After a couple of thousand hours operating Darts
Loose rivets, the word whoomph seems incongruous. The word "Stagger" comes to mind as being more appropriate.
A few Dart statistics - 90% of the energy produced was for making noise, 1.7% for jet thrust, and the remaining 8.3% used fto stagger the propellors.
I kid thee not!
Regards,
Old Smokey