UGLY IS PRETTY: LEAR 25 VS PILATUS PC-6

When you go to a party where you don't know anybody, you should always go for the 'Ugly' girl, because she will be happy that you chose to spend time with her.

- HUGH PRYOR

MORE THAN LIKELY, you will enjoy a splendid evening full of laughter and genuine friendship, and you will meet her at later venues, where you will enjoy each other's company. There is none of the hassle which you get if you are escorting a racy blonde bombshell.

Similarly, the Pilatus Porter PC-6 is ugly, but fun and a great friend in difficult circumstances.

In comparison, Lear Jets and in particular the Lear 25, looks racy and sexy, but like many beauties, she can be cantankerous and occasionally extremely dangerous.

Based on a failed Swiss jet fighter, the Lear Jet was born in the days before supersonic flight became the norm for fighter aircraft.

Aeronautical engineers then did not really understand the problems of compressibility in trans-sonic flight. Notably, pilots did not appreciate that, as the wings approach the speed of sound, a shock wave builds up, rather like the bow-wave of a ship, above and below the wing, more above than below. As the speed increases, the shock wave moves back across the chord of the wing.

Wikipedia describes how Mack Tuck affected even the piston powered fighters of WW2, noting that "The fastest World War II fighters were the first aircraft to experience Mach Tuck. Their wings were not designed to counter Mach Tuck because research on supersonic aerofoils was just beginning; areas of supersonic flow, together with shock waves and flow separation, were present on the wing. This condition was known at the time as compressibility burble and was known to exist on propeller tips at high aircraft speeds.