[farnas-one]

اولأ:

البحث الأولى عن طريق الأنترنت... السؤال من له علاقة بهذه الرياضة من تثق فقط في أمانته ... لأن الشغلة صارت تسويق فقط..

ثانيا:

البحث الدقيق عن الوكلاء فى بلدك أو اى بلد قريب من بلدك والزيارة لكل وكيل بدون رغبة فى الشراء مهم بدون رغبة فى الشراء فقط مبدئيا السوال والمقارنة بين المنتجات من ناحية السلامة أولا.. ثم الجودة .. والسعر ... المناسب .. وخدمة ما بعد البيع... واذا قررت الشراع الفعلي أستخر الله فى أمرك وثق أنه لا يضيعك أبدا.

ثالثا:

المراقبة الثاقبة لكل منتج اذا صدف و أن أحد الأشخاص فى بلدك يستخدم هذه المعدات بدون ما تحسسه أنه تحت الأنظار لكى لايؤثر عليك فى أتخاذ القرار النهائى لشراء...

رابعا:

المحرك يجب أن تكون قوة دفعة كافية فقط لرفعك الى السماء فالقوة الدافعة الأكثر من اللأزم تسبب لك مشاكل عزم دوراني خطيرة... وأنصح الشباب اللذين يقولون بأنه كلما زادت قوة المحرك كان أحسن..فى نظرهم على شان تطير فيه ترادفي مستقبلا وهذا خطاء فادح قد يسبب لك ألتواء(risers) بسبب قوة الدفع وزيادة قوة العزم؟
تذكر فقط تحتاج الى قوة دفع على حسب وزنك؟...

خامسا:

ثقل مركز الشركة اللتى تشترى منها بالعالم أعني هل هي شركة مشهورة بالتصنيع..السمعة الجيدة..حجم أعمال الشركة بهذا المجال..أبتكارات الشركة فى علم (paramotore)...

سادسا:

أعتمادية المحرك وصلاحيته فى أجواء بلدك مقارنة بمحركات أخرى...تأكد أنه يتوفرله قطع غياره بمحلات الدبابات اذا أمكن... أعرف شباب عمرهم ما طلبوا أي قطعة غيار للمحرك من الشركة الأم..أذا كان البديل متوفر وبسعر معقول وجودة جيدة...

سابعا:

نسبة طول المروحة لوزنك...نسبة حجم الجاجز الواقي لمروحة (cage) لطولك .. اذا كان جحمه كبير ربما عند طيرانك منخفض يضرب بالأرض..

ثامنا:

يجب أن يكون المحرك مزود بنظام تشغيل كهربائي من أجل السلامة...

تاسعا:

نسبة وزن المحرك للقوة الدافعة ووزنك... تذكر كلما كان وزن المحرك خفيف سهلت عملية أقلاعك من الأرض في كل الظروف الجوية...
المهم.....المهم....المهم....

عاشرا:

نظام تعليق المحرك ويوجد فى العالم ثلاثة أنظمة...سوف أذكرها مستقبلا فى موضوع مستقل لكى تأخذ حقها... و من خبرتي المتواضعة في لـ (paramotore) أنصح بشدة بالتعليق العالى (high hang point)...
https://www.flyingway.com/vb/showthread.php?t=12627

Well, we are medium-high hanging points.
If the low points are OK for the free flight, it is not the same for paramotoring !
With an engine on your back and more than this a propeller, you have a lot of new forces (at least 3, see below) that apply to the pilot.
Torque being one of them.

Simple to explain him :
You must absolutely take into account the axis of the propeller.
If you hang below this axis, it means that the prop will push you to the ground. You will be bended all time during your flight.
If you hang above, the prop will push you to the sky and your comfort will be far bigger.

Medium-high hanging points and soft harness are the best conditions for the pilot comfort, ease of piloting and on top of that safety.
Avoid low hanging points in paramotor (our harnesses have high hanging points for paramotor and low for free flight. This to show that our choice is reasonable and made with expertise).


A long explanation below to give him expertise on that.

This time, he should follow your advice !

Philippe
Primary Propeller Forces,
as pertaining to powered paraglidingwritten by Keith Pickersgill
There are three Primary Propeller Forces that all pilots of powered-paragliders should have an in-depth understanding of. These are the primary causes of accidents among new pilots. All PPG training courses should cover these in detail, both at theoretical level and to consider the practical application of these in powered paragliders.
Let me say this: without a thorough understanding and appreciation of these propeller effects, powered paragliding may be dangerous. Yet, with the proper mindset toward powered flying and sufficient training (practical AND theory), it may well be the safest form of powered flight.
The Three Primary Propeller Forces Are:
1.Propeller Torque Effect
2.GyroscopicPrecession
3.AssymetricBladeThrust
All three forces produce strong forces on the motor, pilot and wing which must be considered at all times. These three forces (and others) also affect all propeller-driven aircraft, however these forces are particularly noticable in powered paragliders, due to their compact nature. Conventional aircraft have large, rigid wings and fuselages, both firmly fixed to the prop via the engine, which offer great resistance to the effects of these forces in the form of mechanical moments, or leverage. A powered paraglider wing is NOT rigidly fixed to the motor. The maximum extent of the resisting components is only a few dozen inches, being the pilot's elbow to elbow laterally, and kneecaps (or toes) to propeller in length.
(1) Propeller Torque effect.
As the prop spins anti-clockwise (as viewed from behind) on most pusher prop configurations, the engine tends to want to spin in the opposite direction, due to the drag induced by the blades, as well as the inertia of prop, crankshaft and flywheel, during acceleration.
Imagine if you held the blades still (resisted their rotation) and pulled the starter rope slowly. Because the prop cannot turn, the engine will turn instead, albeit in the opposite direction. In a similar fashion, the spinning prop is to a small extend being "held back" by the drag it experiences with the air, so that force is absorbed by the tendency of the motor to rotate clockwise to compensate.
This results in the motor not being vertical, but will appear to be rolled over to one side by a certain amount.
If, as in most cases, the propeller spins anti-clockwise as viewed from behind, the engine will attemp to spin clockwise.
This has the effect of lowering your right-shoulder, and lifting your left shoulder, which in turn produces a right-roll or banking effect on your wing, which then tends to turn to the right.
·The amount of Propeller Torque Effect, depends on prop mass, prop diameter, prop pitch, and prop RPM (engine RPM over Reduction-drive ratio), but is basically directly related to available power.
More power, means (unfortunately) more Propeller Torque Effect, and more tendency for the wing to bank and turn to the right. However, there are ways to reduce excessive right rolls.
·The extent to which the motor banks in response to the torque effect, depends on how much resistance there is to this. Some resistance is a natural result of the risers trying to hold the engine level.
Additional resistance to torque-induced roll can be built-in to the design, and there are certain measures the pilot can utilise. These "Torque Counter-Measures" come in two types:
oPassive counters: Those you design in, or set before take-off. e.g. set the right carabiner higher than the left, so that in flight, the two are more equal (or longer carab on right side); or pack any extra gear (tools, oil, camera, etc) on the left side; or your motor and/or harness may have some assymetry built-in; or you can increase any cross-overs or cross-bracing present.
oActive counters: Those the pilot can induce in flight, including: left-side weightshift, left counter-steer, assymetric trim setting (slower on left side), or differential speedbar (more weight on left side), reducing the power level; or any combination of these.
Warning!!!! Any amount of brake you use in flight, especially on full power (e.g. takeoff and climbout), is too much brake input!!! The only exception is just enough steering input for direction control. A powered paraglider flies best with ZERO brake!!!!! So, if your torque induced turn is excessive and you try to counter with just left brake, you will very likely stall the left wing with disastrous results!
Try to launch allowing for plenty of open space to the right, and allow the wing to slowly turn to the right during climbout, slowly circling the takeoff field, until safe cruise height is reached, then backoff power and resume straight and level flight.
Primarily due to the Propeller Torque Effect, it is much easier to execute right-hand turns, than left-hand turns in a powered paraglider, unless the power is at a low setting. In some cases, it may be close to impossible to execute a sharp left turn without stalling the left wing.
Always plan low passes with an escape to the right!
To summarise, Propeller Torque Effect causes the motor and wing to "Roll" or "Bank" to the right, inducing a right-hand turn.

The other two Propeller Forces are often confused and mistaken for each other:
If you rotate in the yaw axis until you are not facing the same way as the wing, you may be in serious trouble, especially if this happens just after launch.
This rotation can be one of two things:
1) Gyroscopic Precession, or 2)Assymetric Blade Thrust
2) Gyroscopic Precession (GP)
A spinning propeller (also your crankshaft, flywheel and reduction pulleys) acts as a gyroscope, which tends to initially resist any forces attempting to change it axis of rotation.
If such a force persists or is strong enough, the spinning prop will NOT be deflected in the direction the force is applied, but in a direction 90 degrees further around its rotation.
Example: If you try to push the bottom of the prop disk forward (as in tilting it over backward), and the prop is spinning anti-clock as viewed from behind, the force will be effected 90 degrees anti-clockwise from the bottom, i.e. on the Right-hand side of the prop disk. So, trying to tilt the prop-disk over backwards, will result in the prop disk deflecting to the Left!
In paramotors, this happens mostly when the pitch of the motor changes. If your prop rotates counter-clockwise (as viewed from behind) as most pusher props do, then if you (and your motor) pitch upwards (i.e. lean backwards), then the motor will yaw sharply to the left, such that you may end up facing your left wingtip!!!
This is dangerous, as your thrust is no longer forward (direction of wing's flight), but toward that wingtip. The right wingtip will dip down sharply (being pulled by the thrust), and the wing will roll over to the right (starboard) and start turning to the right, but you are facing (and being pushed) to the left! This leads to a disastrous situation.
This is similar to the "Lock-out" problem experienced by pilots under Tow or Winch launches.
I have seen this happen to many pilots without them being aware of its cause, nor its remedies. Most survive purely due to instinctively releasing the throttle.
Change in pitch (which leads to the precession or left yaw) could be caused by any of:
·Sharply applying brakes - the wing slows down, the pilot/motor swings forward of the wing and, having high attachments, leans over backwards, i.e. pitching upwards.
·Going suddenly from cruise (or glide) to full power - same effect as above.
·From a sitting upright (or leaning forward) position, to suddenly leaning back and lifting the knees to a more comfy position.
Unfortunately, sometimes pilots do all three in one motion, which can lead to a catastrophic situation.
One instructor had a student spin 16 times under his wing in under two seconds! The wing continued flying out to sea, and the lines had 16 twists; the pilot had no input to the wing. He killed the engine and started unwinding, the wing carved a gradual curve back to shore, but he struck a building before regaining control of the wing, while flying downwind. A hospital stay and some serious injuries later, plus a motor almost written off, due to Gyroscopic Precession!
Here is something every paramotor pilot MUST do:
·Take a bicycle wheel and hold it by the axle.
·Ask someone to get the wheel spinning quite fast.
·Then try to tilt the wheel over in one direction.
·You will be surprised by the forces and the inevitable result...
·You will find it IMPOSSIBLE to tilt the wheel in the direction intended - the stronger force you apply, the more powerful the deflection in another direction!
·Try to predict which way the wheel will deflect with various forces.
·Then try the same with the wheel spinning in the other direction
Bear in mind that a propeller has MUCH MORE rotational energy than your experimental bicycle wheel and will have MUCH MORE precession forces.
The only thing a pilot can do when precession kicks in, is to gradually back off the power and wait for recovery and level flight, then slowly re-apply power. Just hope this does not happen near the ground. Unfortunately, it is most likely to happen just after launch when you least can afford to back off the power.
POP QUIZ: just to see if you understand the cause and effect of GP: Imagine doing a low flypast and the left side of your propeller-cage brushes against a bush on the ground (heaven forbid this really happening), and so tends to swing the motor and pilot sharply to the left. WhatwilltheresultingeffectbefromGyroscopicPrecessi on?

3)AssymetricBladeThrust (ABT)
Assymetric Blade Thrust can also cause the pilot/motor to turn away from the direction the wing is flying.
It is caused by the spinning propeller disk not being vertical in flight:
If, as is usually the case in flight, your propeller is generally tilted backwards (i.e. the pilot and motor are leaning backwards), then we have Three contributing factors:
Assume the prop turns in the same direction as above.
1.First Factor: Each blade, as it travels from the top downward, will sweep forward (relative to the engine). Equally, on its upward travel, will sweep backwards. In flight, the airspeed of the blades will differ as follows:
As the blades travel downwards (and sweeps forward) on the left-side, the blade-airspeed will be the Flying Airspeed, plus Rotation Velocity, PLUS forward sweep speed.
On the right-side, as the blades travel upwards, their airspeed is Flying Airspeed, plus Rotation Velocity, MINUS rearward sweep speed.
So, each blade has higher airspeed while descending on the left side, but less when ascending on the right side.
This induces more thrust on the Left Side, which tends to cause the motor to yaw to the right.
2.Second Factor: As the motor is tilted over backwards at the top, the Angle-of-Attack (AOA) of each blade, while descending on the left side, is increased (relative to a vertical prop disk); similarly while ascending on the right-side, each blade decreases in AOA.
This also causes more thrust on the left side of the prop disk, and less on the right, causing a right-yaw, adding to the first factor.
3.Third Factor: Usually in a paramotor, the pilot's body shields some of the airflow to the prop. As the motor (and pilot) yaw to the right as a result of the above two effects, the airflow comes increasingly from the left of the pilot's forward line, exposing more of the left side to cleaner air (less shielding on left) and causing more of the right-side to be shielded from clean air.
This also causes increased thrust on the left side, and reduced thrust on the right side, further adding to the first two factors.
The result, is a constant thrustline aimed to the right of the flightline. This causes the wing to bank to the left, even though the motor is trying to turn to the right.
Typical symptoms of this problem, is where the pilot experiences regular and continious oscillations from right to left and back and over again, without any control input or turbulence. Often, attempting to prevent these oscillations with brake input just worsens the situation. This is caused by the ABT pushing the motor over to the right of the flightline, the wing initiates a left bank without any left brake, until the natural lateral pendular-stability takes over and the pilot swings back to the bottom of the wing, but inertia causes him to overshoot to the otherside inducing a right-bank, starts recovering, but then the ABT pushes him over again, leading to a continious side to side swinging action. The only remedy is to remove the cause of the ABT by ensuring the propeller disk is closer to vertical in flight. This is usually just a case of adjusting the trim of the harness or moving the attachment points further backwards.
The difference between the two major effects, GP and ABT, is that the first is a momentary force, which dissapears after the changing pitch, whereas the second is an almost constant force, with the pilot/motor combination almost continuously facing to the one side of the wing's flight direction.
The first, GP, can suddenly appear sometimes unexpectedly, and can surprise the pilot in its extent and severity.
The second, ABT, is almost constant, depending on the extent to which the prop disk is tilted relative to the vertical.
Both are quickly conteracted by reducing power.
Read that line again!
GP can be prevented by a healthy understanding of precession and preventing sudden changes in pitch.
ABT can be prevented by a proper static hang-check, and setting the attachments points and/or Centre of Gravity to ensure the motor (and prop) is as close to vertical as possible. Remember that even a perfectly vertical static prop will tend to lean over backwards by as much as 15 degress due to the thrust being 6 or 7 meters below the drag (length of lines seperating motor/thrust from wing/drag).

Thorough understanding of the three major propeller effects (Torque Effect, Precession and ABT) should be part of every powered paragliding training course. They account for the majority of incidents and accidents.
I hope this helps prevents a few incidents; and assists the general knowledge, safety and enjoyment in this fledgling recreation aviation sport of powered paragliding.

تقبلوا تحياتي
أخوكم..aero

[IIVII]

بارك الله فيك اخي الكريم ..

معلومات قيمه

تحياتي لشخصك الكريم

[farnas-one]

مشكور أخوى ...على وقتك اللذى خصصته لقراءة الموضوع؟
تفاعلكم معى هو المحفز لدى لتقديم المزيد..
أخوكم...aero

[جناح جده]

يعطيك العافيه كبتن aero
وكلامك ونصايحك في محلها وبيض الله وجهك

وطيران موفق

[farnas-one]

أرجو أن تكون مشاركة مفيدة للجمبع وخاصة لمبتدئين؟
شكرا..جناح جدة
أخوك..aero

[شهاب الجزيرة]

يعطيك العافية كابتن


ومشكور على النصايح

[farnas-one]

لا شكر على واجب...
هذا من واجبي تجاه زملائي في الهواية ...تزويدهم بكل جديد في عالمparamotore على حسب معرفتي المتواضعة في هذا المجال...
و نسأل الله التوقيق للجميع...
تقبل تحياتي ...
أخوك..aero

[بيسان]

مشكور اخي الكريم علي هي المعلومات القيمه والاصادقه والامينه

بيسان ارجو المراسله

[عاشق جو]

الله يوفقك ما قصرت معلومات قيمة لاغنى عنها مشــــــــــــــــــــكور

[HZ1HN]

يعطيك العافية على موضوعك الجميل

[الاجدل]

الله يسعدك ويبارك فيك

ولاهنت

ومشوره في محلها من شخص نثق فيه وفيه معلومته

تحياتي

[parachutist]

يعطيك العافية ونتمنا أن نراك في أقرب وقت ممكن
حتى نتبادل المعلومة الصحيحة ودراستها بشكل جدي
لكي نتوصل إلى ماهو صحيح.......

مشكور وماقصرت على الطرح الرائع

[farnas-one]

لا مانع لدى...
ولو كام هناك ما تعتقدأنه غير صحيح مما أطرح الرجاء الرد ليكون علني ويعلم باقي الأجوة من يتلاب بالمعلومات أو يعطي نصائح لا صلت لها بالصحة أنا أقدم فقط تجربة ممرت بها وكانت تجربة مرة أكتشفت الهدف الأساسي من تلك النصيحة وهي التسويق المثل تلك الأنظمة لدى البعض والبعض فقط يعطي نصيحة و لم يتعمق في الموضوع...نحن في هذا الكون نخضع للارادة الله وقدره بسنن سنها العليم الخبير...جل شأنه...
و أنعم على الانسان بالعقل لكى يتدبر ويفكر في ملكوت لله وخلقه...
تقبل...تحياتي
أخوك...aero

[farnas-one]

تنويه:
أشكر المشرفين والمراقبين ...لا أعلم كيف وضع لى على الاسم خبير مظلات... أشكر الأخوة على ذلك ولكن رحم الله أمرئ عرف قدر نفسه اجو من الأخوة الكرام ألغائها بالنسبة لى مشاركات الأخوة بالتجارب في هذه الهوايه هو الهدف الأول وتمهيد الطريق اللأخ القادم بحيث لا يقع مثل ما وقعت... ولكن وقعت ..وقعت طائر سرعان ماطار...
أنا لست خبير مظلات....أعيد و أكرر ...أنا لست خبير مظلات...أنما أقارن المنتجات وتعريف بجودتها وأخرابتكارات الشركات المصنعة لها وأبداء وجهة نظر قد تكون صائبة أو خائبة...أناطيار paramotore لسى في ربع أول درجة من درجات هذه الهواية...
و نحن جميع نسعى لنشر هذه الهوايه بالسعودية لكى ترتقى الى العالمية ولن يحدث ذلك لا بتكاتف الأيدى...هذه يدى.. فمدوا أيديكم بصدق... وشاركونا بتجاربكم الرجاء شاركونا بتجاربكم لا...تبخلوا علينا بما عندكم...و أى شخص يرى أن موضوع معين يفيد الجميع الرجاء منه التكرم وطرحه ... أو يحس أن موقع أنترنت يفيد نا بمعلومة الرجاء وضعه بالمنتدى كرابط...
أشكر الأخوة مرة أخرى على الصورة المرسلت كتوقيع أشكرك.... وأنا لا أعلم من أنت...
تقبلوا تحياتي
أخوكم...aero

[ولد المقاتلات]

مشكور ويعطيك العافية

[الجناح الأزرق]

مشكور ويعطيك ااااالف عافية




طيران موفق



تقبل تحياتي

[farnas-one]

لا شكر على واجب أبو سالم...
تقبل...تحياتي
أخوك...aero

[ajeeb2002ok]

تواضع جميل جدا

[عاشق السيارات]

مشكور على الموضوع

[flysaudi]

جميل جداً وطرح هادف وفي محله الله يوفق الجميع
شكر خاص للكاتب

[Saddam]

مشكورين بصراحه على طرحكم هذا الموضوع القيم 5/5

وانا بصراحه .. ناوي اجرب الطيران الشراعي واكنت الفكره انه انا اشتري المظله واروح اقرب طعس واطير لكن لله الحمد .. انكم موجودين في هذا المنتدى الطيب ..

وانا بأذن الله اول ما انوي الطيران الشراعي راح اجيكم واعطيكم خبر وانتوا مو مقصرين معي بـأذن الله تعالى

شكرا لكم مره اخرى

اخوكم الصغير نواف
تحياتي

[gondaci]

ألف شكر أخي العزيز وبارك الله فيك

[sam1982]

.:: farnas-one ::.

يعطيك العافية أخي العزيز الكابتن : farnas-one

موضوع في غاية الأهمية , ومعلومات مفيدة جداً

لكـ كل الشكر والثناء والتقدير أخي العزيز farnas-one

على هذه الجهود الأكثر من رائعة وعلى هذا الرقي والإبداع

في الطرح و المناقشة الجادة التي قلما نجد مثلها

في الكثير من المنتديات

والنصائح التي أعتبرها وهذه وجهة نظر شخصية

{{ النصائح الذهبية }}

وأعتبر هذا الموضوع مرجع هام , وإلى المزيد من التقدم والإزدهار

تحياتي وأحترامي لشخصكم الكريم

وسلمت يداكـ على ما خطته أناملكم الكريمة

تحياتي وأحترامي للجميع

أخوكم S A M 1 9 8 2