Autorotation capabilities accurate?

[Cibit]

I push it all the way down and trim so your level as you descend but don't know if this is quite correct. Generally works well enough to walk away from the landing:music_whistling:

[towsim]

A couple of month ago I assembled a small document based on the helicopter training course for the US Army at Fort Rucker, Alabama. I tried to include the specifics of the DCS Huey. It even includes the autorotation procedure. If it does not reflect the experience of the DCS Huey specialists, please cremate it.

HelicopterBasics.pdf

[NeilWillis]

Thanks Towsim, a useful little tome.

[Flanker52]

Thanks for the help guys.

 

I think I figured out the problem. Now I pull all the way back on cyclic, do a force trim. And I can bring the nose up and glide it down. Without doing the force trim, I wasn't able to lift my nose at all once dropping collective.

 

Now I just have to work on the flair.

[Flanker52]

I have uploaded many videos on youtube on spotlanding autorotations. It is possible (thought not easy)

 

Thanks, I'll check them out.

[Hawkeye5]

For those who want to learn how to fly a Huey or MI8 CORRECTLY....... we have the training...

 

...AND the know how!

 

Some of our training includes:

 

 

Basic Wings:

o Hovering in place for 1 minute

o Hovering Turns

o Forward Hovering flight

o Side-wards Hovering Flight

o Rearward Hovering flight

o Taxiing: Hover and Air

o Take-offs: Hovering and surface

o Straight and Level Flight

o Normal Climb and decent

o Approaches: to a Hover and to the Surface

o Helicopter Traffic Patterns

o Roof top Landings

o Multi-ship formation flight

 

Senior wings:

o Navigate by Pilotage and Dead Reckoning

o Shallow Approach to a Running Landing

o Confined area Operations

o Slope Operations

o Simulated Engine Failure at altitude (Autorotation at altitude)

 

 

Master wings:

see us......for more info

 

We use Teamspeak and have all sorts of resources that are available to those who wish to "get it right", with out struggling.

 

Check us out ! here http://1stcavdiv.conceptbb.com/

 

We are an INTERNATIONAL group (Australia--Europe-Canada and USA) and have new members joining frequently. We also fly the MI-8 just as often as the Huey with just as much info as the Huey

 

 

We do our best to emulate the 1st Cavalry Division, 229th Helicopter Assault Battalion as it was in Vietnam.

 

MISSION OF THE 1ST CAV DIV

Our mission is unite people world wide who love the Huey and want to experience the joy and exhilaration of flying in a formation of Hueys or MI-8's as they approach a hot LZ to drop troops in an air assault. We are constantly designing missions to challenge our skills and provide hours of fun and excitement to our flying experience. We have two actual Huey pilots who spent time as instructors, as well as a current UH-60 Blackhawk pilot, that are available to train even the most novice helicopter pilots. You'll be flying like a real pilot in no time.

 

 

We'll assist you in getting rid of those Nasty habits in no time!

 

 

 

[Flanker52]

Is there a way to simulate Tail Rotor failure?

[outlawal2]

Can't do that without actual damage being done. The tail rotor is directly connected to the drive train and no way to disconnect it.. (Without an RPG anyway.) They are built this way so that the tail rotor will continue to be fed power even if the engine dies.. (It will receive it's power at that point due to the wind flowing thru the main rotor and the main rotor will provide the tail rotor power.)

 

 

Not sure why you would want to do this anyway as it is a definite crash when that happens.. No getting around it..

[sondo214]

Well I had the same desire, but this kind of failure is not implemented. So try the following. Go to external camera and zoom to the tail rotor from exactly behind. Move your pedals so that you find the position when the tail rotor seem to have 0 pitch. It should be somewhere close to full right pedal. Note that position in your head (you can display the axis diagram to help you do that easier). Now during flight just kick the pedals to that position (T/R pitch goes to 0, you have no thrust produced from it). You have now a simulated T/R failure. Do not move the pedals at all during autorotating. In a real T/R failure moving them whould do nothing cause the T/R has failed! Forgot to mention you have to shut down the engine as soon as you start to spin (as you would do in a real failure). The quickest way to do so is by pressing 'F' and cutting the fuel.

 

Have fun!

Edited September 16, 2014 by sondo214

[sondo214]

[quote=outlawal2;2178304

Not sure why you would want to do this anyway as it is a definite crash when that happens.. No getting around it..

 

Totaly dissagree...

[outlawal2]

Totaly dissagree...

 

I can tell you for a fact as someone that has time in real helicopters IRL that a helicopter with a dead tail rotor is most definitely a crash... There are a few examples out there where someone got lucky, but it is just that. LUCK

 

Your example of losing tail rotor authority does not take into account that without the tail rotor your helicopter will spin out of control in the opposite direction of the main rotor. It is totally uncontrollable and not recoverable. It doesn't just glide nicely.. That is the whole point of the tail rotor is that the entire helicopter will spin the opposite direction of the main rotor without one..

 

Lose the tail rotor and you are BlackHawk down...

[sondo214]

By doing the method I described you are not loosing only T/R authority. You are loosing the T/R as a system. Try pushing whole right pedal when flying. Will do exactly what you describe. Spin oposite of the M/R direction. We are saying the same thing. And given sufficient altitude and using the right teqnique you can stop that spin and land

[outlawal2]

By doing the method I described you are not loosing only T/R authority. You are loosing the T/R as a system. Try pushing whole right pedal when flying. Will do exactly what you describe. Spin oposite of the M/R direction. We are saying the same thing

 

So you are saying that spinning the helicopter completely out of control while attempting a landing is not going to cause a crash? Even if you touch the ground gently you will still have dynamic rollover from the momentum... Remember that the longer you are without a tail rotor the faster the spinning effect will be.. It continuously gets worse and worse..

 

I am sorry, but almost definitely a crash will ensue..

[sondo214]

So you are saying that spinning the helicopter completely out of control while attempting a landing is not going to cause a crash? Even if you touch the ground gently you will still have dynamic rollover from the momentum... Remember that the longer you are without a tail rotor the faster the spinning effect will be.. It continuously gets worse and worse..

 

I am sorry, but almost definitely a crash will ensue..

 

As soon as you cut the engine the forces that caused the spin cease. Do we agree with that? So you have to fight the spin generated the seconds from when you lost the T/R until you cut the engine. Given sufficient altitude and the right technique it can be done, yes and then you can autorotate as you would normaly but without yaw control. You dissagree with that?

[outlawal2]

You are not cutting the engine until AFTER the spinning starts.. (You are correct though that once the engine IS cut, the spinning shouldn't get worse it should diminish slowly so I stand corrected there as far as this example goes.)

 

As far as autorotating normally, no you wouldn't because there would still be power being generated by the main rotor and while the opposite effect of spin would not be as drastic as it would be with the engine running, it would still be there and without a tail rotor you would still be spinning out of control... Albeit slightly slower.. Still uncontrolled nonetheless

 

(And this makes my head hurt! LOL)

 

DAMN the dynamics of helicopter flight is a daunting subject for sure.. Try reading the book by Wagtendonk "Principles of helicopter Flight"

http://www.barnesandnoble.com/w/principles-of-helicopter-flight-w-j-wagtendonk/1008248911?ean=9781560276494

 

That tomb will give you a headache in no time for sure!

LOL

[outlawal2]

And further research on the net has shown multiple articles by veteran pilots supporting your view that yes you CAN autorotate a helicopter successfully with no tail rotor... Looks like my thoughts on the matter are certainly difficulties that you will need to counteract, but they don't make a crash imminent..

 

Looks like I will be spending some time researching this further as I really thought that a tail rotor loss was pretty much guaranteed death and that is not the case...

 

My apologies Sondo...

[sondo214]

Happy you found out! The only reason the helicopter spins (and needs a T/R) is the engine. As long as you cut that force the system is in equilibrium. The turning M/R does not generate fuselage spin no matter how fast it spins. It's basic physics. Anyway. I hope that DEV's implement this failure soon and you will see that it's not that hard to coop with (given sufficient altitude and right technique I say again). In fact is very easy! The reason why in RL many such failures have ended in crash are other. Not going to discuss them here. PM me if you are interested in further discusion.

 

RL Navy heli pilot here also :thumbup:

[GunfighterSIX]

RL Army Pilot here. You still have some TRQ even without the engines running, caused by other small factors like resistance or friction in drive components for one. But the resistance caused by aircraft body and vertical stabilizer is enough to counteract that small force. To say it is not hard to coop with tail rotor failures is a bold statement. If the conditions just happen to be in your favor, you have a chance. Most times the tail rotor fails at a bad time. Just study a few helicopter crash investigations and you will see that. Loss of tail rotor is often a violent event. 60's can't out run the loss like other aircraft, and if Huey's loses any components, their CG shifts and the helicopter noses over. I am not saying your wrong, but most of the time tail rotor failure results in catastrophic loss of the aircraft.

 

http://www.navytimes.com/article/20090209/NEWS/902090332/Families-sue-Seahawk-maker-fatal-crash

Edited September 16, 2014 by GunfighterSIX

[sondo214]

Gunfighter I totaly agree with every word you say! Easy to Coop with was meant when you expect it to happen (because you simulate with the method I wrote) and have sufficient altitude and maybe some speed! In RL if/when (hope not) will happen little you will understand what happened before you are beep in the ground! Totaly Agree...

[Flanker52]

Can't do that without actual damage being done. The tail rotor is directly connected to the drive train and no way to disconnect it.. (Without an RPG anyway.) They are built this way so that the tail rotor will continue to be fed power even if the engine dies.. (It will receive it's power at that point due to the wind flowing thru the main rotor and the main rotor will provide the tail rotor power.)

 

 

Not sure why you would want to do this anyway as it is a definite crash when that happens.. No getting around it..

 

 

I was under the impression that a Tail Rotor failure is not a certain crash - it can be dealt with in the same way as engine failure, through autorotation. But I think you do need a good amount of altitude. I'm certain that real helicopter pilots practice tail rotor failure pretty often. At least according to the Vietnam huey books I have read.

 

Incidentally, I figured out how to practice this but by accident. I was practicing autorotations and a few times my flare was too high and my tail rotor smacked the ground quite hard. I tried to take off again and noticed my tail rotor was damaged as I was spinning all over the place. So I pulled max collective and managed to get back up to 1000 ft or so. Then I did I treated it like an autorotation and I actually managed to land it.

 

So It seems it can be practiced but it's a pain.

[KLR Rico]

If tail rotor failure = automatic crash, there would be no such thing as an autogyro.

 

I rest my case.

 

:)

[towsim]

The heli pilots actually have a procedure how to compensate the tail rotor. The procedure is part of the training course and is called 'Simulated anti-torque fixed right pedal' . The details are as follows:

 

The main advice to turn the nose from right to center is to reduce throttle to minimize torque, reduce collective, increase airspeed to the minimum airspeed for directional control.

 

• 
  
• The entire procedure starts on crosswind by informing ATC about the procedure (priority in traffic).
  
• On downwind , the procedure is discussed with the flight instructor.
  
• The final is intercepted at 800 feet AGL with 60 KIAS.
  
• On final, the flight instructor holds the right pedal 10 degrees to the right of the aircraft heading.
  
• The approach heading should be established with 20 degrees to the left from the runway heading while the track is the runway heading.
  
• When a shallow approach angle is intercepted, decrease the collective to maintain the angle. Progressively decrease airspeed to determine minimum airspeed for directional control.
  
• Once the speed is determined, hold the speed until touchdown.
  
• At touchdown, retard throttle to align nose with the runway heading (minimized torque) .
  
• Apply collective to cushion landing.
  
• After touchdown, maintain heading and ground track with collective, cyclic and throttle.
  

 

The procedure was published as part of the helicopter training of the US Army at Ft. Rucker, Alabama.

[sondo214]

If tail rotor failure = automatic crash, there would be no such thing as an autogyro.

 

I rest my case.

 

:)

 

That is not totaly true... Autoguros do not have motored main rotors. The spin via windmill... It's different

[KLR Rico]

^ And when the TR fails and pilot responds by entering autorotation, it's different how?

[sondo214]

First of all you have to stop the spin that has developed the seconds from when the T/R failed untill you cut the fuel to the engine. Many factors affect the extend of this (speed, torque the time of failure, attitude of the heli to name some). This is done by rolling the aircraft to the direction of the spin (while at the same time you are autorotating, whatever this means (RPM,speed etc.)) and basicaly making the uncoordinated spin a coordinated turn. When you achieve this you slowly roll horizondal so that the spin/turn stops.

 

The second difference from a normal autorotation is that you do not have yaw control with whatever this means in trying to navigate the heli to a safe spot to land.

 

The first part is the most difficult to cope with. If more than a couple of seconds pass until the fuel to the engine is cut, the spin may have become uncontrollable even to an extend that you cannot control your arm (by the great centrifugal forces) to cut the fuel in RL. In the Sim this will not be an issue though...

 

Worst scenario is hovering at low altitude. Best scenario is having 80kts speed (tail fin will reduce the spin developed) and sufficient altitude (to stop the spin, autorotate and find a spot to land)