RAF hang test after mods

jm-urbani

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Hi

I don't know abo about Raf 2000 but I know a bit gyros (being an home builder trier myself)

you'll certainly know 100 % of what I will say but I'll but l'ill repreat it just in case

the goal of hanging a giro and placing the rotor head at an horizontal point so that the gyro noses down to at least 8° is to simulate the rotor lift (that does not exist when you are performing the hang test) .

when you will fly the rotor lift will "pull" your giro and bring it back to a virtually a horizontal attitude, hanging is a pragmatic method

if you don't give you gyro at least 8° nose down during the hanging you risk to fly nose up and if you are too much nose up it is possible that event with the stick fully ahead at the dashboard your gyro won't be able to pitch nose down at a sufficient angle to land properly and you will be forced to land using the engine reducing the engine thrust ( which leans that if your engine stops you will land nearly vertically and crash)....

in france on a gyro 2 guys I know have mounted a 30 kilos heavier engine then the original engine resulting in a 4° nose down angle at the hanging test ...

pb is that they were saying ... there are other gyros like mine with the same engine and they did not modified the cheek plates ...

one of the 2 crashed the gyro ( bending the drop keel tube), and the other hardly crashed ... they were reluctant to change set a correct angle and change the cheek plates.

I advice you to make new cheek plate and set the angle at least at 8°, if the angle appears to be to important the only consequence is that you will fligh a bit nose down which is not a proble because you still be able to land (you won't get to your control stops)

you have to know that most of the time if you want to tune perfectly your gyro so that it flie perfectly horizontal you will have to change you cheek plates a couple of times until you get the perfect attitude of your gyro at cruise speed ..

if you have modified you gyro it is normal that you have to correct the rotor head position in comparison with the other raf2000

don't take any risk at the end of you built
 

Gyrob

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Oct 30, 2019
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Thanks for your feedback. I have heard of others who either added weight up in the nose of the aircraft, or else the pilot was very heavy and facilitated the proper balance. I just had not heard of others building new cheek plates with different balance attachments. Good to hear your success.
Thanks again.
 

jm-urbani

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French Riviera
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home built mono seat
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Hello,

the issues you are facing are apparently well know :


I was thinking about cheek plates as a common mean of shifting the rotor head backward and forward in order to reach the right hanging angle but obviously the RAF 2000 rotor head is not mounted on cheek plates and you are not going to built cheek plates where they don't exist now on this gyro

if your raf owners counter parts have achieved 5° to 10 ° you should find out why it is not the same for you,

not easy to modify a gyro as a matter of fact .

ins't it possible to lean the mast back a couple of degrees more ? or is the position one the maximum possible angle ?

bon courage
 
Last edited:

Gyrob

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Oct 30, 2019
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The RAF has two plates, one on each side of the upper mast, that the rotor head is mounted to. There are two bolts holding these plates on - an upper bolt and a lower bolt. By shifting the hole fore or aft on either of the bolts will shift the angle of the rotor head. These are the plates I was referring to as the cheek plates. By changing the angle of these plates to lean the rotor head assembly back will change the balance of the hang test.
My guess is that several people have done this, but I'm just not reading or hearing about it. Most I have talked to have just added lead weight in the nose of the aircraft.
 

jm-urbani

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would be great if you could putting lead in the nose ..
 

JETLAG03

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Virollet 17260 FRANCE
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300+ flexwing (pendulaire) newly trained on gyrocopter ((autogire)11h)
Just for my one clarity,the hang test is done lifting at the teeter bolt ?

phil
 

jm-urbani

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Messages
688
Location
French Riviera
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yes, usually with your stick in the level flight position because your teeter bolt is going aft when you pull the stick ( then your nose down angle is changing a bit according to your stick position

hanging must be done with you in the seat, with fuel in the tank (some say half of fuel, other say full tank)
 
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