Prototypes - Proof of concept or Production Ready?

[nincomp]

As people here know, there were quite a few prototype aircraft tested in WWII. Were many of the tested prototypes essentially the same as the production models? I ask this because it is often very difficult on "one-off" prototypes to replicate metal components as they would be when mass produced. The specific production tooling for a new design, such as castings, forgings, stampings, etc for a new plane would not be available. Would it?

I do not know the primary goals of the first prototype. If the primary purpose is to test the flight characteristics of a design, the details of the construction techniques are less critical. If the purpose is determine the durability of the aircraft at its limits, on the other hand, construction techniques must match the production aircraft.

My question also includes those aircraft what eventually entered production despite requiring major re-designs after testing the first prototype.

Thanks

 

[davparlr]

Typically X indicated experimental "proof of concept" and Y indicated preproduction design. For instance the XP-80 was strictly experimental whereas the YP-80 was a close to production design. This is true today also.

 

[drgondog]

Proof of concept for X, ready for production Y

 

[nincomp]

Thanks guys.
It is nice to find out that some questions have simple answers!

 

[nuuumannn]

The definition of "prototype"

Prototype - Wikipedia, the free encyclopedia

In terms of aircraft the prototype is generally the first one.

 

[drgondog]

As people here know, there were quite a few prototype aircraft tested in WWII. Were many of the tested prototypes essentially the same as the production models? I ask this because it is often very difficult on "one-off" prototypes to replicate metal components as they would be when mass produced. The specific production tooling for a new design, such as castings, forgings, stampings, etc for a new plane would not be available. Would it?

I do not know the primary goals of the first prototype. If the primary purpose is to test the flight characteristics of a design, the details of the construction techniques are less critical. If the purpose is determine the durability of the aircraft at its limits, on the other hand, construction techniques must match the production aircraft.

My question also includes those aircraft what eventually entered production despite requiring major re-designs after testing the first prototype.

Thanks

There are examples where production tooling was funded along with constructing the Prototype - but AFAIK only during wartime. The B-29 and P-80 are examples. For the latter, Kelly Johnson was well aware of the damage to the P-38 program when Lockheed had no money and couldn't afford investing in Production tooling. When the first one crashed, they had to build the next several by hand in order to continue flight test.

This was a major factor in getting the P-38 compressibility problems reproduced and analyzed as well as preparation for war.

 

[stona]

In British terms both mock ups and prototypes were more proof of concept. The idea was to sell the concept to the Air Ministry thus obtaining funding for further development leading, hopefully, to a production aircraft.

Cheers

Steve

 

[nincomp]

The definition of "prototype"

Prototype - Wikipedia, the free encyclopedia

In terms of aircraft the prototype is generally the first one.

Thanks. As I understand it, most of the aircraft prototypes fell somewhere into the "Functional Prototype" category. The problem is that "Functional Prototype" is a pretty broad category since part of the definition you pointed out is the rather nebulous: "(it) will, to the greatest extent practical, attempt to simulate the final design, aesthetics, materials and functionality of the intended design."

I knew that sometimes multiple prototypes were built to avoid the problem that Lockheed ran into with the single P-38 example. In fact, the P-38 is a very good example of why the prototype needed to have a structure as similar as possible to the production model, as it ran into significant "tail shake" issues (some caused by compressibility) and the loss of elevator control at high speed. It was important to know how well the airframe could deal with the stresses caused by this relatively new problem.

From what I gather, the XP-60 used much of the fuselage from the P-40. I simply do not know if this type of "borrowing tooling" was a common or not.