AngryViper.101 Posted March 15 Share Posted March 15 Hi I have started to learn the AH-64 However, I recently came across the follow problem. When I am flying, say 140knts at an altitude of around 800feet, collective set to +- 78% Copilot seems to think I am experiencing a retreating blade stall, is this leading me in the right direction? next time I will reduce the engine power to 80% and see if that keeps the altitude? The phenomenon you’re experiencing is likely due to a condition known as retreating blade stall1. This occurs when the helicopter’s forward speed decreases to zero, causing the retreating blade to stall1. In forward flight, the advancing blade (the one moving into the wind) generates more lift than the retreating blade (the one moving away from the wind). This is due to the combined speed of the helicopter and the rotational speed of the blade. However, when the helicopter slows down to 0 kts, the retreating blade’s relative wind speed decreases, reducing its lift1. At the same time, the angle of attack on the retreating blade increases to compensate for the loss of lift. If the angle of attack exceeds the critical angle, the retreating blade stalls1. This can cause the helicopter to start falling and shaking, as you’ve experienced. To recover from a retreating blade stall, you would typically need to reduce power, which decreases the angle of attack on the retreating blade and helps it regain lift1. It’s important to note that this is a complex aerodynamic phenomenon and can be influenced by various factors, including altitude, temperature, and the helicopter’s weight1. i7-11800H @ 2.30GH | 16Gb 3200MHz | GeForce RTX 3060 | Samsung 1TB SSD | KINGSTON 520GB SSD Link to comment Share on other sites More sharing options...
scoobie Posted March 15 Share Posted March 15 I think you're not making yourself clear. The title says "when I pull back to 9 kts", the post says "when I'm flying 140 kts". Is it 9 or 140 then? The quotes you pasted below your post are - most of them - just wrong. Retreating blade stall is not when you approach 0 KIAS, but when going very fast. So at 9 KIAS - no. At 140 KIAS... I don't know (sorry), still haven't got down to Apache properly, but it doesn't sound too fast for the Apache. Check VNE on one of those MPD pages if it happens again (provided that the page on MPD is implemented). If you're above VNE - yes, could be retreating blade stall. But maybe what you're talking about is this... how do they call it... this "hard pull" manouver to go from fast cruise to a hover as quickly as you can? If so, it may be what they call "settling with power" and you just THINK it is stall. Or maybe you slow down below ETL incidentally having too high vertical velocity (downwards) and just enter VRS? Hard to say what exactly you're doing. 2 i7-8700K 32GB 2060(6GB) 27"@1080p TM Hawg HOTAS TPR TIR5 SD-XL 2xSD+ HC Bravo button/pot box Link to comment Share on other sites More sharing options...
Floyd1212 Posted March 15 Share Posted March 15 Yeah, I'm not sure Copilot is doing you any favors with that description. Try Googling the terms "settling with power" and "vortex ring state" that scoobie mentions above, and read up on those subjects from reputable sources. Also, don't ever reduce the engine power back from the FLY position (all the way forward). You can manipulate the collective as needed to fly the helo how you want, but leave the power levers alone. 2 Link to comment Share on other sites More sharing options...
AngryViper.101 Posted March 15 Author Share Posted March 15 okay, i will send a track or next time try and summarise this more clearly ... i7-11800H @ 2.30GH | 16Gb 3200MHz | GeForce RTX 3060 | Samsung 1TB SSD | KINGSTON 520GB SSD Link to comment Share on other sites More sharing options...
Solution Tom P Posted March 15 Solution Share Posted March 15 OP Have you done anything prior to learning how to fly the 64? I.e watch BradMicks Flight lessons? Or are you jumping in treating it like a fixed wing and just doing fast control inputs? How are you going 140kts at 78%? And are you going from 140kts rapidly down to 9kts by pulling back on the stick? Because that would be a bad time. I attached Brad's youtube playlist in my post. I would suggest watching it, as he was a real life Apache instructor. 3 Link to comment Share on other sites More sharing options...
Yurgon Posted March 15 Share Posted March 15 (edited) 12 hours ago, AngryViper.101 said: Copilot seems to think I am experiencing a retreating blade stall, is this leading me in the right direction? Who or what is "Copilot"? Some fancy language model AI thing? Because man is that one horribly wrong explanation that you posted there. As was said before, retreating blade stall is a phenomenon that can happen when the helicopter is flying very fast in any direction (realistically that only happens in forward flight, but as far as retreating blade stall is concerned, the helicopter could just as well be flying sideways or backwards). Just to be absolutely clear: Quote The phenomenon you’re experiencing is likely due to a condition known as retreating blade stall. This occurs when the helicopter’s forward speed decreases to zero, causing the retreating blade to stall. No, just no. This is 100% wrong. Retreating blade stall occurs when the helicopter's speed in any direction is so high that in order to compensate for the advancing blade's lift, the retreating blade must increase its angle of attack beyond the critical angle of attack and, in turns, stalls. As far as I know, the outcome of retreating blade stall would be a very severe rolling tendency plus a very severe pitch-up tendency that can easily get the helicopter out of control and get everyone on board killed. The corrective action when a retreating blade stall is even just suspected is to reduce collective, and then reduce airspeed. The text you posted includes a link to StackExchange, and it looks like the answers given there are 100% spot-on, so it's even more baffling that anyone, or anything, would refer to that and then write the exact opposite of what happens in a retreating blade stall scenario. In any case, a video or a track of your attempt would be very welcome, as that allows us to take a look at what's actually happening. Edited March 15 by Yurgon 1 1 Link to comment Share on other sites More sharing options...
Floyd1212 Posted March 15 Share Posted March 15 3 hours ago, Yurgon said: Who or what is "Copilot"? Some fancy language model AI thing? Yes. Link to comment Share on other sites More sharing options...
AngryViper.101 Posted March 16 Author Share Posted March 16 Thank you for all the advice. I have since changed my Curvature to 35 + and dead-zone on my stick to 5 This has helped and I have to trim and trim and trim, so still learning that a normal stick jumps to center and on the helo you want to force trim to keep the trim position of the cyclic, this has helped me a lot. Landing is another thing I must perfect, can do it now, but it takes me several minutes to put the Apache softly and safely on the ground. Whenever I charge in too fast reducing collective I end up in a horrible situation. i7-11800H @ 2.30GH | 16Gb 3200MHz | GeForce RTX 3060 | Samsung 1TB SSD | KINGSTON 520GB SSD Link to comment Share on other sites More sharing options...
shagrat Posted March 17 Share Posted March 17 vor 23 Stunden schrieb AngryViper.101: Landing is another thing I must perfect, can do it now, but it takes me several minutes to put the Apache softly and safely on the ground. Whenever I charge in too fast reducing collective I end up in a horrible situation. That's why you regularly see real world AH-64D approaching a landing deliberately and gradually slowing down, gently transition to a hover in ground effect and carefully putting it down, instead of gung-ho it and risk a crash. Keep in mind this is a flying tank, not an OH-6 Little Bird. 2 Shagrat - Flying Sims since 1984 - Win 10 | i5 10600K@4.1GHz | 64GB | GeForce RTX 3090 - Asus VG34VQL1B | TrackIR5 | Simshaker & Jetseat | VPForce Rhino Base & VIRPIL T50 CM2 Stick on 200mm curved extension | VIRPIL T50 CM2 Throttle | VPC Rotor TCS Plus/Apache64 Grip | MFG Crosswind Rudder Pedals | WW Top Gun MIP | a hand made AHCP | 2x Elgato StreamDeck (Buttons galore) Link to comment Share on other sites More sharing options...
Yurgon Posted March 17 Share Posted March 17 1 hour ago, shagrat said: instead of gung-ho it and risk a crash To which this pilot very famously said "Hold my beer!"... 1 Link to comment Share on other sites More sharing options...
shagrat Posted March 17 Share Posted March 17 (edited) vor 55 Minuten schrieb Yurgon: To which this pilot very famously said "Hold my beer!"... ...and crashed! I wanted to point out, that you see Apache pilots, usually landing slowly and carefully, as the AH-64D is a tad bit on the heavier side. Examples: FARP landing in Afghanistan, Kumar province and a landing on a gras field for an event Edited March 17 by shagrat 1 Shagrat - Flying Sims since 1984 - Win 10 | i5 10600K@4.1GHz | 64GB | GeForce RTX 3090 - Asus VG34VQL1B | TrackIR5 | Simshaker & Jetseat | VPForce Rhino Base & VIRPIL T50 CM2 Stick on 200mm curved extension | VIRPIL T50 CM2 Throttle | VPC Rotor TCS Plus/Apache64 Grip | MFG Crosswind Rudder Pedals | WW Top Gun MIP | a hand made AHCP | 2x Elgato StreamDeck (Buttons galore) Link to comment Share on other sites More sharing options...
krazyj Posted March 17 Share Posted March 17 and its probably a move he can pull when hes at sea level but in high alt not so much. Anyways, to OP I think you need to go through the training missions, they are good and explain things for you. and `i dont know where on earth you found that absolutely horribly wrong description on retreating blade stall, sounds like something one of the influencers on tik tok would come up with. Have you flown other helicopters in MSFS,XP or DCS before ? 2 Link to comment Share on other sites More sharing options...
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