AeroVonics AV-20, clocks and minor mods

[Captnmack]

Remember that this Clock requirement stems from, no Gyro Timed Turns, Holding Patterns Entry and Leg Lengths and Timing Missed Approach Points..thus making a Direct View Clock a necessity...

[0TreeLemur]

30 minutes ago, Captnmack said:

This is what I use....

Man, that really kills your useful load....

[Ragsf15e]

Ok, let’s say I installed the AV20-s, but I didn’t want to put in a new temp probe... can I use the temp probe for my jpi 930 to feed both units?

[orionflt]

47 minutes ago, Ragsf15e said:

Ok, let’s say I installed the AV20-s, but I didn’t want to put in a new temp probe... can I use the temp probe for my jpi 930 to feed both units?

No, it has to be independent

Brian

[0TreeLemur]

My A&P installed a Davtron temp. probe in the access panel that lies just forward of the left fuel tank.   Minimally invasive, far enough from the fuselage to not be influence by engine temperature, and not too hard to route the wire up to the left-hand side of the panel.  The probe was about $80.

[Ragsf15e]

1 hour ago, Fred_2O said:

My A&P installed a Davtron temp. probe in the access panel that lies just forward of the left fuel tank.   Minimally invasive, far enough from the fuselage to not be influence by engine temperature, and not too hard to route the wire up to the left-hand side of the panel.  The probe was about $80.

Awesome.  I have a jpi temp probe right there too.  How’s your av-20 attitude and aoa?  Are they smooth and useable?  I think I’ll install one if I can get some pireps, but I may not add the oat probe .

[0TreeLemur]

All AV-20-S functions are working except I'm having trouble calibrating the probeless AoA function.    Not sure why, it seems straightforward, but I need to contact the company after the holidays and things open back up.

[Ragsf15e]

Any chance you could do a short video of the attitude indicator and aoa screens in flight next time you’re out?  Thanks for all the info/pirep!

sheesh, I have a lot of questions.. just thought-how does it deal with aoa and flap settings?  Critical aoa increases with flaps if I remember correctly?

Edited January 1, 2019 by Ragsf15e

[0TreeLemur]

The AHRS AI seems to be fine.   Once calibrated at cruise, it behaves smoothly and generally agrees with the vacuum driven device.

The "calibration" of the AoA requires specification of two numbers: cruise AoA and peak Cl AoA, which of course depends on flap setting.   I went out last weekend with my son to attempt a calibration, but it didn't go so well for reasons unknown.  In level flight, the AOA should be pretty close to the pitch angle which we measured with a smart-phone inclinometer app.   For instance, using the input cruise AoA (3 deg.) and 12 deg. max Cl. AoA (approx.) the thing never really seemed to agree with the smart phone inclinometer.   There is no separate flap setting, so I guess you might want to calibrate it for landing flaps.  We didn't get that far.

I'm hoping the company produces a good video explaining the process, because I either did something wrong or the algorithm in the firmware for calculating AoA from sensor data has a bug. 

Sorry, I'm probably not going to get any video just now, I'm in the throes of IR training.

-Fred

[Ragsf15e]

No worries, thanks for the info!  I found a couple videos online and they look smooth as you said.  I hope the aoa portion eventually works for you.  Good luck with the IFR training!

[Bob - S50]

I don't know if you already tried this, but the manual says to calibrate the AOA, use the 'dual graph' mode of the AOA/G meter.  Go to that screen and then use the view button to switch to the dual graph screen.  Once in flight press both bottom buttons to clear the values.  Then:

"To utilize the dual graph mode as an aid for determining the desired
calibration points, the peaks can be cleared while slowing and
approaching the pre-stall condition. Slowly approaching the stall
point will record the peak positive AoA.
Slowly returning the aircraft to normal cruise mode will then record the
peak lower AoA."

Once you have those values on the graph you can go into the setup screen and set those values for the upper and lower limits.  Once you've done that I'd go test them out and see if you are happy with them.  If not, try adjusting them a degree at a time in the desired direction until you are happy.

[M20kflyer99]

I have an AV-20-s on the way.  I called yesterday about shipment status and specifically asked about using it for the IFR clock requirement.  The person on the phone stated that it does not meet the requirement.  It may change in the future with the FAA changing its regs.   Could just be a CYA.

Edited January 3, 2019 by M20kflyer99

[milotron]

I asked them the same thing about the OAT indicator and they said something similar indicating that if the OAT was on the required equipment list, the AV-20 could not replace it.

Seems to me that the Davtron devices doing clocks/timer/OAT/volts have approval for this?

 

iain

[McMooney]

On ‎12‎/‎28‎/‎2018 at 2:59 PM, aviatoreb said:

https://www.amazon.com/LEGO-9001161-NINJAGO-Figurine-Alarm/dp/B00H3LR2YQ/ref=sr_1_27?s=home-garden&ie=UTF8&qid=1546030707&sr=1-27&keywords=clock+mini

Awesome i'm installing that clock, right on the dashmat.

[Marauder]

All of this stuff is clear as mud. I looked up the Davtron Model 877 which I have in my plane. It is a FAA PMA approved item. Like the AV-20, they talk about installation requirements (minor vs. major) but no mention whether it is considered a direct replacement for a legacy clock (the Davtron only display seconds when in timer mode).

 

 

 

Perhaps the difference is that it is a dedicate permanent clock display.

 

 

Sent from my iPad using Tapatalk Pro

 

 

[milotron]

45 minutes ago, Marauder said:

 

Perhaps the difference is that it is a dedicate permanent clock display.

 

I suspect this is the case. The same reason the clock on your GPS doesn't count; you can switch away from it.

[gsxrpilot]

4 hours ago, milotron said:

I suspect this is the case. The same reason the clock on your GPS doesn't count; you can switch away from it.

According to you. According to me, the clock in my GPS counts just fine. It's all a matter of interpretation. I have yet to find a CFI, AI, or DPE who's flown in my airplane, to disagree with my interpretation. I've also passed a ramp check. 

This is most certainly a CYA situation with the AV20s. It's the same with Davtron. They haven't gone through the long, painful, and profit eating process to get the FAA to bless the clock as a primary replacement. But I have no issue installing it as a minor mod with an A&P sign off as my primary clock.

[milotron]

17 minutes ago, gsxrpilot said:

According to you. According to me, the clock in my GPS counts just fine. It's all a matter of interpretation. I have yet to find a CFI, AI, or DPE who's flown in my airplane, to disagree with my interpretation. I've also passed a ramp check. 

This is most certainly a CYA situation with the AV20s. It's the same with Davtron. They haven't gone through the long, painful, and profit eating process to get the FAA to bless the clock as a primary replacement. But I have no issue installing it as a minor mod with an A&P sign off as my primary clock.

Aside from the clock buried in the AUX pages of the GNS430W, I actually have NO clock at all permanently mounted in my plane. So far a I can tell it has been like this since 1995 and has been airworthy and IFR certified since then and it lived in the US until 2014. 

The only timer is the flight timer in the ADF!

Not sure that it is strictly enforced.

 

 

 

 

[Andy95W]

4 hours ago, milotron said:

 

Not sure that it is strictly enforced.

It's not.  Nobody really cares unless there is something else going on with the plane or pilot.

But what else do we have to talk about on a Thursday evening?

[201Mooniac]

Well since we are talking about clocks, what is the opinion of the legality of the clock on the G500/G500 TXi display, should that count as a legal clock?  No seconds display on that one.

[hypertech]

18 hours ago, gsxrpilot said:

According to you. According to me, the clock in my GPS counts just fine. It's all a matter of interpretation. I have yet to find a CFI, AI, or DPE who's flown in my airplane, to disagree with my interpretation. I've also passed a ramp check. 

This is most certainly a CYA situation with the AV20s. It's the same with Davtron. They haven't gone through the long, painful, and profit eating process to get the FAA to bless the clock as a primary replacement. But I have no issue installing it as a minor mod with an A&P sign off as my primary clock.

This.  As far as I know, the only clock ever in my plane since the factory is the Davtron.  So, I don't think it has anything to do with whether the seconds are permanently stuck on the screen or not.  The AV20s functionality seems to do what it needs to do, its just not tested and certified to be the sole source.  It probably could be but just hasn't.  A clock seems like such a minor thing hopefully there's a reasonable way around it or to get it approved.  

I like the idea of adding the AV20s to my plane to get a redundant backup AI for cross-checking.  If no other developments happen on the clock issue, I'll just leave the Davtron somewhere else in the panel.

[jetdriven]

7 hours ago, 201Mooniac said:

Well since we are talking about clocks, what is the opinion of the legality of the clock on the G500/G500 TXi display, should that count as a legal clock?  No seconds display on that one.

It says minutes and hours wirh sweep second presentation, or digital display. No requirement for seconds on digital clock display. 

[M20S Driver]

Has anyone installed an AV20S recently?  I am considering installing one and I was wondering about the installation cost as well as its AOA performance.

M20S Driver

[Niko182]

1 minute ago, M20S Driver said:

Has anyone installed an AV20S recently?  I am considering installing one and I was wondering about the installation cost as well as its AOA performance.

M20S Driver

The AOA performance is shit

[Ragsf15e]

48 minutes ago, M20S Driver said:

Has anyone installed an AV20S recently?  I am considering installing one and I was wondering about the installation cost as well as its AOA performance.

M20S Driver

Bunch of folks complain about the AOA functionality but the temp, Attitude, and clock functions seem to work well.  It seems to be a reasonable backup attitude indicator.