Clarrie me old
I suspect that asking to follow some one down the runway is seen as somewhat trendy.
Game set and match on that one.
I've seen it all before, they probably saw a lighter heavy doing it by following behind a heavy heavy needing the full length.
The speeds as you say, are relative and no problem given the time it will take the heavy heavy to get to the TO end the light heavy will be way beyond the DER.
I've had em do it to me unannounced on the longer dirt uncontrolled mining strips and as you turn around and start to open the taps whilst keeping rolling to minimise FOD, there in front of you is a windscreen full of dust and disappearing tail, now we gotta turn around yet again to regain the full RWY length, with more dust and FOD flying
.........unflattering words followed.
To put an ultralight
in front just isn't gonna play and a little thought by the ultralight mob would see the logic.
Having said that, as
Chuck says, ultralight or not if it goes pear shaped, it will be difficult to explain to the insurance company why you did not use the full length available regardless of whether it is in excess of your requirement.
Monkey see monkey do.
