PPRuNe Forums - Sky Cranes

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Roughly how much can a sky crane lift?

And to anyone who flies one, is it not one of the coolest things you can do in a helicopter?

Mady

Do you talk about the Erickson or the Mi-10K?

S-64E = 10 tons
S-64F = 12,5 tons
Mi-10K = 11 or 14 tons, depending on the engines

Skycrane is a registered trademark of Sikorsky Aircraft. Hence the use of the "Aircrane" name by Erickson.

The S64E/CH54A external load limit is 20,000 pounds.

The S64F/CH54B external load limit is 25,000 pounds.

thanks - didn't really know the difference - thought there was only one sky crane!

If what you say is true that is one hell of alot of weight - It could lift a lorry!

Will someboy please work out how many r22s or r44s it could lift - probably something crazy like 150+???

mady

Quote:

Will someboy please work out how many r22s or r44s it could lift

Well, mady, the Dry Empty weight of an R22 is approx 880lbs, an R44 approx 1600lbs.

And I'm sure that you know how to use a calculator... :E

B73

g-mady,

I have a few hours in a Crane, and thoroughly enjoyed it. I never had a full check-out, CP only, so I waited a bit here, hoping one of those Ericksen crane-drivers who really know it would post.

The aircraft is built from the ground up as a flying crane. The main rotor shaft is vertical (unlike the 3 to 5 degree forward tilt of most helos). This means it is perfectly level in a hover, but is about 10 degrees nose down in cruise. Lock your shoulder harness as you rip along at 110 knots, 10 degrees nose down!

The main shaft leans 2.5 degrees to the left, so that the fuselage has no roll attitude in a hover, again, to make it a perfect hook platform. It lands on all three gear simultaneously!

The back seater looks at the hook, and flys the aircraft with a side arm joy stick that "talks" to the autopilot - a sort of fly by wire. The precision is unbelievable, with perfect visibility.

The power was awesome, it easily carried its rated hook load - 10 (A model) to 12.5 (B model) tons. The rotors were stolen from the S-60 experimental crane,
http://www.aerofiles.com/sik-s60.jpg
and were also first cousin to those of the S-56 (H-37 Mohave).

http://www.eichhorn.ws/assets/images/sikorsky_s56.jpg
They were precourser to the H-53A/D rotors.

The hook is connected to a winch drum that takes the load up, and lets the aircraft just hover. The drum is isolated to allow very stable hook operations without vibrations making the load bounce up and down.

The aircraft had a 4 point load-leveler system that was actually 4 small winches in each corner of the underside. This allowed the aircraft to hold a standard pallet that could be loaded up prior to the arrival of the aircraft, which could taxi up, attach the pallet, lift it into position, then fly away.

Several standard load carriers were developed, in addition to the pallet. A box like a Conex was one, and also a hospital module.

The Crane was Igor's dream, and the last aircraft that had his full attention. It was a marvel!
Here is a fine site with some details about the A model crane (one main wheel per side) The B model was somewhat heavier and more powerful:
http://www.fiddlersgreen.net/aircraf.../info/info.htm

Nick,

A while back I saw a photo of the Man himself complete with Fedora riding that platform underneath the first crane....you got that by chance....would be great to see it posted here.

I spent a couple years working on Aircranes and I can say it is a really marvelous machine. The work it could perform was incredible and I was always amazed that it held together. It was not however the smoothest machine in the sky by any means. In order to get the blades into clean air we ran a split track. Every other blade was about 3 inches higher or lower than the preceeding blade while sitting on the ground. When you were picking up a heavy load the track split could get as much as 2 feet! Definately a rough ride. I've never been airsick in my life but riding in the back seat of a crane while logging, looking down between my legs at the load while bouncing around was a recipe for turning green.

Nick mentioned the rotor sytem being close kin to the H-37 Mojave. In fact the blades on the CH-54A (S-64E) were the same as the H-37 with the addition of the BIM indication system. The B model crane (S-64F) had wider chord blades from the CH-53 as well as basically a CH-53 rotor head which was quite a bit different than the E model head. You'll notice when you see an Aircrane on fires all the mechs are running around in coveralls. Thats because they have to grease the rotorhead each post flight which consists of about 140 grease zercs! It's about a 1 hour job to squirt grease in every one and about another 2 hours to wipe up what was slung all over the rest of the machine from flying that day.

I have to say I like staying clean for a living now but I do miss the days on the Aircrane.

Max

Here ya go, SASless, Igor and his engineering VP's riding below an S-60 Crane:

http://www.sikorskyarchives.com/imag...lose%20upL.jpg

The pilots were Jack Peterson and Jim Kay. Jim told me the old man got out of the seat and was walking around, without a harness while at 1500 feet and 50 knots!! Talk about personal courage!

Just to be pedantic,

the mast is inclined 3 degrees forward and 3 degrees to port (aft looking forward).

Sorry, couldnt help it......

Is anyone still using the aft facing seat? The ones I've been around have been VR from the front.

Yes, the aft facing seat is still being used for precision external load placement.

Max Gross Weight Demonstration

When I first went to work at SA Jim Kay showed me a picture of a Skycrane lifting 40,000 lbs. That was almost twice it's empty weight. I believe the demo was flown by Pete Peterson and Jim. Pete was quoted as saying "that the only limitation that was exceeded was the published max gross weight.

Heavy Lift Heritage

The 50s and early 60s saw Igor and his cohorts doing quite a bit of shopping in their existing parts bins to create new aircraft. The evolution of Sikorsky heavy lift rotors from the S-56 (CH-37) to the S-64F (CH-54B) and beyond is a great example.

The entire S-56 dynamic system, including the 72’ diameter main rotor system, was transplanted into the S-60.

The S-56 main rotor was then used in the S-64E (CH-54A), with the exception that an additional blade was grafted onto the hub for a total of 6. The vertical and horizontal hinges, spindles, sleeves, horns, and other miscellaneous hardware was retained, as well as the unique K-bar for the pushrod. Of course the swashplates were new to accommodate another blade..

The S-64F (CH-54B) retained the 72’ rotor diameter, but used a 6 arm S-65 (H-53) non fold style rotorhead. The blade is indeed related to the S-65 blade, but is nicknamed “high twist” because it was aerodynamically optimized for hover compared to the standard S-65 blade.

All of the previous blades had aluminum spars. Going forward, the titanium spar Improved Rotor Blade (IRB) originally intended for the CH-53D (at a 72’ diameter) was actually first applied to the 79’ diameter CH-53E, again with another arm added to an all new , bigger diameter rotorhead, for a total of 7 blades. And of course the CH-53K is all new, but it retains the 79’ rotor diameter…. so in a way, it can be said to be a descendant of the S-56!

Had the S-56 not been stuck with the R-2800's and had been allowed to have Turbine Engines instead....think what that could have meant in performance alone.

Granted the Nose Ramp concept was a bit backwards.