lml@lancaironline.net Mailing List Archive

Charley,

All good on your comments. For those who interpreted my remarks as stating that all high performance aircraft (including the IV) are untested for deep stalls or slow flight please take the below to heart. The IV has had similar testing.

The point I was trying to make related to purposely doing deep stalls as part of an ongoing training syllabus. Deep stalls in high performance aircraft can easily lead to a roll that goes past wings vertical. Most pilots I have introduced to aerobatics initially get disoriented when the wings go past vertical and instinctively pull rather than relax pressure or push which insures a spin. As has been clearly stated in the list by Charlie K ,LOBO, and others...... slow flight and stall onset are included in a proper training syllabus.

Aerobatic airplanes are in varying degrees a pleasure to fly from zero airspeed on up. The entire envelope can be experienced and precision can be achieved throughout which is part of the reward. High performance aircraft generally don't offer a rewarding feel or precision response when stalled which is an additional reason to avoid deep stalls as each one is an adventure.

Hope this clears the fog a bit.

Jack Morgan

From: Charles Brown <browncc1@verizon.net>
Subject: Re: [LML] Stalls
Date: January 5, 2013 11:19:58 AM EST
To: lml@lancaironline.net

Jack,

On the contrary, all airliners are designed to FAR Part 25 and if you google FAR 25.201 (stall demonstration) and 25.203 (stall characteristics) you will find that they have to be designed and demonstrated to stall tamely, clean and dirty, straight ahead and in 30 deg bank. I've done stalls in a 737-300 during flight test at Boeing, and it's tame.

Furthermore, airliners and certainly the Legacy are designed to go slow as well as fast, through the use of slotted flaps (and, on airliners, leading edge slats). It's no coincidence that the stall speed of a Legacy is 59kt, Greg Cole went to some trouble to design those beautiful, highly effective slotted, cambered flaps and we pay a cruise speed penalty for those big ugly flap hinge brackets. But with stall speed below 70kt, you can run your instrument approach at 90kt and use the lowest minimums (Cat A) on the chart.

What gives, guys? Forget the inadvertant stall and let's suppose your engine quits over rocky or forested terrain. The best available open area is too short but every knot you can peel off your approach speed increases your chance of survival. Knowing and trusting your plane down to Vstall could easily save your life.

Charley

On Jan 4, 2013, at 9:09 AM, Jack Morgan wrote:

Following the below reasoning.... all of the current swept wing airliners and business jets have a problem with "very bad design"!!! I hope all the Lancair drivers out there will ignore those who wish that an airplane could be designed to go really fast and really slow in the same design. Particularly the IV needs to be flown with the respect that a high performance airplane demands. It is well known how to handle high performance aircraft and doing deep stalls is not on that list. LOBO is your best source of what our best practices are based on experience gained to date for all the Lancair designs.

If you want to improve your chances of getting out of a deep stall in a IV go get a hundred hours of aerobatic training. That will also convince you not to stall a IV in the first place!

Jack Morgan