34DD.
Quote:
"For me an aircraft (in this case a gliding Tiger Moth descending at a fixed rate) has lift equal to its weight otherwise it would accelerate downwards."
You are missing something fairly fundamental:
Lift is less than weight during a descent.
To keep your aircraft on the same flight path you don't need to show that there enough lift to balance your weight, you just have to show that when you add up *all* the forces that they *all* balance.
If you email me I'll send you some JPEGs of some sketchs showing whats going on.
As an aside, lift is also less than weight during a climb as well. Counter-intuitive, but a great way of winning beer once you can prove it.
[A purist would argue that lift is less than weight even in level flight, but that is a level of nit-picking beyond the scope of this thread!]
CPB