18. GENERAL MODEL SAFETY

18.1  General Safety
(a)  Models should be built to a standard such that they will not fail under normal circumstances, giving  particular attention to control surfaces and connections.

(b)  They should be thoroughly checked prior to each flying session and after any hard landing.

(c)  It is recommended that rounded spinners or safety propeller nuts of the domed type are fitted to internal combustion and electric powered models and that gliders and pusher powered aircraft noses should also be rounded (no needle noses)

(d)  Care should be taken by the operator that propellers are of suitable size and construction for their engine or motor’s operating speed. All propellers should be carefully balanced. Cheap and efficient propeller balancers are available from your local model shop.

(e) Do not use propellers on i/c engines that are designed for use on electric motors.

(f)   On internal combustion engines and electric motors, damaged propellers must not be used. Inspect your propellers regularly and replace any that are not in good condition

(g)  Metal propellers must not be used.

(h)  The use of locking prop nuts is recommended, especially for 4-stroke engines. A backfire or ‘kick’ can loosen a prop nut and locking nuts will prevent the propeller flying off. The safety factor of locking prop nuts on four-stroke engines is more important than the recommendation to use ‘domed’ safety nuts so, if you have to choose, go for the locking nuts.

(i)   Heavy ballast, or any other heavy part, subject to jettisoning in flight is prohibited. Jettisonable ballast must be of a safe nature e.g. water.

(j)   All R/C models are subject to in-flight vibration, landing knocks, transport damage etc. Be sure that receivers and batteries are well protected, servos are fixed securely, control linkages (pushrods, snakes, closed loop etc.) are robust enough for their purpose, are properly supported where necessary and are as slop free as possible and that all control surface hinges and horns are fitted correctly. Pushrod clevises should fit control horns cleanly with no sideways strain and they should be fitted with a plastic or silicone tube ‘keeper’ as a secondary closure.

(k)  When starting an engine make sure that the model is restrained and cannot move forward. Restraint is best done by either a helper or by some mechanical means.

(l)   Never put yourself in a position where your face is in line with a turning propeller. A broken propeller will fly out and forward so make all engine adjustments from the rear if possible. A broken propeller will also be a danger to anyone standing nearby so take care that no-one is in line with it when starting your engine.

18.2    A Safer Flying Field and You
When you arrive at a flying field and before you start flying, we recommend that you take a few moments to consider the surroundings and the flights you will be making.

Think S.W.E.E.T.S.

       S    –     Sun
       W   –     Wind
       E    –     Eventualities
       E    –     Emergencies (Inc. Failsafes)
       T    –     Transmitter Control
       S    –     Site Rules          

Sun – Where is the sun in relation to where you will be flying? Will it affect your flight patterns? What actions will you take if you accidentally fly ‘through’ the sun? Should you be wearing sunglasses? Remember that low sun in winter can be a particular problem.

Wind – Consider the wind strength and direction. How will this affect your flights? Will you have to modify your normal take-off and, especially, your landing patterns? From your local knowledge, will there be any turbulence with ‘this’ wind direction and strength? And how bad might it be?

Eventualities – What will you do if you hear or see a full size aircraft or helicopter flying at low level near the field? What if the landing area is suddenly obstructed when you are on finals to land? What will you do if a nearby footpath or bridle path suddenly has walkers or horses on it?

Emergencies – You may have an engine cut at any part of a flight so consider where your deadstick landings might be safely made and which ground areas you should definitely avoid. How will you warn other field users if you have an emergency?  You may also have a complete loss of signal and therefore before every flight you should check that the failsafe is working how you expect it to.

Transmitter Control – Is the site pegboard in operation? If not, why not? Where has the pegboard been placed? Are you familiar with the system and understand how it works?

Site Rules – Are there any specific site rules you should be aware of? Most importantly, where are the no-fly zones or dead airspace areas on the site?

The answers to most of these questions are contained within these Safety Codes and your local Club rules but you will be making the final decisions as to whether flights can be made safely. If conditions are poor or a site is unsuitable remember that a decision not to fly can be both valid and sensible. We would also recommend that you review the sections on the sun and wind throughout the day as they obviously change over time and this may affect some of the decisions you will be making.

18.3    Radio Control Flying Safety
(a)  Before you do anything else, make sure that you understand and are complying with the field  frequency control system. NEVER switch on until you are sure it is safe. ALWAYS check the pegboard – on EVERY flight.

(b)  Before every flight, check that transmitter trims, rate switches etc. are in their correct positions and that each control surface on the model moves freely and in the correct sense.

(c)  Immediately before take-off, flight controls must be checked for full, free and correct movement under full power if applicable. If there are any doubts as to their operation, DO NOT FLY.

(d)  Flyers using adjacent frequency channels should first perform an interaction check. If they regularly operate together they should perform the check every two or three months.  See the previous section on Radio Control and Your Club for details of the simple check you should perform.

(e)  Inexperienced R/C flyers should never fly without an experienced helper.

(f)   Unless positive controls are in force, all flyers should use the same take-off area at any particular flying session.

(g)  Do not taxi in or out of the pits area. Wheel or carry your model well clear of the pits before commencing taxying and stop the model well clear when taxying back after landing. Do not put other flyers at risk.

(h)  Before take-off, check that both ground and sky are clear and never take off or land towards other pilots, spectators or the pits area.

(i)   Always make the initial turn after take-off away from spectators and parking areas. Diving manoeuvres should always be pointed away from spectators, parking areas and other people.

(j)   Always maintain a clear view of the model and allow plenty of room between the flight path and spectators, other flyers or model pit areas.

(k)  DO NOT OVERFLY houses, domestic gardens, car parks, traffic, railways, organised games or spectators.  You may not be able to control people walking by at a reasonable distance from the take off/landing area but you should take care not to overfly them at low level.

(l)   At any sign of malfunction or jettisoning of model parts, land as soon as it is safe to do so.

(m) Do not distract pilots, particularly when they are controlling models taking off or landing.

(n)  Clubs should exercise strict control over the take-off/landing area used. Pilots about to take off should inform people already flying. Pilots landing should have priority but must call out their intentions ‘loud and clear’ and must NEVER assume that they have been heard. A pilot going out to take off may not hear a call over the noise of his model’s engine.

(o)  NEVER assume that the landing area is clear even if you have called landing. In emergency situations call for help from your fellow flyers and always be prepared to land in a safe place off the landing area if necessary. In ALL cases, the safety of people is paramount.

(p)  Care must be taken at all times to avoid overflying operating transmitters. Pilots should stand together and should not be allowed to wander over the flying area when operating transmitters. Clubs should take action to prevent operating transmitters being taken out on to an active flying area when, for example, models are being retrieved (see the section on ‘Radio Control at your Club’).  There are exceptions to this particularly in some silent flight operations, and extreme care should be taken not to overfly transmitters in these cases.

(q)  Under no circumstances whatsoever should you move to the far side of the flying area so that you can land your model between yourself and the pits area.

(c)  Under no circumstances whatsoever should you fly between yourself and the pits area.

(s)  Take extra care when flying in adverse weather conditions. It is easy to lose sight of your model in fog or low cloud. Strong winds and turbulence can be a stimulating challenge but can catch out the unwary. Flying in rain can give serious radio problems if water gets inside your transmitter.

(t)   The staging of deliberate mid-air collisions at airshows and public displays is banned and they are not covered by the Association’s insurance.

18.4    Pre Flying Session Model Checks
On arrival at the flying site:

(a)  Check airframe for any transit damage.

(b)  Check that servos and linkages are secure.

(c)  Check undercarriage for secure fixing and correct alignment.

(d)  Check propeller for damage and secure fixing.

(e)  Check receiver aerial for damage and, with 2.4 GHz equipment, that the orientation is correct.

(f)   Carry out a range check if any changes or re-installation of equipment have taken place since the last session or if a history of range problems exists.

(g)  Carry out a failsafe check and make sure that it does what you expect.

(h)  Check that the receiver and transmitter batteries have sufficient capacity for the intended use.

18.5    Checks Before Each Flight
(a)  Obtain frequency clearance. Exactly what you do will depend on the rules of the site but be sure you understand exactly what you are doing and do not forget this step.

(b)  Pay particular attention to using the correct sequence appropriate to your model.  For 35 MHz this is usually ‘get the peg, Tx on, Rx on’.  For 2.4 GHz, you should be aware of any local transmitter usage limitations and if a flight peg is required, it must be obtained before the usual Tx on, Rx on sequence.  Note that some radio equipment and occasionally a specific model set up, require that the Rx be switched on first.  If this is so take extra care.

(c)  Check that all controls operate freely and do not bind or stick at any point in their movement.

(d)  Check that all controls move in the correct sense. For conventional models, stand behind the model and look for;

Elevator stick back – Elevator comes up.

Aileron stick right – Right hand aileron comes up.

Rudder stick right – Rudder moves to the right.

(e)  Check that all control surfaces are in their correct positions with the transmitter trims at neutral.

(f)   Look for any minor radio malfunctions such as slow or ‘jittery’ servos, glitches etc. If in doubt, DO NOT FLY.

(g)  Check Rx and Tx battery capacity is sufficient for the intended flight with an added safety factor.

(h)  With i/c models

(i)     After starting the engine and allowing it to warm up, check that the pick-up from idle to full power is satisfactory. Hold the model with its nose pointing upwards at a steep climbing angle for ten or fifteen seconds and check engine operation at full power. If the engine falters or cuts it is usually set too lean and must be re-tuned. Repeat the test until the engine runs correctly in the nose-up attitude.

(k)  With electric models

(i)     The first and most important principle of electric flight ground safety is to understand that the instant you start to plug in the flight battery, the model you are holding may transform itself from a dead airframe into one with its motor running at full revs and all controls moving. No matter how good your other safety checks, you must be prepared for this to happen every single time you start to connect the flight battery. If a separate Rx battery is fitted then you have the opportunity to check the operation of the radio equipment before the flight battery is plugged in.

(ii)    Since plugging in the flight battery is nearly always a two-handed job you must give serious thought to how your model will be restrained BEFORE it does something you don’t expect.   When plugging in, positive restraint, either by a helper holding the model or by some other method, and staying completely clear of the propeller must always be part of your regular routine.

(iii)  Electric motors have very different power and torque characteristics to normal IC model engines. You must take very great care when setting up their control systems and handling them as an accident, such as the propeller hitting your hand, which would stall a glow engine, might just make an electric motor turn even harder.

(iv)  Just before you go out to fly, DOUBLE CHECK that all transmitter trims, rate switches, mixers etc. are in their correct positions and that the transmitter meter is ‘in the green’ or that you have the correct model selected and that your aerial is extended.

(v)   Finally, with the aircraft held securely (usually on the ground for i/c models but not if the failsafe is set to retract the undercarriage), open up to full power and re-check all flying controls again for full and free movement, also noting any glitches, hesitations or odd vibrations.  If ANYTHING seems odd, DO NOT FLY

(l)   Be S.M.A.R.T. with your transmitter.

       S…. Switch on

       M…. Model selected is correct / Meter in the Green

       A…. Aerial secure / extended

       R…. Rate switches all in correct positions

       T…. Transmitter voltage good and Trims all in correct positions

18.6    Checks After Each Flight
(a)  Receiver OFF then transmitter OFF (Unless your equipment manufacturer specifies otherwise).

(b)  Clear the frequency control system.

(c)  Clean the aircraft down

(d)  Check propeller, airframe, undercarriage, wing fixing etc. for security of fastening and for possible flight or landing damage.

(e)  REMEMBER – Never fly with a damaged aircraft or propeller, or with any possible radio problem.

Next Section 19. SAFETY ADVICE FOR SPECIFIC MODEL TYPES

 

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