HELICOPTER TRAINING SYLLABUS
Ask Harry Helicopter
HELICOPTER TRAINING-
Study and preparation guide for people busy or starting with an initial helicopter license
BASIC HOVER IN GROUND EFFECT
AIM: To teach the student to hold a given position relative to the ground, maintaining constant heading, height and Rrpm.
WHAT ARE WE GOING TO DO?
We'll find the biggest area in the Southern or Northern Hemisphere, position the helicopter there and hover. Simple.
WHY?
Like they say in the classics: "Flying is heaven but to hover is divine". I guess what makes helicopter flying so intriguing and the reason we want to fly them is the fact that it can hover. Need I say more why we need to hover? Let me put your mind at rest; you might not be able to hover in the first session, but guess what you don’t need to. There are normally a couple of sessions available to hover so there is plenty time.
HOMEWORK:
Ground effect: When a helicopter hovers close to the ground the induced flow passing through the disc will be deflected outwards when hitting the ground. However some will be deflected upward and inwards creating a dome of slow moving or stagnant air under the disc. This dome actually opposes the induced flow thereby reducing the induced flow which effectively increases the angle of attack. A helicopter can therefore hover with less power in ground effect than out of ground effect.
Tail rotor drift (translating tendency): In order to compensate for torque a tail rotor is used. Due to the fact that the tail rotor is attached to the end of the tail boom a sideward force (pull) will exist pulling the helicopter to the right in the case of a counter rotating rotor system.
Tail rotor roll: In order to compensate for tail rotor drift left cyclic pressure is used which in turn will lead to tail rotor roll. In the case of a counter rotating rotor system the helicopter will hover with left skid low.
Pendular action: Since the fuselage of a single main rotor system helicopter is suspended from a single point and has considerable mass it is free to oscillate longitudinally or laterally in the same way as a pendulum.
Over pitching: Over pitching is the result of having applied too much collective with not enough Rotor Rpm. In other words we have too much rotor thrust with not enough centrifugal force which results in the blades coning up and thereby reducing our effective disc diameter.
COMMON MISTAKES/ADVICE:
For the first session your instructor should show you the effects of controls in the hover as it differs very slightly from the effects in forward flight.
I suggest that you begin with one control at a time!
The collective is normally the easiest. Most of the time we would like to hover in ground effect (IGE) so a lot of students struggle to maintain the desired height for ground effect.
Remember we refer to skid height when we talk about our hover height. Especially in the beginning one shouldn’t look at the skids to determine this height, but rather use your peripheral vision to get a feel for the correct height. Over controlling is obviously a common mistake so rather think of it as applying pressures to the collective and not making movements.
In theory if you leave the collective the helicopter should maintain height for quite a while so all the up and down movements that we see in the beginning is self induced. Also remember not to squeeze the throttle too hard as this will prevent the throttle from turning and we might end up with a low Rrpm situation (Over pitching). This stands true whether you fly a helicopter with or without a govenor. Remember the recovery action for over pitching is to reduce (lower) the collective pitch setting and open the throttle even if it means opening the throttle fully.
The most common mistake when it gets to the yaw pedals is over controlling or over shooting our reference point (point on the nose in front of you).
It is very important to have your feet in the right position when flying the yaw pedals. I recommend flying the pedals with the ball of your feet and to push your heels outwards to get a better platform for your cyclic arm. Effectively all you need is a pressure on one foot. Assuming we fly a counter rotating helicopter this will be the left foot. So the right foot needs to be like a stopper. When you want to apply right foot pressure rather think of it as releasing the left foot pressure.
When the nose swings and you make the corrective yaw pedal movement remember to release the pressure slightly just as you get to your point on the nose to prevent overshooting. Tenseness on the yaw pedals is obviously a common mistake in the beginning. If you think about it if you apply the left pedal for instance your right foot will sense a pressure under the foot and you will step on the yaw pedal to relieve the pressure, conversely if you apply right pedal your left foot will sense a pressure and you’ll step on the left pedal and so it becomes a vicious circle. A very important aspect to remember when it comes to the yaw pedals is the fact that if you are over active on the yaw pedals it will influence a lot of other things for example the rotor rpm which will have an affect on your height, which in turn will result in you pulling collective which will then have an influence on your rotor rpm. Sometimes students tend to be a bit over cautious and give the helicopter a bit too much leeway. There’s a fine line between taking CHARGE and letting the helicopter do its own thing. At the end remember it’s just a machine which we must respect but also take CHARGE of.
When it comes to the cyclic if I may give you a couple of tips: Fly attitude on the horizon; make small attitude changes; make even smaller cyclic movements (in fact don't move it at all); relax; relax; relax; open your hand a bit (don't squeeze the living s… out of the cyclic grip); if you move stop the helicopter in your present position, don't try to bring it back where you started. One way of relaxing your grip on the cyclic is to deliberately open your pinky and ring finger slightly as this muscle movement is opposite to the rest of your hand trying to squeeze the cyclic. Having said that always hold the cyclic in such a position that you are able to reach various buttons like the radio transmit button and the cyclic trim for example.
Your primary reference should be the horizon and as you get the hang of it you can bring your scan closer to the helicopter but remember the essence is SCANNING so don’t fixate on a given reference point. Keep moving your eyes. Another way to describe fixating is to say: “you look but you don’t see”. I always tell students your brain is like a computer and your eyes are the medium of information you give the computer. If you just stare at the horizon it’s the only information your brain can interpret but the more you look around the more information your “computer” can process and the more information there is to work with the calmer (less tense) a person gets.
If you make an attitude change always fly the helicopter back to the hover attitude. In other words if you make a cyclic or for that matter a yaw pedal movement relax or reverse the movement slightly otherwise the attitude change will just get bigger. For example if we move forward we don’t just RAISE the attitude, we select a slightly higher but SPECIFIC attitude. If we select a new specific attitude we’ve got something to work with, but if we just pull back on the cyclic we don’t know how much or how far to pull.
When starting to fly with all three controls for the first time and things go a bit pear shape don’t try and fix everything at the same time because invariably you’ll use the wrong control to stop a particular movement. Calm down and stop (fix) one movement at a time. Ultimately in my opinion, the secret when it comes to hovering is to ANTICIPATE the movement before it actually happens. How does one do it you ask? Unfortunately it takes practice and experience.
CONFINED AREA & OGE OPERATIONS
AIM: To teach the student how to enter, maneuver within and leave a confined area safely.
WHAT ARE WE GOING TO DO?
We’ll find a confined area on the airfield or in the General Flying area and practice what the aim says.
WHY?
I think one of the main reasons for wanting to fly a helicopter is the helicopter’s ability to take off and land from virtually any place.
HOMEWORK:
Confined area operations.
COMMON MISTAKES/ADVICE:
I must emphasize that the aim is not to teach you to land in the smallest place possible but rather to teach the correct technique for landing in a smallish place. A common perception is that confined area operations is a low level tight circuit type of exercise. ITS NOT.
Confined area operations start with planning on the ground. Look at the performance figures for OGE (out of ground effect) hover performance in the Aircraft Operating Manual. Determine the weight, look at the temperature and establish if you can hover OGE. I am not saying you must ignore the In Ground Effect performance but I take it for granted that by now you do realize that the Out Of Ground Effect performance is the most restrictive.
When arriving at the confined area planning is of the utmost importance. Things to consider are the following: Shape and size of the confined. Type of surface and slope. The position of the sun and the surrounding area (undershoot and overshoot area). It is also very important to get yourself an aiming point in the confined area, in other words a point on the ground as far possible towards the front of the confined where you would like to see the helicopter once you’ve landed. The significance of this is that you must remember things start to look different as you get lower and closer on your approach to the confined area. A lot of doubt starts to set in but if you fly towards your aiming point it will serve as reinsurance and conformation about what you saw when you did your inspection turns of the confined area.
Also give some serious thought to power available and power required to land and take off in the confined, although the planning was done before take off consider fuel burnt and temperature variation other than that used when you did your planning. Once the inspection turn is completed plan your pattern the same as a normal traffic pattern. Confined area operations normally gets done at unplanned and unfamiliar areas to the student, so when planning and flying the traffic pattern the pattern height normally gets judged with the naked eye.
Once you’ve established you pattern height look at the altimeter so you can at least judge your progress when it comes to maintaining altitude on the downwind leg and for the remainder of the pattern for that matter. Like I said before people tend to descend too quickly whilst flying the traffic pattern resulting in a low level exercise.
During the final approach into the confined a common mistake is to fly too fast resulting in a harsh flare and lowering the collective excessively. A lot of students defend this by saying they scared of settling with power or they want to avoid flying in the shaded area of the height velocity diagram. Being scared of vortex ring is good but in order to land in a confined area you’ll have to fly into the shaded area of the height velocity diagram as some stage, so MAKE PEACE WITH THAT. The art is off course to minimize the time you spent in the shaded area of the height velocity diagram but initially I suggest being more on the conservative side i.e. rather too slow than too fast. Another common mistake is for students to look at the Manifold Pressure (MAP) gauge whilst on the final approach to the confined in order to fly the glide slope. Looking at the MAP gauge WILL NOT keep you on the glide slope or in your profile. Fly what YOU SEE and FEEL in your backside whether the profile is right. I’m not insinuating that you must ignore the power but you need to fly OUTSIDE and create an imaginary glide slope in your mind and stay on that profile. Sometimes I get the feeling that student’s think they not allowed to lower the collective beyond a certain point. It’s true off course that if you lower the collective excessively the helicopter might go into a state of autorotation but still sanity must prevail.
During the final approach phase be “go around” orientated. Never be scared to initiate a go around and try the approach again. If you do a go around climb up to your circuit altitude so as to prevent a low level pattern resulting in another bad approach.
Depending on the type of confined area the take off out of the confined area might be a pure vertical take off or the type where you can go slightly forward and vertically upwards in order to gain from translational lift.
During the approach and take off phase it is very important to get the MIX right between height and speed. How do you know its right? In my opinion you’ll feel it in your arse!
Many a time I’ve observed student’s body language during a confined approach, where the body yells out “go around” but the student does nothing. When I ask them afterwards if they’ve considered going around most of them acknowledge in the affirmative. Why then don’t they do it? When you refer back to the sequence on limited power I asked the same question. Why don’t pilots sometimes do the obvious correct actions? My answer is the same; maybe another book is in the making. I sometimes think it’s a question of pride or some pilot’s think by going around it makes them a lesser pilot. I have gone around hundreds of times in my career and I would still like to do thousands more. People swallow your pride or you might end up like this:
All information contained on this website is for informational purposes only.
*Disclaimer:
www.askharryhelicopter.com does not warrant any company, product, service or any
content contained herein.
Here’s an example of Sequence 8 -
© Harry Helicopter Training Syllabus 2008 -