Taxiing for take off

[Lee Smalley]

i see so many half decent fliers that can't taxi, its like they have never practiced it, they just line up on the strip full power and haul it off, take wings off and just tell them to drive it around like a car for 10 mins then put wings on and tell them to do the same, then when happy tell them to do multiple take off and landings smoothly you should get used to using the rudder constantly and smoothly, you should not dab at the rudder ...try doing that with a spitfire with a scale u/c and see what happens!!

[PAUL HARVEY 1]

my next plan of attack then is to take the wings off and go up and down the strip just like a car to try and feel the plane

[Ian Jones]

Hi Paul. Hmm, landing on tarmac with little experience might not be good for the model. That wouldn't help build your confidence either.

Do you have someone helping you?

[PAUL HARVEY 1]

my take off would be on tarmac but landing can be on soft grass. im on my own no one helping

[Ian Jones]

Why not take off from grass? If the grass isn't suitable for take-off then it's unlikely to good for landing either particularly if it's too long - it'll almost certainly have the undercarriage off.

I strongly recommend a visit to a model flying club and a chat with some of the flyers of the same model.

[Dave Hopkin]

+1 for going the club route

If it helps you can find any local clubs using this link **LINK**

If you allow your location to be shared it will center the map on your location

[Biggles' Elder Brother - Moderator]

This Spitfire pilot doesn't seem to agree with you Lee!

Works fine for me - scale or otherwise. But as I say - different folks different strokes - and do what works for you!

BEB

[Peter Jenkins]

BEB, remember that the Spitfire was steered by differential braking. The brake handle was on the spade grip and the rudder bar position controlled the amount of pneumatic pressure applied to the brakes. So, pilots generally used full rudder with a dab on the brake handle to turn one way then applied full rudder ready to apply a dab of brake to taxi straight and then another dab to turn again to achieve the zig zag taxi pattern necessary to see where you were going. This used to be standard on RAF fighters until the introduction of nosewheel steering on the Tornado. Not sure if the Harrier introduced that first though - I'm sure someone will tell us!

[Biggles' Elder Brother - Moderator]

I wasn't referring to the taxing Peter - I was referring to his actual take off run - in the early stages of which you can clearing see him "dabbing"!

Just to be clear here - I'm not talking about "slamming" the rudder in. I'm talking about a process in which you feed in a bit of right then basically "rock" in a bit more right in "dabs" as you go. As I say - maybe not everyone's cup of tea - but works fine for me even on "tricky jobs" with narrow U/C's etc.

BEB

[Peter Jenkins]

Ah, apologies, got hold of the wrong end of the stick - or should that be rudder! I would agree that you don't always just need smooth application of rudder as when you run over a pebble or long bit of grass the drag is instantaneously applied to the wheel so you need a bootful of rudder initially to counteract. On the other hand, I've seen pilots get into pilot induced oscillations when they have too much rudder available in such situations and it goes from bad to worse! Best thing is to close the throttle and start again. What you do need to do before starting the take off run is to rehearse your actions in the event of an "eventuality" leading to and "emergency" - anyone for SWEETS?

[Peter Beeney]

By coincidence I’ve recently been flying a Uno Wot with an elderly(ish) OS 25FX as the pulling power, too. This is taking off a rather wet and soggy grass strip at the moment, and so this does require some care. The trick is to try and judge when it’s going as fast as it can on the ground, (which is very slowly), then try and raise the nose with full up elevator, at the same time hoping that it will just lurch into the air, then when this eventually happens instantly letting go of the elevator and then allowing it to fly level far enough to get a reasonable flying speed - whilst all the while endeavouring to keep it as straight as possible! For many years I flew off a tarmac runway, on balance I prefer grass overall, but for taking off I’d certainly consider tarmac to be the easiest, perhaps purely because the model is very quickly airborne; I reckon the less time you have to spend on the ground, the better…

Relating to the rudder throw, I’ve always employed full control throw on all the surfaces, it’s how I learnt to fly back in the dim and distance, so I guess I have to be careful how much I move the sticks. . . in the main just enough to get the model to do what I want it to do. .

Many years back I spent a lot of time at Old Warden watching the full size displays. When they started flying the Spitfire there, usually displayed by the late Neil Williams, sometimes it was possible to get fairly close to the action, mostly because they used every inch of runway for the take off run. If I could get somewhere more or less behind it was possible to watch it all the way down the runway. I think two things always totally held my attention here, the way the rudder wasn’t just being ‘dabbed’ on take off, it was constantly being slammed hard over and back again, almost right from the moment it started to roll, but the plane amazingly stayed continually in a straight line. I supposed the pilot could sense when it was going to swing. The second impression I got was the seeming interminable time it took to actually get airborne, it appeared to be taking forever just to get some speed. But back in the day the subsequent very fast low level display was unforgettable!

The one thing I would say about my particular Wot model is that the landing has to be about right. Mine is rather unforgiving, in the sense that it has to be flown all the way in; a moment’s lapse in concentration results in a reprimand, do it properly though, and you arrive with a gentle three pointer right in front of yourself. In my view it is thus a good model for teaching landing approaches…

The rudder on the Wot is not really that powerful, either. Adequate, but not exactly what I’d expect it to be. Plenty of movement but the model does seem rather heavy, I’ve yet to weigh it, and I also have the impression that the GoG is a bit forward. And also I’ve no idea how many previous owners it’s had, or how old it is even, but it has been around for a while.

Good luck with yours, Paul.

PB

[Lee Smalley]

Yeah taking off in a full sized spitfire is exactly the same as a model!!! Please feel free to do exactly that with a model spitfire, just not mine, you would zig zag across the strip and probably rip the retracts out.

[ceejay]

i would be very worried by the "full up" on the elevator to get off the floor as soon as poss, i sense a tip stall coming and a bag!! surely any aircraft be it real or one of our toys needs to be at flying speed before its hauled off the ground, besides i do like to try me best to do scale like take off, nothing makes me cringe more than seeing a model spitfire climbing out like a funfly.

but hey thats just me!!

chris

[Lee Smalley]

you do need full up in my spit initially but as speed builds up you relax the elevator until you are just about t take off, by this time i have barely any up left held in, so the take off is as per scale, as this forum is about models not full size !! you do not dab full rudder in during the take off run (certainly not with my spit) the full size has oodles more torque and probably needs that much rudder to stop her swinging, the video is even more of an exaggeration as she is a MK14 or upwards and either has a griffon engine or later Merlin with even more torque and power.

if you do not hold in full up on the initial take off run she just noses over, personally i don't teach anyone to dab anything smooth progressive inputs is where i like to fly, but thats just my way

[Chris Bott - Moderator]

This is just an excuse to post a great video really, but check out the rudder pedal work here as the Mosquito starts his takeoff run. Only possible, I recon, because he can feel very minor yaw through the seat of his pants. We don't have that luxury of course.

[monty2]

Thanks for that great Video and sound track. Takes me back many years to my childhood. Those Merlin's sound wonderful, never mind that yank machine that intruded for a while. Never thought I would see all those Merlin powered machines again in my lifetime. Many thanks again it was wonderful

[sticky fingers]

absolutely briliant, the Canuks really do things very well.

[David Hardaker]

Chris B

In my experience, on landing or takeoff, it's a case of seeing the aircraft go off line, rather than feeling it. Which is why you pick a distant point to keep straight on. (usually!)

David

[Martin Whybrow]

I also flew a Uno Wot with an OS25AX; it was difficult to get it off the ground and needed lots of elevator to unstick it which resulted in a few stalls immediately after take-off (I was still a newbie at the time). I swapped the engine for an OS40LA that I was given and it was so much better. I suspect the 25 would be OK taking off from a bowling green, but it struggles on our field.

[Peter Beeney]

ceejay,

I’m also worried about that full up elevator, too, it’s simply done in an attempt to get off the floor at at all, due to the spongy ground and very slow moving model; it just about manages to stagger into the air. This is indeed why I’m saying I do it carefully, I had one or two practical lessons about flick rolls on take off in the early days when I bought my first proportional radio, around 1970; and I’ve been diligently practising hard at avoiding this caper ever since… and, so far, the ‘yank it off’ technique has been successful every time.

I quite agree about the scale like take off for scale models, but this one is only an ancient hack Uno Wot, and it won’t be a big loss if I break it anyway. As it happens, I’ve usually found scale models like Spifires and others are often something of a pussy cat when taking off and flying, but there can occasionally be some interesting exceptions; although perhaps it’s invariably the small short coupled biplanes with lots of eager power and a propensity to attempt a torque roll whilst still on the ground that can really captivate your full attention. I certainly try not to zig zag models while taking off, simply by moving the sticks as necessary, slow, fast, or whatever, to keep it going in a straight line.

Some model stats; only for interest, really. It came with a 10 x 6 prop, which I thought was a bit OTT, so I changed it for a 9 x 6 ACP. This turns at 12.5k, so a potential speed up to 70 mph; and indeed once it’s flying it is quite nice and lively, so I reckon that together with the rather precise landing approach required this will be just the ticket for improvers wishing to start turning up the wick a modicum. OS spec the motor for 0.84 bhp at 18000 rpm, these sort of revs might be a bit tricky to achieve, but I may well try other props, if a 9 x 5 will spin at around 14.5k I’ll still have more or less the same sort of speed but perhaps a little more inspiration to get off the ground quicker; and if I consider the standard rule of thumb that says to allow 10% extra for unloading in the air I haven’t lost very much at all. Electrical power is supplied by what now must be a rather ancient 4 cell 800 mAh nicad, which has probably seen better days, but is still around 90% capacity. After 3 full length agile flights, 20 min each?, I’ve not timed them yet, it’s down about 200 mAh. The tank is the square blue fronted Slec type, is that a 9 oz?

So all in all, and in answer to the Paul’s OP, I’ll join the consensus of opinion and say practise + practise makes perfect. But once you have full confidence and you’ve got the right prop on the motor which is on full song, on a tarmac runway into a gentle headwind you’ll be able to nip off so fast it won’t really have time to swing about; and you’ll then be wondering what all the fuss was about…

PB

[Lee Smalley]

And then fail your a or b cert with that kind of take off ...well done!!