this kinda thing was introduced far behind 3 decades ago ,but for different purpose its was planned to use partial compressor air to blow above the wing near trailing there by making laminar flow and reducing stall speed ,but for some efficiency reason it was not used!
but when engine fails ! it will be a dead thing
@Divyam i think Harrier is an answer for your question ! in hover no control surface works ,only airjets located at extremities controls 20 ton jet