Steering on final with rudder

[Dafydd Llewellyn]

Thanks dafydd. Thats great information. Having tested several homebuilts I do have an Idea of what your saying. However my original question was about steering with the rudder 'only' when too fast, which Oscar later corrected and said he was too slow.We have done lots of 'ribbon testing' on our aircraft to observe the airflow approaching and during the stall. Almost all have indicated this reverse flow you speak of and is a curious factor that i like to demonstrate, particularly with aifoils that promote :"grabbing" of the aileron at the point of stall. Aircraft like the foxbat, which has a very strong Aileron grab tendency (my term) which bangs the stick hard over at the break. Also the piper sports, which has a very rear cof g at the best of times (33% MAC i think) is another aircraft that tended to misbehave in this fashion. Approaching the stall when the separation point would move forward past the aileron there was a strong pull on the ailerons. The interesting thing is it didn't always pull the same way..Its a feature of that particular aeroplane that I dont like, when you increase the AofA the aileron feedback changes significantly, and you even feel forced feedback (again, not a technical term, my description) which feels like someone else on the controls pulling the aileron into the turn direction..Not nice, I dont like having a ghost on the controls with me..

Ps. Please note, im only a pilot not an engineer so i can only relate what i feel to my limited knowledge of the mechanics.

 

Cheers

It's called "aileron snatch" and an aircraft that exhibits it would not pass type certification. My question is, how did these aircraft get to market with that fault? I consider the system that allows this to be deficient.

All this is, of course, quite off your original topic; if you're well above the stall speed, it's not dangerous in my view to correct lateral drift on mid- final using crossed controls - though I think it preferable to use the crabbing technique in that situation. However I do use the cross-control method on mid-final, to assess the crosswind strength; my personal criterion is that if it takes more than half the available rudder or aileron throw to counter the drift with the fuselage aligned with the runway, it's time to find another runway.

 

 

[motzartmerv]

Aileron snatch!!!!. Now how will I remember that??

 

Both the aircraft are LSA not type certified (I believe).The difference between the two has always confused me to be honest. Oh that reminds me, you may be able to answer this.

 

For Type certification under 95.55 the VS is meant to be less than 45 kts. The J160 doesn't come close to that figure. Having been involved with Jab production can you explain this? Ive always been curious.

 

Cheers

 

 

[Dafydd Llewellyn]

Aileron snatch!!!!. Now how will I remember that??Both the aircraft are LSA not type certified (I believe).The difference between the two has always confused me to be honest. Oh that reminds me, you may be able to answer this.

For Type certification under 95.55 the VS is meant to be less than 45 kts. The J160 doesn't come close to that figure. Having been involved with Jab production can you explain this? Ive always been curious.

 

Cheers

I didn't do the flight testing of the J160; my part of it was finding compliance with the structural aspects. However, I think you will find the requirement is Vso, i.e. the stall speed in the landing configuration, not Vs (strictly, Vs1) which is the stall speed with the flaps etc retracted. The J160 was certificated, as I recall, against JAR- VLA, which also requires Vso not greater than 45 Kts CAS. Note - calibrated airspeed, not indicated airspeed. There had been sufficient wrangles with CASA over the testing of stall speed by that time, that people were being very precise about it; I got sufficiently annoyed about it that I developed a form of calibration airspeed sensor that gave roughly double the pressure difference of a normal pitot/static system - I called it the "2Q" head - and had it wind-tunnel calibrated. Alan Kerr used a differential pressure transducer and a micro-manometer to calibrate it before & after the stall test flight, and the results were digitally recorded, so we reckoned the error was less than 1/4 of a knot. CASA issued the Type Certificate - you can download it from the CASA website - so evidently they agreed that it complied with the JAR-VLA 45 knot requirement. Rod Stiff wanted to shave that as close as possible, because one knot increase in stall speed means about 2.5 knots increase in cruise speed.

 

 

[Oscar]

Merv, if you look at: http://www.comlaw.gov.au/Details/F2011L00617 you'll find that it's VSo of 45 kts. The 160C POH states the VSo at 45 KCAS and 48 KIAS, and won't have been able to get certification without demonstration of that (most probably to the satisfaction of a CASA test pilot). Pardon me for intruding here; Dafydd can probably give you a way more complete answer.

 

Edit: he did....

 

 

[Oscar]

Merv - re 'aileron snatch' - there's a similar sort of thing can happen with rudder, called (I believe) 'rudder lock'. I did a 500k attempt in a Standard Libelle glider, ( a type I'd never flown before then, with a check out that consisted of 'here's the water dump valve, fill it up before you go and don't dump it until you absolutely have to' - no mention of the propensity to rudder lock). I guess the instructor may have trusted me not to get it to the point of that happening - and I didn't, though having several somewhat memorable climbs in tight and very lumpy thermals with a gaggle around me. I guess I must have been keeping it straight enough, though I remember very fondly that it was quite delightful to fly right on the edge of the stall in the thermals, with miniscule stick movements and just light dancing on the rudder; some of those thermals went from about 1500 AGL to around 8,000, so lots and lots of turns even at somewhere over 1,000 fpm ROC.

 

 

[motzartmerv]

Rudder snatch? Wow. I can understand the ailerons doing it, by what function would cause the rudder to do it? Some form of disturbed air flow buffeting on one side or something. It's an interesting subject.

 

Re the 160 stall speed. I know the poh states 45 kts, I've never managed to duplicate that figure. All though its likely to be kcas problem that relaes to earlier posts from daffyd and bob re calibrated instrumentation for testing purposes.

 

At mtow I've only managed a clean break at about 49 kts ias .

 

Just quietly, I think the 160 is the best acft jab have produced. :)

 

 

[Dafydd Llewellyn]

Rudder snatch? Wow. I can understand the ailerons doing it, by what function would cause the rudder to do it? Some form of disturbed air flow buffeting on one side or something. It's an interesting subject.Re the 160 stall speed. I know the poh states 45 kts, I've never managed to duplicate that figure. All though its likely to be kcas problem that relaes to earlier posts from daffyd and bob re calibrated instrumentation for testing purposes.

At mtow I've only managed a clean break at about 49 kts ias .

 

Just quietly, I think the 160 is the best acft jab have produced. :)

Rudder lock is somewhat different to aileron snatch; it's a gradual reversal of the rudder hinge moment with increasing yaw, so when you set up a full-rudder yaw, and take your feet off the pedals, the rudder doesn't come back - you have to push it back. When you see an aeroplane with a dorsal fin ahead of the vertical tail, there's a fair chance it either suffered from rudder lock or the designer anticipated that it would. It's merely annoying in a glider, but extremely dangerous in a larger, faster aircraft. It tended to be common in the older German gliders which had a very small fixed fin and an enormous rudder, and no aerodynamic balance on the rudder. The worst Aircraft I found for it was the Ka2.

 

Was your ASI calibrated? They are allowed up to 4 knots error. Stall speed testing for certification is quite a complicated business; if you want to study it, look up FAA AC 23.8a - which was the issue applicable to the J160. Attached is an excerpt from AC23.8b which was changed slightly; the applicable case is the middle one, and under issue (a), the stall speed was the lowest speed reached; under (b) it's the speed at which the stick hits the stop. The procedure is to do a large number of stall events, with the speed versus time being recorded so a curve similar to this can be drawn for each event. The mean rate of deceleration is the slope of the line between 1.1 Vs and the point at which the stick hits the stop. So you get a large number of results of stall speed versus deceleration rate. It is necessary to have samples at deceleration rates above and below one knot per second (all speeds in CAS). You draw a line of best fit through all the points, and the speed at which that line crosses one knot per second is the stall speed. It's actually one of the more difficult tests to perform in certification flight testing, because you have to fly extremely precisely.

 

I tend to agree with your appraisal of the J 160.

 

 

 

[Oscar]

Merv, I think it's a case of too much aerodynamic balance, but don't hold me to that, what I know about aerodynamics is that I don't know enough to be an 'expert', or try to pose as one because I'll screw up somewhere. I've heard that there are some other gliders with the same problem, and some of them can require more than the 'prescribed' force to get the bastard unlocked, but that's hearsay only.

 

Re your KIAS - just by chance, is that on the same aircraft as the one you have the 'interesting' IAS situation in a sideslip? And if so, does it have a Dynon EFIS with a Dynon AoA/pitot head instead of the Jab one installed? From the 160 POH, the KIAS at VSo is 48 kts and you have 49, which isn't much different really, but if it is the same aircraft then may I politely (and we are being reasonably polite to each other, for once ) suggest that you might find it interesting to try moving the Dynon sensor position around and seeing if it changes your readings? That super-dooper pitot thingy that Dafydd talks about I've seen, and it sticks out about a metre or more in front of the wing when installed (dangerous bastard to be doing your pre-flight if you're wearing close-focus glasses, on a Jab.), and to get a really accurate static you need a funnel on a bloody great length of trailing tube, so it's pretty obvious to me that position error for both pitot and static is a real problem for a neat installation. I somehow doubt that you can expect to get Jab's factory results with a different sensor, and the POH is (obviously, again) based on their installation.

 

 

[Dafydd Llewellyn]

The 2Q head substitutes for both the pitot and the static sources, and it does so with very little tubing, especially if one uses a differential pressure transducer instead of a mechanical ASI. Attached is what it looks like, and the calibration curve for the one Jabiru use. A trailing static is not as suitable for stall speed testing, because if the aircraft is descending, it suffers from "lag balance" - the change in static pressure due to changing altitude creates an error, which can be quite large. This is due to the time it takes to fill the tube and the instrument case, which can be considerable for a trailing-cone static. Note: Systems such as the Dynon use a differential pressure transducer - but for certification testing, it needs to be calibrated immediately before and immediately after each test flight. If I'm using the 2-Q head with an ASI instrument, I usually cross-calibrate it against a trailing-cone static and pivoting-vane pitot, in level flight, just as a double-check.

 

 

Jabiru_probe_calibration_2004.doc

 

Jabiru_probe_calibration_2004.doc

 

Jabiru_probe_calibration_2004.doc

[Oscar]

Well, damn! So below 19 kts, that thing wouldn't self-align? Going to be pretty useless for Thruster VNE checking, then...

 

 

[motzartmerv]

Yes oscar, the Same aircraft that had the slipping annomoly. I can't shift the sensors around as its type certified and also it's been relocated to tamworth.

 

I must say I've never been too concerned about it, it's a high wing loaded little plane and must be flown accordingly. I've always carried an extra 5 kts on the poh numbers Because it jus feels much more happy there. And it won't float like the other models will if your a bit quicker.

 

Te only time it feels nasty is when it's slow, the lift doesn't drop away all friendly like under 60 kts it goes Into express elevator mode.

 

But it's a much easier problem to manage then the floating issue the bigger wing models seem to give.

 

Thanks for the references daffyd, I'll look into that. Very interesting stuff.

 

 

[Oscar]

. However my original question was about steering with the rudder 'only' when too fast, which Oscar later corrected and said he was too slow.Cheers

Merv - not only too slow, but aft of the rear c/g. limit. Not by enough to cause it to be totally uncontrollable, but it felt like standing on top of a ball-bearing in a gusty breeze. Same damn flight I lost the rudder pedals on final and had to avoid some stupid bugger pulling his glider across the field exactly where I was aiming for touch down. Since it was John Rowe's personal aircraft that he'd set a world speed record for a task in a few weeks previously and tuned to perfection, he was NOT amused by my landing, until I told him about the rudder pedals and he realised I wasn't wearing a parachute and so was below minimum pilot weight. I got an 'oh, well, ok then', which was I think John's 9/10 rating.

 

 

[Oscar]

Yes oscar, the Same aircraft that had the slipping annomoly. I can't shift the sensors around as its type certified and also it's been relocated to tamworth.I must say I've never been too concerned about it, it's a high wing loaded little plane and must be flown accordingly. I've always carried an extra 5 kts on the poh numbers Because it jus feels much more happy there. And it won't float like the other models will if your a bit quicker.

Te only time it feels nasty is when it's slow, the lift doesn't drop away all friendly like under 60 kts it goes Into express elevator mode.

 

But it's a much easier problem to manage then the floating issue the bigger wing models seem to give.

 

Thanks for the references daffyd, I'll look into that. Very interesting stuff.

Was the Dynon factory installed? because if so, then (for once!) you and I are in agreement, Jab. should have modified the POH to reflect the Dynon installation KIAS. And I agree ALSO (this is 'Dear Diary stuff!) that the 160 dumps lift rather suddenly; I've been training on one and my landings are fine down to the last 20 feet, when my bi-focals plus a distortion in the bottom of the screen plus too many ingrained gliding habits that I need to revise of stopping as soon as possible after the threshold has been reached mean that the last round-out bit is frustrating me - the thing isn't ending up where I think I am commanding it. Still only a few hours up, I'll beat the little bugger yet. Oh, and a thicker cushion so I can see forwards in the round-out is on my list.

 

 

[metalman]

Whilst I hesitate to add more fuel to this fire, the above question begs an answer, which may help clarify things:A test-pilot's approach to stall behaviour requires that one brings the aircraft to the stall, and then sit there and observe what happens - but catch it before it goes into a spin. In the pre-certification flight testing of the CA21 skyfox, the original Jabiru, and the Seabird Seeker, I spent a lot of time investigating stalling the aircraft at its extreme CG positions, in every configuration, straight and in turns, at all power levels. They all showed the same basic characteristic, i.e. they became very vague in their aileron response, and would undergo a mild wing drop, which would recover itself and maybe go the other way. In the case of the CA 21, that would repeat, getting a bit more severe each time, until after two or three cycles the airoplane would spear off into an incipient spin. In the case of the Jabiru, the wing-rock would continue more or less indefinitely, and the Seeker would damp out after one or two cycles - mostly. Whilst in this phase, one could (sometimes) pick-up a small wing drop with rudder whilst holding the stick back, but the ailerons were ineffective at best - but essentially they all went out of control laterally, before there was any G-break (nose drop) - which meant they were fundamentally non-compliant. Finding a fix for this meant I got more practice in stall recovery and post-stall behaviour than I really needed.

All three of them used a rectangular wing planform - which is known to be a feature that promotes initial stalling in the centre of the wing; two of them has washout; and all three used a wing airfoil that stalled by progressive separation from its trailing edge - i.e. a so-called "docile stall" airfoil; this could be seen by the behaviour of a wool tuft at the wing trailing edge - at 5 kts above the stall, it was laying on the top of the wing, pointing forward. They were also all high-wing aircraft.

 

What the textbooks on wing design do NOT point out, is that an aft-stalling airfoil gets reverse-flow on the top surface as it approaches the stall; and this extends further and further as you slow down. It eventually reaches the aileron hinge line, and by that time, the ailerons are definitely NOT working the way they are supposed to.

 

Now, I have only theoretical reasoning based on these observations to go on, but what I think happens is that these aircraft all develop a patch of separated flow on the top of the wing, starting at the trailing edge close to the fuselage, just as the textbooks say they should. However it may start on either wing first; and if it does, that wing will drop a bit. That causes sideslip which "blows" the separated patch across to the opposite wing, so the wing-drop reverses - etceters ad nauseum. This is the mechanism of the "falling leaf" manoeuvre, and the original Markey Ultrabat (VH-ANT) exhibited exactly that when I test-flew it, so the behaviour is not confined to high-wing aircraft.

 

It followed that wing modification that managed to contain the separation bubble, should correct this behaviour - and indeed they did, on the Seeker.

 

However, if you have an aircraft that behaves this way, it is quite possible to "correct" a mild wing-drop with rudder - though in many cases the aircraft will do that itself, but rather more slowly and somewhat erratically. Most aircraft are elevator-limited at the stall, at least at forward CG, and will only get to the beginnings of wing stall - so if you happen to be flying one of these, and the CG happens to be in the right place, you can sit there with the stick hard back and pedal it all day; but don't project that behaviour to all aircraft, or the same aircraft at full aft CG, or you may get a really big surprise.

 

Once I had modified the Seeker to contain the stall bubble, it stopped exhibiting the rock & roll behaviour - but it then became obvious that the aileron response was reversed from about 5 kts above the stall down. So it then got VGs across the full span - and in that configuration, the stall speed went down about eight knots - and the stall was then so violent it put the aircraft on its back & took 600 feet to recover despite my being ready for it. It took several further iterations to get it where it is to-day - i.e. almost impossible to stall or induce a wing drop. That's another story, and proprietory information; but I do speak from practical experience. I think few of the contributors to this thread would have gone to the trouble of weighing their aircraft with the pilot aboard before & after the flight, to make sure the test was done at precisely the aft CG limit - and therefore they have experienced only a limited sample of what their aircraft can actually do. It is dangerous to draw conclusions on such limited experience.

Dafydd, I've flown a seeker a couple of times, the last time I did some stalls in it( I'd have to look in my logbook to get the rego) ,it's the only aircraft I've flown that the rudder was totally ineffective in the stall, I had stick hard back, mushing down and you could go full rudder deflection either way with no effect on roll or yaw ,frankly I found it a concern ,it didn't want to spin but if it did I wondered when the rudder would start to work again ,I asked a mate who flys for them a lot if it's the same in a power stall and he says yeh, like I said I've never flown anything like it, are they all the same

Matty

 

Just found a pic ,it was VH SUA

 

 

[djpacro]

Not to be picky dave, but are you saying that the pilot in a sidelsip only uses rudder to steer? Or do they still use rudder and aileron together, all beit in a crossed fashion. If you tell me that a pitts pilot locks aileron solid and uses his feet to steer down final ALONE...I will come to Melbourne and eat the aeroplane..!!..

Well, since some of us never seemed to get to the same level of understanding in the other thread I won't even try to respond in the depth warranted by the question. Minimal secondary effects of controls in the Pitts. In a sideslip tracking straight down final the pilot knows what the response to aileron and rudder would be so use the controls to do what needs to be done to maintain the required sideslip (to keep the runway in sight) to track straight to the runway.If the two of us ever get together at the same location as the Pitts you're welcome to try yourself.

 

 

[djpacro]

OK it's been driving me crazy. A thread with this heading has been on and off the instructors forum for weeks. What is the secret that the instructors are keeping to themselves? What pearl of wisdom would make my landings more predictable and professional? What are those two pedals for anyway?

I hope you are happy now!

[kaz3g]

A Shortwing Kooka I flew, it was a barge. Nothing reminded me of it so much as driving a Centurion Tank years later. First single-seater an Arrow, thence a Pilatus B4 and a Boomerang (which was the nicest thing EVER to sideslip in, it would hold about 30 degrees nose off track. Blaniks are really dignified gentlemen of the air, not the best at most anything but impeccably behaved in any circumstance. Lexus behaviour; for a Mercedes 6.3 AMG ride, try a Janus with full water. First solo flight - a Motor-Falke (and that was the barge you have when you are tired of the frisky antics of barges.)

I flew Mike Valentine's ES 52 a few times. He loved it but I found it a poor performer compared to the mighty Blanik

 

You could lay off a mighty yaw into wind on final in the. Blanik and it remained beautifully stable. It was very kind to stall and spin and recovery was easy. I got my Asst Instructor's rating after a check out in a Bocian by John Viney. This graceful old plywood bird had a wingspan as long as your average backyard and the stalled wing would give an audible sigh as you entered a spin. Sitting high in the back seat, you had an exceptionally good view of the world rotating over your head.

 

Kaz

 

 

[Dafydd Llewellyn]

Dafydd, I've flown a seeker a couple of times, the last time I did some stalls in it( I'd have to look in my logbook to get the rego) ,it's the only aircraft I've flown that the rudder was totally ineffective in the stall, I had stick hard back, mushing down and you could go full rudder deflection either way with no effect on roll or yaw ,frankly I found it a concern ,it didn't want to spin but if it did I wondered when the rudder would start to work again ,I asked a mate who flys for them a lot if it's the same in a power stall and he says yeh, like I said I've never flown anything like it, are they all the sameMatty

Just found a pic ,it was VH SUA

That's a common misunderstanding. The Seeker is most unusual; its wing has a three-stage stall; the first stage stalls only the part of the wing between the leading-edge fences (i.e. the bit directly ahead of the tailplane). That has two effects: Firstly, the wing downwash acting on the tailplane is reduced - which limits the elevator power to pull it any deeper into the stall. Secondly, the wing fences shed powerful vortices at high alpha, which do two things - firstly, they prevent the stalled area from migrating further outboard; and secondly, they provide greatly increased directional stability at high angles of attack, because when the aircraft yaws, the sidewash from the lower part of the vortices acts on the vertical tail to push it back to the centre. If you apply full crossed control at around 1.4 times the stall speed, you will see about two ball widths of skid. If you then slow down whilst holding full crossed control, the skid will reduce to about half a ball width when the stick is on the back stop. That's not enough to make the stall patch extend outward, so it simply keeps on flying. It's not "mushing" in the normal sense*; I've done many flight demos in VH-SUA and one of them is to heave it into a full power steep turn with full aileron, full rudder and full back stick, starting at 65 knots - which is just 9 knots above the zero flap stall speed. Anything else would do a flick roll; the Seeker just turns & flies away - with a slight aerodynamic buffet from the stalled centre section.

 

I did a complete set of spin tests (68 cases) on the higher-powered version (VH-SZF) with the aft CG limit at 30% MAC instead of 28% MAC as for -SUA; it does not spin; it will do a half-stalled incipient, falling into a spiral after half a turn. Keith Engelsman (ex CASA chief test pilot) verified my results.

 

The airflow kit on the Seeker was the subject of intensive development; it uses vortex control to limit the lateral spread of stall. Such a system behaves altogether differently to a conventional aircraft. Forget your traditional experience; it does not apply to the Seeker. It's the only aircraft I know of in which you can apply full crossed controls and then bring the stick right back to the stop, without a violent wing drop - it just keeps flying. Turning stalls, power on or off, flaps up or down, it makes no difference. It was designed for powerline patrol, and it is extremely well suited to that job; there will be no stall/spin accidents in it unless people operate it outside its certificated CG limits.

 

*Mushing refers to an aircraft that has such restricted elevator authority - usually due to a restricted aft CG limit and/or limited elevator travel, so you cannot use the full lifting capability of the wing. The Seeker does not do that; it lets you go to the fine edge of the peak wing lift - but no further, at any CG within the certificated range. And it does so by its fundamental aerodynamic design, not by a fly-by-wire system.

 

 

[Oscar]

And, speaking as a very low-time power pilot, in general flight it's just a delightful thing to fly with nicely-balanced controls; as an ex-glider pilot I'm not used to being able to see the ground past my feet but it just wants to oblige by staying delightfully co-ordinated in a turn without any apparent effort on the part of the pilot. Absolutely the nicest way to look at Fraser Island when the real pilot says: 'here, you take the damn thing, I have stuff to do'.

 

 

[Dafydd Llewellyn]

I flew Mike Valentine's ES 52 a few times. He loved it but I found it a poor performer compared to the mighty Blanik You could lay off a mighty yaw into wind on final in the. Blanik and it remained beautifully stable. It was very kind to stall and spin and recovery was easy.

 

Kaz

And that's with an aft CG limit at 38% MAC

 

 

[Oscar]

I flew Mike Valentine's ES 52 a few times. He loved it but I found it a poor performer compared to the mighty Blanik You could lay off a mighty yaw into wind on final in the. Blanik and it remained beautifully stable. It was very kind to stall and spin and recovery was easy. I got my Asst Instructor's rating after a check out in a Bocian by John Viney. This graceful old plywood bird had a wingspan as long as your average backyard and the stalled wing would give an audible sigh as you entered a spin. Sitting high in the back seat, you had an exceptionally good view of the world rotating over your head.

 

Kaz

Yep, I agree with that. I'm in the process of getting my RAA pilot certificate, and my instructor (who was also a gliding Instructor in his past life) asked me - after my first five or so circuits - if I was making a conscious decision to roll out of the turn onto final into a sideslip approach, because I did it consistently, or was it just old habits? I hadn't realised that I'm used to lining up the threshold off to one side.... and doing a lot of my initial training in Blaniks is probably why.

 

I did my first check-flight at Narromine with John Rowe in a Blanik. As far as I can remember, the voice from the back said: ' You're way high' as we turned final, followed by 'I'd like you to end up somewhere near the flight line' as we rounded out, followed by 'you're a bloody Cooma pilot, right?' as we taxied up and stopped behind the last glider on the line. In the CGC flying at Polo Flat, you were expected to do the last flight of the day ending up at the hangar door; the Libelle syndicate members used to stand out the front of the hangar and put their foot out and require their flying member to drop the tip onto their boot. Failure to so do was punished by having to buy the rounds for the evening.

 

 

[pmccarthy]

I hope you are happy now!

I'm really glad I asked. Have learned a lot -some of it quite useful!

 

 

[Teckair]

If the two of us ever get together at the same location as the Pitts you're welcome to try yourself.

You sure about that? What if he eats it?

 

 

[motzartmerv]

I think I'm safe, he did say aileron and rudder were used together;) I knew not even he would say they aren't.

 

 

[Teckair]

I think I'm safe, he did say aileron and rudder were used together;) I knew not even he would say they aren't.

Yeah fairly safe, don't know where you would get a blender that big anyway.