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. |
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. |
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.. |
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.
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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!. |
Ah, the sunshine and snorkelling det to Belize Shy?
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Originally Posted by ShyTorque
(Post 11066343)
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!. |
Originally Posted by [email protected]
(Post 11066379)
Ah, the sunshine and snorkelling det to Belize Shy?
[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! |
The other engine refused to start despite the efforts of some of our ground crew/engine mechs on scene. It usually got it to start. |
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.
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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? |
Very interesting, thanks for the informative replies
I’m 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 ? |
Originally Posted by gulliBell
(Post 11066017)
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!
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https://cimg6.ibsrv.net/gimg/pprune....c05635fad.jpeg
Most of our departures required the rolling technique. God Bless the Alouette 3 and the abuse she took without complaint! |
Originally Posted by gulliBell
(Post 11066015)
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.
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Originally Posted by stilton
(Post 11066508)
I’m 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 ? |
Originally Posted by Greek God
(Post 11066540)
https://cimg6.ibsrv.net/gimg/pprune....c05635fad.jpeg
Most of our departures required the rolling technique. God Bless the Alouette 3 and the abuse she took without complaint! |
When you bleed RPM on an Alouette III....you have accomplished something!
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I’m 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 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. |
Originally Posted by John Eacott
(Post 11066592)
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 |
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