A Skycrane!

I love flying Skycranes! They are not a comfortable helicopter to fly in by any means nor do they go far or fast, but boy can they pick up a lot of weight! It’s nice to watch the fire go out when you drop that much water on it per shot. As far as aerial firefighting goes and when utilized properly as a fast moving “initial attack” tool around urban interface, the Crane is absolutely the best helicopter for the job I have ever flown. It works really well here in Greece with the added ability of picking up salt water from the sea.

But now, after almost 3 months on the road, I am happy that today is my last work day I am getting a few day break away from the orange beast. I thought it would be appropriate to post a comic about Cranes to celebrate the occasion.

Orange is actually not the best color for flying around in the smoke I have found btw. We always get all kinds of questions about this helicopter. And most of the time, people even let us finish our sentences, LOL. I’m sure you guys all have met somebody who bombards you with questions without listening to the answers. We also have the guys who come up to us with a question and then proceed to dazzle us with how much THEY know about the machine 😉

Let’s open the blog section for Crane relate questions y’all might have. I’d be happy to answer them.

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20 comments on “A Skycrane!
  1. Brent says:

    Could you explain the split-track for the uninitiated?

  2. Merijn @ home says:

    Mike,

    Do you still have time to fly in Greece?
    I understand that you had to attend yet another Reception where you were honoured for the fire fighting in Lefkada city centre?
    Kuddo’s again for a job well done!!

    http://lefkadanews.com/lefkanews-article.php?news=23580&lefkada=lefkadaepikairotita&cat=66

    Merijn

  3. mike says:

    Usually helicopter blades are “tracked” to all fly in the same plane which will get rid of vibrations and “hops”. But on the Crane they found (probably by accident) that the blades actually fly smoother and create more lift if they fly in 2 different planes. Some say there are too many blades in the rotor disc (6, so only separated by 60 degrees) and they affect one another. The second blade coming around is flying right through the turbulence of the first one and so forth….
    So we do the following: we adjust the blades so that the first blade tip will fly up to 12 inches higher than the second blade tip and the third blade tip will fly on the same path as blade 1 and so forth. With 6 blades you will end up with 3 “high” and 3 “low flying” blades. That will give each blade better air to fly through.

    You can actually see it when you watch Skycrane footage. The more weight the Crane picks up, the “further apart” the blades fly. You can also see it on pictures when it is photographed from an angle from the top that the rotor disc is not coned “smoothly” compared to other helicopter discs.
    I hope I explained that right 😉

  4. mike says:

    @Merjin:
    Ha! Yes! We’re raking in all kinds of medals this year in the Wildfire Olympics 😉
    Thanks for the kudos!

    There is still enough hours left over in the day to fight fire as well. We are still working 16 hour duty days…

  5. Fred Wedemeier says:

    Cool – A genuine, valid, tail number…

  6. mike says:

    It sure is, Fred 😉
    And no coincidence it is either. It’s the old gal I took (and passed, in case anybody is wondering) my FAA type ride in.
    The tank numbers keep changing all the time though. Not sure where “737” currently is. We have 748 this summer with 747 in Elefsina even though we don’t go by tank numbers in Greece….

  7. Dysko says:

    Once I had the chance to see up close and personal an Italian Forestry Corps Skycrane, almost 10 years ago, when I had just started studying aerospace engineering and my aircraft spotting hobby.
    It was based in a small airport in northern Italy near the sea. I tried asking if I could visit the helicopter, but I wasn’t allowed due to “security reasons”.
    Fortunately, the commander of the Forestry Corps detachment was in the bar nearby and overheard my request, so he let me visit the helicopter and even allowed me to climb in the cockpit.
    It is quite an impressive machine!

  8. Bernd says:

    mike, that’s also what I gather about split track, however, not all pilots seem to agree that it makes for a smoother ride: http://www.pprune.org/rotorheads/188473-sky-cranes.html#post2072624

    One reason may be that although a “high” blade following a “low” blade will have smoother air, a “low” blade following a “high” blade may actually in be in stronger downwash from the preceding blade than in an evenly tracked rotor. So possibly the total effect is really much lower than purported, and the whole thing is propagated as gospel, just like the “laminar flow airfoil” of the P51 (which on production aircraft and in front-line service didn’t achieve much more laminar flow than other wings), or the “tapered wing” on the Piper Archer II and Arrow. Just my thoughts. After all, if the method were effective, why don’t the super-heavy Russian helicopters use it? The Mi-26 seems to have a single unsplit rotor disk.

  9. mike says:

    I agree it might not make for a smoother ride for the reasons you stated. Not having flown a Crane without split track I have nothing to compare it to. But I have a former CH-53 pilot sitting next to me as I write this who says he doesn’t see much of a vibration difference between the two (CH-53 flies on the same track).
    And what works on one US helicopter might not necessarily work on a completely different Russian helicopter. Also, it seems to me nobody in the discussion you posted is actually a pilot so how would they know?
    The info about more lift comes from our logging pilots who always fly right at the max capabilities of the Cranes…

  10. Bernd says:

    mike, thanks for the reply. True, they are not pilots (I originally overlooked the “back seat” part of the post I linked to). However, pilots are not necessarily good at aerodynamics, either;

    I’m also unclear as to whether “split track” is an option on the Skycrane. If not, how would they know how it behaved without that special trick?

    Anyway, “TIL”, as they say these days. 🙂

  11. Rick says:

    Is there a reason that the skycrane seems to gain more cables on the left side of the fuselage in each panel of the cartoon?

  12. mike says:

    @Bernd: I am not sure I understand the question. What do you mean an option? The Crane flies either way, but you can adjust the pitch links so the blades fly a split track. Helicopters are hand made and they are like snowflakes. Every blade is different. Even on other helicopters it sometimes takes a blade to fly higher or lower than the others in order to smooth out the rotor. There are some pre-setting we use, and then we go by the RADS system (track and balance equipment) which tells us which way to adjust the blades in order to get what we want.

    And you’re right, not all pilots are good at aerodynamics. But most pilots are pretty good at noticing if the big @$$ log came off the ground when they lift up on the collective or not 😉 – no math involved…

  13. mike says:

    @Rick: The left side of the crane has a bunch of fuel and hydraulic lines, the right side has all the bell cranks and push rods.

    The reason why the number changes and you don’t see exactly 6 bigger tubes, numerous smaller ones, and two fuel filters is the same as why you see talking chickens wearing glasses: it’s a cartoon! yes, it’s that simple 😉

  14. Bernd says:

    @mike yes, that was what I meant. So the track of each blade is not factory-set, but can be adjusted. Sorry, I’m still somewhat ignorant of rotary wing specifics, and flying helicopters is not yet on my bucket list. Next steps are Night-VFR and IFR. So thanks a lot for the elaboration.

    And sure, in that case, the difference in lifting capability should be noticeable. 🙂

  15. Fred Wedemeier says:

    Mike, I once watched a crew install a corporate logo and lettering on the side of a 50-60 story office building. Through binoculars, the movement of each letter as it was being mounted was imperceptible. When Skycranes are used for that kind of work, do they have some kind of stability control system, or is that 100% pilot skill?

  16. mike says:

    @Fred: This helicopter has an AFCS system installed (Automatic Flight Control System) which helps you a little in a hover. Mainly what it does is cancel out small inputs coming from winds, vibrations, and so forth, but you still need to constantly fly the aircraft. There is no auto-pilot and no auto-hover like modern helicopters (i.e. Coastguard) have. And on top of that, the Crane is a very “twitchy” aircraft for it’s size, way more sensitive than a Huey for example. It really surprised me in the beginning because I thought it would be sluggish because of its size.
    I think (but don’t quote me on it) it is because you have so many blades going around in circles at the same time. You just “think” of moving the stick and it’s already flying that way. To make a long story short though: Yes, it’s all pilot skill.

  17. Rick says:

    Okay – just wanted to make sure it wasn’t a test to see who was paying attention…it was such a nice linear progression from frame to frame…

  18. Jay says:

    I flew Cranes in the Nev ARNG in the 1980’s. I understand that some of our ships are still in civil service doing lifts and fighting fires. I fought fires a bit with a bucket. Lot better set up now. I loved flying the Crane.

  19. Heli says:

    Aircrane/Skycrane: some get quite anal about it dunnunda. The cockpit looks enough like an S61 that I reckon someone mixed up the parts bin!

  20. mike says:

    @Rick: You make a good point – Stefan quite often puts things in the background, doesn’t he?

    @Heli: I think it’s supposed to be “Aircrane” since Erickson bought the civilian type certificates (on my license it shows up as “SK-64”) vs. “Skycrane” back when Sikorsky made them originally, and “Tarhe” as it’s military version….

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