Earthstar Forums

A very good read. I noticed that the Boeing engineers also talked about tail clearance on landing and take-off in the discussion about flying the AOA. We have a similar situation on the Gulls and particularly the 2000, as it seems to sit a bit lower than the JT’s, and I noticed that getting the plane too slow on landing can cause a tail strike, and that is another good use for the little wheel in the back. Our planes have a sweet spot in speed when landing that has to be learned on each plane as they are slightly different from each other as well as the indicated airspeeds at landing. Too fast and they float, too slow and they plop or smack the tailwheel. All in the learning and transitioning process of our planes and all in all, I guess it’s better to feel the sink rate and eyeball the landing sight rather than trying to fly another gage or indicator to the ground. I think I’ll move on to another project, door support struts anyone?

kb

... and it vindicates Dave's question about AOL versus flap setting. A
"clean" wing will stall at a different AOA than one with flaps deployed.
That does limit its usefulness, especially where it counts most, on the
turn to final, where most stall accidents happen.

Let's say you come in for a dead stick landing. Of course you would try to
come in steep, with some flap deployed. Mark, if you need to "stretch" the
approach a bit, would you reduce flap angle before pitching down to gain
airspeed, or would you pitch down first? Or simultaneously?

Flaps on dead stick landing.
I will set up a dead stick landing with plenty of extra altitude. Than as necessary I will add flaps to add drag and slip if needed, keeping in mind that you need to give forward stick in a slip to maintain airspeed. 60 or more. It's better to have to much altitude since there are things that can be done to bleed off that altitude like S turns but never 360 since you will usually be to low after a complete 360.
Happy Flying
Mark
Sent from my iPhone

Kess, please please give it try. OpenGC (12yrs, ~BSD) is a good candidate to base the front end on. AoAss calibration on one model seems to be the only major challenge

The Boeing PLI is way more complex with redundancy in the backend components & that it also drives couple of other indicators & that it must have at least two operating systems for the front & backend & that it is built with the most stringent engineering & test processes around

I bought an AOA indicator a while back from a Canadian guy who makes a rudimentary version in his garage. I haven't installed it yet in the Odyssey, but probably will next time I take the nose off to change out the battery. I have no need for it for regular flying, but I do occasionally land on really short fields.

http://www.stoneylake.org/pipcom/AOAr.htm http://www.stoneylake.org/pipcom/AOAr.htm

Nobody can dispute what Mark and Gary have said. They know their stuff. Gary makes a very good point about practicing stalls and slow flight. One time I was flying a Cessna 172 with its airspeed indicator in mph instead of knots. I was turning final and forgot that I needed to mentally convert to knots and was flight too slow. The thing that alerted me was that the controls felt mushy which alerted me quickly to my error and I immediately dropped the nose and added power.

I would like to have an angle of attack indicator myself, especially when it is easy to acquire in an EFIS. Some of my reasons are:


1 In a turn, the stall speed increases. The only way I know to compensate is to keep a table in my head of load factor and the square root of it versus bank angle. I have to estimate my bank angle or read it from the bank indicator and multiply the airspeed by the square root factor. Also, the stall speed depends on the load carried and other factors. An AOA would tell me directly.


2 I like the idea of monitoring angle of attack during approach and during turns.


3 There are situations where distraction, unusual air currents can make it more difficult to know how close to stall one is getting. Some AOAs have audio warnings which is an additional help.


4 I feel that it will help me to get to know the behaviour of my Odyssey when I get it flying in a few months. I think it will be a good training guide for me, because of the way I think. Maybe I won't need it after I get the feel of it, but on the other hand I that might find that getting used to using it makes its use a habit which helps keep me out of trouble.


5 If I lose the airspeed indicator and the AOA is still working, it gives me a back up besides my feel for the aircraft.


There is a really good article in the September 2013 "Kitplanes" magazine on page 22 by Paul Dye with comments by Jerry VanGrunsven Louise Hose (Paul Dye's wife). I recommend reading it.


A really good book that I think every student pilot and pilot should read is "Stick and Ruder" by Wolfgang Langewiesche. It has really good discussions on angle of attack.


John Fletcher
Toronto, Ontario, Canada

I'm re-reading Stick and Rudder these days. Great book. Here's a pretty good take on short field landings. The video towards the end is worth watching. http://www.backcountrypilot.org/the-app ... ude-flying http://www.backcountrypilot.org/the-app ... ude-flying

Hi John..
Really thanks for the link to BackCountry Pilot.
Really excellent instructional articles. Fresh thinking, practical, and exciting - especially the video clips at the end of the articles.
Thanks again.
RMM

PS-to John Fletcher.
Good to hear from you. Hope the spring and summer takes your Odyssey build to completion.

Great stuff. Thanks for posting this.

One final note about AOA indicators, I did forget about the flap thing that when you deploy the flaps, the airfoil and therefore stalling speed changes. Also the AOA changes with density altitude and actual landing weight which makes looking for that sweet spot in landing a challenge at times. That said, our planes are extremely agile, and can correct quickly which is why they are such a delight to fly. Oh, and the knots vs mph in Cessna’s. I was out with a friend some years ago in my C-150, stitting in the right seat letting her fly the plane, and I realized on landing that she was getting too slow because she was used to knots as in the C-152 that she had flown. Whew! Had to work fast to save the landing. Until that sweet spot is honed, use the airspeed to help get the feel for the right set-up, and as Mark says, never get below 60 mph, and if you’re a bit heavy use 5 or 10 more down to the runway. Like Mark, altitude is your friend and you can always dump it with slips.