Monday 2 May 2011

An exact replica???

Not as easy as the title suggests,
this has been an argument since the first Tower of London Axe was replicated.


Sorry "restored".
A small issue is the restored axe has had 5 new heads, and 9 new handles, but it is still the original Tower of London Axe, right?
An 80 year old airplane, be it restoration, reproduction, or replica, is not going to be as it was the day it left the factory. It cannot be, as methods and materials have changed, so while it can be pretty close, if the intent is an airworthy aircraft, it must be built to operate in a world of Aviation which has moved on 80 years as well.

Back in 1931 the crosswind had yet to be invented. The first crosswind coincided by cooincidence with the invention of the first directional runway, but in 1931 airports were still mostly square fields, so landing into wind was standard practice, and the runway surface was grass, bumpy and sometimes pretty short.
All of the above lent itself well to tailskids, and three point landings.
In our modern aviation world, crosswinds are well and truly a regular occurence, paved runways make a tailskid the equivelant of an ice skate, and try landing your skid equipped aircraft on a grass strip... you will be asked to replace your 200 yard divot.
So, what can we conclude from the above? well we are not going to be able to build an exact replica, no matter how pure our intentions, and we will have to consider the environment we hope to operate the aircraft in, and build it accordingly.

The original Laird Super Solution had a tailskid, poor brakes, no radio, an extremely early version of the P&W wasp Jr engine, a non sensitive altimeter, linen fabric, no means of inspection, a mixed material wire braced fuselage construction, and who knows what type of assembly glue.
So, there will some minor changes in the interest of aircraft and pilot longevity, the replica will have a tailwheel, hydraulic brakes, a small portable radio and transponder (hidden if possible) a more modern and therefore more reliable R985 engine, dacron fabric, nutplates and inspection panels where appropriate, an all 4130 steel non wire braced welded fuselage, and all wings assembled with epoxy glue.
(I am still searching for a non sensitive altimeter)

The items which will not change include the original airfoil, or relative chord (M12) the overall dimensions, the propeller, the wing rib and wing construction method, the ailerons, fuel and oil tanks, tail construction, trim, controls, the colour scheme, and the balance of the instruments.

I shall also add a couple features not found on the original in any form, an extra set of crossed wires between the gear legs, as without them the full landing and flight loads are transfered to the wing spars.
Engine to cowl isolation mounts, as the original had none, and I can only imagine the vibration, not to mention the inevitable cracking of components.

So, while I intend to replicate the Laird Super Solution as faithfully as possible, and the final result should look exactly like the original internally and externally, there will be a certain number of small concessions to the modern world of safety, and operation.

None of the changes will in any way take away from the aircraft visually, nor will they change the flight characteristics one bit. The Super Solution of today will fly exactly as the Super Solution of 1931, and is that not the best possible result for a modern replica?

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