To Microsoft : Please Give Us A Realistic Rudder!

[Guest]

One response and a General CommentChickenHawk said "... Please note that all the rudders do is cause the airplane to roll slightly which causes the turn (NOT the rudder turning it)."Well, I agree that the rudder will induce roll, which will cause the airplane to turn. But would it turn if you applied rudder but kept the wings level with opposite ailerons? I think it would. (Can't verify it though, as I'm not currently a real pilot. And please note, I'm not suggesting this is the proper way to turn!)My reasons are:1. As I mentioned in my first post, forcing the airplane into a yaw exposes one side of the fuselage to the oncoming slipstream. A C172 has a lot of flat surface on its side, probably about half as much as the wing, so surely this is going to cause side pressure.2. With the airplane in the yaw'ed position, the thrust from the propeller is no longer aligned with your direction of flight, but pointing slightly in the direction of your yaw. The lateral component of the thrust will pull you around in a turn.General CommentHere's an interesting thing to try: Do a low pass directly over the edge of a runway. As you cross the threshold, try various techniques to get over to the other side of the runway, and see how long it takes you. After you've done the pass, pause and do an instant replay, from top-down view. Note how long it takes for ANY lateral movement to begin (D1), and the total distance required to cross the runway (D2). Here are my results, crossing a 75ft wide runway flying a C172.Method  D1  D2Light rudder pressure (minimal roll)  1000ft  3000ftMedium rudder (induces roll)  800ft 1800ftHeavy rudder pressure, but keep wings level 1800ft  4000ftDo you think this is realistic? I don't. In general I think lateral movement should begin almost immediately, and based on my limited time in a real plane, I would guess you should be able to cross over to the other side of the runway in a couple hundred feet, although the third method might take a bit longer(?). Anybody care to go try this in a real plane? (Mind you don't try anything if it's dangerous, especially that third one)Russ

[Guest BP]

I agree wih Charles brief sumation. >>I remember this to be real bad when flying the Cessna 310 which has tip tanks and a rather small vertical stabilizer.<< Yikes, unrelated, but I watched in horror, a lineman top off a Lear 35, RIGHT TANK FIRST! Damn near killed himself when the a/c began to lean (left strut nearly fully relaxed)....AGAINST the Fuel truck!He missed the hint something was wrong when he failed to notice himself stepping down one rung at a time on the step ladder as he happily pumped jet fuel into the tip tank. HAHA! "The trick to flying is cordinated rudder/aileron". I.e. Standard bank, rudder + aileron, establish the bank, neutralize the rudder, is basicly the way it goes. Use the slip indicator, aka Needle and ball to oppose any slipping. I also use the rudder quite often to make adjustments during IFR approaches. Also, contrary to popular belief, you can quite literally fly a race track pattern using only the rudders. I wouldn't recommend it to new pilots as it requires frequent trim and throttle adjustments, but it proves the theory that, "Yes, The rudders can and do something." During my instructor years, aside from students having difficulty landing/taking off, the other problem I had was convincing them to use the rudders. :-) Light aircraft tend to hide the need for them and so many fly off over the horizon never really using them (except for taxing around the airport or worse, understanding their "true" purpose.

[LAdamson 240]

> Also, contrary to popular belief, you can >quite literally fly a race track pattern using only the >rudders. I wouldn't recommend it to new pilots as it >requires frequent trim and throttle adjustments, but it >proves the theory that, "Yes, The rudders can and do >something." Then the Dreamfleet ArcherII passed! :) I kept it in a nice racetrack pattern with rudder, from tower view, thanks to many past years of R/C aircraft racing. It did tend to climb when applying opposite rudder for the "straight away", which had to be quickly adjusted with forward pressure & trim. As to how much a real aircraft would tend to climb.........................I can't say. I just havn't done any rudder only real life race track patterns. But I'll make a note to try it.L.Adamson

[Guest aca_dia]

Many GA aircraft will snap back from being yawed in many situations. Also your statement about aerodynamics is a bit off. When you first yaw the aircraft left or right the flight path of the aircraft does not necessarily change(you are merely changing the direction the nose is pointing). The side of the aircraft now exposed to the relative wind them may demonstrate some keel and even some vane tendencies and help the aircraft point into the relative wind again. This would be a form of positive static stability (about the vertical axis of the aircraft). The aircraft does not

[Guest]

>The side of the aircraft now exposed to the relative wind >them may demonstrate some keel and even some vane tendencies >and help the aircraft point into the relative wind again. Not if you maintain rudder pressure, which is the situation I was talking about. >The aircraft does not

[Guest Ferer five]

I'm talking about sustained >rudder pressure. >The whole boat (side of the airplane, >get it?) has now become a rudder, held in that position by >the "little rudder" at the back. Due to the density of the >water, the boat will change direction. >>The same affect will happen with an airplane moving through >the air, except air is much thinner so the affect is much >less. >>Russ Big difference, though. A boat won't sink if you keep rudder pressure but an airplane will eventually spiral to its demise if you keep a lot of pressure applied because of the coupled roll resulting in an ever increasing spiraling skid. In fact it's a very similar situation to the loss of one engine on a twin where the line of thrust is suddenly offset laterally from the CG. Twin training is mostly about that: at high engine power setting if you loose one engine and delay any corrective action, the plane will quickly yaw towards the dead engine and at the same time roll over towards that same dead engine because of added lift on one wing. This usually result in deadly accidents because of the very quick and total loss of control. The remedy is a prompt application of a lot of rudder and some bank towards the good engine.In short, in real flying, do not attempt sustained firm rudder application. As I said above, roll and yaw are cross-coupled through more than one mechanism, which is why lateral stability is the result of a number of design trade-offs.Charles

[Guest aca_dia]

You are certainly correct that you can cause an aircraft to eventually turn if you use only rudder. The turn however will be a horribly uncoordinated skid and the same resultant aerodynamic effects I mentioned in my last post will still cause the nose of the aircraft to move back towards the relative wind if the rudder pressure is released. I tested this in a real 172N this morning by holding nearly full rudder for 30 seconds and releasing it (AKA a forward slip & by the way you need a fair amount of opposite aileron control to prevent loss of control of the aircraft). Your original post questioned why there is snap back effect and that the rudder in MSFS is not realistic. I find it to be fairly accurate for the GA aircraft I fly.Also your connection with a boat rudder and an aircraft rudder is not a 100% accurate. Yes a boat rudder works much like an aircraft rudder (Air & water are both fluids and the same dynamics apply). When you move the rudder on either craft you change the chord line of the vertical stabilizer on the aircraft or a portion of the keel/rudder in the case of the boat (boat keels and rudder designs are considerably more diverse than most aircraft so lets not go there right now). This change in chord line increases the angle of attack on one side or another of the keel stabilizer or keel/rudder. The resultant is that side begins to produce lift that moves the vertical stabilizer or the aft portion keel/rudder in that direction. The difference is that a boat is moving in effectively a two-dimensional plane and has a hull that is designed to take advantage of this force not resist it. We can also get into the different types of stability, buoyancy, etc which also separate how a boat differs from an aircraft.The basic point you have to recognize is that with most aircraft the inherent stability that is designed and built into each aircraft counters the same attempt to use rudder alone to turn the aircraft. Yes you apply a similar force using the rudder on a plane, but the aircrafts design & stability resists the turn. Sorry if my descriptions are bit off. It

[Guest byoung]

Well folks,I have been using MSFS since 1985. The improvements have been great over this period of time, no doubt.The key is Microsoft's philosphy about MSFS....Is it a Toy or a Simulator? Is it a Game or a Simulator?As soon as the line is drawn and more importantly understood by Microsoft, then "real development" can take place. Then they need to hire real "Flight Simulator" programmers and use the current game programmers to enhance the scenery, etc.Until then, for now, I believe Microsoft consideres MSFS just another game.FS 2004 wil be the real test.X-Plane is making a good run, but still lacks good ATC functionality and scenery. But my understanding is their flight dynamics are pretty close.Just my two cents worth...Barry

[Guest nirvana]

deactivate "auto rudder"!

[LAdamson 240]

> I tested >this in a real 172N this morning by holding nearly full >rudder for 30 seconds and releasing it (AKA a forward slip & >by the way you need a fair amount of opposite aileron >control to prevent loss of control of the aircraft). Your >original post questioned why there is snap back effect and >that the rudder in MSFS is not realistic. I find it to be >fairly accurate for the GA aircraft I fly. >I was hoping someone would do this.........thanks!I didn't yet get a chance too.L.Adamson

[LAdamson 240]

>As soon as the line is drawn and more importantly understood >by Microsoft, then "real development" can take place. Then >they need to hire real "Flight Simulator" programmers and >use the current game programmers to enhance the scenery, >etc. >>Until then, for now, I believe Microsoft consideres MSFS >just another game. >I believe they already HAD some real "flight programmers", and in fact, I know they did, and probably still do! I've always maintained that I could get from point A to point B even in the defaults with little or no trouble, and that the controls work generally as they should. Even speeds will match close to the book. Some simulations I've run into are so off, it's not even worthwhile attempting to fly. Am I saying that everything will happen in the simulated default twin that could possibly happen in the real one......................NO! MS doesn't carry it that far, and of course that apparently irritated some beta-testers!I don't think it's Microsoft's place to create "text book" airplanes where everything becomes as real as possible. The 3rd parties are already spending those extra thousands of hours to create specific aircraft to our own particular tastes.And if Microsoft just considered this a "game", instead of a product that would appeal to real pilot's or those interested in real aviation................would they have bothered buying the rights to Jeppeson for real navigation and airport data? Or how about topography and real weather?As an example, just go back to the original default Cessna Caravan. We had hundreds of opinions on what it should fly like---------including a heavier feel than the 182's. Then it turns out it had spoilers (visually modeled by MS)to assist the ailerons, and that the "feel" is actually closer to a 182! Even real Caravan pilots commented that the numbers were close. My main complaint of the defaults was "dampening" in pitch and roll. But this was quickly taken care of by a few add-on files. But at least judging from the Caravan model, it's obvious that someone from MS had an inkling of what's going on........L.Adamson

[Guest aca_dia]

"I was hoping someone would do this.........thanks!"Yeah when ever you forward slip most GA aircraft (everyone I have flown including twins) the yaw will only stay in for as long as you hold the rudder. I remember on my CFI check ride I had to do a steep spiral to a power off 180 over a runway and land to commercial pilot short field landing specifications (Within 100' after a specified point). Well my planning during the spiral left me high at crosswind above the runway (but to low to spiral again). Due to strong winds I did not do a great job adjusting my pattern to fly a normal 180 and was very high on final. I can still remember the examiners words

[LAdamson 240]

>I find the >rudder model is particularly good when side slipping the >aircraft for cross wind landings. Seems just like the real >thing.Yes, I remember a few months ago where I was side slipping the default 172 (with Ron Friemuth's flight model) for some testing and pics............. and it really did seem quite authentic.The RealAir SF260 seems so real when slipping to loose altitude, that I nearly jump for joy!!! NO KIDDING!! :) I can keep it pointed where I want, in total cross control & when the releasing control pressures it behaves just like the real thing.L.Adamson

[Guest Dean]

>I don't think it's Microsoft's place to create "text book" >airplanes where everything becomes as real as possible. The >3rd parties are already spending those extra thousands of >hours to create specific aircraft to our own particular >tastes. The biggest improvement Microsoft could make would be to expand the capabilities within the simulator's A/C systems. This way the developers can achieve the desired results without the extensive trickery they have to employ now. This was one of the core features of the Fly A/C that the developers loved. Dean Karis

[Guest]

I see now that my initial analysis of the shortcomings of MSFS flight dynamics pertaining to the rudder was incorrect. I was focusing on the snap-back effect and calling for it's elimination, but I no longer think that is the real problem. Several people have asserted that real GA aircraft will always exhibit snap-back when rudder pressure is release, and I agree with them.There is one important question though. What will the aircraft snap back to? I think it is clear it will snap back in such a way as to align itself with the current direction of flight at the moment the rudder is released. This is due to the keel effect which someone mentioned earlier. It WILL NOT snap-back to it's original heading, because between the time you apply rudder pressure and the time you release it, the aircraft will have turned, unless it was a very short application of rudder.And therein lies the problem with MSFS, I believe. When you apply rudder pressure, the aircraft is VERY RELUCTANT to turn. It takes at least 5 seconds of sustained application of light rudder pressure before any appreciable amount of turning takes place. (See post #15 above). My experience flying a real C150 was that the airplane began turning almost immediately.I realize that this is of no concern to some of you, as it is apparent that not everyone uses the rudder to make small heading changes. However, several people have reported in this thread that they were taught by their CFI to use the rudder for this purpose, so it would be nice if MSFS modeled this a bit more accurately.Thank-you all for your helpful comments. Russ