Taxi runs and maiden flights

[Paul De Tourtoulon]

1 hour ago, GrumpyGnome said:

We have our pits area parallel to our main runway, about 15 yards separation, with a safety fence between them. There is a taxiway linking the end of the pits, to the Runway. Pilots are not allowed to taxi in the pits - planes being carried to the taxiway, or runway. Then planes are taxied to the appropriate take off point.

 

Probably 50/50 split of pilots using taxiway, or not.

 

ANYONE going in front of the safety fence, for any reason (including placing a plane on the runway for takeoff) has to make those flying aware of their intention, and get a response.....

like ours, tables have a proper safety fence separating the pilots from the rest of the field, planes are carried out to the taxi way, engine pointing to the runway,

after landing the engines  are stopped halfway down the taxi way, where there is an opening 2 metres wide to carry the model to the tables.at the opening in the fence their is a concrete table so if there is a runaway plane the 800 kilos of concrete will stop it.

 

 After 1/2h here is our club pilot section, 10 concrete tables, orange lines = fencing 1m20 high yellow pointers openings one for planes Taxiway ( top ) and the bottom one to gain access to the Hélicoptère and drone take off square.

[Martin Harris - Moderator]

The most directionally unstable model on the ground that I have is a Flair Nieuport so it may be an inherent characteristic of the design Paul?

 

I suspect there are still clubs where the norm is to take the model out to the strip, stand behind it and take off from there - something I discouraged in more established members and taught beginners to taxi out and take off standing in the pilot's box from when I first started instructing.  I was very happy when the BMFA scheme adopted this technique as a standard requirement for A and B tests.  I saw so many near misses and models damaged as a result of pilots "wandering" about on the active runway and stumbling along with guidance from extra people when trying to return to the pilot box.  Taxying models is now really a required skill at my club for the majority of pilots who don't always hand launch.

 

I'm afraid that I disagree that continuing with a flight is always the better option.  I  use a back track and long take off run for all but the lightest of models I'm maidening in order to give me the option of aborting if I feel it's the best course of action.  There's an old  adage that the two most useless things in aviation are fuel in the bowser and runway behind you but they are both very true. I would also advocate a careful rotation {or simply allow the model to break ground itself) avoiding a rapid climb away - from a close to level attitude an aborted take-off and subsequent landing is unlikely to cause major damage and even a rapid reduction in power shouldn't cause any problem.  In the event of an unexpected pitch up then it's different - control of the attitude and air below you are your friends so continuing to climb away under power (and control) is probably the best option.  Admittedly, it is  rare that the abort is the better option but as Paul discovered, an uncontrollable model in the air is far more dangerous that the same thing on the ground where removal of power can normally be the preferable and probably instinctive reaction when things are heading for a nasty conclusion.

[Nigel R]

No taxi-ing for me. Pits are only about 10m from runway. Carry, place, return to pilot box, take off. The Benefits (or maybe drawbacks, with the wrong pilot) of a small site.

 

I generally won't bother with a taxi test. If I've passed the noise check and pre flight are all good then it's time to get it up all the way 

[Jon H]

I have a flair Nieuport as well and it is a bit tricky on the ground. I did tame it considerably by fitting a sprung undercarriage and this really helps it as it stops all the bouncing. 

 

Still, it is one of only 2 models i own that i stand behind for takeoff as it is still a bit unforgiving. 

 

While its probably another argument entirely i always stand behind models for takeoff on their maiden flight. The reason is that directional stability is the most important thing as it allows the use of the full runway. Its no good if you exit stage left at a random point as the poor chap in the video at the bottom clearly demonstrates (the action starts at 2min 30). A runway big enough for a full size and yet he manages to reduce its useful length to about 10 feet. I know people often talk about airspeed being more important and its hard to judge from behind, but i find that the airspeed sorts itself out if you run far enough down the runway in a straight line. Airspeed is clearly important, but hauling the thing off before its ready as you are heading for the weeds following a loss of directional control is often the root cause of this issue. This in itself comes back to another problem, and that is the sad neglect of the tall flappy bit on the back of the fin. The poor chap in the video clearly didnt know what it was for and it would have really helped him. 

 

On reasons to abort i would say that any engine/power issue (especially on multi engine aircraft), control issue, loss of directional control, or other mission critical problem should call for an abort. 

 

 

[Nigel R]

Turns out using the rudder is quite important.

 

That aside, throttle gunned about 30ft in, no rudder correction, swing, did not abort, haul off deck, oops.

 

High wing loadings are not forgiving.

[Jon H]

16 minutes ago, Nigel R said:

 

 

High wing loadings are not forgiving.

 

 

Another example here. Held the elevator in for too long, started drifting left, still hangs on to the elevator and its up with a lovely left torque swing. If you pause you can see full right aileron but no rudder input at all. Once it was off the ground full right rudder and aileron together with the elevator moved to neutral would probably have saved the day. 

 

I think the was surprised by how quickly the model lifted off and then it was all a bit of a panic with an all too predictable end. 

 

 

 

 

[Paul De Tourtoulon]

Sad to see those sort of beginners mistakes wrecking two nice models, the P 51 didn't have a fighting chance looking at the pilots 'footwear',,,🤐

[Nigel R]

Well at least the retracts didn't rip out.

[Cuban8]

I'm playing devil's advocate here............would electronic stabilisation/autopilot stop the examples of dumb thumbs that we've seen in the videos? If the tech can save a cheap beginners foamy from destruction, then I'd have thought any assistance with saving a very expensive scale model might be welcome. None of us are perfect, and errors are sometimes made by even the most experienced model pilot. Modern jet liners don't allow the pilots to exceed certain limits of control or incorrect inputs and fast jets are unflyable without electronic control - if it's good enough for them and might  help us in certain circumstances, then why not.

Edited August 30, 2022 by Cuban8

[Jon H]

39 minutes ago, Cuban8 said:

I'm playing devil's advocate here............would electronic stabilisation/autopilot stop the examples of dumb thumbs that we've seen in the videos? If the tech can save a cheap beginners foamy from destruction, then I'd have thought any assistance with saving a very expensive scale model might be welcome. None of us are perfect, and errors are sometimes made by even the most experienced model pilot. Modern jet liners don't allow the pilots to exceed certain limits of control or incorrect inputs and fast jets are unflyable without electronic control - if it's good enough for them and might  help us in certain circumstances, then why not.

 

Even with a gyro if you hold full up elevator its going to stall. With the wing stalled the controls become ineffective and the gyro cant do anything to help you. 

 

I am also not a fan of this idea that everything has to be easy. If the model can fly itself then what is the point? I flew my P39 at the weekend for the first time in several months and had forgotten its need for small corrections all the time. Some may view this as a pain, but i enjoy it as its part of the character of the model and its up to me to sort it it. I need to up my game to keep up, and if i cant then that is my problem and not the model. Without some element of difficulty there is no sense of satisfaction then you get it right. There are exceptions, like the seagull hurricane which simply wont fly, but generally i like to keep to a basic stick and rudder mentality. 

 

I dont like gyros on trainers for this reason. It might make it easier to learn to fly, but is that really the right approach? Might these chaps with their big warbirds have an over inflated sense of their own ability? Have they fought torque swing and other issues in the past or have they had gear take care of it for them? I dont know but it seems some basic skill/understanding is missing. 

 

You are right about airliners and fighter jets, but they are a different kettle of fish. One is unflyable by a human, and the other has hundreds of people on it. Also lets not forget that automation done badly is very unhelpful. Im looking at you 737max. I appreciate that this is an exception but still. Would AOA sensors and all that really be reliable on a model?

 

And while no pilot is perfect, we can follow procedures and decide ahead of time that if event X occurs do Y. If you loose directional control, abort takeoff. Dont just drive it flat out it into the weeds and hope for the best. We (humans) are really rubbish at making a decision when we are startled so unless you have this X=Y sort of thing pre programmed into its going to be much more difficult to react in the right way. I think this is where most of these accidents originate. Try to think ahead of the model, dont just react to it. 

 

 

 

 

Edited August 30, 2022 by Jon - Laser Engines

[Brian Cooper]

It is impossible to write a set of rules for every conceivable situation. 

 

At the end of the day, there's no substitute for experience.  

[David Davis]

11 minutes ago, Brian Cooper said:

It is impossible to write a set of rules for every conceivable situation. 

 

At the end of the day, there's no substitute for experience.  

...and a basic knowledge of aerodynamics.

[Paul De Tourtoulon]

10 minutes ago, Brian Cooper said:

It is impossible to write a set of rules for every conceivable situation. 

 

At the end of the day, there's no substitute for experience.  

Quite right, I have seen quite a few crashes on helicopters and even M/plex EPP electric planes trying to program a module on a plane that already flies .

[Cuban8]

It just strikes me that with such powerful tech that we accept so readily on our trannies and radio systems, that there might be a reluctance to use drone type autopilot technology on very expensive models. If a system can fly a model with very little pilot input it can surely be tuned to give a useful degree of assistance when it detects that things are not going well. Not all models would need it or find it desirable and if a modeller wishes to have no assistance built in to their multi £k model, then that is their choice.

 

[leccyflyer]

As is my wont I've just been reading an old back issue of RCM&E whilst having my lunch and a reader's letter brought this thread to mind. A modeller returning to the fold after being out of the hobby for 30 odd years had built the Tony Ninjuis 72" span Spitfire as a first model this time round. It subsequently emerged that he did go for a more suitable trainer and began to learn to fly, but his first step was a test taxi with his new Spitfire in his back garden. He said that his other half intervened at that point and noted that it would be a terrible shame if he broke the aeroplane and he then went on to get a suitable trainer.

[Jon H]

i can see what you are getting at cuban but my view is that warbirds (as our 2 examples are warbird based) just aint that difficult. If we mirrored the two videos but substituted an extra, or a cub, or any other model irrespective of price, the core issues of loss of directional control, poor planning/decision making etc would remain. The only difference is that WWII fighters are unforgiving of these issues and will bite you. Getting away with it on other models for years builds bad habits. 

 

Keeping a model straight on the takeoff roll is a basic and fundamental skill that even an A cert pilot should have and while some models, like my nieuport, are less willing than others to stay straight its still not something that should be beyond the ability of anyone here. 

 

As the other guys have said you cant beat experience and promoting automation as a means to try and make it easier and tempt people to take a shortcut is not the right approach to the problem in my view. 

 

 

 

 

[Chris Walby]

I think we are moving on to new territory, but that's ok.

 

As for technology I have to disagree with Jon, well in part 😉 so best I explain my rational. Technology can help but it can also be a hinderance and the old adage for "don't push a bad decision" springs to mind.

 

As an example lets pick on my SU47, ok the wings are facing the wrong way but its all relevant to the conversation (you might notice the odd position of the nose wheel after the first attempt of take off!). 

 

Now some might say for a relatively inexperienced pilot this was more than I could bite off and you would be right, but you don't gain experience by flying the same high wing trainer forever! 

Facts: Even though this has twin 70mm fans, it sufferers from a loss of lift on the take off roll due to large cheat holes on the underside disturbing airflow. Longer UC just turns it into a high speed shopping trolley from a stability point of view.

 

OK its a handful to fly but the problem is getting it to that stage

 

So the answer is to hand launch it and this is where its very marginal and critical on the control inputs to allow airspeed to increase, but not allow it to touch the ground. No problem as all you need to do is launch it 20 times and gain the experience, but if it hits the ground it gets damaged and I lose the chance to gain the experience!

 

Leap of faith moment

Other products are available, but Spektrum do a RX with gyro and safe, now if gyro's are Marmite I hate to think what you guys think of safe (for another thread please) and hear me out...

The model should have been flown and trimmed prior to AS3X (gyro) and safe being set up and I have safe set for 15 degrees climb rather than the standard level setting. Now its just a case of switch safe on, power up and launch (I still have control with the sticks should some input be needed) and away it goes with a consistent launch. Once its gained a bit of height and speed I switch safe and the gyro off and grab the tiger by the tail, but at least its in the air.

 

In summary, yes you can use technology and it is better or as good and a experienced pilot, but flying around with safe on is very boring. Now this brings me to two important points, firstly if its a flying dog the technology will only hide it until you switch it off and then you will be higher and faster, thus at greater risk of damage/injury if control is lost and secondly for me its a means to an end and just that (for launching tricky models).

 

Parting thought - the problem is training and well sorted models. Everyone gets used to ultra reliable electric models with little or no vices. The high wing foame trainer hardly ever needs re-trimming and no poor manners and that's all the trainee experiences...until they come across something way more challenging.

 

Lastly - Thanks Jon for your advice "Always have a plan B" because one day you'll need it and that is not a good time to run out of ideas. 

 

 

 

 

 

 

 

 

 

 

 

 

[Chris Walby]

While I was typing the thread continued...

 

Experience is a great thing, if you get the opportunity to actually gain it. Well mannered foame's don't give the new pilot that experience, pilots jump the middle ground and progress onto flying models of with they don't have experience (me included), but there are some dogs out there (SG Hurricane and SU 47) that are fundamentally screwed and the technology might stop them becoming bin liner fodder.    

 

Technology has its benefits or we would all still be using castor...It can be used to assist us in our hobby of flying models and thus the enjoyment, but once it becomes all controlling then its just a means to an end IMO.

[Martin Harris - Moderator]

3 hours ago, Jon - Laser Engines said:

 

While its probably another argument entirely i always stand behind models for takeoff on their maiden flight. The reason is that directional stability is the most important thing as it allows the use of the full runway. Its no good if you exit stage left at a random point as the poor chap in the video at the bottom clearly demonstrates (the action starts at 2min 30). 

 

 

Crashed petrol model and fag hanging out of the recovery crew’s mouth?

 

I’ve never really understood the argument that directional control is easier stood behind the model except perhaps for early pilots who have yet to connect with a model coming towards them - not many of us stand on the approach line while we’re landing. Being comfortable with your procedure on a maiden is important and if you and your club are happy then go for it but as our club’s safety officer, I have a dislike of people wandering around on the field unnecessarily and a sneaking suspicion that the occupants of the pilot’s box are slightly safer if an errant model is heading towards its pilot rather than away from him!

It’s a shame that standing behind the model didn’t seem to help the “pilot” in the video - at no time did I even see the tiniest movement of the rudder!

[john davidson 1]

Gyro certainly helps hand launches by the pilot, without a helper it gives you time to get your throwing hand on the stick, several times I have rushed and missed the stick 

[Nigel R]

Couple of guys in the club use gyros on small hand launch EDFs; avoids the thing going south before they get a chance to get both hands back on the controls.

 

I'm on the fence as to gyros in big stuff. Getting experience of torque, swing, in flight oddities, etc, is a bit of a chicken and egg... That said, on the warbird front, there was a reason why the traditional path went from trainer -> low wing trainer -> fast, high wing loading aerobat -> warbird. The small steps maximise chance of success at each step.

 

The SAFE system is a bit of an odd one. I think a simulator is cheap and will get you way past the point that a SAFE equipped model can.

[Jon H]

I too dont like people dancing around on the runway for ages. I have seen some chaps stand out there for what seems like an eternity faffing about with one thing or another. With power and control checks done its not a long process getting out and getting going. At my old club we had a runup box on the edge of the runway to do your power/control check. You can then ask for clearance from the pilots, then either taxi out or walk out. Obviously hand launch models had to walk out no matter what so we covered all takeoff's under the same rules as it was easier than trying to create complicated exceptions to rules. 

 

Still, i have seen that most find it easier to keep the model straight when they are behind it as right is right and left is left and its more instinctive. Its also much more obvious when it deviates a small amount so reacting earlier is easier. As you say though, it didnt help our mustang pilot and i dont think i saw it move in either video. 

 

On my own models my nieuport and P39 are the two i still stand behind when taking off as they are least controllable when it comes to heading. They are also the two that i cant taxi into position so i have to talk out there anyway and its faster to walk out, send it, get off the strip. Otherwise everyone has to wait for me to trudge over to the box. I can and have taken off to the side, but in the case of the nieuport especially with its cross wind sensitivity its just more comfortable from behind. 

 

 

[Chris Walby]

15 minutes ago, Nigel R said:

Couple of guys in the club use gyros on small hand launch EDFs; avoids the thing going south before they get a chance to get both hands back on the controls.

 

I'm on the fence as to gyros in big stuff. Getting experience of torque, swing, in flight oddities, etc, is a bit of a chicken and egg... That said, on the warbird front, there was a reason why the traditional path went from trainer -> low wing trainer -> fast, high wing loading aerobat -> warbird. The small steps maximise chance of success at each step.

 

The SAFE system is a bit of an odd one. I think a simulator is cheap and will get you way past the point that a SAFE equipped model can.

I agree safe is odd,  in fact its more that odd and definitely should not be used by novices as they will have to relearn controls all over again once safe is switched off. For me safe is just a launch tool that is used to improve reliability of getting it in the air. Gyro's can be used to expand the envelope of when you can fly a model and it still be enjoyable as opposed to just trying to avoid the ground.

 

As for gyros in big stuff is it really necessary, well perhaps if the model is such a dog it needs it (SG Hurricane). The alternative is to modify the model (SG Hurricane) by moving the engine/firewall, UC and a load of other things to get it close to half mannered then the gyro is a much cheaper option.   

[Nick Cripps]

I don't think SAFE is particularly relevant for the standard training methods used by most clubs in this country and actually hinders progression.

 

I think it is aimed at those who live in the outback without access to training facilities and who learn to fly by themselves on a large prairie with not another soul in sight.

[Paul De Tourtoulon]

Gyros in big jets is the normality over here for some raison they say to stop the planes fishtailing ( not sure if it's the right term  )

 Nothing in my Rafale.