Turkey sends Rolls-Royce another pitch to co-produce engines for the TF-X jet

[satyamev]

the metallurgy in jet engines is very difficult to master. Its not even a case of having the design and drawings, in metallurgy, the slightest environmental changes introduce marked variations in the product.
Even in a low tech metallurgical operation, common to reject batches of material because the furnaces behavior changed unexpectedly. Its not a exact science.
A lot of handholding is required.