dutchroll Posted November 24, 2015 Posted November 24, 2015 Have to admit that "steering with rudder" on final approach is an anathema to me. Doing that during basic military flying training would've earned you an uncomfortable debrief. Adjustments on final approach were by way of "heading change", done the classic way. Steering with rudder on final approach in a big jet would probably earn you a "what the $@#* are you doing??" (and it really does screw your approach up quite a bit). So either way on those aviation career paths, it's beaten out of you very early. Note that this doesn't preclude sideslipping, if the circumstances warrant it. Just that gross sideslipping was very frowned upon as a "normal" procedure. Emergency, yes. Normal, no (with the exception of setting up the sideslip at some point if doing it for a crosswind landing of course). For crosswind landings, either the "crab" approach technique or the "sideslip" approach technique are perfectly valid. Some planes prefer one over the other, e.g., for those which are geometry-limited and you don't want any significant bank angle at touchdown, the crab approach is preferred and taught. For others, especially smaller GA aircraft, the sideslip approach is normally taught. Both can bring you unstuck if you're not taught well and/or don't do it properly, and various types of mishandling on final approach can cause you to depart controlled flight, hence the importance of good solid instruction and competency in stall recoveries, etc. As for stalling and spinning it into the ground, the guy who test flew mine put it nicely (and being a graduate of the US Navy Test Pilot School at Patuxent River, he would know): "it won't spin if you don't let it yaw, no matter what else you do". 1
Yenn Posted November 24, 2015 Posted November 24, 2015 How do you control descent on finals if you have an engine failure. don't have flaps and don'tknow how to use the rudder? Correct speed for a normal approach is usually quoted as 1.3 * stall speed. With gusting wind you may well stall if doing that speed, or at least drop a wing and aileron is not the way to recover. There seem to be a lot of pilots around nowadays that don't know how to use the rudder.
Pearo Posted November 24, 2015 Posted November 24, 2015 Pearo, you were asking me about practicing techniques at altitude - the only one talking about a wingdrop on final is you.What I am suggesting is that it is highly unlikely I am going to stall on final (when already aligned with the runway and not turning) because I am using rudder to keep aligned with the centreline. The rudder inputs required are minimal. And if you have flown an aircraft like the J160 which exhibits noticeable adverse yaw, it is more straightforward (at least for me) to use gentle rudder inputs to remain aligned with the centreline rather than a number of coordinated aileron inputs. So, I don't understand all the hoo-ha - it is not like I am steering around the circuit with rudder! I am still making coordinated turns in the circuit. And last time I checked, side slipping is still a standard manouver for aircraft without flaps, and is very useful technique for aircraft with flaps. Even the wing down /combination crosswind approach requires a slip. The thing is, people do stall on final. It happens, there is enough accidents in the past that show it. My suggestion to people to see what happens when you stall out of balance is to show that a wing drop or incipient spin is a very likely outcome. As I stated earlier, this was just to prove the point that flying out of balance can be dangerous. Further to my point, if you are low and slow, then why risk it? I personally like to reduce my risks when flying.. Now I say that flying out of balance CAN be dangerous, but that does not mean it has to be. I just last week slipped an aircraft all the way to the ground during a simulated engine fail, not once was I anywhere near stall speed, however I was acutely aware of my airspeed the whole time.
2tonne Posted November 24, 2015 Posted November 24, 2015 I guess you are right, it is only by some miracle that I haven't ended up a smudge in a paddock somewhere... If I was routinely flying final that close to stalling that slight rudder pressure (I'm talking ball not outside the goal posts) would put me into a stall, then I would give it all away right now.
Pearo Posted November 24, 2015 Posted November 24, 2015 I guess you are right, it is only by some miracle that I haven't ended up a smudge in a paddock somewhere...If I was routinely flying final that close to stalling that slight rudder pressure (I'm talking ball not outside the goal posts) would put me into a stall, then I would give it all away right now. Like I said, people do it. It happens. Plenty of accident reports about it.
2tonne Posted November 24, 2015 Posted November 24, 2015 I'm not so sure about the plenty of accident reports. Granted, stalling on base to final turn is recognised as a problem, but I am not aware of too many stalls on final other than perhaps the rare stretching the glide after engine failure. 5
Teckair Posted November 24, 2015 Posted November 24, 2015 What started all this was an incident that happened to me. I was doing a tailwheel endorsement for someone who over shot the base to final turn, his reaction was to stand on the left rudder pedal this caused a severe yaw. Before I knew it my bum was trying to escape the seat, the ball was hard over to the right, when I tried to sort the situation out he told me he had been trained to fly like that. We had enough airspeed to survive that time but if that happened at a slower speed then..... As for people who say it is too hard fly final balanced I disagree I have always done it and I do not snake all over the place. 1 1
2tonne Posted November 24, 2015 Posted November 24, 2015 Yikes! That manoeuvre would have scared the .... out of me.
Teckair Posted November 24, 2015 Posted November 24, 2015 Yikes! That manoeuvre would have scared the .... out of me. Instructors have to put up with stuff like that and the money is not worth it.
SDQDI Posted November 24, 2015 Posted November 24, 2015 What started all this was an incident that happened to me. I was doing a tailwheel endorsement for someone who over shot the base to final turn, his reaction was to stand on the left rudder pedal this caused a severe yaw. Before I knew it my bum was trying to escape the seat, the ball was hard over to the right, when I tried to sort the situation out he told me he had been trained to fly like that. We had enough airspeed to survive that time but if that happened at a slower speed then..... As for people who say it is too hard fly final balanced I disagree I have always done it and I do not snake all over the place. I don't think anyone is arguing about the base to final turn, even those pro rudder on final say that all turns in the circuit should be balanced. I do prefer to setup holding my line with rudder for at least the last 100feet, earlier if it is windier just so I get a feel for how much wind and obviously on the really windy days it helps me to know if I have enough rudder authority to do the job or if I need to change technique (less flap and a bit more speed). I have used the crab and kick technique but find it a lot more workload for the same result.
Phil Perry Posted November 24, 2015 Posted November 24, 2015 Yep - I was being polite and not directly pointing out that 3 axis 'rudder' flying on touchdown in a WS will end in the beasty having a lay down on its side on the runway to rest ... and that is far too common ... and I came to 3 axis flying through hang gliders so in air control of a WS was not an issue ... but had to unlearn the rudder and really focus on nose straight on short finalYep - the upwind flick works on the 100hp beasties as well as the 50mph older stuff ... but to be frank a lot of the newer WS pilots who have never flown light slow WS tend to use the nice sprung underarriage and just land it a bit skewed and let the trike take the punishment (not great because the wing stress on the top of the pole as the wing (60kg plus of it) swings around a lot and you end up replacing the monopole and/or twisted hang brackets at annuals a lot more) Yep the Flash 2 is an interesting beast to fly - and agree - the stall is easy to find and demo ;-) I fly my Raven wings on my trikes here and my new Currawong is ready to go out and run around the sky ... once I weigh it and get it registered If you get it the Curruwong is a small Australian Raven ... and my Currawong wing is a 9m span 11.5m^2 Raven type wing ... will be fun to see how it flys on a direct compare with the Raven wings - I have three trikes - 40hp, 50hp and 100hp and 4 wings - mix n match ;-) Woo Hoo! Most interesting Kasper,. . . I wonder if you've encountered the "Chaser S" a lovely little single seater, originally fitted with a Rotax 377,. . .I used to fly one of these regularly as the owner was terrified by it, as the wing is so small, but with my current fat barstard weight, I doubt if the thing would takeoff at Heathrow or Gatwick now . . . maybe with a sawn in half 912. . .? The Raven. .. yes, I helped my mate Johnnie Carter to rebuild one he'd bought after it had been bent a bit,. . .lovely light thing to fly,. . two fingers and a thumb was all that was required. . . and that top fin was huge compared to the Mainair kites. . . as with the early Pegasus aircraft. . . I ferried a Peg XLSE2 once from a farm near Glasgow down to the Midlands for a friend, and it was an absolute delight to fly. . .got to be patient of course, with a 45mph cruise. .! But what the hell,. . .If you're enjoying the flight, it doesn't really mattter, and the landing speeds on those things were beautifully slow in comparison to modern hotships. . . Still love the old stuff mate. . . .probably goes with me age and attitude. . . . Phil.
Phil Perry Posted November 24, 2015 Posted November 24, 2015 Yikes! That manoeuvre would have scared the .... out of me. Nah,. . .not scary at all. . . .until you witness someone do it at a lower speed,. . . . . . . . . . .
facthunter Posted November 24, 2015 Posted November 24, 2015 Kicking in full rudder on a turn for final is weird. I wonder what fool promoted that idea? Try it in a Baron and you are dead. If you are initiating a sideslip you bank the plane first, then stop the nose falling with rudder. Nev
kasper Posted November 25, 2015 Posted November 25, 2015 Most interesting Kasper,. . . I wonder if you've encountered the "Chaser S" a lovely little single seater, originally fitted with a Rotax 377,. . .I used to fly one of these regularly as the owner was terrified by it, as the wing is so small, but with my current fat barstard weight, I doubt if the thing would takeoff at Heathrow or Gatwick now . . . maybe with a sawn in half 912. . .?The Raven. .. yes, I helped my mate Johnnie Carter to rebuild one he'd bought after it had been bent a bit,. . .lovely light thing to fly,. . two fingers and a thumb was all that was required. . . and that top fin was huge compared to the Mainair kites. . . as with the early Pegasus aircraft. . . I ferried a Peg XLSE2 once from a farm near Glasgow down to the Midlands for a friend, and it was an absolute delight to fly. . .got to be patient of course, with a 45mph cruise. .! But what the hell,. . .If you're enjoying the flight, it doesn't really mattter, and the landing speeds on those things were beautifully slow in comparison to modern hotships. . . Still love the old stuff mate. . . .probably goes with me age and attitude. . . . Phil. Don't worry about the Chaser - yes a fast wing for its age and not as slow as the Raven - but it will get you in the air - the aerial arts wings are good ones ... I have photographic proof that the JPX on the HalfPint can get Chris Draper into the air ... it did look a little strange on finals ... sort of a round yellow balloon shaped chap with goggles dangling under the wing ... but a 377 or 447 on a chaser wing will lift 100kg pilots easily and in good short order ... though the minimum speed is increased quite a bit. I too loved the sheer pleasure of flying an XL - loved my Panther XL - inverted belt drive fuji with a the xl wing ... did everything at 50mph and took arms of a gorilla to go over 55 ;-) 1
Teckair Posted November 25, 2015 Posted November 25, 2015 Kicking in full rudder on a turn for final is weird. I wonder what fool promoted that idea? Try it in a Baron and you are dead. If you are initiating a sideslip you bank the plane first, then stop the nose falling with rudder. Nev I doubt if the instructor in question thought he would do that, to me this came about because he had been taught to use rudder only for directional control on final and we were starting on final. If I did not think this was a serious issue I would not bother posting about it considering so many people have been taught that way and think it is a good idea it makes me feel like a voice in the wilderness. 1
dutchroll Posted November 25, 2015 Posted November 25, 2015 I doubt if the instructor in question thought he would do that, to me this came about because he had been taught to use rudder only for directional control on final and we were starting on final. If I did not think this was a serious issue I would not bother posting about it considering so many people have been taught that way and think it is a good idea it makes me feel like a voice in the wilderness. It's weird. I can't fathom that teaching method. And I can't think of a scenario in my entire career from a light single engine trainer to a big plane where if I'd used a "rudder only for heading control on final approach" technique, I wouldn't have got my ar$e kicked. 2
kaz3g Posted November 25, 2015 Posted November 25, 2015 Aileron to keep the aircraft centred over the runway and rudder to keep the nose pointing at the far end of it...kaz 3
Contact Flying Posted November 25, 2015 Posted November 25, 2015 Teckair, Crab to very short final is fine, but a side slip at the very last is necessary to counter drift as we touch down on the upwind main wheel. Otherwise we will just flop down with a side load. The crab changes nothing about the rudders ability to fine tune wings level, either crabbing on final or in cruise. Now we simply hold the wing level with aileron while walking the rudder just right, just left, etc. dynamically and proactively to keep a directed course of our butt (center of gravity) to the target. The target on final is the numbers or desired touchdown spot. The target in cruise is a distant feature or compass heading. Ailerons, because of adverse yaw, are a much less precise trim device than is the rudder. The WWII bombardier, looking through his sight while twisting the rudder trim, didn't care whether he was in a crab or not. The pilot had set up the general heading. He was just fine tuning the heading for somewhat precise bombing. We actually do much better hitting the numbers using rudder for directed course and aileron for wings level. Thanks for the comment/criticism, Contact 1
Contact Flying Posted November 25, 2015 Posted November 25, 2015 kaz3g, Thanks for the video. That was a very good lesson. In side by side airplanes, remember that we line up the longitudinal axis with the center line by looking straight ahead. Army helicopter instructors call it putting the center line between our legs. We can't look over the nose. We instructors are not always careful to point that out. On paved fields, notice that the tire marks are left of the center line because pilots sitting in the left seat are looking over the prop and squeeking it down a little crooked. Nasty in tail wheel, but most tail wheel airplanes are tandem here in US. Also in our western states, pilots occasionally run out of fuel in the afternoon trying to get to a runway more aligned with the wind during summer afternoons when winds often become extreme. A good solution to this problem is to land across the runway angled more into the crosswind. We still have to crab then slip or better side slip all the way down. And we have to use the apparent brisk walk rate of closure or some power/pitch approach to guarantee getting down in the 1,000 feet (300 and some meters) between the downwind corner of the runway and the upwind big airplane touchdown zone marking. Thanks again, Contact
facthunter Posted November 25, 2015 Posted November 25, 2015 Tecky sorry if it looked as though I was having ago at you. I certainly was not. Pilots do do things that are close to inexplicable and I worry where they get their ideas from sometimes. Wing warping was first then aileron. Both increase lift and cause roll BUT at the expense of EXTRA drag and if you are near a stall on that wing may push it to the stall by increasing the effective angle of attack on that side. The extra drag is anti turn so delays the heading change and tends to make you oscillate through the desired heading by the nature of the movement. Applying rudder at the same time as you apply aileron will stop the adverse yaw and increase roll rate. Try doing fairly steep figure eights, and see how you need quite a bit of rudder. Nev
Garfly Posted November 25, 2015 Posted November 25, 2015 Jim, one of the commenters on the YouTube video above, said: "Not sure why the video is titled Dutch Roll when it demonstrates side-slip. The Dutch Roll maneuver is executed completely opposite from the side-slip. While side-slip is cross controlled the Dutch Roll is coordinated. But what do I know. I'm just a rookie private pilot working on my taildrager endorsement." And I'm a bit confused too, because in your e-book (link below) you seem to refer to "Dutch Rolls" as a tool for practising coordinated turns - that is, taking care of adverse yaw with the right amount of rudder "in the direction of desired roll" - while this guy is teaching something quite different, cross-controlled slipping - but, in this exercise, maintaining altitude. thanks, Gary (http://www.recreationalflying.com/threads/safe-maneuvering-flight-low-level-techniques.142553/#post-530233)
facthunter Posted November 25, 2015 Posted November 25, 2015 Dutch roll originally was a yaw/roll couple that was very evident on the early B 707 at approach speeds. Wing sweepback (designed for higher subsonic speeds) was part of the cause. Nev 1
Teckair Posted November 25, 2015 Posted November 25, 2015 It's weird. I can't fathom that teaching method.And I can't think of a scenario in my entire career from a light single engine trainer to a big plane where if I'd used a "rudder only for heading control on final approach" technique, I wouldn't have got my ar$e kicked. I do not get it either and think it is a bad idea, I imagine if you did it in a passenger jet you would make your passengers airsick. 1
facthunter Posted November 26, 2015 Posted November 26, 2015 Only if you are going around on one engine. Nev 1
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