hey at least they decided not to use hypergolic fuel in the sr-71 tho having a jet that was on fire all the time would be pretty bad ass looking. Titanium would probbably handle it and it'd eventually warm up the skin and close the gaps.
Whilst the SR-71 didn't run on hypergolic fuel (because reasons -- including leaky tanks and supersonic skin-heating, so JP-7, which specifically has a high flash point was used for fuel), the ignition system for the aircraft, including its afterburner ignition system, used hypergolic fuel (triethylborane) to initiate combustion, with a limited number of ignition cycles aboard each mission.
Afterburner light-ups were limited by the availability of TEB aboard.
I remember thinking from one of the books on the sr71 equating restarts to setting off a stick of Dynamite in the tailpipe... But I was younger then and didn't know about these fuels. Thanks for the details