Jump to content

SA342 Aerobatics


SUBS17

Recommended Posts

The mingun version is lighter again especially when you unload the amo with better visibility. just saying.

 

An BTW watch out for VNE coming out of the loops. :D

Control is an illusion which usually shatters at the least expected moment.

Gazelle Mini-gun version is endorphins with rotors. See above.

 

Currently rolling with a Asus Z390 Prime, 9600K, 32GB RAM, SSD, 2080Ti and Windows 10Pro, Rift CV1. bu0836x and Scratch Built Pedals, Collective and Cyclic.

Link to comment
Share on other sites

Um.

 

I learned to fly on the Gazelle. I know it definitely wasn't cleared for inverted flight - pretty sure 100 degrees of bank was the limit - and I'm almost certain that the reason it wasn't cleared for loops and rolls was that it wouldn't do them.

 

I recall the Lynx as being the first helicopter in British service which could be looped and rolled without crashing - a function of the rigid rotor head (like the Bo105). The Gazelle had an articulated rotor head and wouldn't take the stresses on loops and rolls.

 

Cool videos but they don't really sell the accuracy of the flight model very well.

 

*Caveat - I really like the Gazelle and it's a fun module to fly. It's realistic enough if you keep it within the real limts...

[sIGPIC][/sIGPIC]

 

Wildcards BlackJack_sml.jpg

Link to comment
Share on other sites

Kiowa is also prohibited to a certain roll by the book. Can it roll more then that ? Sure!

Has that been done? Sure!

 

Just saying. Only because something is prohibited by the book does not automatically include that it is not capable of doing so.

 

CH53 is also not allowed to exceed x° in roll. Has it been done? Yes. Is there evidence ? Yes, youtube us marine ch53 doing a roll and a loop

Link to comment
Share on other sites

I recall the Lynx as being the first helicopter in British service which could be looped and rolled without crashing - a function of the rigid rotor head (like the Bo105). The Gazelle had an articulated rotor head and wouldn't take the stresses on loops and rolls.

 

The fully articulated rotor system in itself is not a problem. The main stress in a rotor system is centrifugal force and the lift that like to lift the blades is kept safe by the rotor rpm and the cewntrifugal force. Most helicopters is however made for positive G’s only and the coning angle that makes the blade tips fly higher than the rotor hub is supposed to be upwards.

 

Negative G will make the blade tips fly lower than the rotor hub, making them go closer to the tail bom. On top of that, for a roll the steering input will make the blades go up or down and when ”down” is over the tailboom there might be no clearance left, cutting the tail boom off.

 

Fully articulated rotors have a flapping joint, most often quite close to the rotor mast. This means that the blade have to move quite much (up or down) to develope a rolling forve on the rotor mast. This also makes the margin less for contact with the tail boom, and it makes the helos slower to steering input than a rigid rotor.

 

Summed up, rolls in helos with fully articulated rotors are often quite slow wich causes the need for very big steering inputs and blades flying close to the tail boom. Safety margins are reduced And if not performed properly you might come down in pieces.

 

Semi rigid rotors(seesaaw) are not safe a all in low G situations. The helicopter is virtually hanging free under the rotor hub and if not enough G forces it will loose stability and the rotor will tilt in relation to the Helicopter body, until mast bumping occurs and ou die.

 

Loops can be done in virtually any helo.

A correct performed loop doesnt give any other forces than increased G when pulling up and pulling out, and not even that low G when upside down if the helo have a decsent speed when entering the loop.

Loops can theoretically be done even in an semi rigid, but with very hig risk of ending up in a low G —> mast bump —> crash. So its not recommended at all.

 

Articulated helo loop, 1949:

 

 

Kiowa is also prohibited to a certain roll by the book. Can it roll more then that ? Sure!

Has that been done? Sure!

 

Just saying. Only because something is prohibited by the book does not automatically include that it is not capable of doing so.

 

Exactly!

 

There is no certification criteria for aerobatics in civil helicopters. That means, in almost any case in the world that the limit for civil certified helos is 60 degree of bank and +/-30 degree pitch attitude. Even the Bo105 isnt certified for aerobatics in the civil world so 60bank/30pitch is the limit. The Red Bull helos are certified as exprimental I think, and on exception with help of Airbus helicopters.

 

There will always be a big difference between what can be done and what is legal to do, in some parts depending on regulations but in most parts depending on that the safety level would be very much reduced if some manouvers would be allowed.

I know for the civil Bo105 that they in most cases have another center of gravity because the battery is mounted in another position than the ones I flew. I dont know for sure but I think most military Bo’s with less regualtions in roll and pitch have the battery in the nose. Theres an option for this and I did read that Red Bull Bo’s (of course) have this option incorporated.

Taking just *any* Bo105 and doing loops, rolls and flips wont of course be legal, but it would also be at a reduced safety level as the center of gravity probably would be less optimal.

 

Tex Johnston rolled the B707 when not approved for this:

[T.M HOTAS Warthog Stick & Throttle + T.Flight pedals, Varjo Aero, HP Reverb pro, Pimax 8KX] 🙂

[DCS Mirage 2K; Huey; Spitfire Mk IX, AJS 37, F-14, F-18, FC3, A-10 Warthog II and a few more ]

i9 13900KF@5.8/32Gb DDR5@6400/ Gigabyte Gaming OC RTX4090, ASUS STRIX Z790-F , 2Tb m2 NVMe

Link to comment
Share on other sites

I'll just park this here :D

 

 

 

 

The only DCS Heli I haven't successfully done a loop in is the KA50 :megalol:

Control is an illusion which usually shatters at the least expected moment.

Gazelle Mini-gun version is endorphins with rotors. See above.

 

Currently rolling with a Asus Z390 Prime, 9600K, 32GB RAM, SSD, 2080Ti and Windows 10Pro, Rift CV1. bu0836x and Scratch Built Pedals, Collective and Cyclic.

Link to comment
Share on other sites

I’ve only looped and rolled the Bo. :)

 

[Edit]And quite some planks...but they dont count.

[T.M HOTAS Warthog Stick & Throttle + T.Flight pedals, Varjo Aero, HP Reverb pro, Pimax 8KX] 🙂

[DCS Mirage 2K; Huey; Spitfire Mk IX, AJS 37, F-14, F-18, FC3, A-10 Warthog II and a few more ]

i9 13900KF@5.8/32Gb DDR5@6400/ Gigabyte Gaming OC RTX4090, ASUS STRIX Z790-F , 2Tb m2 NVMe

Link to comment
Share on other sites

In the same way that I've only looped and rolled the Lynx. Plus quite a few planks as well, but like you say they don't count.

 

Looks like I was mistaken about the Gazelle's abilities, though I also remember at least one colleague being killed when he pushed the envelope too far.

 

Not gonna get in a fight about it though. Nice to see some intelligent and informed discussion :)

[sIGPIC][/sIGPIC]

 

Wildcards BlackJack_sml.jpg

Link to comment
Share on other sites

In the same way that I've only looped and rolled the Lynx. Plus quite a few planks as well, but like you say they don't count.

 

Looks like I was mistaken about the Gazelle's abilities, though I also remember at least one colleague being killed when he pushed the envelope too far.

 

Not gonna get in a fight about it though. Nice to see some intelligent and informed discussion :)

 

The most dangerous part( might get some hit by someone for saying this), is the ”servo transpiracy” in the Gazelle. The hydraulics is made weak to protect the hardware. If you G-load it to hard the controls lock, and you’ll find yourself into deep trouble.

This issue/feature is probably the way Colin McRay died flying hos AS350 low and fast.

 

In the UK military I know every pilot was learned about this and also got it showed from an instructor.

 

Its the same with the Bo105, low speed and steep right turn, you might end up with too little roll authority to roll back before the ground bites. We got an extensive training on this and learned to stay on the right side if the limit, and also how to handle the trouble if the stick med the hard limit snd still to little roll response( = lower collective and the secondary effect increase the left roll substantially.

[T.M HOTAS Warthog Stick & Throttle + T.Flight pedals, Varjo Aero, HP Reverb pro, Pimax 8KX] 🙂

[DCS Mirage 2K; Huey; Spitfire Mk IX, AJS 37, F-14, F-18, FC3, A-10 Warthog II and a few more ]

i9 13900KF@5.8/32Gb DDR5@6400/ Gigabyte Gaming OC RTX4090, ASUS STRIX Z790-F , 2Tb m2 NVMe

Link to comment
Share on other sites

True, but it also had a nasty habit of stalling the fenestron as well. But yes, I do remember G limits (though it was 40 years ago and I've had a couple of big bangs on the head since).

 

There was something else that it bot you with, but I can't remember what. Just remember arriving at a crash site to see the student and instructor sat in their seats, basically unhurt, upright, with the rest of the aircraft scattered around them in barely recognisable pieces...

[sIGPIC][/sIGPIC]

 

Wildcards BlackJack_sml.jpg

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...