Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

Rolling take offs in a Helicopter

Rotorheads A haven for helicopter professionals to discuss the things that affect them

Rolling take offs in a Helicopter

Old 22nd Jun 2021, 12:22
  #21 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 5,225
One could try the Towering Takeoff Method used on the Bristol Sycamore; notorious for lack of power and manoeuvrability.

On the ground accelerate the rotor to max permissible. IIRC 287 Rrpm.
Pull the collective up at the same time opening the throttle to keep as the power at max whilst you overpitch to min Rrpm.
Pitch forward with the cyclic at the same time milking the collective to maintain Rrpm as you transition forward and down.
When you achieve level flight continue take off as normal.

Worked every time.

Still used in a way. On the S76A+ we would use a similar technique so that one could throw it over the side of a platform and allow gravity to achieve VTOSS.
Fareastdriver is offline  
Old 22nd Jun 2021, 12:55
  #22 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 73
Posts: 17,053
The Bell 47G2 at Redhill on a Summer Morning with two of us aboard made for an interesting takeoff.

A certain large framed fellow with an Aussie accent and I were to do some training in the G2 in anticipation of my doing a Check Flight for my UK ATPL.

Being full of Gas (the aircraft) and the two of us onboard.....I hit the Up Stop on the Collective and Max Throttle and other than some vibration change....there was no discernible movement by the skids.

When asked by the CFI...."What you going to do now Shag?".....I uttered those famous last words of some helicopter pilots....."Watch this!".

The grass was still wet with Dew.....and with a bit of wiggling of the cyclic we were off like a herd of Turtles until we finally gained enough speed to achieve ETL....and leave the ground.

In time...we were at Pattern height and went on to doing Confined Areas....with Towering Takeoffs being done in ultra slow motion.

There are real risks in doing limited power takeoffs as there can be less than adequate margins should you goof it up.

We used to pick up to a three foot hover....check handling and power available....then land back and proceed to do a takeoff from the ground barely touching the toes of the skids to the ground to use the least amount of power possible when we were at max power at the three foot hover.


As seen in the video.....as a Gun Ship does a takeoff but in the video it does have an excess of power required looking at the way it maneuvers.


SASless is offline  
Old 22nd Jun 2021, 13:27
  #23 (permalink)  
 
Join Date: Oct 1999
Location: Nigeria
Age: 54
Posts: 5,053
When asked by the CFI...."What you going to do now Shag?".....I uttered those famous last words of some helicopter pilots....."Watch this!".

The grass was still wet with Dew.....and with a bit of wiggling of the cyclic we were off like a herd of Turtles until we finally gained enough speed to achieve ETL....and leave the ground..
I hope that didn't knock the ash off the end of his parked fag/cigarette but?
212man is offline  
Old 22nd Jun 2021, 13:27
  #24 (permalink)  
 
Join Date: Apr 2000
Location: EGDC
Posts: 8,724
FED - sounds like a similar technique to the Single Engine Water Take Off (SEWTO) for the Sea King which some of us were able to practice on the Waterbirds Course in Nova Scotia.
crab@SAAvn.co.uk is offline  
Old 22nd Jun 2021, 15:20
  #25 (permalink)  

Avoid imitations
 
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 13,371
I once had to ferry a Puma "single engine" from an oiled sand strip on a Caribbean island. The other engine refused to start despite the efforts of some of our ground crew/engine mechs on scene.

We used the normal running takeoff departure technique, basically as described above. That was uneventful because we regularly practiced them. I was actually rather more concerned about the over water flight that followed because we were the only available local SAR cover!.
ShyTorque is online now  
Old 22nd Jun 2021, 16:14
  #26 (permalink)  
 
Join Date: Apr 2000
Location: EGDC
Posts: 8,724
Ah, the sunshine and snorkelling det to Belize Shy?
crab@SAAvn.co.uk is offline  
Old 22nd Jun 2021, 16:23
  #27 (permalink)  
 
Join Date: Oct 1999
Location: Nigeria
Age: 54
Posts: 5,053
Originally Posted by ShyTorque View Post
I once had to ferry a Puma "single engine" from an oiled sand strip on a Caribbean island. The other engine refused to start despite the efforts of some of our ground crew/engine mechs on scene.

We used the normal running takeoff departure technique, basically as described above. That was uneventful because we regularly practiced them. I was actually rather more concerned about the over water flight that followed because we were the only available local SAR cover!.
One of our 332s did the same while on contract to UN in Liberia around 1994. They had shutdown, but were then alerted by lots of shouting on the hand held radios, as their group of frantic Pakistan (?) peace keepers came running back being pursued by unfriendlies. I can't remember if the second engine failed to start, or they just thought it prudent to go with what they had!
212man is offline  
Old 22nd Jun 2021, 16:38
  #28 (permalink)  

Avoid imitations
 
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 13,371
Originally Posted by [email protected] View Post
Ah, the sunshine and snorkelling det to Belize Shy?
It was tough, but someone had to do it.

[I have to admit, I really didn't like the place much at all. With very high OAT and over 95% humidity during the summer I was usually on the point of melting, especially in the cockpit. Then, being based in Germany, having to go from from operating plus 28C to -28C in the winter, or vice versa a couple of days later was "interesting". It was so stressful that those poor delicate Harrier pilots in the same block as us had to have air conditioned rooms. Helicopter pilots not so privileged].

There's a bit more to the above story, btw. We needed the AOC's personal permission to carry out a single engine transit. He willingly gave it, he was supposed to be on the aircraft and had no other way of getting back to the mainland! Not to mention the Air Commander and every RAF Harrier pilot in Belize at that time, some of whom had gone out to the island by a private speedboat. It had also broken down with steering failure and could only go round in tight circles!
ShyTorque is online now  
Old 22nd Jun 2021, 16:56
  #29 (permalink)  
 
Join Date: Oct 2006
Location: UK
Posts: 5,225
The other engine refused to start despite the efforts of some of our ground crew/engine mechs on scene.
As I had to shout up to my crewman in Belize a couple of times. "BELT THAT BOX WITH THE SHINY COVER"

It usually got it to start.
Fareastdriver is offline  
Old 22nd Jun 2021, 17:46
  #30 (permalink)  
 
Join Date: Sep 2005
Location: Montreal
Posts: 646
Running takeoffs are pretty common where I've flown, both wheels and skids, when heavily loaded or in reduced RVR. Never had to in the 139 or 407, all that power I guess. Watch any fire-fighting machine slide and skip its way through translation when heading out for the season - stuffed with nets, bucket, long lines, engineer, tools, and a jag of fuel to minimize fuel stops to contract location.
malabo is offline  
Old 22nd Jun 2021, 18:19
  #31 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 73
Posts: 17,053
212man......nope...that cigarette long ash never quivered or fell from that takeoff.....but the next morning it fell to the floor...Butt and Ash....along with his Jaw but that is story best told in private!

I hope that didn't knock the ash off the end of his parked fag/cigarette but?
SASless is offline  
Old 22nd Jun 2021, 20:23
  #32 (permalink)  
Thread Starter
 
Join Date: Apr 2004
Location: Planet Earth
Posts: 1,961
Very interesting, thanks for the informative replies


Iím thinking a helicopter taking off from a ship underway is always doing the equivalent of a rolling take off ?

Does this require a particular technique ?
stilton is offline  
Old 22nd Jun 2021, 21:13
  #33 (permalink)  
 
Join Date: Jul 2011
Location: N/A
Age: 44
Posts: 77
Originally Posted by gulliBell View Post
Oh yeah, I seem to recall a Bristow S76A doing a running landing at 80 knots at Barrow Island with jammed controls and he pulled that off OK, apart from cooking the brakes. Now that would have been exciting!
There was an Israeli Apache that lost tail rotor drive and landed with more than 120 ktsÖ Just keep it nicely level and aligned and easy on the brakes!

casper64 is offline  
Old 22nd Jun 2021, 21:37
  #34 (permalink)  


Mmmmm PPruuune!
 
Join Date: Jul 1998
Location: UK
Posts: 588

Most of our departures required the rolling technique. God Bless the Alouette 3 and the abuse she took without complaint!
Greek God is offline  
Old 23rd Jun 2021, 00:51
  #35 (permalink)  
 
Join Date: Sep 2011
Location: USA
Age: 52
Posts: 330
Originally Posted by gulliBell View Post
Ummmm, 54 knots? And if you're doing 50 knots on the wheels in a 76 that does seem awfully fast, even though it's within limits. I certainly wouldn't want to be taking the taxiway exit at that speed, nor even 40 knots for that matter.
Never broke nothing and never had a complaint from mx....brilliant solid aircraft.
Sir Korsky is offline  
Old 23rd Jun 2021, 00:56
  #36 (permalink)  
 
Join Date: Aug 1999
Location: Gold Coast, Australia
Age: 73
Posts: 4,307
Originally Posted by stilton View Post
Iím thinking a helicopter taking off from a ship underway is always doing the equivalent of a rolling take off ?

Does this require a particular technique ?
Not at all: you're lifting to a hover over a particular spot, sometimes in a strong wind. From the hover you move sideways off the ship and then transition into forward flight, climbing to a nosebleed 200ft.
John Eacott is offline  
Old 23rd Jun 2021, 00:57
  #37 (permalink)  
 
Join Date: Aug 1999
Location: Gold Coast, Australia
Age: 73
Posts: 4,307
Originally Posted by Greek God View Post

Most of our departures required the rolling technique. God Bless the Alouette 3 and the abuse she took without complaint!
And there lies a particularly brave photographer!
John Eacott is offline  
Old 23rd Jun 2021, 01:08
  #38 (permalink)  
 
Join Date: May 2002
Location: "Deplorable but happy as a drunken Monkey!
Age: 73
Posts: 17,053
When you bleed RPM on an Alouette III....you have accomplished something!

SASless is offline  
Old 23rd Jun 2021, 01:33
  #39 (permalink)  
 
Join Date: Mar 2005
Location: N/A
Posts: 4,098
Iím thinking a helicopter taking off from a ship underway is always doing the equivalent of a rolling take off ?

Does this require a particular technique
The only difference operating on a ship is the ship heaving, rolling and pitching. In order to land once had to get the ship to run down wind in big seas, to get a steady deck, and then land facing the stern and into the 40 knot wind.

SAS, 5800? One I can't answer, never noted the RPM when running out of pedal and having to chop the throttle, only time I ever saw that figure was on start up, shut down, or pulling pitch at the bottom of an auto. My Vietnam time was in the H, though went for rides in the left seat with the C chaps on my days off to see how they went about their business.
megan is offline  
Old 23rd Jun 2021, 03:45
  #40 (permalink)  
Thread Starter
 
Join Date: Apr 2004
Location: Planet Earth
Posts: 1,961
Originally Posted by John Eacott View Post
Not at all: you're lifting to a hover over a particular spot, sometimes in a strong wind. From the hover you move sideways off the ship and then transition into forward flight, climbing to a nosebleed 200ft.

Understood

I made the comparison as when lifting off from a ship underway in a helicopter you already have the relative wind that would be generated by a rolling take off on land
stilton is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.