Disc Loading....what is too low?

[Tsemler]

okay so with all this in mind, how much would an extra 40 kg ballast effect loading?

[Waddles]

No veiled agenda yet. Just speculating.Waddles

[Tsemler]

Okay so i was doing a little research (as im not the technical type of person) as to what other kinda loading is out there on some machines and the was one that stuck me. http://www.rotaryforum.com/forum/sho...t=disc+loadingPost Number 12 with a disc load in of 0.85 lb/ft²So im guessing here that altho not ideal you can still fly with a lighter than ideal disc loading??? Right??? say like the about .85? But in saying that you would need to have the 9* down hang test so you have the full range of control? So say if you had a hang of 2.5* you will not have alot of forward stick but a lot of backstick correct?if you had more weight out the front it would bring that downward hang a few more degrees down too correct? there for giving more nose down control?This is all interesting stuff for me as i"ve never bothered looking into the technical side of things as i"ve been happy with my machine and just flew the thing.Trent

[Greg Mitchell]

Based on the figures stated so far at 1.1 or 1.12 lbs/sq/ft given an

[tonydenton]

ok i"ll let every else do the mathimatics but birdy can you do a quick rundown on the "stick side shift"if your sliding back. i think i know what you mean, but i wouldn"t mind hearing it. and i had also thought that a too small a rudder vert/stab could be a problem if it was over rotored , ?????

[birdy]

Sumthns abit cockeyed ere. ???I posted ere yesterday, ands now its gon?Ill try agin.So say if you had a hang of 2.5* you will not have alot of forward stick but a lot of backstick correct?Yes, and AS below cruise with higher than cruise power setn [ nose high att] will mean a forward push is not an option to regain speed, coz your already on the forward stop.The head, at rest on the ground, should be level at least, preferably 1 or 2* nose down, COUPLED with a hang of at least -6*.If your hang is only -2.5*, youll never have enuff forward stick to fly safely.Iv just heard sum disturbing news from sumone who knows bout the head setup/hang angle, but ill keep mum till its "official". the "stick side shift"if your sliding back.Tony, if the machine is nose high, min AS and on full tap, and you start sinkn, your safest option is to stick to the side [ the high side of prop torque] before you push forward. [ if you aint already on the forward stop.]Generaly, any inteligent driver will only be in this situation while headn into wind.If you just push forward, youll burn up more alt and loose more rrpm tryn to regain AS than if you side stick first. Not to mention your dropn into the gradient, which means the head wind is getn weaker as you drop.If your already on the forward stop, its your ONLY option.

[asra]

Any thoughts on low disc loading PLUS a hang test at 2.5 degrees??Waddles. Hi AllanIs that with pilot? and how much fuel?If it was with pilot and half tank of fuel as usual, then it would mean not much forward stick, but heaps of back stick. It would also usually mean the machine would fly approx 6.5 degrees nose up in straight and level. Would this de-stabilize the machine? well no, but a HS set with neg incidence could cause the pilot to run out of forward stick travel during forward flight. This is still not a safety problem yet. The low disc loading would cause the blades to flap more in flight as the blades produce less centrifugal force due to there lower loading and slower speed. The biggest issue I see here is if the machine had a very low disc loading, and it also flew with a nose high attitude then during straight and level the thrust line would also unload the rotors an amount.Not sure if this is what your thinking AL.Regards SamL.......

[tonydenton]

yeah ok thanks birdy that is what i thought you meant.

[tonydenton]

another question to any one. the talk is with hang angle, and disc loading. you can do a hang test and have it pass to specs, irrispective of rotor size. i thought anyway.so the only way would be to fly it over rotored, or low disc loading ? and then ..... know ?????

[asra]

another question to any one. the talk is with hang angle, and disc loading. you can do a hang test and have it pass to specs, irrispective of rotor size. i thought anyway.so the only way would be to fly it over rotored, or low disc loading ? and then ..... know ????? Hi TonyYes, the rotors have nothing to do with the hang test. A successful hang test can be carried out with or without them fitted.The rotors only come into play during the CofG test as they need to be fitted for it.Regards SamL.............

[Greg Mitchell]

Tony,To address the second part of your statement.... " so the only way would be to fly it over rotored, or low disc loading ? and then ..... know ?? "This is not the case.

[birdy]

Which way do rotax 2bangers spin the prop?

[asra]

Which way do rotax 2bangers spin the prop?Right hand down, clockwise from the rear.

[tonydenton]

so mitch your going up 30% to recomended in the book. i can"t say i blame you . i"m looking at the same. soo.. what is too much ?sam i"ve seen your photos of hang and c of g test before. i just can"t remember how the c of g. is effected by rotor length. can you tell me where your post is again ?

[asra]

Hi Tonyhttp://www.asra.org.au/smf/index.php?topic=2712.0Regards SamL.............