Msuldo,

Ages ago when I started this thread, I never expected to read something like you have written, dropping in from such a height would seem like a certain one way ticket, was it just massive bulk bodywork that saved you and your pal.

thank you for that short but very gripping piece of your flying history.

Peter R-B
VfrpilotPB

AAAAHHH Belvedere !
Stable because Raoul Hafner ,the designer didn't believe in power operated controls,although they were fitted after a few flights,one engine at each end because it was born as a piston design but modified for turboshafts when they first arrived on the scene in the mid fifties ,able to fly at AUW on one engine (with an auto doubling of power if one failed) but never intended for the RAF who got the short straw when the original customer ..the RN cancelled in favour of the Wessex ,hence the lack of cabin windows,the stalky front landing gear,and the overall fuselage dimensions.
Mind you Belvedere Mk 2 would have beaten the Chinook hands down if Bristol's had been allowed to build it.Aft mounted Gnome engines(3 or 4),rear ramp,four blade rotor system ,cabin plug option for civil use, but cancelled because the short sighted government didnt see any use for large helicopters once they withdrew from east of Suez.
Hindsight is a wonderful thing !

Three or four engines.....long ladder to get into the cabin....narrow as a sausage....oh yeah right it would have beat the Chinook! Even the RAF is celebrating thirty years of flying the Chinook.

Some of us are celebrating 44-45 years of flying Chinooks....and in the future there shall be Kids celebrating 90 years.

We should also recall the Wessex was originally designed by Sikorsky and some variants are still flying in commercial service today fifty plus years later.

Belvedere vs Chinook
 

The Chinook is a great aircraft even with all of it's warts and blemishes. The Belvedere did enter production and service in the RAF. My interest is their aerodynatics. Why does one reqiures supplimental stability controls and the other doesn't. Is it pilot training or a fix to the airframe?:confused: I would like to understand the tandem rotor helicopter not cause an argument between rotorheads.

Designers learned as they went....the "A" model Chinook had a very sharp end to the Aft Pylon and was quite sensitive in Yaw. The subsequent models had a squared off end to the Aft Pylon which provided the equal of about 37 feet more fin or some such number....and was much more stable in Yaw. The A and B models had dual channel three axis SAS systems.

Starting with the "C" model the aircraft were equipped with an additional Pitch SAS system.

The earlier Piasecki CH-21 has no SAS but did have stabilizing fins on the Aft Pylon.

The H-25 or HUP had neighter SAS or Fins..

http://boeing.com/history/boeing/images/hup.jpg

SAS:Uh-oh! Don't mean to be disrespectful, SAS, and I certainly could be wrong about this...but I believe the HUP did have *both* of those things, depending on model.

HUP-1 had fins on the side of the aft cowling.
HUP-2 had no fins and a crude SAS.
HUP-3 had a more sophisticated SAS (that could, I've been told, autohover).

My dad flew the HUP-1 and -2. Said they weren't very pleasant to fly.

SAS and FH1100,

Thanks for your input! The best information comes the guys who drove these machines. Please forgive my ignorance, I drove OV-1's while in the Army but escorted a few Chinooks into some bad places.

Belvedere Development.

The turbine powered version bore no relation to the ship borne torpedo firing botch-up that the British Navy wanted. It was similar in appearance, though larger, and more importantly, earlier than the Chinook. I cannot find any drawings of it at the moment but the ones I have seen were very impressive.

However, shoveling money into the back pockets of benefit scroungers, illegal immigrants etc, had a far higher priority for public money so the project was scrapped.

The Belvedere Mk.2 was nothing like the original version SAS less...it had a level undercarriage ,larger cabin and was very Chinook-looking ,even though the design predated the Boeing aircraft.No coincidence that after it was cancelled some top Bristol designers emigrated to Philadelphia ?!

The success of the Chinook since just shows what a world beater the Brits would have had if the government hadn't cancelled it ...

As for the S-58 the British conversion to twin turbine power turned a heavy poor payload aircraft into something that could fly OEI at max AUW.

I was more familiar with the Army version....which in those days...helicopters were considered more in line with Jeeps and Trucks than aircraft.

The CH-34 had "ASE" , and auto pilot system with a Barometric Altitude hold feature....which did not find its way to the Huey or Chinook. It is no surprise the HUP was far better equipped than the H-25.

As in most helicopter designs of the US Military....there are many different models of the same aircraft.

http://www.flugzeuginfo.net/acimages...gronenthal.jpg


From the US Army Aviation Museum at Fort Rucker, Alabama.....

http://upload.wikimedia.org/wikipedi...R_edited-2.jpg

This may be of interest, picture taken from the RAF news, showing Belvedere picking up a crashed Lightning. The Lightening crashed after the Pilot ejected, after an undercarriage failure. BAC wanted it back for examination, as it was by the sea, and the tide was coming in.

Aircraft was flown by Flt.Lt Youngs, and Flt.Lt. (Bunny) Austin, with me as crewman. After we managed to get it back, we found it was full of sand, and seawater, so was way over the 6000lbs hook weight.http://i866.photobucket.com/albums/a...g?t=1312388386

There never seemed too much concern about what was slung under a helicopter back then: and always a short strop, too ;)

http://glostransporthistory.visit-gl...d%20Wessex.jpg

Bet that was a fun load to fly Dave....Not! Just as well it was more dense than anticipated.

Heli 1, while it probably would have garnered a few orders, i am not convinced a Belvedere Mk2 would have done that well. Just as many other UK designed ac of the 60s didn't - many foreign air forces were already buying US or Soviet ac due to their lower costs and better availability, never mind the hidden cold war subsidues. Most CH 47s have been bought by the US Army, so do you really see them buying from us rather than US built...? Coupled with the fact that the RAF would probably only bought about 30 , the production line would have probably closed 1970 before we woke up to the real value of such beasts as we have now.

Tallsar.
Of course the US Army wouldn't have bought it.US politics would have seen to that ,even if it was twice as good,but when you look at UK purchases of Chinook since then,now close to entering three figures, and a few other possible overseas sales..Canada,Australia etc it would have been a decent run and justified the millions spent on Belvedere development.

Like many British projects,it was just ahead of its time.

Heli one,

like the Spitfire, RR Merlin and more, then the Jet Engine, the turbine, the fully flying tail components, The Buccaneer, other supersonic designs, Concord/TSR2, to name just a few:D

if our politians had had brains then,.. the UK Inc would be in a good state now !

Peter R-B:ugh:

Tall Star
Yes it was tense, as the pilots were not aware that it had been slung wings down, so I had to keep saying "you must get some more height", as the wings were in danger of clipping the ground. Trouble was they were using all available power.

Here is a picture of why it could never enter Naval service. Embarking on HSM Albion, en route to the far east.

http://i866.photobucket.com/albums/a...g?t=1312471087

Belvedere MK II
 

Heli One, you had written that the MK II would have 3-4 engines. It sounds as if the design was conceptual in nature. To exceed the performance of the CH-47A, which had 2 X T55-L7's at 2650shp each ( or to address beating the CH-53A which was on the scene as well with 2 X GE T-64-6B at 2650shp each ), it would have needed the four engines I suspect.

I certainly concur with your remark re the talent available. Sikorsky as well as Boeing were very lucky to sign up UK engineers, who were hard working, extremely talented and an asset of immense importance. And they certainly added a note of civility to our often loud and noisy design decision meetings.

As I believe SAS was getting at, however, the task facing Bristol in starting with the model 192 and coming up with a product that exceeded the built in capabilities of the 47A and 53A, was funding an an investment that probably wasn't justified by the total expected sales revenue ( whether the money came from Bristols or UK Gov't funds ).

Thanks,
John Dixson

Hel1 - i think you missed my point. In the 60s, the RAF only ever had a requirement for 15 Chinnook. It was not the late 70s that some cash was found to buy the 33 to meet a new BAOR task ... And then reluctantly. In other words, there simply was not a requirement for enough Uk built ac for our own services to sustain profitable production. Why would Australia and Canada then buy an overly expensive Belvedere 2 compared with the small number of more cost effective CH47s they would have found cheaper and more supportable. Had the RAF and the Army had the vision to want a lot more in the first place, then maybe a sustainable and cheaper product could have been made. Forget not that with the Defence budget as always under great pressure, all the money in that era was going on Polaris, TSR2 and the reequiping of BAOR with hundreds of tanks etc. You would have found very few voices supporting spending precious R&D money on a large helicopter...and thats in the military staffs, not the government.

Hmmm Tallsar...since when in the 1960-1970s did we ever base military orders on sustainable production ? I'll leave others to produce a list !

Instead I will comment on the proposed Type 191/193 naval variant ,which as the Belvedere picture on Albion shows ,was overly ambitious .However it was sized for the larger HMS Eagle class carrier lifts.As the picture shows there was a novel way of fitting the rotor blades if removed but the 191 had blade folding ,using chinese scaffolding I think to stow the rear set! Certainly I wouldnt have wanted to be working on them on deck in a sea state 5!

Three 191s were virtually completed when the contract was cancelled ,with a vee tail unit (fitted the lift better) and a Wasp type heavy duty landing gear.None were fitted with the intended Leonides Major piston engines and instead were used as Gazelle turbine engine and transmission test rigs for the Belvedere.One eventually ended up in the pit at Ternhill.

The similar Type 193 for the Canadian Navy was cancelled before any were completed and reallocated to the RAF order.Canada went for the CH-124 Sea King instead.

I admit that the whole 191-192 programme was financially a disaster,with all the investment lost , but in terms of keeping the UK at the head of the technology game and independent of foreign powers it was successful. Sadly its demise saw the breakup of a very good design and engineering team and although some of the specialism went to Yeovil to work on Lynx and future projects (including tilt rotors and tilt wings) the tandem rotor expertise withered away.

The Belvedere had a very interesting starter system for each engine. Their lordships of the Air Council decreed that the aircraft should be independent in the field, of any external starter aids, so the BTH cartridge initiated Avpin system was fitted.

The only trouble was, the Avpin tank was above the cartridge breech, so if there was a seal leak over night, Avpin would fill the cartridge chamber.

The result of this, was that when you went to do the first start in the morning, the whole thing would explode.

The fix for this was to armour plate the co-pilots seat, the rear engine was no problem, as you had enough time to evacuate.

Some Interior Pix
 

Some people posted some really impressive photos of CH47s from the outside, but I didn't see any interior ones, so I thought I'd put up a handful.

http://photos.copters.com/img/v29/p522049218-4.jpg

As a HHGTTG fan, I love:

http://photos.copters.com/img/v33/p452390857-2.jpg

http://photos.copters.com/img/v34/p514080265-3.jpg

http://photos.copters.com/img/v29/p1045095242-3.jpg

Sorry for the poor quality, it was a quick grab of some photos...

These are exterior and not very exciting, but perhaps of some interest:

http://photos.copters.com/img/v30/p571188093-4.jpg

http://photos.copters.com/img/v34/p1048755157-5.jpg

Wow! After all the development that went into making the 47D/E and they didn't even change the locking wire on the rotor heads!

Nice to see they haven't changed - I used to build 'em at ODI.

Saturday Shows Crippling Flaws
 

The Chinook: big, slow, noisy and with a critical flaw. If you hit the interconnect shaft game over as the rotors collide and destroys the aircraft. On the V-22 take out the interconnect shaft and you get a caution light.

The Sultan

So......Sultan.....why have it at all then if it is excess to need? Would the Osprey not be much cheaper to build it did not have one? Is this a Bell way of upping the price much akin to the 500 Dollar Toilet seat or 700 Dollar Hammer we have heard so much of in the past?:ugh:

I guess you shall try to convince us there is no way an RPG could hit an Osprey and not take out an engine and the shaft at the same time....eh?:rolleyes:

Spent a lot of spare time thinking up these kinds of comments during your time off?

I cannot but wait to hear this explanation!:rolleyes:

You know, I remember the scandal about those 500 dollar toilet seats and 700 dollar hammers when I was in school and was outraged. Now that I have had plenty of years in aviation and am aware of the cost of aviation related tools and components I realize all of the complaints about those prices were from media idiots and political grandstanding. You can barely buy a nut or bolt from Sikorsky or Bell for those prices and that is on the commercial side, nit the military.

Huey,

Along about that time I was involved in Fraud Investigations for what is now NCIS. In a training class at the Navy Supply School in Athens, Georgia....an Officer there tried to explain away how all that so innocently happened and how there really wasn't a problem and there was no attempt to cheat the Navy.

His example was the accounting method used to figure the costs of each line item within the contract. At the time he was speaking I happened to have a General Services Catalogue on the desk next to my notebook. As he talked, and I was taking notes of what he was "teaching" us.....I keyed on something he said having made the note.

He was talking about hand tools....and how the accounting method was really the problem. He flashed on the viewing screen part of the contract that applied to what he was saying. In that list was a thing called "Device, Impact, Manually operated". A layman would have called it a "Hammer" and a Specialist would have called it a" 12 ounce Ball Peen Hammer".

I went to the GSA Catalogue and roamed through the Hammer section and found literally hundreds of different kinds of hammers, wedges, mallets, ball peen hammers, tack hammers, roofing hammers, claw hammers, sheet rock hammers, brick hammers....you get my point.

He was dumbstruck when I told him of that and the fact at no point was there an entry for "Device, Impact, Manually operated" anywhere in the GSA catalogue.

He got really flumoxxed when I asked him why the builder of the F-18 did not just call it a fecking hammer instead of what they did if they were not trying to pull a fast one?

A hammer is a hammer is a hammer.....is it not?

One outcome of those investigations was a program called BOSS....Buy Our Spares Smart....that encouraged employees to challenge any questionable pricing and rewarded them with percentages of the savings made. A simple practice borrowed from the private sector historically unknown to government.

I think, that I have discovered the reason why my tandem loops on take off! I just want to see what the experts here on the forum think... The flapping hinges are too weak that allows the advancing blade angle to pitch up and with precession the result is a pitching up moment at the front of the rotor disk. What do ya think?

Tandem thread
 

Guys,

I didn't mean to poo-poo your thread...I was enjoying the war stories very much. I promise not ask any more technical questions!:sad:

Admittedly, I'm no expert on rotor aerodynamics. But I believe the purpose of rotor hinge joints is to make them flexible, not stiff. Blade pitch itself is controlled separately by the swashplate linkage, and not much by the flap hinge. As for asymmetrical lift between advancing and retreating blades, there shouldn't be much in hover/TO.

As for Sultan's comments about the CH-47 being big, slow, noisy, etc., I would not necessarily call the CH-47 slow. I believe it's as fast as the current CH-53, and a bit faster than the current UH-60. The fore/aft driveshaft on the CH-47 is indeed much more critical than the interconnect shaft of the V-22. The forward rotor of the CH-47 is driven by this driveshaft alone, so a failure here would mean a loss of the aircraft.

A civilian Chinook was lost near the Shetlands because of this - wasn't the shaft, but the forward gearbox corroded and failed (from memory, correct me if I'm wrong, someone). See AAIB report here.

And as for speed, RAF Chinooks in Afghanistan have been known to outrun their Apache escorts if they need to get back to the medical facilities at Bastion in a hurry.

Hook are slow!!!
 

When I was in Vietnam, we routinely had to asked the Chinooks to slow down! :ok:

rif raf,

I was using different hinge materials at that time. I was never sure if it was the design or poor material choices. I later disovered what the problem was...it was my choice of airfoils. I was using an 8H12 airfoil blades that has an up reflex to it. When the blade start to advance, the up relex made the blade pitch up uncontrollable. Over time, I had changed the head design several times but still had the pitch up problem. The only common factor was the 8H12 airfoil. Then I changed the blade airfoil to a profile with a slight down relex...it now works better. The model still pitches up but not to where it's uncontrollable.

Now I'm working on the control mixing. At this scale, any change is difficult. To begin the work on the controls I'm using the MC-4 tandem helicopter's lay-out as a refence. It's the simplest control system that I can find.

Gearbox failure
 

Nr,

Does the Chinook have a chip detector in the front gearbox? I would have thought that for something as serious as a gearbox failure there would be some indication like a chip light.

ISTR 5 Mag-Chips - Each Engine Nose Box, Aft & Fwd Boxes and finally the Combiner - all with Fuzz-Burners (well they did in my time!)

Any "Light" deserved a short notice landing - Nowadays I suppose there must be an ultra-serious think about carrying on for more than the current height!

I'll have to see if I can dig up some of the cooler pics I have laying around. Of the more unusual are a few of me slinging another Chinook which got shot down while we were in Afghanistan. The bird I was flying was your typical OD green while the dead bird was the new desert tan junk. I'll leave it up to you to determine if this paint scheme is worthy.

Actually....neither paint scheme is worth a damn.

As we do not have to worry about Oppo Air.....thus no need to blend in with the terrain beneath us....why not paint them to blend in with the sky above us as that is the direction the bad guys are looking (generally). If they are looking down at the aircraft....it is from a hill/ridge/mountain and thus close enough to make out the aircraft no matter what color or pattern they are.

Since I started this thread , it seems Ive grown very old, and yet only just seen the pictures of the business end of a 47, looking at the cockpit end it looks and seems just like that of any other large Heli, so how quickly can an existing Heli pilot get to grips with the physical side and fly one away, a Ch47 that is.

Thank you for all the input I have just re-read many of the entrys, and I am still MAD KEEN to get in one and see what happens, I am also green with envy when my boy tells me how good they are in the Afghan area.

Peter R-B
formerly VfrpilotPB

Evening, does anyone know of any books that deal with tandem rotor P of F?

Ww

P of F?

And I have to put some other words in to make up some numbers...

The trick to flying the Chinook is learning how small it is.

In time...some folks can get the "feel" for where the Cargo Hook is and how high off the ground the aft gear are....but it is a rare pilot that can also "feel" where the Aft Gear is.

When it came to putting the Aft Gear down on a Rice Paddy Dike....that took some doing. Putting the Cargo Hook into the Hook Up guy's hands was no mean trick but even some never got it figured out.

Pitch Attitude and knowing which particular Pitch attitude was needed or what Cyclic Stick Position was needed when doing maneuvers with the aft gear or sometimes forward gear in contact with the ground took some getting used to as once the gear were on the ground....two inches of aft cyclic glued the gear and then all pitch attitude control was done by use of the Thrust Lever (Collective Lever).

P of F = Principles of Flight to me. :ok: ISTR that AP 3456 Vol. F might be the fount of such knowledge......

MB