Avro Piston Heavies

I had always thought of the C-97 series as
a B-29/50 with the top half of the fuselage cut off and replaced to form that distinctive double bouble cross section the Stratolifter series is known for. Don’t know how accurate that simplification is, but it’s how I view it…

You’ve got the basic idea…but it’s more like the fuselage lobe was added onto the lower B-29 structure. The six YC-97s first flew with B-29 engines and shorter tail, them was reworked with different engines and the larger tail used in the B-50. I haven’t looked at the dates yet to see whether the C-97A or B-50 came first, not that it really matters.

…there was a Twin Bonanza? How was I not aware of this?

Yes, the model 50 was a very large twin.
At first Beech toyed with the idea of having two engines stacked on top of each other in the nose driving a single prop. As you might expect, the fuselage was deeper and generally scaled up to accommodate the large cowling necessary. Well, the CAA mandated a firewall between the engines, so they reverted to conventional wing mounts.
However they kept the large fuselage…it’s basically a Bonanza with a wide center section as well as being deeper. They used the expensive Bonanza tooling for the cabin windows and right side door.
It’s so wide it can sit three across the front seat area and has various seating arrangements in the back…a couch, toilet area and airstair doors were options.
The US Army bought some as L-23/U-8s.

Beech later made a real “twin Bonanza”…a regular size Bonanza fuselage with their Travel Air (basically smaller engines and straight tail) and Baron series.

The Twin Bonanza was enlarged and developed into a “cabin class” twin, the Queen Air…which became the King Air when PWC turboprops were added.

When it was decided to evolve the Manchester into the Lancaster my Grandfather was the Jig and Tool foreman at AVROs Newton Heath factory and he had the job of updating the outer mainplane jig drawings (which he did on his kitchen table after his evening meal). He could do this as the Lancaster’s mainplane used the same ribs as the Manchester only spaced further apart, a trick AVROs, I believe, had used on the Manchester’s tail surfaces.

Wow…some great posts!

A few thoughts…

I had always thought of the C-97 series as a B-29/50 with the top half of the fuselage cut off and replaced to form that distinctive double bouble cross section the Stratolifter series is known for. Don’t know how accurate that simplification is, but it’s how I view it, and when I was thinking about the Lancaster to Lincoln lineage the B-29 to B-50 was another family that came to mind.

Secondly……..there was a Twin Bonanza? How was I not aware of this?

In simple terms, the Shackleton is a direct evolution, as was the Lancaster, from the Manchester design. There are several drawings that are common across all of them, and you’ll find Manchester spars and nose ribs in the horizontal surfaces of the tailplane, and the drawings refer to them as parts that will fit anything from “Manchester 33ft tailplane” right the way through. Similarly the spar booms are Lancaster drawings and only really the fuselage and tail fins are a mostly new design. Cockpit side windows and windscreens are straight out of the Lancaster.

The wing – the dimensions don’t change, as again its an evolution. The distance between engine centres is identical on the centre section at 23 ft 9 in, and 13 ft 3 in between inboards and outboards. The wing section is the same too. The dihedral changes from Lancaster to Lincoln (which was originally the Lancaster B.IV) and the span is increased by the extended tip section to 120 feet from the original 102 feet. The intermediate section was modified to use bag fuel tanks intead of the metal versions.

The Lincoln GR (later renamed Shackleton) inherited the same wing, as did the Tudor. The wing is roughly modified; this can be seen in the inboard flap area, its built as a full length flap but is split into two sections as the extension of the nacelle doesn’t fold with the flap any more. The last iteration is the Avro Type 733, and I was astounded to find these draings in the Shackleton archive at Coventry. This is the modification of the Shackleton MR3 wing for use on the AW Argosy. Depending on what you want to class as the heart of the aircraft; I’d class it as part of the family – even if its only a cousin.

When you look at the wing design, and its evolutions, its an impressive list.

Manchester
Lancaster
York
Lancastrian
Lincoln
Tudor
Ashton
Shackleton
Argosy

Not a bad run, all in all.

You need to be fairly easy going about it though…….
Ken

Perhaps about the Russian connection because they certainly did a lot of modification there, but certainly not about the Boeing 377/C-97 Guppy family.
When the USAF modified KC-97s to have jet augmentation (the KC-97L), I believe they took the outer wings off retired KB-50J and Ks at Davis Monthan to make the conversion.

If the span was altered, then it would become a different wing. A pedantic point, I admit.

Again, it depends on how you define it. Beech has always admitted the King Air uses the Bonanza wing (in airfoil, shape and design) but since it’s modified for a turbine twin, it’s obviously not the exact wing found on a 1947 Model 35 or I suspect, even the wing from the Model 50 Twin Bonanza.

I believe the AW.650 Argosy (series 100) used the same basic wing structure as the Lincoln/Shackleton, although of course that doesn’t really make it part of the same family as the Avro heavies.

Aeronut – From a designer’s point of view it would be the same wing, as the general planform tends to be drawn from the centre line initially. Where the fuselage side lies is almost (not entirely) incidental. If the span was altered, then it would become a different wing. A pedantic point, I admit.

You can trace the lineage of the B-29 all the way to the Tu-95 Bear – via the Tu-4, Tu-80 and Tu-85.

You can also trace it from the B-29 to the Aerospacelines Super Guppy – via the C-97 and Pregnant Guppy.

You need to be fairly easy going about it though…….

Ken

What would you say are some good comparisons?

How about theB-29 to B-50? Re-engineered with a different alloy and obviously re-engined and a slightly different wing (larger flaps) but the same basic fuselage.

BTW, there is a great new book on the B-50.

The Avro lineage from Manchester to Shackleton is actually quite close, slipping in the Lancaster and Lincoln between the two. Take the basic fuselage of the Lanc / Lincoln and slice in half from end to end and splice in a 3ft wide section in the middle. Add a deeper floor cross section…. Using the wider Lincoln wing sections to accomodate the bigger Griffons, and use the Lincoln’s larger tail sections and you have pretty much hybrided from one to the other….

It is the product of genius and ingenuity of course penned by Roy Chadwick that enabled this family lineage to grow as Air Ministry specs arrived on his desk. Simple to adopt, straightforward to engineer, and very cost effective for Avro!

There’s lots more in depth than my brief description but I’m sure you get the idea…..

Every time I climb aboard our Shackleton I sense that lineage… it is incredible to think about!

http://www.avroshackleton.co.uk/

Not quite the same wing as a Lancaster, as the York and Lancaster had an identical wing span yet the York’s fuselage was wider.

[ATTACH=CONFIG]242964[/ATTACH] Let us not forget the Avro York which used the same wing, engines, tail and undercarriage of the Lancster with a new box section fuselage.

What would you say are some good comparisons? (Perhaps Comet to Nimrod or perhaps the F4D Skyray to the F5D Skylancer?) Sounds to me like they are related, but only in terms of general arrangement, and lessons learned from the Lancaster.

Thanks for your remarks!

The Lincoln was a fairly heavy redesign – there was a fuselage stretch between the wing and tail, the nose was different, the wingtips were different, the dihedral was reduced and there were structural alterations throughout. It wasn’t quite a clean sheet design, but it was a fairly thorough change.
The Shackleton was also a fairly major change from the Lincoln. The fuselage was completely different (much wider – more space in there!), the fin and rudder were enlarged… the wings are very similar to Lincoln wings, though.