John Smith gathered this data while flying with Tim Ong who demonstrated glide performance to him in N199L some years ago. Following is a summary of what he observed, and which he and I now have as part of our Supplementary POH. Whilst these specific numbers are for the Lancair Legacy we hope the information will be of some use. The numbers for the Lancair IV are very similar.
Approximate descent rates at 120 – 130 knots for the Legacy vary from 500 fpm clean and full coarse pitch to as high as 3000 fpm with fine pitch, gear down and flaps 30.
John has kindly converted the data into pictures for obvious reasons and to form the beginnings an article on Legacy engine out descent rates! Clearly, pretty important to get that prop pulled ASAP especially if one is shooting for High Key (above ident touch down point) at 3000ft (minimum) and Low Key (abeam touch down point within 1.2mile) at 1500ft. It is a very tight circuit in a Legacy and this high key low key procedure is something that is rarely taught in General Aviation in Oz.
I for one know that this procedure works very well in the Legacy or any high performance aeroplane.
Glide distance available in the various configurations
How long do you have. The rate of descent can be eye watering if you leave the prop fine and configure early with flaps and gear. Go and practice a few and get some numbers for yourself, it may save you one day.