Todays mission was for a 50th birthday party.
Sky writing is not as simple as it first appears. Its not just a case of going up and doing it!
Firstly I draw the message in as I will fly it “looking down” then I work out how long it will take to fly at 110 knots. (2 miles a minute) You also have to write from right to left for added complication. oh, also get it the right way up!
The next thing to do is look at the met office form F214 “spot winds” This dictates the start point in the sky. Take the wind speed and divide by 60 for distance of drift in 1 Minute.
With the time it will take to write the message you then workout a start position upwind of the target reading area. So, with a 30 knots wind at 10,000 ft and a message taking 4 minutes to write drift will 2 miles.
Plan the start heading so the resulting read is correctly orientated. Occasionally a line feature on the ground can help but this is rare. Whilst writing its extremely difficult to see your start and stop points especially when you’re only just above the inversion.
Proper Planning Prevents Poor Performance.