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Posted

I think a full size helicopter, built correctly, might be able to do that. However, the g forces would kill the pilot inside (or at least cause them to black out and crash).

Posted

oh yeah... do it all the time. Just a minor rerig of the collective and overclock the cyclic to 150%.

 

From my Robbie Ranger life story:

 

"Hey ladies, I just got back from a really dangerous cross country training flight. There I was, upside down in a cumulonimbus when the engine quit. For a moment I thought I was going to die but since I'm a better stick than my instructor, I said "Listen loser, I am god's gift to aviation, hand over the controls and I'll salvage this." I entered an inverted autorotation and did a split S."

  • Like 1
Posted

Of course they can Jonathan. Ask any robbie cfi....most first time student pilots fly just like this 90% of the time. Thats why we end up raging alcoholics!! Hahaha

  • Like 2
Posted

I think a full size helicopter, built correctly, might be able to do that.

 

Absolutely not. Not with todays technologies and materials. The airframe and dynamic components could never cope with the forces. No engine / drivetrain could provide such power to weight ratio.

Remember, as you scale up the length of an object by the power of 1, you also scale up the volume (and thereby the weight) with the same factor by the power of 3. Make a solid cube of a given material twice as long and it gets 8 times as heavy. Also the static and dynamic forces and inertias increase proportionally to the weight gain.

 

Ok, it's a bit simplified because we are not talking about solid cubes but this is the basic issue of making things bigger. This is why elephant-sized spiders would also need elephant-sized legs in order not to collapse under their own weight (maybe not quite because they have twice as many but you catch my drift).

 

The way I see it: You can use the Mi26 to pull buildings out of their foundation but if you try to throw it around in the air like you are used to from the Hu369, you will probably rip it to pieces. A comparable proportion exists between the Hu369 and the toy in the video above.

Guest pokey
Posted (edited)

 

. Make a solid cube of a given material twice as long and it gets 8 times as heavy.

 

i must be missing sompin' here? Lets say i take 2 ice cubes, both weighing 50 grams, now if i let them fuse together, they won't weight 100 grams, but 400?? or would they be 800???? (lets ignore any part of them melted)

 

of korse ! now if we made the same ice cubes twice as large (not just in length) then yes, it would take 8 cubes to double its size

Edited by pokey
Posted

 

i must be missing sompin' here? Lets say i take 2 ice cubes, both weighing 50 grams, now if i let them fuse together, they won't weight 100 grams, but 400?? or would they be 800???? (lets ignore any part of them melted)

 

He was assuming you'd still shape it to be a cube (making it twice as tall, twice as wide, and twice as long). That would take eight cubes.

  • Like 2
Posted

But rotor are round...like pie. Allllll new calculus issues..cant bring in cubed formulas to configure cones.

Posted

The closest you come to heli aerobatics is Chuck Aaron an a highly modified Bo105. His routine can be found in view on the net.

I am fairly certain I do not want to be either in his helm or that model during any of it.

Posted

The Flying Bulls use 100% factory standard, unmodified BO105. They just have drastically reduced overhaul and replacement intervals. Everything else is a very common urban myth.

If you think Aaron is impressive, check out the original Siegfried Schwarz...

Posted

The Flying Bulls use 100% factory standard, unmodified BO105. They just have drastically reduced overhaul and replacement intervals. Everything else is a very common urban myth.

If you think Aaron is impressive, check out the original Siegfried Schwarz...

Where do you get that information? I'd have to go back to my notes, but not what I remember Chuck telling me about his 105..

Posted

Where do you get that information? I'd have to go back to my notes, but not what I remember Chuck telling me about his 105..

Yeah it has a modified fuel system at the very least...the rest he doesn't tell many people.

Posted

Where do you get that information?

 

From a friend who maintained, inspected and rts'ed the RB helicopters for a living.

 

It's not really surprising that the BO can do this kind of flying out of the box when you look at what it was initially designed for.

 

 

Yeah it has a modified fuel system at the very least...the rest he doesn't tell many people.

Next time you see him ask what exactly was modified on the fuel system... ;)
Why would they want everyone to believe that no other bo's would be able to do what they do? Go figure... The naked truth is that these manoeuvres don't require a special bo, they just require a special pilot. And changing stuff like the rotor head every 100 hours (IIRC).
Very expensive fun these guys are having but great to look at and priceless promo...

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