An HP-14's Benign Spiral

By Doug Adcox

Soaring January 1980

I found Jim Mash-Webber's "Safety Corner" article on the B.S.M.(Benign Spiral Mode) decent technique most interesting; it brought to mind some comments I'd read by Ned Jacoby of Balboa, California. I was, at the time, in the market for an HP-14 and had written Ned asking for his opinions on the flight characteristics of the '14. Ned graciously responded with a lengthy and informative letter, a portion of which reads as follows:

"Schreder flaps are very effective and full flaps will find you descending at such a steep angle you'll feel like you're going to slip under the seat belt harness. (One thing you might like to try someday when you've got some height and are experimenting around is to simply slow the ship down, put down full flaps, take your hands and feet off the controls, and see what happens. On our HP-14 the ship would slowly drop its' nose while turning gently, the speed would go up to 55 kts and stop while the nose slowly came up to the horizon; then the nose would gently drop and the whole process would repeat itself. Our rule for flying -- based on that experiment -- was to put full flaps down if our speed got to 70 max. and then let the ship fly itself out of cloud. I never had to do it, but several times it felt nice to know that I could.)"

Since Jim's article seemed to deal specifically with spoiler-equipped ships, I thought perhaps the above comments by Ned would lend some supportive information to those pilots who might be flying ships with the 90-degree flap mode. Bear in mind, however, that the characteristics just described by Ned were for his particular HP-14, and may or may not be applicable to other HP-14s, or other ships with 90-degree flaps for that matter. I pass Ned's comments merely as food for thought, and to offer a contrasting (or rather supplemental) statement to Jim's excellent article. Perhaps those readers flying ships with 90-degree flaps could substantiate or contribute additional information along these lines (I never got the HP-14, sob!)

Doug Adcox

Chickamauga, Georgia