Different Conway marks question

[peak45139]

I used to test Conway 201's at Rolls-Royce in Derby in the 1980's off the Victor aircraft & VC10 Conways were always known as "big Conways" though I never saw one during my time working on the test beds there. Think they were termed Conway 301's? I've seen talk of Conway 540's & 550's on another thread on here too

How many different marks of Conway were fitted to VC10s?
Do the C1-K aircraft today (singular!) still have the same mark of Conway that they had in 1966 when delivered?
Do the Super VC10's (K3 & K4) still have the same mark of Conway they had in their 1970's passenger days?
Did the K2 have the same mark of Conway that they would have had in their passenger days?
Is there any difference in the Conway mark currently fitted to the K3, K4 & C1-K or are they all the same?

[Gwyn]

Hi,

I am ex-BOAC and flew VC-10 and SVC-10. As far as I remember the Standard had the 540 fitted throughout it's complete life including those that went to Gulf Air and then onto Abingdon for storage.

The Super had the 550 fitted again throughout it's complete life including EAA right up to Abingdon storage. The 550 was the engine that suffered high alt. compressor stall due to extra stage added for more power. Putting on the engine/airframe anti-ice cured that problem somewhat but it was a bit of a shock when it did happen followed by a very sheepish looking cabin crew member asking if an engine had just exploded.

Rgds

[Jelle Hieminga]

Generally the Standards used the Conway 540 while the Supers used the Conway 550, but things got muddled when the RAF got involved.

When they bought the 14 C Mk1s they specified the Conway 550 for those airframes, creating a Standard fuselage with Super engines (it has other 'Super' features as well, including the fin fuel tank). Then when the K2 airframes got converted these were also fitted with the 550 engines to create commonality throughout the fleet. The K3s already had this same engine fitted.

Interestingly there are references in the BOAC manuals that it was possible to mix engines in one airframe. IIRC the Super could be fitted with one 540 engine if no other engine was available.

I've never heard the term 'Big Conway' before but compared to the Victor's Conway 201s the diameter of the VC10 engine was increased quite a bit to increase the bypass from 25% to 60%. This was possible as burying the engines in the wings was not necessary any more. This may have caused this nickname. To keep things simple the official Rolls-Royce terminology was 'RCo.42' for the Conway 540 and 'RCo.43' for the Conway 550.

[harryl]

Gwyn refers to compressor stall problems with the Conway 550, but in fourteen years of operating the RAF VC10 (from their inception in 1966) I never once experienced such an event; were the engines modified in the light of BOAC experience, before the RAF took delivery?

Jelle, thanks for a great website!

harryl

[Laurieg]

We have experienced them a few times on post installation EGRs but these were normally due to FCU set ups, with the occasional intake blanking from the fuse if we had a crosswind.

I did experience one on a take off roll in Naples. Went with a hell of a bang! I thought a tyre had blown. No immediate signs of damage but the engine flat refused to start, (high EGT, low N2, no accel). I gagged to engine and the kite went home. Turns out the HPC was well broken.

[peak45139]

Thanks for these replies everyone. So am I imagining that there was a Conway 301 in VC10 use?

[Jelle Hieminga]

Well, as it turns out there appears to be a basis for your imaginings. I just checked and I have the Conway 301 listed as the engine for the RAF's C Mk.1 variant. I must have copied this from somewhere but I cannot remember where that was. Right now I have a feeling that the 301 and the 550 are the same engine, but I cannot confirm this. Perhaps there is a civil and a military designation for the same variant. I'll have a look at this question later on, if anyone else is able to answer this question then please do!

[Tonkenna]

I have the manuals here at home and will check over the week end exactly what they are... I had in my mind that the RAF VC10s had Mk 301s...

Tonks

[Jelle Hieminga]

I looked at a few publications that I have nearby, but it seems that the RAF calls the C Mk.1 engines the 'Mk 301'. This is from the 'Pilot's Notes - Technical' for the C Mk.1. I will have a further look when I'm home.

[Tonkenna]

That's what I thought!

Tonks

[Laurieg]

Yup! The 301 is fitted to all marks now. The difference is in the component fit at bay level.

[ACLVC10]

All very technical for me, nevertheless still very interesting subject.

[DJ-Tester]

Hello All,

All of the engines we have tested in the last 10 years at least have been Mk 301's. I can't remember seeing anything but in the last 20, but I have seen a lot of different engines with lots of numbers so I will look it up next week. As far as instalation is concerned, I wouldn't know, but they are,(were), all the same as far as we are concerned, (apart from mods etc).

Don't know if it's been posted, but there are 10 Conways for sale on ebay at the moment. £2,999, bargain!

[peak45139]

Thanks again for all the answers. Still don't really understand where 540's & 550's fit into this then if its been established that all the RAF's are 301's!