{"gt_parse": {"text_sequence": "t aircraft construction would st art to soften due to t he heat of friction, and s ome new material would ha ve to be used instead. Stainle ss steel was considered, b ut the Bristol 188 proved this to be difficult and expensive.B y 1956 there was enough official i nterest in this research for the Supersonic Tr ansport Airc raft Committee or STAC to be f ormed under Si r Morien Mor gan to investigate th"}}