The AV 30 Looks Good

[0TreeLemur]

2 minutes ago, jamesm said:

Silly question I  suppose that I should know the answer. but does anybody know how many of these pneumatic to digital devices along with the airspeed, altimeter,vsi,  can be hung off the existing  pitot/static system(lines) ? I am thinking with all the electronics whether it be G5's,AV20/AV30,Aspen, Altitude encoder,.....that some of us are adding to our planes seems like there would be  some sort connection loss. that might induce error in remaining round dial analog instruments .

Hi James,

No loss because there is no flow.    Pressure transmittal only.  If there is flow, then you have a leak and your system isn't legal to fly.

Not and A&P, just an engineer specializing in fluid mechanics.

[0TreeLemur]

31 minutes ago, jamesm said:

Silly question

BTW- there are no silly questions.  Only silly answers.

[jetdriven]

3 hours ago, jamesm said:

Silly question I  suppose that I should know the answer. but does anybody know how many of these pneumatic to digital devices along with the airspeed, altimeter,vsi,  can be hung off the existing  pitot/static system(lines) ? I am thinking with all the electronics whether it be G5's,AV20/AV30,Aspen, Altitude encoder,.....that some of us are adding to our planes seems like there would be  some sort connection loss. that might induce error in remaining round dial analog instruments .

Fred2O is correct there should be no pressure loss because there should be no leaks. 

[tigers2007]

Well I just gave my A&P the green light to pull my AI and DG for overhaul at AQI. Instead of spending $10k right away to get an Aspen E5 with ACU and EA100 (installed price), I’m gonna be patient one more year and save my pennies and look forward to AeroVonics and maybe even the G5 allowing output of AI data to the Century. At least my Century IIb won’t be going nuts anymore with the fresh AI and DG.

Things seem to be moving quickly now thanks to the FAA relaxing a little bit on these fancy electronics.



Sent from my iPhone using Tapatalk

[carusoam]

The only thing disappointing is....

The AV-30 with the AOA indicator(?) has issues... (find that thread around here) apparently the device gets confused by bank angles...

Still kinda new, but make sure it works for IFR flight...

Best regards,

-a-

[David_H]

This still looks like a step forward even if the AOA feature isn't robust.

[carusoam]

Hard to rely on any of it when one part of it doesn’t work as promised...

That is why I fly a factory built airplane... there are enough challenges with proven machinery...

AOAs are great, but if I can’t trust it to work, when do I use it?

If the instrumentation builder can’t make it work, why include it...?

My experience of qualification and validation of instruments in mission critical machines has me on edge for stuff like this...

Following a faulty AOAi around the traffic pattern doesn’t look very safe...   when would I use the AOAi... What’s the worst that could happen if it fails?  (Probably not very good in the hands of somebody that is not expecting a failed instrument... heck it worked when it was straight and level)

When does the clock not work?

See how important this stuff can be?

PP thoughts only, not an instrumentation or quality control guy...

Best regards,

-a-

[pinerunner]

I waiting to be sure they get the HSI part working and with a remote magnetometer. I get funny readings from my compass going east/west.

[milotron]

I see now they are offering an autopilot interface for the AI in the coming months. This will be my choice to replace the King AI for my KFC200.  I have pre-ordered two of these in anticipation of this feature.  No need to wait for BK or Garmin to come up with something.

Edited March 2, 2019 by milotron

[McMooney]

I'm really hoping they get this certified sooner rather than later,  prefer the look of these over A G5.

 

[McMooney]

Just now, McMooney said:

I'm really hoping they get this certified sooner rather than later,  prefer the look of these over A G5.

 

Okay just read garmin added the M20e for certification with the gfc500, G5 looking good again 8).

[cliffy]

If you pull up the utube of Yeager getting an F15 ride at 89 yrs old and listen very carefully to the cockpit brief by his pilot

the pilot mentions the AOA instrument on the panel. Listen very carefully and you'll hear Yeager respond  "To me It's a stupid instrument, it tells you what the Angle of Attack is, if you don't know you shouldn't be flying it"  !!!!!!!!!

[Shadrach]

On 3/2/2019 at 2:48 PM, cliffy said:

If you pull up the utube of Yeager getting an F15 ride at 89 yrs old and listen very carefully to the cockpit brief by his pilot

the pilot mentions the AOA instrument on the panel. Listen very carefully and you'll hear Yeager respond  "To me It's a stupid instrument, it tells you what the Angle of Attack is, if you don't know you shouldn't be flying it"  !!!!!!!!!

I’m a big fan of Gen. Yeager, but this would not be the first time he’s been quoted while saying something stupid.  

It’s been said many times that he was an incedibly natural pilot. I’ve no doubt that is true.  It’s also been said that he struggled with the acedemic side of his profession.  The idea that “real pilots” know their aircraft’s precise AOA is lidicrous. I’ve spent a lot of time getting to know various airplanes in slow flight. I just completed a flight review where I was ask to complete 360 turn at 57MIAS in my F model(@2300lbs). The plane stalled dirty, power off at 52MIAS. I had a good feel for the buffet and the break because I approached the stall gradually and methodically in slow flight. The idea that one should and could know AOA during accelerated and banked maneuvers is silly. I agree you can sense when a wing is nearing stall, but that is not the same thing as knowing your margins long before the stall occurs.

Edited March 5, 2019 by Shadrach

[M016576]

8 minutes ago, Shadrach said:

I’m a big fan of Mr. Yeager, but this would not be the first time he’s been quoted while saying something stupid.  

It’s been said many times that he was an incedibly natural pilot. I’ve no doubt that is true.  It’s also been said that he struggled with the acedemic side of his profession.  The idea that a “real pilots” know their aircraft’s precise AOA is lidicrous. I’ve spent a lot of time getting to know various airplanes in slow flight. I just completed a flight review where I was ask to complete 360 turn at 57MIAS in my F model(@2300lbs). The plane stalled dirty, power off at 52MIAS. I had a good feel for the buffet and the break because I approached the stall gradually2 and methodically in slow flight. The idea that one should and could know AOA during accelerated and banked maneuvers is silly. I agree you can sense when a wing is nearing stall, but that is not the same thing as knowing your margins long before the stall occurs.

The context of his comments, too, were in relation to a visual dogfight (the feel of buffet at or near an accelerated stall)- And his point is accurate in relation to his experience indogfights with the equipment he used: no fighter pilot should be looking down in the cockpit at their AoA gauge while fighting another jet in visual range.  A fighter pilot needs to be able to “feel” the performance of his/her jet, while maneuvering in relation to the other jet.  That particular AoA gauge in the Eagle is, however, very useful for landings (just as it is in a mooney).  It’s also useful for computing maximum range and maximum endurance profiles.

In modern fighters now, that AoA information is displayed in HUD and in the various helmet mounted displays: and is most certainly an important part of a fighter pilots scan during all phases of flight.  

So yes- he was wrong in that video.  But also right.

[aviatoreb]

1 hour ago, M016576 said:

The context of his comments, too, were in relation to a visual dogfight (the feel of buffet at or near an accelerated stall)- And his point is accurate in relation to his experience indogfights with the equipment he used: no fighter pilot should be looking down in the cockpit at their AoA gauge while fighting another jet in visual range.  A fighter pilot needs to be able to “feel” the performance of his/her jet, while maneuvering in relation to the other jet.  That particular AoA gauge in the Eagle is, however, very useful for landings (just as it is in a mooney).  It’s also useful for computing maximum range and maximum endurance profiles.

In modern fighters now, that AoA information is displayed in HUD and in the various helmet mounted displays: and is most certainly an important part of a fighter pilots scan during all phases of flight.  

So yes- he was wrong in that video.  But also right.

Job - so what was your punchline regarding modern operations with the latest equipment?  Did I read/interpret correctly that with hud display in your visor that you specifically remain aware (watch) lift reserve from aoa even during that most extreme eyes outside the cockpit scenario of a visual jet air-air fight?

[Shadrach]

3 hours ago, M016576 said:

The context of his comments, too, were in relation to a visual dogfight (the feel of buffet at or near an accelerated stall)- And his point is accurate in relation to his experience indogfights with the equipment he used: no fighter pilot should be looking down in the cockpit at their AoA gauge while fighting another jet in visual range.  A fighter pilot needs to be able to “feel” the performance of his/her jet, while maneuvering in relation to the other jet.  That particular AoA gauge in the Eagle is, however, very useful for landings (just as it is in a mooney).  It’s also useful for computing maximum range and maximum endurance profiles.

In modern fighters now, that AoA information is displayed in HUD and in the various helmet mounted displays: and is most certainly an important part of a fighter pilots scan during all phases of flight.  

So yes- he was wrong in that video.  But also right.

 I have a statement and a question.

I have no experience in dogfights simulated or otherwise. I have however heard interviews with WWII pilots where they recount inadvertent accelerated stalls  in the heat of battle. I would think that a display that shows max turn AOA might be useful on a HUD. Especially if it was color coded or better yet an audible tone. Bank and yank to max performance.

Given the comments were made in the context of military ops, do you think most Naval Aviatiors would be happy to give up their AOAs for carrier ops? 

Also, saying that a pilot should be able to “fly and feel the wing” is not the same thing as as saying that an AOA is a stupid instrument. So I don’t think he was right at all, I think he was just being the crusty old curmudgeon that he’s known to be.

[M016576]

19 hours ago, aviatoreb said:

Job - so what was your punchline regarding modern operations with the latest equipment?  Did I read/interpret correctly that with hud display in your visor that you specifically remain aware (watch) lift reserve from aoa even during that most extreme eyes outside the cockpit scenario of a visual jet air-air fight?

Yes- and it’s used as a measure to exactly control your AoA (which is possible through the use of digital flight control computers) to either A) gain energy, B ) max perform by setting the best turn rate and/or radius based on your tactic, or C) fly past the lift limit to slow down quickly.

in any jet that is fly by wire, knowing and controlling your Angle of Attack is critical to max performing the jet- and is heavily used,  not just for landing, max range and endurance... but for all aspects of air combat.

Edited March 3, 2019 by M016576

[Gary0747]

Looking at the AV20S connector there is a provisional input from a UAT receiver. Does anybody know anything about this?  I see nothing in the manual.

[M016576]

17 hours ago, Shadrach said:

 I have a statement and a question.

I have no experience in dogfights simulated or otherwise. I have however heard interviews with WWII pilots where they recount inadvertent accelerated stalls  in the heat of battle. I would think that a display that shows max turn AOA might be useful on a HUD. Especially if it was color coded or better yet an audible tone. Bank and yank to max performance.

Given the comments were made in the context of military ops, do you think most Naval Aviatiors would be happy to give up their AOAs for carrier ops? 

Also, saying that a pilot should be able to “fly and feel the wing” is not the same thing as as saying that an AOA is a stupid instrument. So I don’t think he was right at all, I think he was just being the crusty old curmudgeon that he’s known to be.

Yes and no... (best fighter pilot line ever: it depends!) 

As both a Naval Aviator in the F-18 (I flew the A, B, C, D as well as the E/F) and then an IP in the F-15C and now the F-35A.... I would never give up the ability to know my Angle of Attack.  But there are differences in the way the instruments are used between a F-15C (which is  a mechanical flight control system) and the F-18/F-35... which are both digital, fly by wire flight control systems.

in the F-15C- the AoA gauge is calibrated into “units” which are basically a linear scale based on a flight control input and a stabilized output AoA... which means that 1-2 units might mean only a .5 degree true AoA at high air speeds, but could be more than a degree True AoA at low air speeds.  As a result- each “unit” wasn’t the same in terms of actual output of performance. “Feel” though- based on buffet cues, allowed for a decent method to find the lift limit of the aircraft without referencing a set AoA... which based on the probes- varied in accuracy at the upper ends of the envelope, and didn’t necessarily give a linear response past the lift limit.  Don’t get me wrong though- I still referenced AoA all the time- it just wasn’t quite to the same level as the digital fly by wire jets.  So that’s why I say that he was kind of right.  Because with his aircraft, he didn’t have an AoA gauge that would have been able to help him in a dogfight (but certainly if the technology was better- it would/could have)!

In a digital fly by wire jet- the flight control computers allow for precise control of a commanded true AoA.  So you literally set an AoA... and by knowing the EM diagram (edit: EM stands for Energy-Maneuverability- it’s a chart that shows energy bleed rates versus a commanded AoA based on thrust, weight and altitude... something we study) of the aircraft- the pilot knows exactly how well his/her aircraft is performing.  It is critical.

for reference- all four of those aircraft display the angle of attack in the HUD (or virtual hud in the F-35) and also in the JHMCS (joint helmet mounted cueing system).

and in all four of those aircraft, you also use AoA for all landings (as opposed to airspeeds), which once mastered, allows for the shortest rollouts and best touchdown Landing zone control.

Oh- and he was definitely being a curmudgeon!

Edited March 3, 2019 by M016576

[Niko182]

6 hours ago, Gary0747 said:

Looking at the AV20S connector there is a provisional input from a UAT receiver. Does anybody know anything about this?  I see nothing in the manual.

You hook up a davtron OAT probe and it'll tell you your TAS, and the density altitude.

[Gary0747]

I was talking about the RS232 input to pin #2 from a UAT. Not pins #1 and #6 for the temp probe. 

 

[M016576]

19 hours ago, aviatoreb said:

Job - so what was your punchline regarding modern operations with the latest equipment?  Did I read/interpret correctly that with hud display in your visor that you specifically remain aware (watch) lift reserve from aoa even during that most extreme eyes outside the cockpit scenario of a visual jet air-air fight?

Yes- exactly- that’s the best/only way to ensure that my jet is “max performing”: scribing either the fastest turn, or the smallest radius through the sky.

Edited March 3, 2019 by M016576

[aviatoreb]

2 hours ago, M016576 said:

Yes- exactly- that’s the best/only way to ensure that my jet is “max performing”: scribing either the fastest turn, or the smallest radius through the sky.

Wow - well I think you may essentially be optimizing some functional related to performance in your head - doing local adjustments to benefit a global optimum performance objective.  Doing this analytically is done by calculus of variations and it is a foundation of optimal control (and also underlies mechanics).  So then it yields an "Euler-Lagrange" equation which is a differential equation whose solution is that optimal path.  ...I think (I'm guessing) you may well be using a local observation (lift reserve) to optimize path - whether you need to think in those terms or not - but if a computer does this for you, then that is how I would approach the problem of designing the algorithm.

Or maybe I have over interpreted this whole thing in a way that is interesting to me.

[cliffy]

HUH?     Just pull hard till she shakes and back off a degree   :-)

 

I had a neighbor years ago that had a PhD in math and wrote a definitive book on control theory

I got to page 4 before I was lost. Still have the book!

Edited March 3, 2019 by cliffy

[aviatoreb]

15 hours ago, cliffy said:

HUH?     Just pull hard till she shakes and back off a degree   :-)

 

I had a neighbor years ago that had a PhD in math and wrote a definitive book on control theory

I got to page 4 before I was lost. Still have the book!

Who is it - Ill look it up. I have a PhD in math and so I bet I can get to page 8!

But...I bet optimal performance for various objectives will not end up being near stall when that shaker goes off.

I assert that for complicated maneuvers that it may well be that there is a very explicit time varying aoa schedule necessary to achieve that optimum.  But too much complexity for practical use?

Edited March 4, 2019 by aviatoreb