We visited the memorial to a WW2 plane crash site on Slight Side. I know that at least one old book gives the grid reference as being on the wrong side of the mountain so we used Paul's phone to get latitude and longitude. Putting this into an Internet converter gives NY 20864 05193. The precision of +-0.0001 degrees corresponds to 1.7 x 10^-6 radians. The radius of the Earth is 6400km so it gives the place on the surface of the Earth to the nearest 10m using the arc length small angle formula.
The air crash was a terrible tragedy. The pilots were flying from Sunderland on a training flight. There is more information at
http://www.yorkshire-aircraft.co.uk/aircraft/lakes/v6565.html which implies the other aircraft crashed in a different location, which might explain the grid reference confusion. You can find pictures of the second site here
https://www.peakdistrictaircrashes.co.uk/crash_sites/lake-district/hawker-hurricane-v6565-v7742-slight-side/
The views were so beautiful on the day that we visited. A sad location.
You can tell which parts were aluminium and which parts were steel.
