Talk:Vickers Valiant

Source

My sources give the following numbers for the different variants of Valiant Bombers: 5 x Pre-Production Valiant B.1 104 x Production Total Mk.1 divided as follows:

  34 x Valiant B.1
  11 x Valiant B(PR).1
  14 x Valiant B(PR)K.1
  45 x Valiant BK.1 (NOT designated as Valiant B(K).1)

1 x Valiant B.2 Prototype

Thierry Rotty.

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Suggest the bits on the Shorts Sperrin be transferred to a separate entry under that name. It was a bit like a large Canberra with two engines mounted one above the other in each nacelle. It wasn't even one of the V bombers!

Ian Strachan 19:28, 29 April 2007 (UTC)

Article already exists at Short Sperrin. MilborneOne 19:56, 29 April 2007 (UTC)

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Thanks for rapid reply. However, the abbreviation for the company Short Brothers is "Shorts", not 'Short' because the latter implies small. The entry that you mention should be re-titled "Shorts Sperrin" and eny extra data on the Sperrin under Valiant, transferred to it.

Ian Strachan Ian Strachan 21:22, 29 April 2007 (UTC)

Although the company is colloquially called Shorts this is not reflected in the official name of the products - perhaps not a discussion for the Valiant page ! Is your sugestion that the Sperrin information is removed from this page - if not then I would suggest this is for the Sperrin article. MilborneOne 11:36, 30 April 2007 (UTC)

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Yes, I am suggesting that the Sperrin info on the Valiant page, be transferred to and co-ordinated with the existing entry for the Shorts Sperrin. Logical, it seems to me. It's the Valiant entry, not the Sperrin one. I'll make the attempt, if you like.

Ian Strachan 17:43, 30 April 2007 (UTC)

Yes I understand the whole first paragraph really belongs in V bomber or/and Short Sperrin. Have a go as anybody can make a change, somebody will allways revert it if they dont like it!.MilborneOne 19:06, 30 April 2007 (UTC)

Wingweb.co.uk

I run a site titled Air Vectors that covers military aircraft and gets cited here and there on Wikipedia. I don't normally touch wikipedia articles other than to correct typos and the like, but I just found out about a site named "Wingweb.co.uk" which is also cited here and there on Wikipedia (for example in this article) ... but whose aviation articles are largely or entirely downloads of Air Vectors articles -- advertized as "original content & images" though they also lifted many of my photos and artwork.

I have no fuss to make. I just want to make sure the Wikipedia community knows that Wingweb.co.uk is a ripoff operation. Cheers / MrG 4.225.208.126 02:56, 7 November 2007 (UTC)

requirements for the Valiant

Reading the history of RAF Nuclear Deterrent Forces by Humphrey Wynn (which I've had for some time but only just got round to reading) I notice that there were all sorts of different requirements created around the late 1940's early 1950s.

B14/46 which was the one the Sperrin were designed to

B9/48 which was the one the Valiant was designed to

B35/46 which was the one the Victor and Vulcan were designed to.

there were all sorts of OR documents as well. OR 229 resulted in the Sperrin and the Valiant, and OR 239 resulted in the Victor and Vulcan. I think I've got this right...

Soarhead77 (talk) 19:25, 15 July 2008 (UTC)

See also Air Ministry specification#1940-1949

Soarhead77 (talk) 13:29, 16 July 2008 (UTC)

IIRC, Vickers were not invited to Tender for B.35/46 as they were considered a 'fighter' company (Spitfire, etc.), and were thought to lack the experience necessary to produce a bomber with the 'advanced' aerodynamic features specified in this Spec - circa 500kts at 55,000ft, so the Chairman of the company proposed that his company design and produce an aeroplane that, although it wouldn't quite meet the B.35/46 specification, could be introduced into service more quickly than the other aircraft. This offer was accepted and the Specification B.9/48 drawn-up around the proposal, which resulted in the Valiant. In short, the Valiant was not able to achieve the higher speeds at the stated altitudes, as it had a less advanced wing design with a lower critical Mach number than the Vulcan or Victor, which were effectively transonic designs, although the Vulcan was limited to an IMN of Mach 0.98 for trim reasons. The higher one flies at 500kts, the nearer the speed of sound one is, with all the resulting problems (for the time) of the Sound barrier. So the Valiant, unlike the aircraft built to B.35/46, could not fly at both the specified speed and altitude at the same time.

Incidently, the world aeroplane altitude record at around this time was not much above the 55,000ft specified for B.35/46, so for the time these were very-high altitude bombers indeed. — Preceding unsigned comment added by 80.4.57.101 (talk) 17:42, 23 December 2011 (UTC)

Valiant crashes

I know there were some Vulcan and Victor crashes. But how about the Valiant? Comments appreciated.Mikeo1938 (talk) 08:46, 4 October 2008 (UTC)

As I understand it (and I'm not a Vickers fan boy), the Victor was an out-and-out lemon but it had a lot of money thrown at it to fix the problems, for some unknown reason. The Valiant was smaller and simpler because it was older, but the performance specs are only slightly lower than for the Victor. The Vulcan was a good bit of engineering for its time, but its time was 10yrs after the Valiant. After the Nassau and Polaris agreements were done none of the V bombers were needed. The MoD then changed the Valiant's role and made many of the units operate at low level and high speed. From WW2, this sort of operation was known to cause rapid metal fatigue. It was a deliberate move to get rid of the a/c. The reasons to prolong the lives of Victors and Vulcans was simply political, and no doubt had more to do with the unions employed at these companies, rather than the companies or a/c themselves. A/c operaqted at high altitudes did not suffer the problem.27.33.243.64 (talk) 08:02, 13 December 2015 (UTC)

The difficulties encountered when building the Valiant

The Valiant used the zinc/magnesium aluminium alloy DTD683 extensively in its airframe, this is mentioned in Eric Morgan's book and confirmed in an e-mail from Albert Kitchenside at the Brooklands Museum.

As is clear from this article from 1951 about a talk given to the RAeS by assistant chief engineer at Vickers at the time H.H. Gardner and available online at the flight global archive.

http://www.flightglobal.com/pdfarchive/view/1951/1951%20-%202503.html (pages 2503,2504 and 2505) just change the page number before .html to access the other pages, they are single page pdfs. (BTW this archive is searchable http://www.flightglobal.com/pdfarchive/index.html which is really useful)

The description of the manufacturing problems created by of the use of DTD683 shows that the material was known to be susceptible to fatigue failure and cracking right from the beginning, the MoS and Vickers thought these problems could be overcome with better forging techniques. engineering etc.

And this is confirmed in a 1953 article again from Flight about a talk given by Mr Black of Vickers Supermarine, describing how these issues had been solved.

I have belatedly noted the reply from below.

http://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200935.html (pages 0935, 0936)

The other problem for the Valiant was the design strategy used by the Aircraft Industry at that time, the so called "Safe Life" was shown in 1955-6 to be seriously flawed in that safety could not be ensured in a catastrophic failure. A paper delivered to the RAeS by a Lockheed chief engineer in 1956 gives the 'coup de grace' to Safe Life.

http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200396.html (pages 0396, 0397, 0398, 0399).

Also in 1956 a paper in 'Nature' by a Birmingham University metallurgist gave the 'heads up' that he had identified a potential problem with DTD683, and the article is followed in a paper by the same team the same year in the Journal of the Institute of Metals, that effectively spelt the end for DTD 683 as it was unstable and could fail catastrophically in an 'auto catylitic' process that could be initiated by stresses that were close to the limits of the material.

What this meant (the double whammy of building to Safe Life that could not sustain a catastrophic failure, with a material that could fail catastrophically) for the Valiant, the Shackleton, Argosy, and others was that a redesign and rebuild was necessary to the new 'Fail- Safe' design strategy. The Shackleton and Argosy were rebuilt, but the Valiant was not, some web flanges made from DTD683 were replaced by steel, hardly an advance as steel is notch sensitive at high altitude.

So the generally accepted narrative of the 'finding' fatigue in 1964 is therefore incorrect DTD683 was always known to have 'low fatigue resistance'

How can the article reflect this, Should a page about DTD683 be created? and then this article could link to that page? Everything you know is wrong (talk) 01:00, 9 September 2009 (UTC) —Preceding unsigned comment added by XD864 (talk • contribs) 20:17, 8 September 2009 (UTC)

Rather than being 'seriously flawed' 'Safe lifeing' is still a principle on-which aircraft are designed and maintained. 'Fail safe' is an alternative, and today the two differing philosophies are being seen as complementary. Neither is the complete answer. For the problems faced by 'fail safe' design see the 1977 Dan-Air Boeing 707 crash for a 'fail safe' failure. I can name several more. Both philosophies rely on adequate and competent maintenance being carried out in a timely fashion. Safe lifeing also doesn't work if this is done improperly, as per the MacRobertson Miller Airlines Flight 1750.

As for Shackletons, the wing spars are 'safe lifed' as can be seen if one queries the reasons for one of the remaining runnable Shackletons being unable to be flown - it needs re-sparring.

Whilst the particular alloy's properties may have been to blame, the Valiant's fatigue problems only really began when it was switched from its original high-altitude role, to that of a low-level one. Aerodynamic gusts lower down are much more severe than at high altitudes, and designing an aeroplane for one regime necessitates differing priorities in airframe structure - at low-level the gusts cause much more frequent and greater wing bending moments. The Valiant was built more lightly, so as to attain the required altitudes, than it would have been if it had been designed from the start for low-level work. The 'Pathfinder' version was more suited for this, as it had a strengthened airframe, but for the sort of flying that was later envisaged a much stronger still airframe was required. This is why low-level aircraft such as the Blackburn Buccaneer (built strongly) and TSR-2 (small wing) look different from high-altitude ones. This is also the reason why the Shackleton's structure is more robust than a Lincoln's, as the former was designed for prolonged use at low-levels, whereas the latter was designed for operations at higher altitudes. Stronger airframes are heavier, so in order to fly high one must build a light airframe. In order to fly low and fast, one must build a strong one that can cope with the greater air loads. Even so, if you use a strong aeroplane enough at low-level you will eventually get fatigue problems, as happened with the RAF's Buccaneer, where one lost a wing during one of the Red Flag exercises in the US.

Therefore, the aerodynamic environment is much harsher at low-levels (and especially at fast jet speeds) so airframe loads are greatly increased when the aircraft encounters gusts. Gusts are greater nearer the ground, due to wind flowing around and over hills and other features of the terrain, especially at the sort of altitudes, c200-300ft and below, that the RAF was by then using the Valiant. Prolonged operations at these sort of altitudes (with perhaps violent manoeuvring thrown in) will rapidly use up airframe life in any large or fast aeroplane. This, the Valiant wasn't designed for. The Vulcan and Victor were better suited to the change of roles, as the Vulcan was built like a brick, and the Victor was built in 'Fred's Shed', where no two aircraft were the same, and which fared better after the tailplane fixing bolts were increased from three to four. They also had the advantage of later, more powerful, engines being in development when the latter two aircraft were being designed. — Preceding unsigned comment added by 80.4.57.101 (talk) 15:59, 18 December 2011 (UTC)

== The Valiant should have been scrapped in 1956 ==

A belated response re the safe-lifing point made in the above - thanks for pointing that out. ::::At the time 1956 it was seen as much more of a dialectic argument i.e. ether safe-life or fail safe, what this dialectic produced was a synthesis, that by the 1970's, also included 'fault/damage tolerance', since then any well designed aircraft will have critical parts of the structure fail-safe like in the Gulfstream G-IV, these components are fail-safe

Wing to Fuselage Connections, Floor Structure,Fuselage Skin Splices,Fuselage Axially Loaded Members, Fuselage Shear Webs,Fuselage Structure from FS 580 - 812

other parts are safe-life e.g U/C or damage tolerant e.g Wing — Preceding unsigned comment added by 82.34.118.67 (talk) 13:33, 14 August 2014 (UTC)

The trouble with British Aircraft pre 1956 (including the Valiant) was the double whammy of building aircraft with a design method that could not guarantee safety in a catastrophic failure [Safe Life] with materials [like DTD683] that could fail catastrophically. This fact was coupled with the fact that not all the metallurgical data was known when these aircraft entered service, for example it wasn't known until 1968 (4 years after the Valiant was scrapped) that for DTD 683, water or water vapour increased crack growth rates by a factor of 10. This was due to the Oxygen in the water rapidly oxidising the "fresh" aluminium at the crack tip releasing Hydrogen at high pressure which was enough to cause the crack to grow exposing more un-oxidised aluminium so producing more high pressure hydrogen and so on, in an auto-catalytic process.

Due to a lack of money cost cutting methods like using tokens that had already been used in a stress test to measure fatigue strength led to an over estimation of the fatigue strength of a material by a factor of up to 100. This was due to the fact that pre-stressing these materials increased their fatigue strength. (See Section 4 para 2 of this ARC Paper http://aerade.cranfield.ac.uk/ara/arc/cp/0232.pdf). In fact this method (pre stressing) was used in a failed attempt to improve fatigue resistance.

This was aggravated by the lack of consideration for fatigue failure which was rare in the older materials used in previous A/c designs.

DTD683 was known to be a troublesome material at least as early as 1951. Here is Mr Gardner of Vickers explaining the problems

structural problems | flight structural | structural efficiency | 1951 | 2503 | Flight Archive http://www.flightglobal.com/pdfarchive/view/1951/1951%20-%202503.html

QUOTE:

Mr. Gardner then turned to a consideration of materials, first

touching on the newer aluminium-zinc-magnesium alloys,

D.T.D. 363 and D.T.D. 683, which, used as extrusions and

forgings, made appreciable weight-saving possible.

two difficulties had arisen: (a) distortion after machining, and

(b) variation of strength across the section. The distortion problem

with this alloy had become of general importance...

... this was an unsatisfactory aspect of the new alloy.

The second effect, which gave low core properties, was one which

needed to be known before design-values for the material were

agreed.

And Mr Black of Vickers Supermarine in 1953

light alloys | cold bending | permanent distortion | 1953 | 0935 | Flight Archive http://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200935.html

QUOTE:

The alloys considered were those

of specifications D.T.D. 363A and D.T.D. 683....

Mr. Black stated, the increased strength

of the materials was accompanied by a lowering of ductility as

measured by the elongation obtained from a tensile test. A low

elongation value was undoubtedly undesirable in an aircraft

material, because only small amounts of permanent distortion

could take place before a fracture occurred, and large amounts of

cold work could not be withstood without fracture.

... the alloys had a reduced capacity to

absorb permanent distortion, a low ductility and a low ratio of

fatigue strength to tensile strength ...

... a high normal stress level in use, and the result was a

greatly increased sensitivity to stress concentrations resulting

from bad design or surface notches ...

... residual internal stress would reach a high level, and was very undesirable.

So the problems were well known, but instead of giving up with the materials they soldiered on thinking the problems were 'solved' after all the Ministry of Supply told them they had to use this material and the UK Aircraft Industry was pretty arrogant about its ability to solve problems having produced war winners like the Spit' and Lanc'

But the Industry had not solved all the problems and it began to dawn in 1955 that their approach was flawed. This is well evidenced in the technical papers of the time available in the Aerade catalog. The research switches from attempts to improve fatigue resistance to research into understanding the process of crack formation, growth rates and ways to stop the failures from being catastrophic.

Airframe Fatigue 1955 http://www.flightglobal.com/pdfarchive/view/1955/1955%20-%200347.html

QUOTE:

On a comparative stress

basis, the new alloys such as DTD.363, 364 and 683 had no

better fatigue properties than the earlier alloys. Thus, for structures

of equal static strength, a reduction in fatigue life occurred,

and one example given by Rhode showed about a fivefold reduction

in fatigue life in transferring from 24 S-T to 75 S-T

(75 S-T is the American designation for DTD683)

The problem of working out a Safe Life was virtually impossible given the large scatter in the fatigue data

cycles | endurance limit | salt spray | 1955 | 0363 | Flight Archive http://www.flightglobal.com/pdfarchive/view/1955/1955%20-%200363.html

QUOTE:

... tests on 57 specimens give lives ranging from 430,000 cycles to 117,423,000 cycles with a mean of 23,324,000; such results underline the magnitude of the problem ...

Things came to a head in 1956 with this lecture given by a Lockheed structures engineer to the RAeS

In it he delivers the "coup de grace" to Safe Life and states that DTD683 was the worst choice for fault tolerant structures

1956 | 0396 | Flight Archive http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200396.html

QUOTE:

Putting this another way the big question is: —

. . . . . . . . .. Laboratory (or predicted or recorded) life...

Safe Life = ----------------------------------------—--------------

.. . . . . . . . . . . . . . . . . . . . . ? .

On the determination of this ? factor hinges the adequacy of the

safe-life method.

Given the scatter in the data above, the nominator [Laboratory (or predicted or recorded) life] in the above equation was also largely guess work. Effectively the equation above becomes.

.. . . . . . . . . . ?

Safe Life = ----------

.. . . . . . . . . . ?

You don't need to be a mathematical genius to see the problem using an ::::equation like that to design 'safe' aeroplanes.

All of this was made even more problematic with the publication also in 1956, of this paper in the Journal of the Institute of Metals by a Birmingham metallurgist team, which condemns DTD683 as it was too unstable (hence the wide scatter in the data).

Journal of the Institute of Metals http://zkt.blackfish.org.uk/XD864/JIM_1790_17-23.pdf

Mr Gardner of Vickers had noted the unstable nature of the alloy in his 1951 lecture.

QUOTE:

The lack of stability shown both in extrusions

and forgings was an unpleasant feature in production.

DTD683 was removed from use 3 years later; 1959, 5 years before the Valiant was. Its use post 1956 was limited to components in compression, such as under-carriage components.

In 1956 several things happened many Safe Life designs built with the new alloys were either scrapped or re-designed like the Argosy or Shackleton, but not the Valiant. Also in 1956 Vickers began flying a Valiant deliberately into turbulence they measured the strains and the experiments produced the disturbing result that the Valiant fleet had a remaining Safe Life of 70 hours, later revised to 300 hours (presumably under some pressure from MoD and Whitehall Mandarins). The problem with low flying was the increased frequency of gusts that would exceed the limits on the airframe. Exceeding the limits was potentially the initiating event for a later fatigue failure, as described in the Birmingham paper and as implied by Mr Black of Vickers Supermarine in his 1953 talk.

QUOTE:

... only small amounts of permanent distortion could take place before a fracture occurred.

This is the reason for the poor fatigue resistance at low level, it is the increased frequency of gusts that cause the problems, but its not just gusts a heavy landing etc can begin the process.

Also in 1956 Macmillan said the following in a memo to PM Eden about defence expenditure.

QUOTE:

"When the story of the aeroplanes finally comes out it will be the greatest tragedy if not scandal in our history"

1956 was the year in which the Government launched a review of the Aircraft Industry, which later resulted in the industry's restructuring. The last 6 Valiants were cancelled in 1956.

According to Flight magazine (corroborated in Eric Morgan's book) only 50 of the 104 (108) Valiants were still in service when the scrapping order came in 1965. Using the (incomplete) data available the average life of a Valiant was 7.6 years with an average of just over 300 flying hours per year each.

In todays money (price of a Valiant in 1956 = ~£500,000) and using a back of the envelope calculation, the cost to the Tax payer was ~£154,000 per hour of Valiant flight time, that number excludes the actual running costs such as wages, fuel etc and just uses the rough purchase cost.

That was Macmillan's "scandal". The "tragedy" was the number of RAF fatalities in non-combat flying accidents, which reached a peak of nearly 1 a day in 1954.

comment added by XD864 (talk

Valiant down

I often read about a Valiant forced down by a Meteor in the first days of the Musketeer, it's even known the name of the crew. Is it true?--Stefanomencarelli (talk) 12:01, 23 October 2009 (UTC)

Accident

• Late 1955 early 1956 Valiant from 138 Squadron RAF crashed on take off from RAF Wittering. Aircrew were buried in the village cemetary at Wittering so exact date should be found at the memorial, I presume there is one Commentary by User:John138 moved from main article. MilborneOne (talk) 21:17, 22 July 2010 (UTC)

You were right the accident was missing, the accident was the 29 July 1955 and pilot was Squadron Leader Eric Rupert Chalk. Added to article. MilborneOne (talk) 21:41, 22 July 2010 (UTC)

Minor typo in 138 sqdn info.

It says 138 disbanded in '62 but moved to Wittering in '65 I can't find a date for the move to Wittering

Fixed thanks to Eric Morgan's 'bible'