you don't need the anti-ice then turn it off. Keep on eye on the SAT temperature on the MFD screen (at the very top). Once that temperature drops below -40ºC you no longer need anti-ice even if you're in clouds. From your screenshot you can see that the SAT is -51º so the anti-ice does not need to be on.

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Your speed bug is set much too slow for that altitude. In SPD climb mode, airspeed is controlled by pitch. the Mach is 0.56 which equates to only 190 knots. Since thrust is constant, and pitch controls airspeed directly, when you tell the aircraft to fly 190 knots, it will pitch the nose way high, which will increase drag so much that the aircraft will soon be unable to climb at all.

 

The CRJ, in climb mode, should be climbed at an airspeed of 250 knots minimum, and most operators go to 280-290 knots above 10,000 feet. The CRJ wing is designed to have maximum lift and minimum drag in this speed range. 

 

Once above 28,000 feet, an indicated airspeed of 290 knots will give a TRUE airspeed of about 430 knots and a Mach speed of 0.74

 

Using wing anti-ice will reduce performance at higher altitudes, but the main problem in your screenshot is too slow a selected airspeed. 

 

  

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1 hour ago, JRBarrett said:

Your speed bug is set much too slow for that altitude. In SPD climb mode, airspeed is controlled by pitch. the Mach is 0.56 which equates to only 190 knots. Since thrust is constant, and pitch controls airspeed directly, when you tell the aircraft to fly 190 knots, it will pitch the nose way high, which will increase drag so much that the aircraft will soon be unable to climb at all.

 

The CRJ, in climb mode, should be climbed at an airspeed of 250 knots minimum, and most operators go to 280-290 knots above 10,000 feet. The CRJ wing is designed to have maximum lift and minimum drag in this speed range. 

 

Once above 28,000 feet, an indicated airspeed of 290 knots will give a TRUE airspeed of about 430 knots and a Mach speed of 0.74

 

Using wing anti-ice will reduce performance at higher altitudes, but the main problem in your screenshot is too slow a selected airspeed. 

 

  

Well I was climbing fine at 290 kts until I got over fl300 at which point the vertical speed started to drop. I then reduced the speed bug gradually to try to get the vertical speed back. But the VS continued to drop and just over FL320 I was pretty much stalled out. (Where I think I took the screenshot). Going to try tonight without the anti-ice to see if that is my problem.

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Tried again, this time with anti-ice off. Was able to reach FL370 ok, but the aircraft was unable to maintain FL370 and M0.7. The speed bled off slowly and the AP trimmed the nose up to 13 degrees and the speed bled off into a stall. It was as if the plane was getting heavier. I looked at the performance page in the EFB (see attached) and couldn't see the current weight on the chart. What's with that? Off the chart? I saw another post somewhere where a user was seeing an increase in weight. Very strange. This all worked fine for me until a few days ago.  Maybe I will try with custom weather. All and any suggestions welcome!

Microsoft Flight Simulator Screenshot 2021.04.01 - 21.54.17.95.png

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30 minutes ago, John2 said:

Tried again, this time with anti-ice off. Was able to reach FL370 ok, but the aircraft was unable to maintain FL370 and M0.7. The speed bled off slowly and the AP trimmed the nose up to 13 degrees and the speed bled off into a stall. It was as if the plane was getting heavier. I looked at the performance page in the EFB (see attached) and couldn't see the current weight on the chart. What's with that? Off the chart? I saw another post somewhere where a user was seeing an increase in weight. Very strange. This all worked fine for me until a few days ago.  Maybe I will try with custom weather. All and any suggestions welcome!

Microsoft Flight Simulator Screenshot 2021.04.01 - 21.54.17.95.png


Several customers have experienced gradually increasing weight in flight. None of us in the test group have ever seen this happen, but there enough reports that we have to believe that something if causing it on some systems. 
 

MSFS apparently simulates ice accumulation by increasing the weight of the plane. This is unrealistic, because the effect of ice accumulation is aerodynamic, but this is something which we have no control over. It is strongly recommended to set the icing effect to “visual only” in MSFS, but we have reason to think this does not fully disable it.

 

You could try some flights with all weather disabled to see if there is a difference. This should eliminate any possibility of icing being a factor.

 

Having wing anti ice on at high altitude will definitely impact engine thrust. 

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vor 4 Stunden , JRBarrett sagte:


Several customers have experienced gradually increasing weight in flight. None of us in the test group have ever seen this happen, but there enough reports that we have to believe that something if causing it on some systems. 
 

MSFS apparently simulates ice accumulation by increasing the weight of the plane. This is unrealistic, because the effect of ice accumulation is aerodynamic, but this is something which we have no control over. It is strongly recommended to set the icing effect to “visual only” in MSFS, but we have reason to think this does not fully disable it.

 

 

I had this effect today the first time after around 15 flights after crossing the alps.

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4 hours ago, marcus_77 said:

I had this effect today the first time after around 15 flights after crossing the alps.

Do you have icing effects on or "visual only"?

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I mentioned in the post about autopilot going haywire that I’ve had exactly this issue. Plane climbs fine until over mid-30k feet and then just pitches up. Anti-ice had been on but turned it off when this started happening. Throttle in climb detent (even max throttle didn’t help). Couldn’t get autopilot to stop pitching up just as described above so just turned it off to finish the flight. 

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Ok. Tried again. Turned off icing effects. i.e. "visual only". Set weather to clear skies. Plane behaving normally. Climbed to fl370 in 18 mins. Now holding M0.72. Nose up trim 6 degrees. Weight is decreasing normally with fuel burn.

 

So I surmise that icing is the problem. Which is a sim issue. However, why doesn't it occur with the FBW A320NX or the WT CJ4? A mystery within an enigma....

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15 minutes ago, John2 said:

Ok. Tried again. Turned off icing effects. i.e. "visual only". Set weather to clear skies. Plane behaving normally. Climbed to fl370 in 18 mins. Now holding M0.72. Nose up trim 6 degrees. Weight is decreasing normally with fuel burn.

 

So I surmise that icing is the problem. Which is a sim issue. However, why doesn't it occur with the FBW A320NX or the WT CJ4? A mystery within an enigma....


I don’t believe the WT CJ4 models engine performance loss when anti ice is on at the moment. Someone please correct me if that’s modeled yet. 
 

I definitely had icing effects in other aircrafts, like the WT CJ4 or some GA planes. 

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3 minutes ago, curben said:


I don’t believe the WT CJ4 models engine performance loss when anti ice is on at the moment. Someone please correct me if that’s modeled yet. 
 

I definitely had icing effects in other aircrafts, like the WT CJ4 or some GA planes. 

Although it sounds as if the sim is modeling icing effects by increasing the GW of the aircraft. So it should affect the CJ4 and A320 unless they are somehow negating what the sim is doing.

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45 minutes ago, junix45 said:

I am suffering from the same phenomenon.

Make sure you have icing effects set to "visual only" in the sim settings.

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Unfortunately we have a proof that this option is not always working correctly. I clearly have seen icing happening with the "visual only" option. We reported that back to Asobo to check.

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Hello, I have exacly same problem after last patch, never before. Icing effect visual only, live weather but actually no any clouds around, I'm flying e.g. 10 minutes at FL350 and it's happening. Aircraft starts to slowing down and in effect drop alltitude. At this time trim goes to maximum nose up (around 15).  After disconnect AP and trim aircraft manualy back to normal, everything is ok until turning AP back, then immediately trim goes up again. Sometimes after few minutes it's goes to normal again but only for another few minutes. AI does not help at all. I just switched weather to Clear Sky and it's seems to be working for now.  

Zrzut ekranu 2021-04-03 134002.jpg

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1 hour ago, Adam Kawecki said:

Hello, I have exacly same problem after last patch, never before. Icing effect visual only, live weather but actually no any clouds around, I'm flying e.g. 10 minutes at FL350 and it's happening. Aircraft starts to slowing down and in effect drop alltitude. At this time trim goes to maximum nose up (around 15).  After disconnect AP and trim aircraft manualy back to normal, everything is ok until turning AP back, then immediately trim goes up again. Sometimes after few minutes it's goes to normal again but only for another few minutes. AI does not help at all. I just switched weather to Clear Sky and it's seems to be working for now.  

Zrzut ekranu 2021-04-03 134002.jpg

I had a flight yesterday using real weather and the plane behaved normally. I had icing effects "visual only". Going to try again today.

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