Once saw an interesting film of the avoid curve being demonstrated on the scout at ETPS. This involved several runs with varying degrees of 'pucker' factor. The curve has two distinct components.
1. The 'knee' and above. From the hover to minimum total drag speed 'say65kt' going up to about 800ft. At heights and speeds above this you're safe!!!
2. The low level/ high speed bit (say 50ft and below and 60kt-vmax).
Not something you should try every day but if your operation fits into the curve whether you're taking off or landing you need to be aware of it. (applies to twins as well as singles, you might lose both).