Originally Posted by safetypee
There’s turbulence and turbulence.
- that's the key, stilton. forgive the pun, but you are talking 'chalk and cheese' here. Wave is rarely 'turbulent' in the true meaning of the word. It is just a disturbance in the airflow. I don't think the OP was referring to wave!
The factors behind the choosing of a 'turb speed' are many, and centre around a combination of protection from excess structural loading combined with retention of sufficient margin of performance for up and down speed changes. I was told the DC-10 (I think it was) actually had a higher 'turb speed' than its normal cruise. My only airliner is the 737 where it was lower.
In true 'turbulence, ie 'mod' or worse, I have always had an eye on the 'magic' buffet boundary markers on the EFIS 737s to ensure I was 'in the middle'. In strong wave you should ideally pitch your speed into the middle of your buffet boundaries (if you can ever identify the 'normal' air!) and this will give you the best speed margins. It is, however, rare to 'run out of power' and if you do, you were at the wrong cruise level as you found.
