With the FAA "lightening up" on installation of safety devices (as they did over a decade ago with shoulder harness installations in classic aircraft), there's been a renewed interest in AOA indicators.

I have generally not been all that interested in AOA indicators in general, feeling that my good ol' ASI is good enough. To a degree, especially flying my Mooney, I'm still thinking that way. However, with the Husky I am often flying into relatively short and sometimes one-way spots (can't call 'em strips) that require maneuvering low on approach, at at different gross weights. And while I've been on the fence, I can appreciate that knowing one's stall margin while cranking and banking down low, could be a good thing - - so I'm gonna go for it.

AOA indicators fall into two basic groups, vane type (mostly pricey and used on military and jets), and the generally more affordable pressure differential sensing type that uses a couple of small ports located so the pressure changes with AOA.

From what I've seen, prices range from about $700 to more than $1,600 for small GA type AOA's

The CYA-100 is a vane type that is prices at $395. http://www.ackemma.com/index.html If you download the instructions on the website, at the end of the file there's a copy of a letter from the FAA that says this can be considered a minor alteration if certain conditions are met, so only requires a log book entry etc.

I've ordered mine through a group purchase on the Mooney group with a !0% discount. (Haven't received it yet, but will bench test it immediately and post a review here).

Owner has agreed to offer a group buy discount for BCP orders as well, subject to the following:

A group buy on the CYA-100 will net a 10% discount off the already (IMO) reasonable price of $395.

Conditions:

At least 10 orders are needed (can't count mine as I ordered with the Mooney group).

Must pay via PayPal, or personal check (w/ clearing delay).

Include Husky user name with order.

A refund check for $39.50 will be included with your AOA.

This offer is good until the end of January.

**

If you would like to participate in the BCPgroup buy, please post here so others can determine if the 10 minimum order is reached.

Disclaimer: I am not associated with CYA-100 in any way.

all the best,

bumper

I've ordered one.

But wouldn't the world-renowned "Bumper Mach IV yawstring" do much the same thing if mounted on a side window ?

And seriously, It will be interesting to see how this works out, and thanks for the offer for a group-buy.

Thanks. cubscout

I love mine and use it every landing, but I never look at it. Having an audible output through the headset is the only way to go, IMHO, if you're seriously focussed on looking outside for the visual cues as the primary reference to land by.
Tastes will vary though, and the noise can be off-putting to passengers if they can hear it.

I emailed, Rip, the owner, and offered to anodize the aluminum parts on a couple of these. He thanked me and advised that they are already anodized, clear. Should have known he would be "on it" and doing it right for a small company.

I plan to hook up audio to my headset so I can hear the warning over my wife's screaming in the back.

bumper

What made you choose this particular AOA indicator over the other offerings like the one below?

http://www.advanced-flight-systems.com/ ... A/aoa.html

In looking at the literature from Advanced, they indicate that it can be installed on an Experimental aircraft with just a logbook entry, but a 337 field approval is required on a Certified aircraft.

Im interested in one. My Citabria doesnt have a stall horn, so an AoA would be nice, even if just to see how close I am to stall in my everyday flying.

I have looked at a bunch of these at OSH and am pretty sure I will pick up the Advanced Flight unit this summer as they usually have a good show special.

I have no real experience other than what I have seen/learned talking to the reps as well as what we all have seen on the web, but I will say this... In life, we usually get what we pay for. I can't help think that a $400 AOA vs/ a $1500 AOA might be comparing apples to cucumbers.

You might want to read this paper from Professor David F. Rogers about determining AOA with differential pressure probes.

http://www.nar-associates.com/technical ... screen.pdf

MAU MAU wrote:What made you choose this particular AOA indicator over the other offerings like the one below?

http://www.advanced-flight-systems.com/ ... A/aoa.html

In looking at the literature from Advanced, they indicate that it can be installed on an Experimental aircraft with just a logbook entry, but a 337 field approval is required on a Certified aircraft.

I'm sure the advanced flight systems AOA is a fine product. The least expensive version is more than double the cost of the CYA-100. Advanced monitors differential pressure (Delta-P) to determine AOA, that's fine and works acceptably well as, but I prefer the more direct vane method. Especially at less than half the price.

bumper

I see no reason for them to be expensive.
They are a tube with two holes, a couple of lengths of pipe, two pressure senders, and a simple computer with display. Being non-cert, it only needs to cost what it costs them to make it + margin.
As long as the tube is of good design, and the sensors are accurate, it should give consistent results.

bigrenna wrote:I have looked at a bunch of these at OSH and am pretty sure I will pick up the Advanced Flight unit this summer as they usually have a good show special.

I have no real experience other than what I have seen/learned talking to the reps as well as what we all have seen on the web, but I will say this... In life, we usually get what we pay for. I can't help think that a $400 AOA vs/ a $1500 AOA might be comparing apples to cucumbers.

Bigrenna,

I like to get the best price I can, though I'm willing to pay for better quality. In this case I'm not convinced the higher priced offering has commensurate value.

Comparing the two AOAs, the display is similar between Advanced's "lower price" Sport model and CYA's display. The audio warning is different in that Advanced uses voice while CYA uses a warble tone - nod may go to Advanced here as I may prefer voice, don't know, but I can live with the warble tone as it's unlike any other warning in my plane. I think CYA's vane sensor is a superior method of determining AOA over 45 degree off-set impact pressure ports. The vane is used on the big iron and military jets for a reason, though they use a heated probe of course. Not concerned with ice, as I won't be flying my Husky in it. Besides, it's likely an iced up wing is going to stall at a lower AOA and higher airspeed than a clean one in any case, so without FIKI, and iced up, one's AOA indicator probably shouldn't be trusted.

bumper

Pusher wrote:determining AOA with differential pressure probes.

http://www.nar-associates.com/technical ... screen.pdf

It is related to how I built mine for about 120 bucks. It screws on outboard of the wingtip position light replacing the stock screw with a longer screw. It is powered by the nav light harness at the wingtip, and a battery in the cabin receiver (wireless xbee). This was buying things at retail...Im certain a person could make them for 80 in low quantities.

AFS has good tech support. Don't know a thing about their AOA worry meter.

Thanks for the explanation Bumper.

Looking forward to your install photos and inflight evaluation.

bumper wrote:

MAU MAU wrote:What made you choose this particular AOA indicator over the other offerings like the one below?

http://www.advanced-flight-systems.com/ ... A/aoa.html

In looking at the literature from Advanced, they indicate that it can be installed on an Experimental aircraft with just a logbook entry, but a 337 field approval is required on a Certified aircraft.

I'm sure the advanced flight systems AOA is a fine product. The least expensive version is more than double the cost of the CYA-100. Advanced monitors differential pressure (Delta-P) to determine AOA, that's fine and works acceptably well as, but I prefer the more direct vane method. Especially at less than half the price.

bumper

I've got the LIft reserve indicator - LRI on 182 not electrical on top of glareshield /probe under wing . Works excellent about 400 bucks . only wish I had the heated version .

bumper wrote:

MAU MAU wrote:What made you choose this particular AOA indicator over the other offerings like the one below?

http://www.advanced-flight-systems.com/ ... A/aoa.html

In looking at the literature from Advanced, they indicate that it can be installed on an Experimental aircraft with just a logbook entry, but a 337 field approval is required on a Certified aircraft.

I'm sure the advanced flight systems AOA is a fine product. The least expensive version is more than double the cost of the CYA-100. Advanced monitors differential pressure (Delta-P) to determine AOA, that's fine and works acceptably well as, but I prefer the more direct vane method. Especially at less than half the price.

bumper

I've got the LIft reserve indicator - LRI on 182 not electrical on top of glareshield /probe under wing . Works excellent about 400 bucks . only wish I had the heated version . http://www.lift reserve.com

Pusher wrote:You might want to read this paper from Professor David F. Rogers about determining AOA with differential pressure probes.

http://www.nar-associates.com/technical ... screen.pdf

Excellent paper and reference...thanks for posting.

MTV

Naval Aviators fly AOA all the way to touchdown every day. However, we cross check AOA to KCAS. At a fixed weight your "on-speed" AOA corresponds to an airspeed. If "on-speed" AOA remains constant then airspeed will change linearly with weight. If you know your stall speed at a light weight and at gross and add the multiplier you like (ie 1.2 x Vso or whatever you like) to each then you can calculate mph change in your approach speed per 100 lbs or whatever increment you like. Now you have a rule of thumb and as long as you know your a/c weight you can quickly calculate your "on-speed" AOA airspeed and consistently fly the same AOA without an AOA indicator. In a jet landing on a carrier things happen a lot faster on final and an AOA indicator allows for a much quicker scan which could save your life. In a GA airplane, especially a STOL aircraft, I really don't see the need for an AOA indicator as long as you have a dependable airspeed indicator.

Bender wrote: In a GA airplane, especially a STOL aircraft, I really don't see the need for an AOA indicator as long as you have a dependable airspeed indicator.

I know many pilots have safely flown back country in mountainous terrain for years with nary a problem. But, when down low in a canyon doing a dog leg approach with a tight base to final to a short "strip" with no visual horizon, an AOA should be a welcome addition. Even with a horizon (artificial or otherwise), I tend to feel somewhat concerned (okay, maybe a lot concerned) when slowed up and turning tight when near the ground when there's absolutely no altitude margin.

Until the wheels plant and slow to a stop, the ground is your enemy.

bumper