AHRS disabling for contest

[soarsz]

The AHRS is nice to have. I like to take a look at it from time to time to assess my angle of bank. I certainly hope I never need it for its main purpose.

There is the question; how does one disable for contest flying. There is mention of this on P 77 in the S-10 manual but the method outlined there is not available as far as I can see on the V 8. I wrote LX and they suggested turn off on the AHRS settings page under Hardware-AHRS by setting mode to off. I tried this and it had no effect. Anyone break the code on this yet?.

[Sean Franke]

US competition rules are not compatible with LXNAV AHRS.  It is possible to get a waiver to fly with an instrument with AHRS 'if the RC determines that the “artificial horizon” or “turn and bank” capability can be effectively and verifiably disabled for the period of the competition.' (US Competition Rules Committee Policy on Instruments Incorporating the Capability for Flight Without Reference To the Ground February 8, 2012).  However, with the instrument in question,  AHRS can be manually turned back on at any point during the competition...a violation of US rules.  AHRS disablement must expire after the competition.  Of course, disabling a safety feature with no opportunity to enable it if needed is another discussion...

Sean Franke

[F Hersen]

You may read on an IGC file the status of the LX  AHRS.

 

François

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[Sean Franke]

Point #5 of the Rules Committee Policy:

5. The procedure for using the device is expected to be:
a. The competitor with a waiver disables the capability at the beginning of the contest
b. The competitor demonstrates to an appropriate contest official (e.g. CD, scorer) that the disabling has been done.
c. After 14 days the disablement expires (i.e. daily checking of IGC logs is not an acceptable process)

Sean Franke

[F Hersen]

LX Manual page 108;  “Mode defines modes of operation of AHRS. AHRS can be switched to OFF mode. This will be shown in the IGC file as a BFI sentence. If the AHRS is active there will be written BFION”.

 

To my mind the competion set with 14 days OFF  no longer  exists .

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[cdeerinck]

Yesterday, I wrote the following to LXNav:

How can AHRS be disabled for competition flying in the US?
Will doing this prevent the V80 and LX9070 from showing artificial horizon, or will going to one of those screens trigger the BFION in the IGC file?
Will Hawk cease to function when AHRS is disabled?

Today, I got this response:

Please make once more activation firmware of the HAWK. FW is attached. It is different than initial.

This will sort out the problem with AHRS.

We will also make one release for customers, that are using HAWK DEMO.

I will not have the chance to install the new firmware until Saturday.

I'm a little unclear yet on how it answers my questions.  It sounds like they thought I was complaining about a bug that they were already aware of.

I think only an analysis of the IGC file will provide clues.  My last flight had a total of 14 BFION and BFIOFF lines in a 3 hour flight. 

It would be important to actually disable it in competition, so that accidentally scrolling past an AHRS screen on my V80 or LX9070, wouldn't disqualify an entire contest day.

Because it is only Hawk firmware, and I don't expect any UI changes, so I am still unclear on how to disable AHRS (Page 108 as cited above doesn't say how to switch it off, just that it can be switched off).

I am very confident that LX Nav will not leave us in a state whereby we cannot fly in US contests legally.

[Sean Franke]

" I am very confident that LX Nav will not leave us in a state whereby we cannot fly in US contests legally."  is one way to look at it.  Perhaps it's not an LXNAV issue but a 10-year-old US rules policy that needs to be updated?  LXNAV would have to provide a way to disable AHRS for 14 days without the option of turning it back on to be compliant...disabling a safety feature for 14 days to accommodate rules.

Sean Franke

[Eric Greenwell]

How was the LXNav AHRS handled in 2021 contests? Has something changed since the end of our racing season last year? Or is this a problem introduced by Hawk, and Hawk was not used by anyone in contests, so the issue didn't come up?

Eric

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[jpg...@gmail.com]

To digress slightly,

The AHRS page has 3 settings: ON, OFF, or AUTO.   AUTO is not described in the manual, does anyone know how that differs from ON?   Presumably with HAWK the AHRS function is running all the time in the background.