Best Aviation Articles

So you’ve considered learning to fly in the UK and even America. Now it’s time to consider why you should look at doing your flight training in Spain.

OK! You want a commercial pilot’s licence or a frozen ATPL as they call it and you fancy sitting up front in the cockpit of a Boeing737 or even an Airbus 320. What exactly do you have to do to get the necessary qualifications and more importantly the job?


I won’t kid you. Starting a career in aviation can be an arduous journey and an expensive one at that. Forget the cosy pictures of the deliriously happy British Airways Pilot, coming home to his lovely cottage in the country, open fire burning and his sweet wife ready to serve his every need. Unfortunately that’s the publicity and it doesn’t work that way in real life.

Reality check! More likely to be a career of loans to fund the flying training, sponsorship if you are incredibly lucky and living hand to mouth for the best part of 12-16 months and then with no guarantee of a job at the end of it. More likely you are going to have to go and become a flying instructor, get scared silly by crazy students, just to build your hours up to make yourself attractive enough to be hired by the airlines.

However, there is a small respite. That is, that there is currently a shortage of pilots around the globe. But don’t kid yourself that the airlines are going to be falling over themselves to hire yours truly!

Anyway, what type of flight training should you consider when spending all that hard earned (or borrowed) mullah and where should you do the training?

Easy isn’t it? Um sorry, no it’s not!

You could train in the UK. Well, you could if the weather holds out long enough. But unless you are considering getting webbed feet from all the rain and water, I suggest you look further afield. Costs for flying training can also be prohibitive in the UK, with everything being incredibly expensive.

So why bother with training in the UK? Er…well actually, you live there!! OK. Fair enough!

Look! These are just a few of the reasons why so many students are now making a point of training abroad – America, South Africa, Malaysia, Europe …,it just makes more sense for the time they can spend flying and for reasons of lower cost.


So why do your flying training in Spain? Easy! America is great, it’s cheap and its fast and the weather is good, but the end result is usually an American FAA licence. If you want to fly airlines in Europe, then you are better off with the JAR ATPL recognised licence, which you can use all around Europe and is also recognised worldwide. Secondly it’s the distance. Spain is only 1.5 hours away… how many hours is America away and finally who wants all the hassles of security, visas, paperwork that was caused by 911…not me!

So, to summarise, make it easy on yourself and do your flight training in Spain. Find a reputable school, that is professional, speaks English and will accommodate your needs. Spain is closer than the USA, it’s cheaper than the UK, the people are extremely friendly and the weather is great. The most important thing for you will be that you will finish with the all important JAR licence, with no need for messy conversions from American to European standards and you will have spent a lot less time away from your loved ones.

Written by Mike Piranty of Aerolink, based at Sabadell Airport, near Barcelona. He can be reached on 0034 647 044 889 or mike@aerolink.es.

Company website is www.aerolink.es/ingles/index.htm (English version)

“…Ever dreamt of obtaining your pilots licence and making it a  life long dream come true combined with the experience of a lifetime. Well this is possible and can be done in the heart of Africa. South Africa is on the most Southern end of Africa and offers a wide variety of cultures and scenes which is unique and also climates of a broad spectrum.

The pilot training is spectacular in Africa. The benefit of doing your licence in South Africa is that it is financially much cheaper. The training is of a high quality and standard and a unique training program is followed to produce a student that is professional and safe in his profession as a pilot. Your first flight you will introduced to the pre-flight of the aeroplane. Your first air experience is a familiarization with the GFA (general flying area) and also the sensations of flying and being in-control of the aeroplane.

From there you will be in the capable hands of the instructor to lead you up the first solo. This is the most memorable experience of any persons flying career. The sweet pleasure of being in-control of the aeroplane and having a sweet touchdown will have the adrenalin rushing and is an unbeatable experience at any level. After a nights celebrations it is back to consolidate on what you have learned. From there you will be getting more comfortable to go solo and the GF will be the next challenge where upper air work will be exercised up to where you will be proficient and ready for the navigation flights. After the navigation flights and preparation for the flight test you will be declared proficient by your instructor to go for the PPL flight test. This will be the most nerve wrecking moment in your life. The instructor will however make you feel at ease and his only aim is to see that you are proficient in your execution of procedures and that you are comfortable in flying the aeroplane. After the arrival from your test and on successfully passing it you will be the proud owner of a PPL licence and you are now ready to go out in to the wide world and fly. This however is a licence to learn and there is still allot to learn from own experiences to come.

After the month of training in South Africa you will be issued with a PPL certificate as proof of the life long achievement that you have dreamt for so long. This will cherish fond memories and will make you long for further experiences in Africa.

Thomas Fabian
African Flight Academy

This article was written by Becker Helicopters Pty Ltd and reprinted with their permission – March 3/08

 

 

 

 

 

All objects are subject to the gravitational pull of the earth relative to their mass. This includes you and me and it includes a helicopter.

As we are standing on the surface of the earth we will feel the weight of our body, which we can count as 1 G force or 1 positive G force. If we were able to conduct a manoeuvre that causes our apparent weight to increase we would increase the G force felt, in effect increasing our weight at that point in time. If we double our weight we double the G force or experience 2 Gs and so on.

If we were able to conduct a manoeuvre that reduced our apparent weight we would decrease the G force felt, in effect decreasing our weight at this time. Any reduction in the standard 1 G force we usually experience is known as a low G or a negative G situation. Reduce our weight by 1 we have experienced 1 negative G, reduced our weight by 2 we have experienced 2 negative G and so on.

In flight we are able to produce both a negative or low G (weightless feeling) and a positive of high G (increasing weight feeling) condition. Because G force deals with the laws of attraction then any manoeuvre that tries to pull us away from the earth (the body with the greatest mass we are closest to therefore the body with the greatest attraction) then we will have a temporary increase in the G force as we experience this acceleration away from the surface. Any manoeuvre that tries to accelerate our movement towards the centre of the earth (in other words assist the attraction) will lead to a temporary reduction in the pull of the earth and we will feel slightly weightless. The faster and harsher these manoeuvres the greater the change in the G force.

For example

You are travelling along in your new Mad Max Charger doing 300kph when you come to a small hump in the road. As you hit the hump you are forced away from the earth so you experience an increase in the G force and you temporarily feel heavy. Very quickly though the earth pulls the Charger back towards it and you start to fall towards the road again and now feel a reduction in the G force and you feel lighter.

 

 

 

 

 

Another example of G force is a typical giant drop rollercoaster. You experience a positive G force as you are propelled away from the surface, and you experience a negative G force as you fall back towards the earth.

 

Playing around with G force is great as a teenager and great in an aerobatic aircraft but in a helicopter with a two bladed teetering type rotor head it can have serious consequences.

Mast bumping

Mast bumping is generally a result of pilot induced over controlling of the cyclic leading to a negative G situation, however the negative G can also be caused by other factors without input by the pilot such as severe turbulence or a rapid lowering of the collective. It is a condition applicable to two bladed helicopters with a teetering rotor head such as the R22/R44, Bell47, Bell 206 Bell205/212 series and other similar designs. Mast bumping is a result of the helicopters main rotor hub (head) making contact with the main rotor mast. The head literally ‘bumps’ the mast and can damage or snap it off. For this to happen excessive flapping of the disc must occur and this is impossible if the helicopter is flown within its designed tolerances.

Excessive flapping may be the result of

• Flight resulting in a negative or low G situation, this may be due to manoeuvring, turbulence or similar
• Sudden, abrupt and large changes made to the cyclic, especially in the fore/aft direction
• Sudden and unanticipated lowering (or dropping) of the collective
• Strong gusty winds (especially updraughts associated with hovering or landing on a cliff edge)
• Excessive sideways flight beyond the maximum allowable limits
• Landings on an excessive slope beyond the design limits of the helicopter

How it occurs

In normal flight when the cyclic is moved it then tilts the rotor disc, which in turn produces a horizontal component of rotor thrust (HRT). This produces a moment between the Horizontal component of rotor thrust and the centre of gravity of the fuselage, which acts as a lever to roll the fuselage, and the helicopter as a unit (rotors and fuselage) will roll in the desired direction.

 

 

 

 

 

If the helicopter for some reason is put into a negative G situation, then several things happen.

The angle of attack on the rotor blades changes and the amount of total rotor thrust at that moment reduces The apparent weight of the helicopter reduces therefore the moment required between the horizontal component of rotor thrust and the centre of gravity of the helicopter is temporarily no longer there. At this stage the pilot still has control of the rotor disc by use of the cyclic but he no longer has control of the fuselage because there is no moment and therefore no force to make it follow the disc. At this point the fuselage will be influenced by other forces.

  

 

 

 

In normal powered flight the rotor disc in a conventional helicopter will always be displaced slightly to the left to counter the effects of tail rotor drift.

 

 

 

 

 

In a negative G situation the total rotor thrust is reduced however the torque produced by the engine and the amount of tail rotor thrust being produced is unaffected, therefore the fuselage while still moving forward will also want to drift to the right and yaw to the left. This right drift and left yaw will cause an airflow to act against the fuselage, which will then cause it to roll to the right without any input from the pilot.

 

 

 

 

 

The pilot will instinctively use left cyclic to counter the unanticipated right roll. With the small amount of rotor thrust still being produced by the disc the rotors will flap to follow the cyclic pitch change and the rotor disc will start to tilt left but the fuselage, not being influenced by the moment between the horizontal component of rotor thrust and the centre of gravity (because there is no apparent weight) will not follow and continue to roll right. At this point it is still recoverable. All the pilot needs to do is take away the negative G and replace it with a positive G and the moment will be restored.

Lets assume though that this does not happen and the pilot continues to use left cyclic to counter the continuing right roll of the fuselage. There will now come a point where the rotor head strikes the mast. The severity of the striking will determine whether the mast separates from the helicopter or is just damaged.

 

 

 

 

 

Below is the end result of a Robinson R22 that suffered mast bumping several years ago. The picture is compliments of Greg Whyte who wrote the book “Fatal Traps” for helicopter pilots and is a definite must read. http://www.fataltraps.com

 

 

 

 

 

Recovery action

Prevention is the best rule. Never get into a negative G situation in a two bladed helicopter system by intentionally using abrupt control inputs. If you do experience a negative G for any reason then the obvious solution is to reload the rotor disc so that you are experiencing positive G. This can be done by

• Using aft cyclic to increase the G force and use right cyclic to follow the roll

• Raise collective to increase the total rotor thrust and help increase the G force

• Once the G force has been restored then you can recover to straight and level flight.

Common scenario

One of the most common scenarios causing mast bumping, is that of a middle aged person who has some fixed wing experience converting over to a helicopter. Fixed wing being much more stable allows the pilot to look longer and more often at maps, and generally allows the fixed wing to fly itself. Also most emergencies in a fixed wing required that the pilot push the control column forward to maintain airspeed.

In a helicopter if the pilots attention is not on flying it is very common for the helicopter to be slowly pitching up, when the pilot does eventually look out side and sees a nose high attitude the natural response is to push the cyclic forward. But as we know this can cause a negative G situation and lead to catastrophe.

 

 

 

 

Dropping of the collective

This is more common in a Bell47 with no hydraulic collective but can be possible in any helicopter if the collective is not rigged correctly although the dropping collective only leads to a mast bump in two bladed helicopters. If the pilot releases his hold on the collective and does not secure it (by putting on some friction or placing his leg against it) then the collective has the potential to move. The movement may be caused by aerodynamic forces on the rotor blades overcoming the collective setting by the pilot and this can happen suddenly and without warning. If the collective drops rapidly to the floor there will be an instant reduction in the flapback of the main rotor disc. Because the pilot has forward cyclic to counter this flapback the helicopter will instantly dive towards the ground and cause a negative G situation. This can have two catastrophic results. First of all mast bumping as described above and secondly the pilots natural response will be to use a large aft cyclic input to correct the dive, at this point the tail is going up, the disc starts to come back and the potential is there for the disc to strike the tail boom.

 

 

 

Never let go of the collective without first ensuring it is secured and not able to inadvertently move. Turbulence Although negative G can be caused by turbulence and in extreme cases lead to some form of mast bumping, the negative G usually experienced is not catastrophic. This is because the turbulence is fast acting. Often a negative G is very quickly followed by a positive G therefore there are no ‘prolonged’ effects. If it is that turbulent you probably shouldn’t be flying anyway!! If you are flying in turbulent conditions and experience a negative G then hold the controls steady and wait for the turbulence to subside. It is also best in these situations to slow down (reduce IAS) so that you not hit the turbulence so fast and also bring the RPM down to the mid green to help reduce RPM overspeeds.

 

 

 

Summary Negative G is commonly caused by pilots inducing a pull up followed by a harsh push over (harsh use of the cyclic) resulting in a negative G situation and the fuselage rolling to the right with no input form the pilot. This roll causes an immediate response by the pilot who uses opposite cyclic (left) this in turn leads to the rotor head striking the mast and may cause it to separate.

 

 

 This article was written by Becker Helicopters Pty Ltd and reprinted with their permission – March 3/08 Graphics were done by a pilot we trained Capt. Sam Jenkins Web Site: www.beckerhelicopters.com
 

 

G forces

After three years, and lots of hoopla, many people wonder how the Light Sport Movement is faring here in the Northwest.  As a flight school owner at Arlington Airport, I would say that Light Sport has taken off, but has not yet reached altitude.

One of the limiting factors in light sport to date has been the relatively few flight schools that have offered training, partially because no-one seemed to fully understand the rules, and it was difficult to find a qualified aircraft.  Getting the CFIs, the local examiners, and the aircraft manufacturers up to speed ate up the first couple of years following the official FAA approval of this new class and category in the fall of 2004.

Over the last year, however, a number of flight schools in the Northwest have added a light sport aircraft to their fleet.  We started our light sport efforts early in the game with an Aeronca Champ, figuring it would fill two bills – light sport and tailwheel.  It received a fair amount of light sport business until we added an Evektor Sportstar.  Brand new, shiny, and modern, the Sportstar siphoned most of the light sport students from the Champ.  Indeed, the Sportstar has become one of our most popular aircraft for LSA students, private students and renters as well. 

Unlike some of the LSA, the Evektor Sportstar is an ideal trainer as it has sturdy aluminum construction, hearty landing gear (for those occasional firm landings) and flies beautifully.  It is comfortable, with great visibility, a panel complete with GPS, and its Rotax 912 engine is very economical.  Other aircraft that have been used in NW training facilities are the Technam Bravo, Echo, and Sierra, all fine flying aircraft.

Now that many flight schools are finally able to offer LS training and manufacturers are able to keep up better with demand (buyers no longer are told there is a 6 month waiting list to get the aircraft of their choice), I believe we will see Light Sport grow even further.  Unlike the recreational pilot license which never really took off (only a couple hundred total licenses issued), light sport has proved its validity with the number of students who have earned their licenses (a couple thousand already) and the number of sport aircraft that have entered the market (hundreds of flavors available). 

According to Earl Lawrence, Vice President of Industry and Regulatory Affairs for EAA, the fact that Cessna has jumped into the light sport market gives “a stamp of approval on the whole process.”  In addition, a number of dealers, like Light Sport Airplanes, West, are investing in these aircraft in a big way.  According to Gordon Suttie, CEO of LSA, West, “There are now many great light sport aircraft on the market, each with its own unique blend.  With multiple aircraft and manufacturers to choose from, we offer a comprehensive range of airplanes with the goal of matching any pilot’s flying mission.”

Of course, some people are shocked by the price of the new LS models (most hover somewhere just over the $100k mark).  Apparently, they expected them to be in the price range of an SUV.  Personally, I don’t think the place to save money is on a vehicle that is going to take you and your loved ones thousands of feet into the air.  Mr. Lawrence of the EAA points out that Light Sport has “reduced the price of new aircraft by at least half.”  A few years ago you couldn’t touch a brand new aircraft for under 200k and now there are many to choose from for under 100k.  And they are still new – new panel, new metal, new engine.  Most are built with the Rotax engines which are simple, reliable, economical, and significantly reduce the aircraft’s operating costs. 

In the real world, economy and fun don’t often go together.  But in the case of Light Sport Aviation, the right combination of economy and fun was achieved. Economies are found in the reduced costs of training, on more affordable aircraft, and on reduced operating costs of owning your own aircraft. And the fun is apparent as soon as you take off – most of these LSAs are very sporty and fun to fly.

With CFIs, flight schools, and examiners finally up to speed on the light sport program,  and with manufacturers ready with many great choices in aircraft, I don’t doubt that Light Sport Aviation, here in the Northwest and elsewhere, will soon reach altitude.

This article was written by
Submitted by Cathy Mighell
Out of the Blue Aviation, Inc.
360-474-1060
and reprinted with their permission – March 3/08

This article was written by Becker Helicopters Pty Ltd and reprinted with their permission – Feb 7/08

DYNAMIC ROLL OVER

When a helicopter is lifting off the ground (or a surface) or is hovering with one skid or wheel on the ground, the helicopter may begin a rolling motion, which under certain circumstances cannot be controlled. This is known as Dynamic Roll-over. The rollover can occur in either direction.

    In general dynamic roll-over occurs when the pilot is too harsh and quick on the controls, not noticing that one skid is either stuck on the ground or the pilot has over controlled and caused the helicopter to commences a roll about the skid. To understand dynamic rollover it helps to have an understanding of static rollover. Static rollover Consider a helicopter on the ground with the blades not turning and therefore no rotor thrust is being produced anywhere. For all intents and purposes then the helicopter is a lump of metal, plastic and fibreglass with the weight of all its parts bearing down towards the centre of the earth about its centre of gravity.    

          If we were to come along with a bottle jack (the type used to jack up a car when you have a flat tyre) and place it under the skid, you could lift the helicopter up off the ground. One skid would raise, the other would act as a pivot point about which the helicopter would be rotating.    

          The interesting thing here is, the helicopter will not roll over onto its side until the centre of gravity of the helicopter passes a line running vertically upwards from the pivot point. At any time prior to reaching that point the jack could be removed and weight would cause the helicopter to settle back onto its skids. Once the centre of gravity of the helicopter has reached the vertical line it would be balancing on the one skid. Once the centre of gravity goes slightly over the vertical line the helicopter will roll onto its side.    

Weight Pull heli to ground	Balance Point	Weight Pulls heli over

In an R22 the helicopter can reach a critical angle of 42° before it reaches the point where it will roll over. What has been described is static rollover where the helicopter is not under power. Why then can a helicopter experience dynamic rollover where the critical angle may be as low as 3° before control is lost and the helicopter rolls over onto its side.         Dynamic rollover Consider a helicopter lifting off the ground and one skid becomes stuck. The pilot continues to increase rotor thrust by raising the collective and the helicopter tries to lift off but now commences a roll towards the stuck skid. (the pivot point) Assuming the pilot does not move the cyclic the rotor disc will now be tilted slightly towards the stuck skid. This will give a horizontal component of rotor thrust. This horizontal component acts from the rotor head along the length of the arm to the pivot point. You have effectively created a moment or a lever that is also trying to roll the helicopter over.    

Increasing Rotor Thrust	Roll Begins

The helicopter as it starts to roll experiences an increase in momentum and will want to continue to roll unless another force is applied to stop it.    

          In normal free flight (both skids off the ground) the pilot is able to use the cyclic to counter any roll. Use of the cyclic produces a couple between the horizontal component of rotor thrust and the centre of gravity of the helicopter. The cyclic is only able to handle a certain amount of roll rate. If you exceed the designer’s limit to the roll rate then opposite cyclic will have no effect. Now I do not know the particular numbers for each helicopter but lets assume for our hypothetical helicopter the cyclic is designed to handle no more than a roll rate of 10° per second or 10000 units of roll momentum which ever comes first. Lets go back to our helicopter that is just starting to experience a roll and put some numbers into a calculation. Lets assume the helicopter weights 1000kgs all up weight. That the distance from the pivot point (skid) to the rotor head is 3 meters and that the design limitation of the cyclic is 10° of roll per second, which may equate to 10000 units of, roll momentum. As we are lifting off the rotor thrust would be increasing to be equivalent to almost 1000kgs of thrust (wouldn’t get off the ground otherwise) The helicopter would look like the following    

          Mathematically it could be described as follows Horizontal component of rotor thrust x the arm to the pivot point x the roll rate squared = units of roll momentum being experienced by the helicopter Therefore 100kgs x 3m x 1°2 of roll per second = 300 units of roll momentum (less then 10,000 units) At this point the roll is quite controllable with cyclic and the pilot is not in any danger. Lets say he ignores the early warning signs and continues to pull the collective without arresting the roll. The helicopter now rolls over further, its rate of roll increases and everything starts to happen very quickly.    

          Mathematically it may look something like 200kgs x 3m x 2°2 of roll per second = 2400 units of roll momentum. Notice that the roll momentum has not just doubled it has increased by a factor of 8. At this point the helicopter is well on its way, it may still be controllable if the helicopters weight is sufficient to overcome the roll momentum, but it is definitely getting scary. The pilot needs to lower the collective and use some opposite cyclic and hope that the reorientation and eradication of some rotor thrust and the weight of the helicopter will allow the helicopter to fall back level to the ground. In most cases though the pilot starts to panic a little here and pulls the collective up more hoping to reef the helicopter off the ground and free the stuck skid. Mathematically  

Mathematically it may progress to something like 300kgs x 3m x 4°2 of roll per second = 14400 units of roll momentum. The helicopter is definitely a goner now and there is no recovery. The helicopter is rolling over due to the excessive roll momentum even though it has only rolled a total say 7° from level. The pilot has experienced Dynamic rollover if the units of roll momentum looked like they were increasing at a very quick exponential rate just wait till you experience it.

Summary

Dynamic rollover may occur at any time a part of the helicopter comes in contact with a solid object. It is particularly relevant when lifting off and landing or at a hover. Experiencing dynamic rollover is really more of a problem with the pilot not recognising the early symptoms and being inattentive. The possibility will always exist and the potential for disaster is only seconds away. Several common scenarios that may induce dynamic rollover include Over use of the cyclic when lifting off or landing on sloping ground. The roll can be amplified either way depending on the pilot’s use of cyclic.

Experiencing tail rotor drift or roll and not compensating

Lifting off close to a refuelling drum and not correcting for any sideways drift

This article was written by Becker Helicopters Pty Ltd and reprinted with their permission – Feb 7/08
Graphics were done by a pilot we trained Capt. Sam Jenkins
Web Site: www.beckerhelicopters.com