AcroGimp

No worries Yo-Yo, happy to wait but I said I would check these behaviors out and wanted to follow-up. If you have an internal build with more accurate stall behavior as well as the functioning trim tab then I expect when that build makes its way to the users we'll see an improvement. Actually glad to know that this is the case since this is inaccurate as-is - better to know it is truly incomplete then to find out ED thinks it is complete/correct. With respect to altitude I flew today's session at same altitudes I fly them in real world 1800-2800 M so no difference of distinction there in my observations. 'Gimp

So spent a little time this afternoon with advanced spin and inverted flight performance and observed a mixed bag. I recorded the flight but am not going to post it since most of the behavior was incorrect. Power On Spin The Power On Spin was close to correct. The airplane displays a real desire to continue flying with power on and the deck angle will be surprisingly high. When it did finally depart it was classic over the top and to the right even though I had been cheating with left rudder, I reversed rudder input and it developed through the incipient phase, I removed power and recovered uneventfully. Inverted Spin The DCS model lacks sufficient elevator authority for inverted spin entries which is wholly inaccurate for the real plane, I've flown entire sorties focusing only on inverted spins and know that at essentially any weight it will give you a clean inverted entry. I tried even with full nose down trim and it was still not enough stick authority to force the inverted departure. ED has work to do here. Flat Spin The Flat Spin mode is close but not quite correct. Entry is from a low energy entry into a botched Hammerhead. As with ALL spin modes observed now, the nose is too low which is I think keeping the airspeed artificially high and probably effecting AOA needed for spin. Rotation rate was close, maybe 80-85% correct. Link below shows a Flat Spin in the real Yak. Aggravated Spin Out-Spin Aileron causes a reversal into a spiral dive in the direction of the aileron regardless of rudder and elevator position in the model which is not correct. In-Spin Aileron was closer to correct in that it accelerated the spin rate of rotation and flattened it out a little, still too nose down - and not correct for aggravated spin in the real Yak. Link below shows an Aggravated Spin with Out-Spin Aileron in the real Yak for comparison. Crossover Spin The Crossover Spin is a mode that actually kills people in the Yak because they miss the crossover and end up riding the plane into the ground. Due to inability enter an inverted spin from a low energy situation, the DCS model is not capable of a Crossover Spin at this time. Link below shows a Crossover Spin in the real Yak (@1:05 in). Stick Snatch/Snap I did wind-up turns in both directions and the stick-snatch/snap behavior was accurate and well modeled, recovery is simply unload the stick a fraction and the model recovered just as the real Yak does. Overall, the more advanced handling characteristics appear to need a lot of work in order to be a reasonable approximation of the real plane and of any training value, especially inverted and spins. 'Gimp (DISCO vVMFA-122)

Here is my current POH/checklist for what it is worth. Got too busy having fun, never finished it, can share Word file if interested. 'Gimp (DISCO vVMFA-122) Yak-52 888306 PCL-V1.1-DRAFT.pdf

In the real plane you do NOT move the Mags switch until the engine is running, the starter switch energizes the start solenoid that lets high pressure air into the start spider and into the cylinders in sequence, it also energizes the 'shower of sparks' which bypasses the magnetos and makes all the plugs active with extra impulses for a good start. In DCS I haven't mapped the Mags switch to HOTAS and need to move the switch prior to the starter button. 'Gimp (DISCO vVMFA-122)

Two thoughts: One, DCS/ED have been alerted by multiple experienced P-51 pilots that the current P-51/TF-51 models are all wrong for ground handling and take-off, no changes have occurred. Put another way, the models in DCS are reportedly significantly harder to handle than the actual airplane according to several folks I know with substantial P-51 time. Two - the real world Yak-52 requires a LOT of rudder input to remain in control and is actually an excellent trainer preparing for higher performance taildraggers. In DCS the rudder and yaw performance are not quite right yet but it does require a pilot pay attention to what they do with their feet and I would think even in its' current state would help someone get betterwith rudder use prior to stepping up to the TF or P-51 Mustangs. I don't have the other WWII props so can't speak to them but the TF-51 is terrifying compared to what I have heard about the real plane from friends with again, a lot of experience in the real thing. 'Gimp (DISCO vVMFA-122)

Finally had a chance to fly the Yak-52 again. I stand behind the bulk of my previous statements and critiques - what ED has gotten right they got really right, sounds with a couple noticeable exceptions, visual model, etc., most of the aerobatic performance and handling is close. There are major issues with drag when configured, airspeed under specific power settings are off, and the rudder trim issue which has been commented on ad nauseum. Specifically when configured for landing the drag for gear and flaps seem to be very off, should not require essentially full power to maintain level flight. I trust this will mature into a very fun and useful module and hope the critique is taken in the spirit it is intended. Happy to answer questions and appreciate suggestions for the video. I will record a separate video on advanced spins and aerobatics later when I have more time. 'Gimp (DISCO vVMFA-122)

Easy setting is 82% RPM and throttle as required but usually less than 800 mmHg, this is good for aerobatic and formation flying. High Speed Cruise is 70% RPM and whatever she'll give you for MP, oversquare is OK Economy cruise is 65-ish %, mine won't govern down below that, and it gets slow I cruise at 70% and near WOT for best economy while still seeing 120-130 kts at ~14GPH of Avgas and 1-1.5 qts of oil/hr, 6,000-9,500', plan on 90 minute/160-170nm legs 'Gimp (DISCO vVMFA-122)

I want my Yak. 'Gimp (DISCO vVMFA-122)

Due to the moment arm from sitting about 6 feet behind you, a GIB (guy in back) makes a substantial impact on cg and is most noticeable in the resulting pitch sensitivity. With a light pilot and heavy GIB you can get to the edge of the envelope Aft, especially with the old Russian avionics gear still behind the back seat. The pitch snatch/snap becomes far more prevalent if you ask too much of the wing but most importantly stick force per G gets VERY light which leads to more accidental excursions into the snatch/snap behavior. There is way more pitch authority in those massive tailfeathers though than would be needed to overcome any out-of-trim situation clean or configured - it might take a heavy push or pull but my experience is the trim is marginal and can always be overridden by the pilot. The speeds reported by @bbrz all sound about right although I can easily get 250 kph in level flight at 82% RPM and maybe 700-ish mmHg, happens when we have a T-34 leading and they let the plane run out a little - we keep formation speeds at 200-220 kph to give a power margin to whoever is on the outside. 'Gimp (DISCO vVMFA-122)

Yak flaps are very draggy, as is the gear when extended - especially with prop set fine/high RPM - it will take a fair amount of power to maintain level flight at 150 kph if configured. For the overhead, I break at 250-ish kph, decelerate on the downwind, gear at 200 kph to hit the perch at 170 kph with gear extended usually at 1600' MSL (1,200 AGL), I will drop flaps and initiate a dogleg to the runway - typically have to add a little power past the 90, prop full forward on short final, touchdown at 120-ish holding nose wheel off. I have only made one landing so far in the DCS Yak, it was a normal landing, not the overhead, and drag/performance seemed close, nothing stood out anyway as grossly incorrect. So long as the identified issues get addressed this will be a fun and useful module with real training value for formation since it lacks the kind of gross excess power the tactical aircraft have - makes you learn the visual geometry, patience and airmanship that 'easier' aircraft will not teach. Should be very good for formation acro IF/when fixed since the real plane is fantastic for it. 'Gimp

In real Yak you have to squeeze the brake lever then set a lever lock that holds it full on. Ideally the brake lever should be a slider, on/off results in a lot of tire squeal. 'Gimp (DISCO vVMFA-122)

+7 to -5 G limit load at gross weight, Yak is strong like bull! 'Gimp (DISCO vVFMA-122)

No I get that @aaraon886, the issue is the plane's behavior is not fully consistent with the tab not being effective either, since it feels right at slow speeds when upright (e.g., takeoff, climbout), but it is not quite right when inverted or when fast it seems there may be more going on than just the tab. Like I said though, I'm happy to wait and see if the tab change and any other updates improve it, I have high hopes for this module but find the current behavior unexpected given the reported origin of this module. Could be an artifact from porting if originally developed for a different engine, etc. 'Gimp (DISCO vVMFA-122)

I'll accept the terminology confusion on what you meant about 'trim position' and I see a slight reduction with respect to required rudder input in your screengrabs but if that is the case then the module does not require enough left rudder for slow speed because without the trim tab influence MORE left rudder would be required in real life. It felt close to right to me on takeoff/climbout but during a figure with big speed changes like a quarter-clover, loop, cuban-eight, etc., there is a massive change in rudder input throughout the figure in the real plane and that is not currently modelled correctly. If you think the tab effect will correct that behavior then I am happy to wait for it to be implemented and revisit the issue. I did note that during loops and quarter-clovers the speed bleeds off a little faster than real plane and I felt that the required left rudder during those phases was unrealistically low - so I suggest there may be more going on than just the tab not being effective, since that should have resulted in more left rudder being required, not less. Thanks for replying. 'Gimp (DISCO vVMFA-122)

@Reflected, trim for takeoff with two aboard sees the trim tab on the left sidewall pointing down about 45 degrees as I recall. The flaps are split flaps so pure drag, no lift, it requires a push on initial deployment but settles down pretty quick. Rapid moves of the prop or throttle lever result in very noticeable changes for acceleration/deceleration - the blades are almost a foot wide and basically 8 feet from tip to tip, it is a giant speedbrake. At mid-speed going from coarse to fine can actually result in acceleration depending on manifold pressure. I don't use a lot of trim since most of my flying is all around the same speeds, I set takeoff trim, set once for a slight nose down condition when in formation or aerobatics since it lets me be more precise with my pitch inputs, and I don't re-trim after the break on the overhead, just make it do what I want down to the ground. 'Gimp (DISCO vVMFA-122)

The real Yak will use a blocker panel in the oil cooler inlet for true cold weather winter ops, I can't barely get mine over 50 C in the winter time in SoCal. Have had to sit and warm-up for 15+ minutes occasionally just to get to where I was safe for run-up. 'Gimp (DISCO vVMA-122)

First off, there is no in-flight trimmable rudder on the Yak-52, it is a fixed tab so it is only ever truly 'in trim' at one speed. For most Yak's in the US this is set at 110 kts (~202 kph) because that is our typical formation sortie speed that gives us plenty of performance margin. The movement of the nose as speed/power change is caused by P-Factor and the slipstream effect. As speed increases that fixed tab becomes less and less effective until such time as it is nowhere near enough and opposite rudder is required to remain coordinated - in EVERY Yak I have ever flown, significant RIGHT rudder is required to remain in/near coordinated flight above 250 kph, ALL of them, no exceptions - it is just like, but opposite, for EVERY Western aerobatic aircraft I have EVER flown (Citabria, Christen Eagle II, Glasiar I, RV-4, RV-6, RV-7, RV-8, Great Lakes, Extra 300L), which ALL require right rudder on takeoff but left rudder as speed exceeds that neutral rudder trim speed. If DCS is not modelling P-Factor and Slipstream effects then that would explain it, but if it is modeling P-Factor and Slipstream effect then it is doing it wrong at-speed for this module, it is currently correct on the ground and during takeoff.slow speed flight based on observations so far. 'Gimp (DISCO vVMFA-122)

With respect to manifold pressure I am not talking about on the ground, I am looking at airborne - 1,000M - 1,500M and Max Cont Power (82% RPM) which is my typical altitude and power setting for a formation sortie - my tired 1400 hour engine produces about 75 mmHg more MP than the DCS module, I need to bump the DCS Yak up to 90% RPM to get close. The power issue is, IMO, a minor issue, the speed/yaw behavior is completely inaccurate, literally the opposite of reality. I may not be able to login (mobile won't recognize my password) but if I can I'll continue while Wifey drives us to Big Bear and I 'work' on the laptop. 'Gimp (DISCO vVMFA-122)

Let's the instructor fail the brakes from the back seat, scares the crap out of you since brakes are for steering as well. 'Gimp (DISCO vVMFA-122)

Yes, to be similar to my real world environment near San Diego I took off from Henderson (KHND) in NTTR. I think the engine is running about 75 mmHg low on available power which is substantial as well, and my engine is tired at 1400 hrs TT. @Beta Sokoi, the Yak oil temp is tough to manage in extreme cold, typically there is an actual blocking plate for the oil cooler to restrict air flow in. Best approach, and keep in mind all of my Yak time is in SoCal so I don't have cold temp issues - best approach is warm engine up (gills closed) with oil cooler door fully closed as well, but I think the Caucasus missions will always suffer from cold oil temp in winter conditions. In SoCal I see oil temps of 55-80 usually, able to safely runup after 5 minutes usually. CHT and oil temp do seem to be behaving accurately in the DCS Yak Module. Heading out for Big Bear Lake, will be back on later. Again, I am offering this up as hopefully constructive criticism, I want to like this module and I want to get my Yak's paint scheme skinned on it. 'Gimp (DISCO vVMFA-122)

Yo-Yo, the issue with speed vs Yaw is that no Yak I have flown, and in addition to mine I have flown at least 7 others, plus Nanchang CJ-6's which are 'somewhat' similar ALL require lots of left rudder on takeoff, and the DCS Yak does seem to have that correct, but as speed increases, usually past about 250 kph (~125 kts) in mine, it starts to require right rudder to remain in coordinated flight, but especially at any speed at or beyond 300 kph such as you see on essentially any downline for an aerobatic figure it requires a substantial amount of right rudder - this would be left rudder in the other aerobatic planes I have flown like the Citabria, Christen Eagle, Great Lakes Biplane or the Extra 300L but that is because their engines rotate clockwise, opposite the Vedenyev in the Yak. This behavior is totally incorrect and seems to be outside the laws of physics. Given the reported origin of this project I simply cannot believe this behavior is present because anyone who has flown the Yak in real life would notice it about 5 minutes after takeoff. I did figure out the start issue as ED has the ignition switch in the rear cockpit set OFF as default, that switch is safety-wired ON in my aircraft since I cannot control people in the back seat. Start behavior is correct, the sound is still all wrong. 'Gimp (DISCO vVMFA-122)

OK, flew it again, still unable to get it started with my real world procedure. Curves at 15 for all 3 axes, no deadzone feels close. Roll rate is maybe 10% optimistic, should be 160 deg/sec as I recall. Taxi, takeoff and climbout, stall and spin behavior are all close, incipient spin is too nose down and initial rate of rotation too high but pops out with proper spin recovery - power off upright explored, will check advanced spins when I get back home on Sunday (power on, aggravated and flat, both upright and inverted). Verified that the speed/yaw behavior is BACKWARDS, I have a screengrab which is feet on floor at nearly 350 kph, that should require ~2 inches of right foot to counteract, it indicates it needs left rudder on both slip/skid balls. Fix that and start sounds/behavior and it will be a good start. 'Gimp (DISCO vVMFA-122)

My Yak lacks enough nose up trim authority to duplicate this behavior but from a pure aerodynamics/physics point of view it should continue to slowly pull up until reaching either the trim neutral speed for that trim setting or critical angle of attack at which point it would mush or actually stall/break. 'Gimp (DISCO vVMA-212)

First off my qualifications: FAA licensed commercial pilot, ~700 hrs total time, 350 in Yak-52 which I have owned for 3 and half years. I am a member of the Red Star Pilot's Association, I hold a Formation Wingman Card and am working on upgrading to Lead. I fly weekly, formation, aerobatics, I lead a casual 3-ship formation aerobatic team, and I even take her out for the occasional $200 hamburger or very short trip. Initial observations as follows from a 10-15 minute free flight: - Airplane does not start like my Yak, my start procedure is simple, straightforward and based on DOSAAF training, I was unable to start Yak on multiple attempts - Start sounds are completely wrong, the pneumatic starter has a very unique and easily recorded sound - this is an instant immersion breaker - Engine rotation on start unrealistically slow - Energy retention in vertical upline maneuvers is incorrect, bleeds off too fast - this shows in quarter clover up, vanilla loop, cuban eight with entry speeds to 400 kph, I know that I can loop the Yak down to 210 kph entry speeds (it is very small edge of stall loop but still - thanks Gennady!) - Engine power seemed off, should have no trouble developing ~750-800 mmHg manifold pressure at 1000m wide open with RPM 82% and it was down around 600 - There is something VERY off for rudder/yaw modeling - aircraft should require an increasing amount of right rudder when speed increases, the model requires left rudder which is literally the exact opposite of real life - Aircraft should require more left rudder over the top when slow - All 3 axes feel WAY too light but I will try curves to tame that - Roll rate 'felt' fast but that could be result of no curves - I'll time it and see how it compares to real world - My Yak has NEVER thrown a wingtip vortex, not once, ever, under any conditions or load - the prop on the other hands throws a beautifully wicked spiral vortex under heavy load in the right conditions It's not all bad news though: Cockpit and exterior models are fantastic, very true to life - in VR it is exactly like sitting in my Yak. In-cockpit sounds when flying are pretty good. The snap/snatch is very well modeled, this is a unique characteristic of the Yak that catches new Yak pilots by surprise and it is exactly as I experience in my Yak when I ask too much. The post stall/ballistic behavior is also very well modeled and matches my experience. Happy to discuss these observations further if requested. As I said, initial impressions based on a short free flight since I could not get the plane started - some may be addressed with control curves but there seem to be some foundational and critical errors in the flight model that I hope can be fixed - I want to enjoy this model. 'Gimp (DISCO vVMFA-122)

Find the recommended WH curve, it seems to work well for my T.16000M TWCS throttle. DISCO