I disagree with Jonathan Scott's suggestion that the ejector seat is one of the great achievements of the modern era (
Letters, 15 January).
It was certainly a great technical accomplishment, but the Engineer's list was based on breakthroughs that had changed the face of the country or affected the lives of millions.
Advances in DNA and the channel tunnel fall into that category but the ejector seat, however valuable for military pilots, does not.
If we are looking for extra candidates from the world of aviation then how about automatic landing systems for passenger aircraft, which have allowed thousands to travel safely in all weathers.
P Turner, Bristol
Project to investigate hybrid approach to titanium manufacturing
What is this a hybrid of? Superplastic forming tends to be performed slowly as otherwise the behaviour is the hot creep that typifies hot...