EMS Audio Inhibit on Start

[NASA515]

I believe this has been discussed before, but despite a very diligent search, can not find the thread(s).

Going from memory, early on, SV triggered a lot of annoying audio alerts during start.  Dynon eventually fixed this by adding an Audio Inhibit during Start selection (page 7-73 of the Installation Manual.)  This fixed the problem.  But, only for a few upgrade version cycles - then it crept back in.  I believe I posted on this, but maybe it was a PM to Dynon support.

In any event, the audio warnings came back.  I have learned to live with them as a minor annoyance - until recently.  My trusty Rotax, which starts instantly, has gotten cranky requiring several start attempts.  I'm troubleshooting the problem, but meanwhile have been forced to start the engine using two or three tries.

Now, the Inhibit on Start audio messages have become a real pain - with a constant stream of Oil Pressure, Engine Monitor, Voltage, Low RPM and whatever else in a non-stop stream from the SV lady.  I checked my config file and Yes, the EMS Inhibit at boot is selected to YES.  I reset it to NO, saved the file, then reselected to YES.  Done this several times.  It appears that the system response is the same whether selecting YES or NO.

I have experienced this on SV Classic, SV-T, and HDX, and multiple SV boxes, and also on two different RV-12 airplanes, so I don't think there's some hidden gremlin hiding just in my box or my ship.

Comments anyone?  Dynon?

Bob Bogash
RV-12
N737G
620 hours

 

[Dynon]

I don't think we think that it's broken, but we've been wrong about that before. To be clear, you're saying that as soon as you power up your SkyView, you're always getting alerts instantly, is that right? The INHIBIT ENGINE ALERTS AT BOOT option is designed to stop alerts after SkyView starts but before your engine does. Once SkyView thinks the engine is running, you'll then get alerts if something goes out of range. So if you're having trouble getting the engine going, its conceivable that SkyView thinks that the engine has started, which effectively "unlocks" the alerts.

 

[NASA515]

No, no alerts after power up (well maybe some - "Message."

The actual verbiage is:

INHIBIT ENGINE ALERTS AT BOOT: NO | YES
When set to YES, all engine alerts, both audio and visual, will occurs until after the first engine start, or 5 minutes, whichever comes first. This option can help inhibit nuisance alarms before the engine is started. When set to NO, engine alerts are always active.

I think the word "NO" is inadvertently omitted from the first sentence. Somewhat contradictory as to BEFORE or AFTER first engine start, but going on the first sentence of the above, the alerts should be inhibited until AFTER the first engine start. I get Alerts, even during normal ops, on ALL engine starts. During the engine start process. I start within the 5 minute time window also. With multiple start attempts - meaning no actual start - then I get cascading alerts from each attempt running together in a cacophony of alerts. Very distressing! And, as stated, during the actual first start attempt, I get the alerts.

Bob Bogash

 

[Raymo]

As a point of reference, the way mine is working is as follows:

Upon SV power up:
* No alerts


After a start attempt but no start (usually cold wx):
* Low fuel pressure audible warning
* Low oil pressure warning
* Low oil temp warning (depending on temp).

It seems that once oil pressure is detected, the alert inhibit is disabled. Maybe if that could be user set, it would help?

 

[NASA515]

Good idea, Ray - or if factory defined, maybe 5-10 secs after detection of oil pressure.

All things Alerted for are params normally moving from outside their "normal" range to inside the range during the Start process.

Bob

 

[swatson999]

I'd rather deal with any noisy alarms in the event of a non-start than begin piling up conditions and checks to prevent them. Again, adding more layers of complexity may not, in fact, result in a "safer" system, and can result in failure (here, it might be failure to alarm when it *should*, which to me is worse than alarming, momentarily, when it shouldn't).

That said, I almost never have a failed start, cold or hot, so I don't really have to deal with this...just saying...be careful what you ask for.

(BTW, might it be simpler to just take of the headphones or turn off the intercom/speaker for a moment in the event of an issue starting?)

 

[Raymo]

I don't find it a bother; it is working as designed. I recently installed a sump heater so cold starts will probably be rare in the future. After start, I want to know as quickly as possible that the oil pressure has not come up to the minimum I have set (which Bob could possibly use in this case - if that is the trigger).

Could it maybe be better? That is for Dynon and customer feedback to determine. Having worked in the software field for nearly 20 years, I've learned that code changes rarely occur for one or a handful of users unless it is a safety item or just a fantastic idea that would surely please many people.

Taking off my headset is not an option with straight pipes and only one good ear remaining

 

[NASA515]

The system is already complex from a software standpoint, since it already contains an Inhibit function.  What we're discussing here is tweaking it, not creating a new one.

As for knowing there is Oil Pressure, I don't need an Aural warning for that, I'm looking at the Oil Pressure gage immediately as the first check during any engine start.  It's an Aural check on my part, which I make out loud, each and every time, which is on my Checklist and which I'm used to making on the Boeings I'm most familiar with.  I don't really need the Dynon Lady replicating my own Aural notifications.

I also find it annoying to hear her call out "Voltage" when my system voltage falls below my preset level, - since - from my analysis of the system parameters via Savvy charts after every flight - a big drop in voltage and a high negative amp condition are perfectly normal during the cranking phase of virtually every engine start.

I DO find it a "bother" and do not like "dealing" with noisy alarms during the engine start process.  I think air safety history, as demonstrated by a number of Airbus accidents in particular, where the crew becomes overloaded with visual and aural warnings during critical events, shows that LESS can sometimes be MORE.

Meanwhile, failing any software resolution, I plan to follow Steve's advice and leave my headphones off until the engine is satisfactorily started and operating normally.

 

[swatson999]

It would help the discussion if we knew what the inhibit was keying on to remove the inhibit...is it oil pressure? RPM? Some combination of the two?

It might just be tweaking it to remove the inhibit only when it is *certain* the engine is running, which it may not be doing now. But, and it's a big but, you have to make sure that the threshold is not set *too* high, which would keep the inhibit in place even when the engine is running in some cases (e.g., idle RPM or something like that).