Complex sentence: The Whirlwind helicopter had been dispatched from RAF Leuchars in Fife and the pilot attempted to fly up the line of Glen Shee but turbulence meant he had to reduce airspeed to with groundspeed less than walking pace.
Split into simpler sentences: The Whirlwind helicopter had been dispatched from RAF Leuchars in Fife. The pilot attempted to fly up the line of Glen Shee but turbulence meant he had to reduce airspeed to with groundspeed less than walking pace.