Into the blue

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First Steps in rc flying.

Good advice to all those interested in rc flying is to initially invest in a solid and reputable flight simulator – Phoenix is generally considered to be one of the best. This reduces the pain and costs associated with crashing your model whilst developing flying skills. Anti-cipate 6 – 12 hours on this before taking your model up and remember that wind and light conditions are different at the flying field to those in the sim when you maiden.

There are good value bundles around including a transmitter (i.e. Spektrum DX6i – a solid transmitter which is good for planes/helis for the first 2 – 3 years in the hobby), one 4 channel receiver (AR400) and the Phoenix Sim itself. Other well known manufacturers of TX include Futaba, JR and many others – many people swear by specific brands. Members will be very happy to discuss the options and merits of all starting points in the hobby.

In terms of models, the Chris Foss Wot4 foam-e is a regularly recommended model – IF you can be accompanied by an experienced flyer with a buddy lead (enables the experienced party to take over control when required). The Hobbyzone Super Cub is also a good solid first plane – having only 3 channels (no ailerons). A trip to a club meeting or the flying field will yield equally valid (and different) guidance to any new starter. Another stand out beginner model is the Multiplex Twinstar II.

How to tackle your first flight with that new model.

Article by John Newton, Heanor and District Model Aircraft Club Instructor.

Introduction

 

The first flight of a new model is always a nervous moment – will it soar skyward gracefully or will it come back to earth with a bump? There is only one way to find out. Over the years the author has test flown many different models from ducted fan jets to flying wings. Here is a guide to making your first flight with that new model an enjoyable and successful enterprise.

Rules and Recommendations

 

The article below is intended merely as a guide. For a full breakdown of rules and advice regarding the flying of model aircraft please refer to the latest British Model Flying Association Members’ Handbook and the BMFA website. The BMFA also provide a very good guide for beginners called “Up and Away” available on their website. This article is mainly aimed at electric models but many of the points apply equally well to I.C. aircraft and gliders.

Before you fly

 

There are several things you need to do:

  1. Ensure your frequency is free for use and that it is o.k. to turn on your transmitter (your site may operate a pegboard system or other form of transmitter control).
  2. Perform a range check on your Transmitter. Remember the BMFAs’ S.M.A.R.T

S              Switch on

M            Model selected is correct / Meter in the green

A             Aerial is secure / extended

R             Rate switches all in correct positions

T              Transmitter voltage good and Trims all in correct positions

  1. Check all of your batteries are fully charged.
  2. Check the model is undamaged and everything is secure including electrical connections.
  3. Check the propeller is secure, undamaged and free to rotate (the right way!).
  4. Run the model at full throttle (ensuring that you are in a safe area to do this and the model is securely restrained) for a reasonable length of time to check it does not overheat or cut out – you do not want to find this out during take off!
  5. Check all controls are moving the right way and by the correct amount (try with the motor running and switched off).
  6. Check your model has the correct centre of gravity location with the battery installed.
  7. The author would highly recommend you have BMFA insurance, most clubs insist on this.
  8.  As stated in the BMFA handbook, think S.W.E.E.T.S, this stands for:

S              Sun – Check sun location and wear sunglasses or a cap if required.

                W           Wind – Check wind direction

                E              Eventualities

                E              Emergencies

                T              Transmitter control

                S              Site rules

Getting airborne

Prior to take off:

  1. Familiarize yourself with no fly areas (dead airspace) and potential landing areas should the model get into difficulties. Plan your flight path taking these into account along with the wind direction and any obstacles.
  2. Take any pre-flight photos. It may also be useful to get a helper to video the flight for analysis later.
  3. Line the model up into wind and check where other models/pilots are prior to takeoff.
  4. Be aware that the model will almost certainly need trimming to achieve level flight so familiarize yourself with the trim switches/sliders on your transmitter and be ready to use them once you have gained sufficient height (you could get a helper to do this).
  5. Are you happy that you are fit to fly the model? If you are tired, stressed, lack sufficient experience, inebriated (!) or otherwise unfit then you should not fly the model as it will likely end in tears. Don’t be afraid to ask a more experienced club member to fly the model first and trim it out for you. This said being the first to fly the model gives an enormous sense of satisfaction and helps build confidence with the model.
  6. Think about the models expected performance and try to plan for it. If it is a glider you may find the roll rate sluggish, a pylon racer may have a high stalling speed, a biplane will have high drag and will not glide well if the motor cuts out. Remember a model can only be flown within its own limitations, you cannot expect a scale model with a high wing loading to be able to fly as slowly as a glider so do not plan to fly it in this way. Fly within both the models and your own capabilities, a model may be capable of very high speeds but only fly at a speed you are comfortable with and remember, you can always throttle back.

Chocks away

We are now ready to take-off. Call “Take-off” to make everyone aware you are about to Take-off. Take a deep breath and open the throttle gradually. Use the rudder to keep the model straight and compensate for the torque of the motor. Use the ailerons to keep the wing level. Allow speed to build before gradually lifting off using some elevator. Climb at a shallow angle with the wings level. Avoid any sudden changes of direction, height and speed.

 

Most people are naturally hesitant on the controls on a first flight. Many a model has crashed due to the pilot being too slow to correct the models flight. Don’t be afraid to use both the elevator and throttle to keep the speed and height of the model as you want it – if the models nose raises up and it looks as if it is about to stall (as often happens) feed some down elevator in and hold it until the model levels out. If the model is haring about the sky throttle back, faster models are nearly always harder to fly as they cover the sky quicker giving you less thinking time and also the controls become more sensitive.

 

The key point to remember is don’t panic, wildly moving the sticks around to their full deflection is unlikely to help a situation. Remember that height is your friend, giving you time to ascertain what the model is doing and how to correct it. If the model stalls allow it to build up airspeed before gradually pulling out of the ensuing dive, frantically pulling in up elevator immediately will likely cause another stall due to lack of airspeed.

Key things to keep an eye on during the flight:

  1. Speed – is the model flying too fast/slow, don’t be scared to alter the throttle to get the model flying at the speed you want
  2. Altitude – is it too high/low?
  3. Attitude (orientation) – Try to keep the model fairly level on the first flight till it is trimmed out and you are comfortable with it.
  4. Position – is it clear of any obstacles and other models, is it close enough to see, is it where you intend it to be?
  5. Sound– does the motor sound o.k., is there any flutter?
  6. Time – how much battery/fuel do you have left, do you need to land?

 

Fly your chosen flight path gaining height as you go. Once you are high enough throttle back to cruising speed and use the trims to set the model so it will fly straight and level “hands off” (be aware that models with low or neutral static stability such as aerobatic models will eventually deviate from their flight path no matter how well trimmed they are).

If it goes wrong

If you start to lose control of the model for any reason or it is not flying as expected check your speed as this often the cause. Is the model flying fast enough? Too slow and it will stall, too fast and the controls may become very sensitive to the slightest movement.

Try to level the model out and to bring the speed and height back to a level you are comfortable with. Think about what may be causing the loss of control and try to correct it – it may be over sensitive controls (use the rates), wrong Centre of Gravity or any combination of factors. Now is the time to decide if you can correct the fault whilst still airborne or if you need to land to make the adjustments required. If all else fails and you cannot get the model under sufficient control, throttle back to reduce the impact speed and try to bring it down in a safe area away from other people, animals and obstacles.

Below are a few problems you may encounter and some possible remedies.

Model tends to veer off track during take-off run – Ground Loop – This is common on vintage models where the main undercarriage is well ahead of the centre of gravity (as in tail dragger types). The drag of the wheels tends to slew (yaw) the model round to one side during take-off. The solution is to move the main undercarriage back and/or use more rudder to catch the swing before it develops (you may find a large amount of rudder abruptly applied is required).

Model rears up when under power – insufficient down thrust on the motor.

Model rolls to left when under power – insufficient right thrust on the motor.

Model appears unstable and very sensitive to controls – try reducing speed. If it improves try reducing the control throws using the rates, if it is still sensitive the centre of gravity is likely to be too far back.

Large amounts of up elevator required to maintain level flight &/or sluggish elevator response &/or poor glide slope – Centre of gravity to far forward.

Model suddenly drops a wing – ‘Tip stall’ – this is when the model stalls first at a wing tip (rather than at the centre) and immediately rolls to that side. To avoid this increase the flying speed and avoid sharp/steep turns and sudden up elevator application. This is more likely on models with high aspect ratio (narrow) sharply tapered wings, swept back wings also tend to tip stall.

Model enters a spin – A spin occurs when the main wing stalls in an asymmetric fashion (usually due to the model being yawing as the stall occurs). As the spin develops the whole wing becomes stalled but one side is more deeply stalled causing the model to rotate (yaw) and descend rapidly. To recover from a spin rudder must be used to stop the rotation then elevator used to level out. Moving the centre of gravity forward and increasing the fin area will reduce the tendency to spin.

For spin recovery remember P.A.R.E. (developed by NASA)

  • P             Power to idle
  • A             Ailerons neutral
  • R             Rudder opposite (rotation of spin) and held
  • E              Elevator pushed down then up to recover when airspeed is sufficient.

Model oscillates both left to right and up and down rapidly – ‘Dutch roll’ – this usually occurs on models with a small fin area and large dihedral, throttling back will help reduce this effect. A cure for Dutch roll is to increase the fin area or reduce the dihedral amount.

Model enters a spiral dive when turning or when disturbed – ‘Spiral instability (divergence)’ – this is in many ways the opposite of Dutch roll, usually being due to too large a fin area or too small a dihedral amount. It should be fairly easy to recover from the ensuing dive using rudder and elevator. A cure for Spiral instability is to decrease the fin area or reduce the dihedral angle (note that wing sweepback has the same effect as dihedral).

Model porpoises up and down –‘neutral or negative dynamic longitudinal stability’ Centre of gravity too far forward or insufficient stabiliser area, again, throttling back will help reduce this effect.

Model enters steepening dive unexpectedly – ‘Tuck under’ – Centre of gravity too far back or insufficient stabiliser/elevator area, throttling back may help reduce this effect. If you cannot pull the model out of the dive with the throttle off try rolling the model upside down and using down elevator to pull out of the dive.

Model appears to vibrate or “buzz” violently – ‘Flutter’ – throttle back immediately and reduce speed, you may need to check for any play in control linkages or insufficiently rigid portions of the airframe.

Flight testing

Once you have the model trimmed and flying happily here are a few things to check:

  1. Take the model high and check the stall to see the stall speed and whether it stalls straight ahead or tip stalls into a spin/roll. Ensure you keep well above this speed during the landing circuit.
  2. If you have flaps, take the model to height, slow down and deploy them to see how they affect the models flight. You may find they alter both the stall characteristics and the elevator trim required.
  3. Half loop the model inverted (at height) and make a mental note of how much down elevator is required to maintain level flight (this is useful if you intend to do a slow roll etc.).
  4. Trim the model to glide level with the power off (without stalling). Power up to approximately half throttle and keep it there. If the model continues to climb steeply under power you need to add some down thrust to the motor (this may only need a couple of degrees).

Landing

When you decide it is time to come in, plan the landing circuit you intend to follow as you did with your takeoff route avoiding obstacles etc. Check the wind direction and that the strip is clear and call “Landing!” to make everyone aware you are about to land.

Most people over-shoot on landing. This is usually due to coming in too steeply and carrying too much speed which is hard to bleed off if you don’t have airbrakes. Try to make the landing circuit fairly low and shallow. Avoid sharp banking turns which could lead to a stall and turn onto your final landing leg well away from you so that you can bring the model in straight and level, using the throttle to keep the speed comfortably above the stall. If you are too high throttle up and go round again – don’t be afraid to have a few practice runs slightly higher up. I would advise against using flaps on the first flight unless absolutely necessary as this is one less thing to think about.

Post flight briefing

Assuming all went well give yourself a well earned pat on the back, the first flight is never easy and requires skill and quick judgment to be successful.

  1. Turn off the model and disconnect the batteries.
  2. Turn off the transmitter.
  3. Check the flight battery to see how much capacity you have used.
  4. Check model for any damage.
  5. Make a note of control surface positions, neutralize the trims on the transmitter then adjust the linkages on the model itself so that the same positions are achieved with neutral trims on the transmitter.
  6. If the model had any unsatisfactory or unexplained characteristics make a note of them so that you can try to correct them for future flights.

 

Whilst the above is not a comprehensive list I hope that I have helped raise a few items that may make your first foray into the wide blue yonder a memorable experience for all the right reasons. I am pleased to say that using the above methods has helped prevent many a crash and led to many successful first flights. Happy landings!

 

May I also say thank you to all the model fliers of the Heanor and District Model Aircraft Club and elsewhere who over the years have given the author valuable help and advice regarding flying models.