How do YOU do a vertical reversal? Torque turn? Pedal turn?

[pa42]

Curiosity is aroused by watching crop-dusters in the USA lay down a swath and then pull up to near-zero-speed, kick the pedal to spin the helicopter from UP to DOWN, and dive back for the next swath.

I know it works in fixed-wing; but aren't these folks in helicopters putting themselves right up inside the nose of the H-V curve, guaranteeing a big splat if the wound-up rubber bands break?

Can't find anything published on the maneuver. Surely the military would be using it a lot if it could be shown as safe & recoverable--anybody know? Is there a technical analysis of when & how? Should the schools be teaching it, or forbidding it?

Dave

[4ero]

You're looking at a torque turn (or maybe even an anti-torque turn)
There's plenty published on it. You don't use the pedal (much) but rather increase torque and let the engine turn the machine around the mast. Sometimes known as an Ag Turn.
Most machines can get down OK from 50ft, about the right height for an ag turn...
I have heard of drivers happing a quick power nap in the turn before now. :oh:

Maybe someone who has actually sprayed can tell us...

[cpt]

Hello 4ero,

I have done some crop spraying (not enough, I should say...lot of fun !) all on Alouette 2.
The technique I was taught in this time, was to avoid as much as possible these vertical torque turn, but rather to privilege torque flat turns....It can be done without stressing the airframe too much if you play with the torque when you reduce power for speed reduction and initiate a right turn, you have the feeling to turn around your boom tip.
For vertical turns, I wasn't reducing speed (50 Kts was the normal spraying speed) and at the top the climb, I was adding some more pitch to turn left, a bit as a fixed wing stall turn ( I also had the feeling to increase the coning angle, for clearance with the tail boom purpose)....It was becoming a bit tricky at heavy weights and/ or in gusty winds....sometimes earth was looking a bit close and the strengh of gravity a bit high.
But we had no school nor real training for that, only casual chats with other pilots.
It wasn't in (french)army or air force training program anyway.
But I assume that all helicopters and pilots have different techniques.....
I believe that a proper course exists in some countries where standard practices are set up.
.....If I could do a living wiith this type of flying, I wouldn't mind to give up my off-shore on almost fully automatic helicopters (here passengers don't find a stall turn as a funny thing
:bored: )

[Nellis]

We use the manoevure on the Mi-24 Hind when attacking targets in the thick bush or jungle found here in West Africa. It is a similar manoevure used by ground attack aircraft when attacking opportunity targets. Basically we pull the nose up to about 40-50 degrees, lower the collective slightly, let the speed bleed off to about 80 km/hr, and use a bit of left rudder to bring the nose around. A little bank into the turn helps to find the target sooner and the nose attitude during the recovery is quite steep ±60 degrees. Once the target has been acquired, aim, fire the weapon and pull off. Flying technique is to not let the helicopter get into a negative 'G' situation as Natasha wakes up and screams in your ear - sounds all Russian actually!!:\ Makes one homesick! :yuk:The warning is low oil pressure in the engines. Firing rockets is a bit tricky, but the Gatling nose gun works well.

[helmet fire]

In Oz, we called it a wingover (for no use of torque to turn) or a Torque turn when using the torque to bring you around. The US Army called it a "return to target" and banned them post Vietnam following several mast bump and mast separations.

Nellis, we tried to avoid them in gunship ops because it gave the enemy such a reduced crossing angle opportunity for them to return fire - but then we are in the Huey which was far less able to absorb enemy fire then the Hind, and could be brought down by anything more lethal than a banana.

[imabell]

vertical reversal?????????????????????????

where did you get that terminology?? or did you make it up??????????

torque turns, (or anti torque turns???) are not a normal part of ag flying or mustering.

the normal turn is a pedal turn, left or right to get you around the corner a little bit tighter and faster.

in ag, if you need to go to the right then you begin by entering a left turn then roll into a right turn along with some right pedal. This will bring the tail around and up increasing the rate and also increasing your height, (aerodynamics), at the same time. As you are rolling out of the turn you reduce the pedal push forward on the cyclic and head off on your next run. Visa versa for the next run as you will be turning left to continue down the paddock.

in mustering we generally only do pedal turns as they are much more efficient and give you a bit of free altitude as you go into the turn, it also gives you a chance to have a look around. It helps you to keep the tail up high, away from trees and the ground.

why is it that so many pilots think that it is unsafe to carry out these types of manoeuvres. is it lack of competent training??, maybe lack of theoretical knowledge??

it seems that vrs and height velocity incursions are dominant fright factors for some people. vrs for instance is something that you have to go out and deliberately induce, it is not an every day problem that we face and if the height velocity diagram was a no entry graph then surely it would be coloured red.

the fact is we operate in these areas on a daily basis and we store this information in the back of our minds and get on with the job. i would rather sit in a hover at 300 feet for a couple of hours with the wind up my bum, (for some inane reason), than fly at low level, miles out over the unforgiving sea, in bad weather, as depicted in one of the photos in the picture thread.

these days it seems that many pilots worry a great deal and unduly about operating in these flight regimes.

helicopter flying is inherently dangerous, we understand that, now these days it seems that a fear of flying has been bred into the system, I think from a lack of proper theoretical education and this seems to have spread over into the practical side of things.

if you don’t know how something works then you are probably not going to make it work properly.

when I learnt to fly in the usa the helicopter examination system did not include any practical helicopter theory and we all seemed to get by. in the uk it seems that even though they think that they invented flight and have a massive examination system to plough through the lack of understanding still prevails. the fact is that helicopters are not plummeting out of the air because of vrs or operations in the confines of the height velocity diagram. if they were I would not get in one.

i think the term dead mans curve should be eliminated from our vocabulary entirely.

during flight tests I have asked pilots to come to a hover at 1000 feet for instance and they break out in a cold sweat at the thought of it, who put that fear into their mind???

keep asking the questions on these threads please, if this is where you are to get your knowledge. it’s a shame the system seems to be letting us down.

http://www.bluetonguehelicopters.com.au/pprune/splat.jpg

[rotaryman]

helicopter flying is inherently dangerous, we understand that,


Says Who?

Not when flown by competent well trained Pilots< just my oppinion,,,:ok:

[deeper]

Rotaryman,

Industry statistics, from a previous thread,

1. Timber industry..........150 fatalities for every 100,000 workers

2. Fishing industry......... 71 fatalities for every 100,000 workers

3. Helicopter industry........70 fatalities for every 100,000 workers

I hope your competency and good training maintains your opinion.

:(

[4ero]

...this thread's taken a bit of a turn of it's own...

imabell ... What nellis describes was what i was imagining to be an anti torque turn, where you lower collective and turn left around the mast (US), maybe there's a better way to describe it. I learned the turn downwind with airspeed on then into wind to turn onto the next swath as a procedure turn or p turn.

What I know about helicopters will fit quite roomily on the back of a circuit breaker , I just hope that I'm around long enough to be as authorative as some of the guys here, and imabell, right again, this is one of the best and only sources of knowledge around.

We've just got this, a good chief pilot, and whatever experience we've garnered so far.

[rotaryman]

Industry statistics, from a previous thread,

1. Timber industry..........150 fatalities for every 100,000 workers

2. Fishing industry......... 71 fatalities for every 100,000 workers

3. Helicopter industry........70 fatalities for every 100,000 workers

I hope your competency and good training maintains your opinion.


You can make make numbers do what you like, How many people are killed just walking down the street or by drunk drivers? or Heart disease and cancer? Flying is as safe as you want to make it!
Or you at least til your numbers up! :=

Sure there are some terible accidents, ive lost friends in helicopters accidents, All Pilot Error!!:(

[3 ROMEO MIKE]

imabell,
Can we get any infomation on the picture you posted
of the pancaked robbie.
Thanks

[cpt]

To Nellis,

The kind of maneuvring you are describing with your Mi24 seems to me ideal to be shot at.....During your reversal turn you are exposing the most vulnerables parts of your helicopter, you have no speed,no high, you are close from your target, you are flying a very predictable trajectory with a big and not very maneuvrable helicopter, and without a surprise factor.
To my common sense it seems very risky, unless you are "treating" a non armed ennemy or if you are covered by a friend.
But having sprayed bugs and fungus only, on non agressive vegetables, RPG7 with other sorts of projectiles were not a concern and I lack experience in that matter.:cool:

[Lowlevldevl]

4Aero,
I'd have thought that a torque turn was a torque turn whether turning left OR right. As long as the MR torque is not in equilibrium with Tailrotor force, torque must make the thing turn...correct?

Imabell,
Anytime I fly ag I try to keep tailrotor inputs to a minimum, so use torque, whether up collective or down to help me around the turn. I do this because one of my old chief pilots warned me about putting any more load than absolutely necessary onto something as fragile and furiously spinning as a tail rotor. I know you are a very wise old instructor and seriously, without any smart-arsedness on my part would like to know what you think.

[Nellis]

cpt,

You are right, it is a risky manoevure and normally only attempted with opportunity targets and a lesser class enemy armed with small arms. The 24 is greatly feared in this part of the world and we can get away with some of the profiles we use. Here the man who makes the most noise wins the battle!

One thing though, the 24 for its size is quite manoeverable and contrary to what the manual states, a pilot can put it into attitudes without any serious sweat. However, it has a bad habit of rolling into the turn when 60 degrees plus bank is selected at speed and the speed bleeds off very quickly. If you are not prepared for, or do not anticipate the rollong moment, you need to use cross controls to recover!.

[cpt]

I don't doubt a second that the Mi24 is greatly feared, I have had the occasion for a close look,and it's a really amazing concept ! (as some others russian helicopters).
I also use to fly occasionaly with former Mi 24 pilots, all of them agree to say they liked it a lot, but their flying techniques seemed to be a little bit different, and I have the feeling they were a bit cold with big and rapid variations of attitude.
I think it's a matter of adaptation to the context....adaptation is a key word in our rotor world !
Nevertheless, I really would like to meet once this Natasha who recorded on the internal vocal alert system (she cannot be "synthetic" )
;) She spoke to me in my few Mi8 AMT flights, and since that....!!!
Ah, those Russians !

[Vfrpilotpb]

To Imabell,


Having spent quite a while flying in the R22, your piccie looks like this particular one landed a little on the high side of fast!

But top marks, the skids are level.:cool:


Regards Peter R-B