On: British aerospace company claims biggest engine ad...

[njharman]

Maybe the principals are easily applied in a just different enough to not violate patent way.

Maybe they don't want to spend the time or money in court instead of on getting to market.

Maybe they know big aerospace companies will be able to out spend them on lawyering/lobying and so will loose.

Maybe they believe their time to make profit > than the duration of patent protection.