On Wednesday, April 8, 2015 at 12:02:26 PM UTC-7, Martin Gregorie wrote:
On Wed, 08 Apr 2015 11:41:01 -0600, Bob Whelan wrote:

In re Bob K.'s and Steve L.'s comments elsewhere on this branch, "Ha ha
ha. Oh the knowing joy of those familiar with 90-degree landing flaps
(and I'm one of 'em)!!!" Regrettably (in subsequently broken
ship/traumatized pilot terms), that particular religious war was lost
long, long ago.

Around 2004 there was another benign spiral thread which caused me to be
a bit of experimenting in an ASW-20. I found that, in calm evening air
trimmed for best glide (57 kts) and zero flap (position 3) and flying
straight, it slowly developed a 25 second phugoid oscillation with an
associated +/- 5kt speed oscillation.

I also tried for a benign spiral: zero flap, wheel down and brakes out,
same trimmed speed and going hands free after setting up a 20-30 degree
bank. After even half a circle the bank angle had increased, the nose had
dropped the speed was increasing. I never let it go beyond that point and
concluded that the ASW-20 doesn't have a benign spiral.

I haven't tried either experiment with the Libelle but should do so this
season, as its always good stuff to know. BTW, my H.201 is s/n 82, so it
dates from before the move to the B series, so it has balsa sandwich
flying surface skins, the small tailplane and upper and lower surface
brakes.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Martin,
I have H201 SN 81 and it will do a beautiful benign spiral! I've had "hands off" for 15-20 minutes when descending from altitude.
Love the Libelle!
Jay