On Thursday, June 4, 2015 at 10:00:04 AM UTC-4, Simon Waddell wrote:

When Lord Derby was once asked why he always flew in four-engined aircraft
he replied that it was because there were no six-engined aircraft.

And to seque back to glider mounted jet engines... What happens if you mount two of these engines on a glider? Enough thrust for self-launching? Redundancy for sustaining (or to circle back on aborted takeoff)? Twice as many things to break? 2X the cost?