Do you need annunciator lights?

[idleup]

Why do some panels have the announicator lights and some dont? when are they desired/required and what operations to they commonly represent?

[tonyjohnson]

Matt,

It is pretty much an individual preference as to whether you want them or not. If you are using an EFIS or engine monitor, many of the common annunciator lights are not needed because the EFIS or monitor will display alerts for such things as oil pressure, over-voltage, and other things that you can plug into the EFIS or engine monitor.

Some people like to have panel backups for the critical systems, like oil pressure and over-voltage. If the EFIS gives a false alert, which has been known to happen, the annunciator light os a cross check.

Some of the annunciator lights are for critical items, others are what I call "status" lights. All of us at one time or another has flown around with a boost pump or landing/taxi lights on. A light on the panel will remind you to turn them off.

Another popular annunciator light is the starter engage light, which alerts you to shut down if your starter is stuck on....and chewing up gears. Of course, this is most helpful on the ground, but that seems to be where the problem would most often occur.

One RV builder from "Down Under" has a light to tell him that the electric cooler in the baggage compartment is on, and that his beer is cold.

It is up to you.

You might search this site for more information. There are some previous threads that discuss the issue.

Tony

[fodrv7]

Matt,
Tony has pretty well covered it.

There is not much effort to add them and if, for example, an annunciator light avoids inadvertently leaving the flap switch 'UP' after a go-around and the motor running until it burns out, it will save you a few $100.

Others can double up and provide secondary functions. I have the 'GALLEY" annunciator ( as Tony mentioned) and it tells me that the beer will be cold on arrival and also after shutdown, that I have left the Master Switch on and the frig (refer) is quickly flatening the battery.

Perhaps what would help would be lists from other builders as to what they deemed necessary.

I did have an EIS light to bring my attention to a Warning on my GRT EFIS, but as I found I always saw the Warning on the EFIS Flight Instruments screen first, I changed it to a Landing Light Annunciator.

So I have;
LANDING LIGHT
STARTER
FLAPS
FUEL PUMP
GALLEY.

Hope that helps,
Pete.

[Ironflight]

Tony an Peter's relies are right on. Some people like them, others don't. I must admit that in my years of flying, I have had vacuum pumps and alternators fail that I did not catch if I had been staring at the appropriate gages at the time - because, well, I just don't stare are those gages. Annunciators would have alerted me, and I added them to my airplanes. They are really great for giving you an early head's up before things really go to worms.

I saved an engine because of a low oil pressure light on my Grumman - if the light hadn't caught my attention immediately, how long would it have been before I saw the gauge, way over on the other side of the panel? Before or after the engine seized? It would be nice to believe that we have the discipline to scan every instrument every minute, but after thousands of hours of routine flying, I know very few people who do....it's human nature.

I put the annunciators in my plane that would give me early warnings....and also to remind me that I've left stuff on....

Paul

[dan]

Depends on what you mean by "annunciator." Don't forget about TSO C129a. Some IFR GPSs do require external annunciation, some don't. For example, the GX60 does, the GNS430 doesn't. Thus the "ACU" (annunciator control unit).

[az_gila]

Originally Posted by dan

Depends on what you mean by "annunciator." Don't forget about TSO C129a. Some IFR GPSs do require external annunciation, some don't. For example, the GX60 does, the GNS430 doesn't. Thus the "ACU" (annunciator control unit).

Dan... I believe the 430 does require the annunciator if it's not in the FAA definition of primary scan area.

Some FSDOs have put a dimension on this as a maximum offset from the visual center line of the pilot...

You have to see what it's telling you...

AC 20-138 applies...

An excerpt...

d. Navigation Display.
(1) The horizontal (and vertical) deviation(s) display(s) and failure annunciation should be located within the pilot's primary field of view, as should any indication requiring immediate aircrew action. For the purpose of this AC, the primary field of view is within 15 degrees of the pilot?s primary line of sight.

(2) Displays used for loss of integrity monitoring, waypoint sequencing, start of a turn, turn anticipation, active waypoint, distance to active waypoint, desired track and actual track (track angle error), TO/FROM indication, approach mode annunciation, and automatic mode switching should be located within the pilot?s normal field of view. The normal field of view is such that the pilot would notice an annunciation during normal aircraft operation. Guidelines for the normal field of view include: the lateral normal field of view is from the center of the airspeed indicator to and including the equipment if installed in the center radio stack. Alternatively, if the equipment is installed to the left of the airspeed indicator, the lateral normal field of view is the center of the altimeter to and including the equipment. The vertical normal field of view includes immediately above and below the basic ?T? instruments (may also be anywhere within the lateral field of view).

UPDATE... the Canadians are much more specific, even though their document is based on the above US FAA AC.
The pictures give good guidelines for anyone planning an IFR panel..

http://www.tc.gc.ca/CivilAviation/ce...23-008.htm#4_0


gil in Tucson

[idleup]

Thanks for the great responses guys.

[N941WR]

Some, if not all, of the EMS units out there have annunciator functions built in.

The Dynon EMS puts a warning across the bottom of the screen and a tone in your year. Thus no need for lights of any kind.

However, I did put in a green fuel pump on light at the top center of my panel.

PS. Do a search, this has come up before and there is a big thread on this topic.

[Paul Tuttle]

I have a GR EIS in my ultralight. Something went amiss with the CH temp one day and the light started flashing. It drew my attention to a situation that was getting worse by the second. At the time I was over a built up area and the warning gave me time to gain a little altitude and find a decent place to land ,which I eventually had to do. I feel personally that had I not had the warning light I would have had a far more serious situation on my hands as those back yards looked pretty small and there were power lines and cars on all the other good landing spots.What ever system I finally decide to go with in the 8 will have warning lights.

RV 8 Fuselage