View Full Version : Bell 47 or Hiller
11-13-2006, 08:13 PM
Any expert comments from those of you who have flown and/or owned either helicopter? Which is a better helicopter and why?
11-13-2006, 09:40 PM
It's been a long time, but I have time in both. As far as handling, I can't remember there being any difference. Both or very solid, sturdy machines. Plenty of rotor eneria (can't spell) for auto's. And if you bungle a full touch down it won't come apart on you.
The Bell 47 Whirlybirds forever.
But the Hiller has it's own charm too.
11-13-2006, 10:09 PM
I tried looking for comparisons between Bell 47 and Hiller and all I managed to find were comments on the Hillers. These are cut and pasted from various sites.
Bell 47, or Hiller 12E. Then if you want to get more spiffy, look at each in the Soloy conversion which are the Allison C20 turbine engine and great for what you want to do. Sure they can be high maintenance but there is also a good used market for them too. I doubt you'll fly more than 100 hours in a year...barely enough to retain proficiency - and that holds true with nearly ANY helicopter you get, and especially with low time. find an experienced instructor with or for either and get a thorough checkout.
I have a few thousand hours in each and recommend them without hesitation for what you are talking about.
My vote is for the Hiller 12 D or E recips. Big enough to haul 2 big people or three average people, and low costs to buy and fly. I've got a 12D, it's very easy to fly and handles wind as good as any light helicopter. Other reasons, they are way over built sort of like a tractor, I guess that's why they're used for ag work so much. The safety record is excellent also.
Down sides, they are slow, and the fuel burn is a little high @ 19gph. They also might not be as smooth as other rotor set ups.
IMO it's the best big little helicopter out there.
The R-44 has an engine that will last 2200 problem free hours vs the Hiller's Franklin (or PZL) engine that leaks oil like the old Bell 47.
How about speed ? The Hiller flies at an outstanding 73 kts VNE while the R-44 does 117 kts VNE.
One advantage the Hiller has is that you can overhaul anything in the field without having to send it to the factory, but my experience with the Robbies is that if you treat it right, it will give you the 12 years and the 2200 hours before overhaul. The Hiller needs an overhaul after 1200 hours.
I've used the 12C & E and ET in thousands
of hours crop spraying/dusting with no problem. Of course I've had the
normal mechanical problems that are endemic to all helicopters but
certainly nothing specific to the Hillers. They are a hard working
machine and take a lot of abuse before they give you major problems.
The Hiller does have some vibration that I laugh and call the "Hiller
Hop" but if the blades are properly tracked and balanced it is usually
a smooth ride. I would like to point out it does not have any
particular idiosyncracies when it comes to autorotations as does the
Robbie, i.e., rapid rpm decay. In fact, I've had some actuals in the
UH12 while spraying and all were concluded successfully with no damage
to anything but the few plants that got crushed by the skids! (well,
perhaps some nip marks on the seat covers....? ggg)
If you'll email me privately I can give you the contacts for someone
who may be able to help you directly in finding a reasonable Hiller
and give you some hard costs. We operated Hillers for spray operations
and also had Bell 47 and 206. I preferred the Hiller for any number of
reasons not the least of which was it could haul a load when it got
How different is the airframe and components of a UH-12B model and
a UH-12E Hiller? I know the B model had flat glass, Franklin engine,
wooden blades and a lower time rotor head (600 hrs.?). Also does
anyone have any pros or cons on the vertical Franklin engine?
Thank you, Eddy
The UH-12B Hiller airframe looks very similar to the UH-12E, but that is where
it ends. The instrument console is different, the engine and transmission
mounts are all different, the fuel cell is smaller, the fuel boost pump is
different, the cooliing fan is smaller and weaker, the tailrotor mounts on the
opposite side of the tailboom and the tail rotot drive is similar, but
different. The main transmission has only a single stage planetary reduction
versus a 2 stage system in the UH-12D & E series. The main rotor head and the
control rotor system is the closest however, the control rotor paddles are
fabric covered on the A,B & C's and the rotor head is an improved design from
the older models. The wood main rotor blades share the same design with the
Bell 47 wood blades, but the Hiller blades are a little shorter. In general, I
would say that the B (or C) model is a great aircraft for the person that wants
to get their license, build some time and not loose your shirt. The aircraft
will probably bring the same , or better price several years from now, as when
you buy one. Like anything it will need its maintenance and that won't be
free, but as long as you are not putting more than 100-200 a year on the A/C,
then it shouldn't be too bad by comparison. It is an old design, and at times
it can be a pain to work on. The military dumped them for the OH-23D (UH-12D)
which is a much stronger aircraft. The D does share the fuselage and most of
the same components as the E model except for the VO-435 engine, but it can be
upgraded if a person wanted to. (The D model is even elegible to be converted
to turbine power If money is no object).
The Franklin engine is (in my opinion) a good little engine. It is not the
strongest powerplant in the world, however as long as it is cared for properly,
it will give years of adequate performance. The small (14mm) spark plugs are
a maintenance problem, but I recomend that a person use fine wire plugs, for
the greatest time between plug fouling. The extra cost is worth the added
security that will keep you from losing power due to a fouled plug just when
you need it most.
11-14-2006, 05:05 AM
They both have good & bad points - I've flown various Bell 47 models but only the Hiller 12E. I personally preferred the way the 47 feels, the Hiller control system is very different (large lag between cyclic input & response)...fly both if you haven't already.
The biggest thing is finding a "good" one of either type - there are a bunch of junk machines out there. Undocumented accident history, false historical records, fake "spray paint" overhauls...get a good mechanic you can trust that's experienced in type to go over anything you're thinking about purchasing!
There are reoccurring AD's on both that can be a pain. Certain parts on both can be hard to come by, and expensive because of that.
Hiller 12E's use a VO-540 - very sensitive to overspeeds since it's already turning 3200 rpm normally, and I never saw one make TBO (1200 hours) without at least a top overhaul along the way. All the Bell 47 models I flew had the VO-435, which usually made TBO just fine. I'd suspect that a Hiller 12D which also uses the 435 would be ok here too.
Take a close look at the tailbooms on either - 47's get corrosion internally especially if improperly repaired after a blade strike. Every 47 I flew had evidence of one, these were all ag ships.
Fuel burn was similar on both, as was maintenance with the exception of the engine as mentioned earlier.
The Hiller can be tight even for two people if either are large because of the odd seating setup for 3 - pilot in the middle & passengers on either side.
11-14-2006, 05:22 PM
Thanks guys this info really helps. I just bought a book from Mr. B47 Joey Rhodes and it gives ton of good advice on purchasing a 47. It appears there are more parts and service available for the 47 and Mr. Rhoes will set up a pre-buy and find a qualified mech in the area you live. He will also help fly or transport it back home after the purchase. Sounds good! There is also a Bell 47 association that seems to give good support to owners.
11-14-2006, 08:26 PM
Given a choice, as a former mechanic, I'd go for the 47. Bell still supports the 47. And I just like it better.
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