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-   -   Is it possible? A modern VC 10 (https://www.pprune.org/aviation-history-nostalgia/637171-possible-modern-vc-10-a.html)

tdracer 5th Dec 2020 04:59


Originally Posted by FlightlessParrot (Post 10940706)
I seem to remember long ago that there was also a rather subtle point about damping oscillations (or something in that kind of area of structural stability--I am manifestly out of my technical depth) that was the result of the engines being hung largely forward of the leading age.

Is this a false memory, or was there something like this that was a further, unexpected, benefit of podding?

Properly done, pod mounted engines on the wing can reduce flutter - basically the engines become tuned mass dampers.

Of course, that's in addition to the advantage of supporting the mass of the engine on the structure that's doing the lifting - instead of cantilevering it well after of the lifting portion.
No idea if there was a connection, but during flight testing of the MD-80, they had an unintentionally hard landing - the entire tail assembly (pretty much everything aft of the aft pressure bulkhead) broke off. :eek:

Genghis the Engineer 5th Dec 2020 07:41


Originally Posted by pr00ne (Post 10938966)
ATSA1

".....The British aircraft industry is now all but dead.."


Yeah, such a same that it's only the SECOND LARGEST ON THE PLANET!!!!!!!!

4th, behind (in order) the USA, China, France. Which is not to say that the UK aerospace industry isn't still huge and capable - although the ability to build, test and certify large aircraft has eluded it for some years. There are increasing efforts to rebuild that capability, and they may get somewhere - but not quickly.


UK can do engines, wings, gear, and still has and trains some exceptional flight testers. The overall large aircraft airframe integration capability is sadly not here any more, and we'd be deluding ourselves to claim otherwise. We should also throw ourselves behind efforts to rebuild that.

On the VC10 - lovely fast, comfortable, nice handling airframe. Also very inefficient low bypass engines located poorly for maintenance, heavy, and systems that should stay firmly in the 1960s where they belong. If you were to build a new one, it would probably look more like a C1(K) than anything BOAC ever operated, but would still be a lot less good for that job than an A330MRTT in terms of just about anything but handling. (Just ask some Airbus Flight Test Engineers about the fun they had creating FBW refuelling laws!).

IF the UK is to get back into part 25 manufacture again, and I would love to see that happening, we should be looking iteratively to first build a modern business jet or turboprop, and it should be just that - MODERN. If it happened to look like a Jetstream or HS125 that should be totally co-incidental. From there, the revitalised capability should then be looking to something that beats late model A320s and B737s on economy and environmental efficiency. That means technology several generations beyond a VC10: latest avionics, 3D printed components, lots of (recyclable) composites, ultra reliable engines and systems giving global ETOPS, massive payload fraction. And if we do, I really hope to be working on it.

G

dixi188 5th Dec 2020 07:56

In the MD80 heavy landing the structural failure was aft of the engines.

Chris Scott 5th Dec 2020 10:34


Originally Posted by megan (Post 10940670)
Not sure of the conflicting factors to which you refer Chris. Both offer wing bending relief but at the expense of increased fin/rudder size to handle asymmetric conditions. Having two rather than four is just economics.

Hi megan,
Not the redundancy aspects, although they remain relevant for certification and performance: simply the issue of wing-bending relief, which would appear to be better with two engines spaced across each wing.

The classic example are the A340 and A330 wings, which are - I believe - basically identical. But the A330 wings don't enjoy as much bending relief outboard.

Where is Owain Glyndwr? He could answer that one...

Chris Scott 5th Dec 2020 11:10


Originally Posted by Genghis the Engineer (Post 10940763)
[...]

On the VC10 - lovely fast, comfortable, nice handling airframe. Also very inefficient low bypass engines located poorly for maintenance, heavy, and systems that should stay firmly in the 1960s where they belong. If you were to build a new one, it would probably look more like a C1(K) than anything BOAC ever operated, but would still be a lot less good for that job than an A330MRTT in terms of just about anything but handling. (Just ask some Airbus Flight Test Engineers about the fun they had creating FBW refuelling laws!).

[...]
G

Great post, Genghis.

Re "systems that should stay firmly in the 1960s where they belong", just want to point out for the information of others that the systems on the VC10 - a second-generation jet airliner - were in most respects vastly superior to those of the first-generation B707. That's not to say that Boeing did not do a terrific job in adapting what they had to get around the weaknesses evident in the early models. By the time the VC10 entered service, the B707-320 was a very different kettle of fish from the early models, and the JT3D turbofan (basically a JT3C turbojet with the front compressor stage replaced with a fan), although a bit lacking in thrust, greatly outperformed the low-bypass Conway in fuel efficiency.

Because the B707 and DC-8 had cornered the market, the VC10 did not have the opportunity to evolve like they did. And, with hub runways already lengthened, the tail-engine concept was never going to be as efficient on long-haul. But it gave the opposition a run for their money out of the plateau areas of Africa..

GroundScot 5th Dec 2020 14:14

And of course.... it had a tail stay that had to be put in position for loading/unloading, as without the passengers on board it had a tendancy to tip..... Wish I could find a photo, but alas not.

I remember a time in DAR when a SVC10 blew an engine just before landing.... The station engineer went out to the country and found a wood turner who made a stool type mahogany block - to stop the blades widmilling in flight, enabling the aircraft to 3 engine frerry back to London [via CAI, FCO] after flight planning it around Kilimanjaro.... oh the old days....

longisland 5th Dec 2020 14:15


Originally Posted by tdracer (Post 10939972)
Now, if the engine is mounted on the wing - it's located near the aircraft CG, so a heavier engine is generally not a big concern to the overall design.

B737 MAX with wing mounted engines certainly turned out to be a problem.

Brit312 5th Dec 2020 14:59

GROUND SCOT We would normally ram a piece of 4x2 down the front and tie it tight to the stator. Any thing would do just to stop that LP compressor windmilling
When you talk about the tail steady I suppose you are talking about the IL -62

GroundScot 5th Dec 2020 16:40

Yes any wood would normally do - but this was choice mahogany he used ..... brought a smile

and no, the SVC10 did have a tail steady. just wish I had a picture. Was stored in hold 5 . I remember as I bashed my head getting it off one day, tricky little sod it was, spent many days in Africa with the wonderful lady of the skies [and the crews on 21 day trips!]

pax britanica 5th Dec 2020 17:07

e
Thnaks for your info on how Airbus is treated nationally , on that basis it doesn't surprise me that we are second since as you say we make some very major elements (components isnt a BIg enough word when we are talkign about wings etc) and all those A320 series add up to lots and although SNECMA -is that right partner with the US on some aricraft I am surre RR is bigger overall.
Problem is can we keep it that way. As it stands dear Boris is willing to risk throwing it all away for 12,000 fisherfolk .

Will AB stay in Uk after 2021 of course they will for a while , which leads me to ask where A350 wings are made, but supply probs additional costs and bureaucracy (recreating a UK airworthiness authority seems to me one of the most pointless things ever done. The world sees aviation regulation as US EU and perhaps China , no place for us at all .

We dont have much in the way of technology in Uk , one can hardly compare Mr Ds Malaysian vacuum cleaners with the German car industry can we, so we badly need to hang on to what we have and if Brexit increases cost how much will it cost for Ab to dangle More money, the southern France life style and an Eu passport in front of a few hundred critical skill people in Bristol and Cheshire and UK aviation goes the way of UK cars -that would be tragic. Some on this thread made the point that who in their right mind was talking 'Empire Routes' re the VC10 in the late 50s early 60s. Well the answer is people like Boris, Rees-Mogg and Duncan-Smith and they are still thinking that way 70 years later.

To revert to nostalgia though the 50s/60s was a wonderful time to be an Aviation enthusiast with so many new designs and so many contrasting aircraft types whereas today experience , computer modelling and cost driven design means that all airliners look the same , some are just bigger than others.

.
A bit of a thread drift but noise ahs featured a lot in this thread and for modern aircraft the most unusual seems to be the A400 with tis distinctively different and more musical note than the veteran Ruskies and equally veteran but updated Hercs -I assume its all those odd shaped blades the props sport.

Gipsy Queen 5th Dec 2020 17:15


Originally Posted by longisland (Post 10941007)
B737 MAX with wing mounted engines certainly turned out to be a problem.

I was about to make the same observation.

Clearly, in this hi-tech age, it is preferable to have the resultants of imbalances controlled by expensive software instead of simple high density materials screwed into one end or the other. In either case, it is the disguise of a shortcoming rather than its elimination. Thanks tdracer.

WB627 5th Dec 2020 17:23


Originally Posted by Herod (Post 10939809)
:ok::ok::ok:

I spent a week in wooden hut next to the runway at Brize. Best week of sleepless nights I have ever had ........ well almost :O

DaveReidUK 5th Dec 2020 18:32


Originally Posted by longisland (Post 10941007)
B737 MAX with wing mounted engines certainly turned out to be a problem.

Albeit an essentially aerodynamic problem, not one directly related to weight/balance/CG.

tdracer 5th Dec 2020 19:34


Originally Posted by dixi188 (Post 10940767)
In the MD80 heavy landing the structural failure was aft of the engines.

Yes, the engines are forward of the aft pressure bulkhead on the DC-9/MD-80/MD-90/717 - which is where it failed.
As I said, I don't know if there was a connection, but the mass of the engines would still have added stresses to the tail structure that failed as the whole fuselage did it's dance after touchdown even though the actual failure occurred aft of the engines.

Jhieminga 5th Dec 2020 19:36


Originally Posted by GroundScot (Post 10941006)
And of course.... it had a tail stay that had to be put in position for loading/unloading, as without the passengers on board it had a tendancy to tip..... Wish I could find a photo, but alas not.

Sixth photo on this page: https://www.vc10.net/Airframes/cn_809__garvg.html

Chris Scott 5th Dec 2020 22:13


Originally Posted by pax britanica (Post 10941071)
e
Thnaks for your info on how Airbus is treated nationally , on that basis it doesn't surprise me that we are second since as you say we make some very major elements (components isnt a BIg enough word when we are talkign about wings etc) and all those A320 series add up to lots and although SNECMA -is that right partner with the US on some aricraft I am surre RR is bigger overall.
Problem is can we keep it that way. As it stands dear Boris is willing to risk throwing it all away for 12,000 fisherfolk .

Will AB stay in Uk after 2021 of course they will for a while , which leads me to ask where A350 wings are made, but supply probs additional costs and bureaucracy (recreating a UK airworthiness authority seems to me one of the most pointless things ever done. The world sees aviation regulation as US EU and perhaps China , no place for us at all .

[..]

You've covered a lot of ground, even in the two paragraphs I've quoted. I'll give it a try, in the order of your asking:

If you were asking about the conventionally-engined A320 family,as opposed to the neo variants, the CFM56 option is Franco-American (SNECMA/GE) and the IAE V2500 is American-British-Japanese-German (P&W/RR/JAEC/MTU). (FWIW, I preferred the CFM56.) The A320neo (new-engine option) also offers two engines: the CFM LEAP (very high-bypass turbofan) and a P&W geared turbofan.

Re Brexit, don't forget that Concorde, Jaguar and Airbus A300B all flew before the UK joined the EEC.

All Airbus wings are made in the UK, mainly at Broughton, Wales; the A400M wings at Filton, Bristol.

I don't know what plans the UK has for licensing and certification post-Brexit (maybe others will comment), but EASA is a relatively new organisation. The UK ARB, later merged into the CAA, was a world leader in the certification of airliners until 1987. Subsequently, it had an input to the JAA and currently the EASA. So we'll see.

Rory57 5th Dec 2020 22:37


Originally Posted by tdracer (Post 10939122)
I think you'll find there are very good reasons why no clean sheet design in the last three decades has put the engines on the tail.

Boeing’s Sonic Cruiser project came close to being a “modern VC10” perhaps? Fast, beautiful, rear engines, not what the airlines wanted...

megan 6th Dec 2020 06:17

G'day Chris, having four would enhance the bending relief as you say, but as I said it comes down to economics, fuel burn is better with just two so I'm told, plus you don't have the capital and maintenance costs of four. Only need to wonder why twins are all the go, a 777 doing what a 747 used to do, though I'd much prefer to have four personally, ETOPs makes me curl my toes thinking of being reduced to one when may be 370 minutes from a runway. Bean counters rule.

FlightlessParrot 6th Dec 2020 09:17


Originally Posted by tdracer (Post 10940709)
Properly done, pod mounted engines on the wing can reduce flutter - basically the engines become tuned mass dampers.

Thank you, that sounds like my confused memory: and, IIRC (an increasingly unlikely condition) it came as a surprise, unlike the weight distribution.

oldchina 6th Dec 2020 13:53

megan:

"ETOPs makes me curl my toes thinking of being reduced to one when may be 370 minutes from a runway. Bean counters rule"

I have no love for accountants, but sometimes they get a bad press.

1) ETOPS rules are argued over and approved by statisticians not bean counters.
2) If Mr B counter added up the cost of a remote diversion, including handling stranded passengers on site, flying in a plane to evacuate
them, fixing the engine or bringing in a replacement, dealing with the disruption to schedules, I'm not sure they'd be keen on ETOPS.




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