ridgey 26 Posted December 22, 2022 Share Posted December 22, 2022 Hi there, The majenta N1 limits above the thrust are frequently being overshot. For example, on take-off with a healthy de-rated (FLEX), the N1 will still shoot past the majenta values. For example if they're set at 83, by rotation the N1 value is 90. Kind regards 2 Link to comment Share on other sites More sharing options...
mhron 31 Posted December 28, 2022 Share Posted December 28, 2022 FLEX isn't implemented and I pretty doubt that it will ever be. 1 1 Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted December 28, 2022 Aerosoft Share Posted December 28, 2022 I am sorry, lasty time I looked FLEX worked. Can I suggest you update your copy? We will however check it again, got any conditions you would like us to check? Link to comment Share on other sites More sharing options...
ridgey 26 Posted December 28, 2022 Author Share Posted December 28, 2022 17 minutes ago, Mathijs Kok said: I am sorry, lasty time I looked FLEX worked. Can I suggest you update your copy? I have the latest copy and I confirmed that YT videos had the same behavior Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted December 28, 2022 Aerosoft Share Posted December 28, 2022 1 minute ago, ridgey said: I have the latest copy and I confirmed that YT videos had the same behavior But again, under what conditions? What YT videos? Link to comment Share on other sites More sharing options...
ridgey 26 Posted December 28, 2022 Author Share Posted December 28, 2022 8 minutes ago, Mathijs Kok said: But again, under what conditions? What YT videos? When I'm home next week I can do a video for my own conditions but also I went onto takeoff tutorials and saw exactly the same conditions Link to comment Share on other sites More sharing options...
amahran 608 Posted December 30, 2022 Share Posted December 30, 2022 I will agree with the OP here; I've brought it up on these forums repeatedly that Flex doesn't actually end up reducing takeoff thrust. I think the plane just ignores the Flex setting and goes straight to full TOGA regardless of the temperature setting. 3 Link to comment Share on other sites More sharing options...
mhron 31 Posted December 30, 2022 Share Posted December 30, 2022 I must apologize to Aerosoft here. I'm just flying over Italy in the CRJ-900 and I tried to do FLEX take-off and it worked. At first it overshot the magenta a bit but then the thrust was automatically reduced to the N1 limit and stayed there till I moved the levers to the CLIMB detent. It looks like I have been ignoring a working FLEX for some time thinking it has never been fully implemented. Link to comment Share on other sites More sharing options...
ridgey 26 Posted December 30, 2022 Author Share Posted December 30, 2022 1 minute ago, mhron said: I must apologize to Aerosoft here. I'm just flying over Italy in the CRJ-900 and I tried to do FLEX take-off and it worked. At first it overshot the magenta a bit but then the thrust was automatically reduced to the N1 limit and stayed there till I moved the levers to the CLIMB detent. It looks like I have been ignoring a working FLEX for some time thinking it has never been fully implemented. But it shouldn't overshoot to TOGA before settling.. That's not the logic of the aircraft and shouldn't be happening 1 Link to comment Share on other sites More sharing options...
mhron 31 Posted December 30, 2022 Share Posted December 30, 2022 3 minutes ago, ridgey said: But it shouldn't overshoot to TOGA before settling.. That's not the logic of the aircraft and shouldn't be happening Ok, so it's half-working. That's still something, I hated when it was fully loaded and initially climbing like a F-16. Let's hope it will work as it should one day though. Link to comment Share on other sites More sharing options...
jay jay 93 Posted January 1, 2023 Share Posted January 1, 2023 How do you implement a FLEX take-off? Link to comment Share on other sites More sharing options...
amahran 608 Posted January 1, 2023 Share Posted January 1, 2023 2 hours ago, jay jay said: How do you implement a FLEX take-off? VNAV page in the FMS, there's a Flex temp option on the left hand side. You can add temperatures up to 50C (-1 degree for every 500' Pressure Altitude) If you see a pink indication on the top of the EICAS next to the N1 reading (before or after engine start), then you have it set. If it's blue and you're not in the middle of starting engines, you didn't do it right. During engine start, it goes to an emergency thrust rating mode that delivers un-derated thrust (one engine is not running, so it assumes it's on a take-off run with an engine failure) 1 Link to comment Share on other sites More sharing options...
Raptor05121 84 Posted January 31, 2023 Share Posted January 31, 2023 FLEX has never worked for me. And that's me holding back on how slow it takes N1 to spool up. Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted January 31, 2023 Aerosoft Share Posted January 31, 2023 18 minutes ago, Raptor05121 said: FLEX has never worked for me. And that's me holding back on how slow it takes N1 to spool up. You got any solid information on how fast the engines should spool up in different environmental conditions? We would be very interested in that as we simply do not have that data. As far as we know the engine manufacturers have never shared that with any customer, so if you have that it would help us a lot! Link to comment Share on other sites More sharing options...
Raptor05121 84 Posted May 18, 2023 Share Posted May 18, 2023 On 1/31/2023 at 2:40 PM, Mathijs Kok said: You got any solid information on how fast the engines should spool up in different environmental conditions? We would be very interested in that as we simply do not have that data. As far as we know the engine manufacturers have never shared that with any customer, so if you have that it would help us a lot! Data? No. I could tell you that they will go full power in about 2-3 seconds, however. Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted May 19, 2023 Aerosoft Share Posted May 19, 2023 21 hours ago, Raptor05121 said: Data? No. I could tell you that they will go full power in about 2-3 seconds, however. But again, that depends a lot on altitude. Link to comment Share on other sites More sharing options...
ridgey 26 Posted May 19, 2023 Author Share Posted May 19, 2023 1 minute ago, Mathijs Kok said: But again, that depends a lot on altitude. Sorry can I bring this back on topic to my original post which is mostly affected on take off? 1 Link to comment Share on other sites More sharing options...
amahran 608 Posted May 21, 2023 Share Posted May 21, 2023 I figured it out. The engine overshoots the flex N1 target and slowly comes back to it by the time you’re rotating. Makes you wonder why bother using flex temp in that case Link to comment Share on other sites More sharing options...
FailCold 0 Posted June 20, 2023 Share Posted June 20, 2023 I also find that the n1 overshoots. If I set the thrust levers to (for example) 50%, the n1 increases to above that amount and then settles back. Similarly, if I demand a FLEX takeoff, when I push the levers to the TO detent, the thrust value commanded by FADEC goes way past the flex value, and gradually comes back down to the commanded value. I do not believe this is correct behaviour - the FADEC should have (as the name suggests...) full authority over the engines, and not allow them to go over/under. Of course, a small amount of hysteresis is to be expected, but not at the magnitude shown by the CRJ simulation. Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted June 23, 2023 Aerosoft Share Posted June 23, 2023 I know it is one of the issues that will be looked at in the pending update. When you say, " Of course, a small amount of hysteresis is to be expected, but not at the magnitude shown by the CRJ simulation. " is that based on real-world experience? As far as I know, how it is now is pretty much as it should be, but as said, it will be looked at. Any solid information it is not would help us a lot. Thank you for your comment! Link to comment Share on other sites More sharing options...
CRJay 429 Posted June 25, 2023 Share Posted June 25, 2023 On 6/23/2023 at 9:22 PM, Mathijs Kok said: As far as I know, how it is now is pretty much as it should be, but as said, it will be looked at. It is not. In the real aircraft, the max overshoot you would see is maybe 0,2-0,3 N1 for 1 or 2 seconds before nailing the thrust target. It does not go to TO/GA N1 and then slowly roll back. I'd love to show you video reference but for obvious reasons I do not film during takeoff. But for example, at ~2:55 in this video from Just Planes you will see it just nails the N1 target bug without any overshoot. 1 1 Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted June 26, 2023 Aerosoft Share Posted June 26, 2023 Okay, thanks for that info. Link to comment Share on other sites More sharing options...
FailCold 0 Posted September 22, 2023 Share Posted September 22, 2023 Hello Team, as per the above, will the throttle behavioir be improved in the upcoming update? Thanks in advance :) Link to comment Share on other sites More sharing options...
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