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AOA indicators in general aviation a/c

Bendix-King have announced one too.

Administrator
Shoreham EGKA, United Kingdom

Bendix-King have announced one too.

Looks quite "gadgety" but nice. But why on earth do the have to introduce a new colour (blue)??? These things have been around since the first aeroplane landed on the first aircraft carrier (so to say) and they have been yellow-green-red ever since. With a green circle indicating that you are approaching at Vref. Why why why do the have to paint that circle blue??? I sincerely hope that this thing in it's current form never gains approval.

EDDS - Stuttgart

A reliable and accurate AoA indicator would be a godsend to an aeros pilot or anyone flying into short and 'difficult' strips.

Barton is my spiritual home.

It's great that so much happens in the field of AOA indicators. The solution Icon presented in their video seemed much more intuitive to me, however.

It's interesting to see Bendix King back in the GA game. They also have a new Mode S transponder KT 74. Suggested retail price is 2.999 USD, so about 500 USD cheaper than a GTX 330, if I have the numbers right.

However, I have lost all faith that they will ever introduce their PFD/MFD system which they have announced an eternity ago ...

LOAN Wiener Neustadt Ost, Austria

The KSN770 is still theoretically running (they got Aspen to fix the software) and they seem to be generating chopped-down versions of it. The one I saw at EDNY had a touch screen that was even worse than the one on my VW satnav, however.

The KFD840 is now dead. They told me at EDNY that the subcontractor who was making it decided to drop it. It sounded like there would be some litigation as a result.

I think the basic problem is that anybody who can hold a soldering iron left more than 10 years ago. King have not done any evident R&D since the KLN94 which was done c. 1998. If you read their maintenance manuals, the picture you get is one of great engineering/electronics talent in the 1970s and 1980s, followed by mediocrity as all the old guys (who cut their teeth in the days of real innovation - 1960s space projects) retired, or went to Garmin. Their products site is just a sad revamp of mostly old 1980s stuff. I see they have even given the 1982 KCS55 a new label... nice to see their new chief is earning his salary.

Anybody with a brain will leave a company that doesn't bring out new products, and that is a disease affecting the whole avionics business, where even apparent "innovation" (say G1000 to G2000) is just re-hashing existing technology and pushing a mass of paperwork around. I think Avidyne have that problem big-time, which is why they are so long in getting their IFD boxes finished. They have been living off their cash cows for too many years, and Garmin stole their lunch and ate it.

The KT74 looks nice. King lost a huge amount of business when they abandoned the push button entry of the KT76C (the best Mode C unit ever IMHO) and went to the rotary knobs of the KT73 which almost nobody bought. Garmin then stole their lunch with the GTX330... which turns out to be incompatible with the RS232 data stream from the King stuff, despite the connection appearing in the Garmin manuals.

Administrator
Shoreham EGKA, United Kingdom

I installed an AOA on my N-reg Cessna R172K under a field approval a few years ago. I’ve heard that field approvals won’t work any more due to very slow FAA response, but it worked fine for me at the time. The field approval was only necessary because I wanted to have it heated which required connection to the electrical system. Without heat it could be installed with only a log book entry. Easy to install under the wing using an existing Cessna inspection hole. The unit is an Alpha AOA and I just love it… don’t know why I waited so long to put it in. I went for the round gauge that sits up next to the compass. Right in line of sight during landings. Prime advantage is stability vs airspeed indicator which allows lower approach speeds and nicer landings. One of the best investments I’ve ever made on the aircraft.

LSZK, Switzerland

An interesting report – thank you.

A Major alteration is done with a 337, and if there isn’t an airframe specific STC then it is a Field Approval. It has to be signed off by a US FSDO. Any FSDO can do it but officially if you are in Europe it is supposed to be done by the NY IFU. They stopped doing avionics and similar 337s in 2010 (they told me). I have since heard the Frankfurt FSDO might do it but have not come across anybody who tried that. Which FSDO did you use? I have done two field approvals post-2010 and in both cases got somebody in the USA to present them to their local FSDO on my behalf.

The electrical connection doesn’t need a field approval. The trigger for a Major alteration is a “basic change to the electrical system” (FAR 43 Appendix A) and this certainly isn’t. It is just a CB and some wiring.

Administrator
Shoreham EGKA, United Kingdom

Which is the best AoA indicator?

I am seriously looking at installing one, because it would enable me to reach the operating ceiling (whatever it is in the actual conditions) in an optimal way.

The Alpha Systems seems to be the most popular product, allegedly also re-badged by Honeywell/King. This seems to use just a couple of pipes and no moving vane sensor.

Last Edited by Peter at 14 Jun 16:35
Administrator
Shoreham EGKA, United Kingdom

From my experience, take the simplest one. We have an analog gage somewhere on the panel (I don’t even know where exactly, because I never look at it) and an “indexer” almost identical to the one labelled “Griffin” in your picture with is mounted on the centre strut of the windshield below the magnetic compass (that I also never look at because it is minimum 30 degrees off…). Thus, the indexer is always in the field of view in the last stages of landing and when the green circle (blue with the Griffin) illuminates I know that I’m flying close to Vref which is all I’m interested in. On climbout, we don’t fly a specific AoA, but Indicated Aispeed as per aeroplane flight manual.

EDDS - Stuttgart

Today I sat in the cockpit of an almost new Citation 4 which has AoA indications on the Collins Proline kit, plus the LHS has a little dedicated AoA display (like the “Griffin” one) for mainly approach speed purposes where it acts as a cross-check on the Collins-computed Vref which itself depends on what loading etc data you enter into it.

The pilot explained that he does use it a lot.

I like the “head-up display” version, the crap demo video notwithstanding. It looks like it can be flipped up/down.

Administrator
Shoreham EGKA, United Kingdom
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