I spotted the error 26 October, did some research about a week before 17 November, wrote the text of this page 1 December 2011
For several years I had a statement in this page that was blatantly incorrect, but nobody noticed it, or they did but they didn't tell me about it. To quote myself (boldface added later):
“Strange but true: if you keep flying to the west from the Netherlands, you will eventually reach Canada, but not along the shortest path. The shortest track first heads for the north-east, and follows a so-called great circle. ”
This should of course be: ‘heads for the northwest’! I you really go slightly northeast from the Netherlands (Amsterdam 52°22′ N, 4°55′ E), you eventually land somewhere near Vladivostok, position 43°8′ N 131°58′ E, initial heading northeast by north or 37°15′34″, distance 4,450 nautical miles.
To Anchorage in Alaska, 61°13′ N 149°54′ W, the figures are 346°53′49″ (north by west) and 3,879 nautical miles.
How long was this error there?
In my own historical records of the web site I find the dates 13 December 2001 and 4 January 2002 for the original Dutch publication. I can’t remember if the part with the error in it was already included then, because I also find the date 31 March 2006, on which I translated it to English and made “additions and improvements”.
The 2001/2002 Dutch original was probably a very crude publication consisting of just an executable with some usage instructions. The program was probably based on a much older original for the HP41C. I may still have the listing for that one somewhere.
So let’s assume the error was present from 31 March 2006 to today. That’s more than 5 and a half years. The Wayback Machine has copies dating from 11 November 2007 in Dutch and 20 June 2007 in English, both with the error in them.
All that time nobody has noticed it or if they have, they didn’t tell me about it. That’s normal of course, I cannot expect my readers to serve as unpaid proofreaders. Moreover, I do sometimes receive helpful comments about errors or suggested improvements, like this one, and there are some for the foneport section that I was told about but didn’t even correct yet!
But I will, one day, time permitting.