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Kyle Boatright

Well Known Member
As someone who has accidentally left the master on occasionally, I've been "saved" two or three times by my electric T&B continuing to whine after I climbed out of the airplane. "Hmm, what's that whine... Oops, the master is on."

Now that I don't have a T&B, I'd like to install a replacement noisemaker to wire to the master. If the master is on, I'd like there to be a 60DB (?) whine under the panel. Enough to hear, but not enough to be bothesome.

Any suggestions?

And yes, I did get to the airport this morning to find a stone dead battery with the master "on"...
 
How about a low voltage light ?

Just a thought? Might be a good thing to wire in a low voltage warning light instead of an annuciator? Master on but engine not putting out > 13.x volts red light flashes. Serves dual purposes.

Bill S
7a fininshing
 
I have a tail strobe and wing strobe on separate switches. IF I were to do it over, the tail strobe would be on a PULL type circuit breaker. That way, it is always on and I know that the MASTER is on when I look at the airplane.
 
Good idea. I like it.

Try wiring it to a switch on the canopy.

AKA: When the canopy is open and the master switch is on -> Sound audible alarm...

I like it and think I might try and build it too.
 
Strobe on

I have always been in the habit of leaving the switch on to a rotating beacon, or anti-collision light or whatever I may be flying at the time, as an attention getter if I leave the master on. It has always worked for me.
 
BillSchlatterer said:
Just a thought? Might be a good thing to wire in a low voltage warning light instead of an annuciator? Master on but engine not putting out > 13.x volts red light flashes. Serves dual purposes.

Bill S
7a fininshing
Click to expand...

Naah, you need an active alarm that calls your attention back to the airplane. Unless you're wiring in a halogen landing light, a light probably isn't gonna do it. And besides, I bet my low voltage light ran for days while the battery was draining. ;-)
 
Kyle Boatright said:
Naah, you need an active alarm that calls your attention back to the airplane. Unless you're wiring in a halogen landing light, a light probably isn't gonna do it. And besides, I bet my low voltage light ran for days while the battery was draining. ;-)
Click to expand...

Kyle, tee an oil pressure switch into your sensor line and hook it up to either a large light or an audio transducer. I have an automotive pressure switch wired to a 3/4" red "idiot" light at the top of the panel. It is called the "Turn Off the Master You Idiot Light". :)

An audio alarm would be just as easy to rig:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=458-1076-ND

Guess you would have to get used to the thing screaming at you when you hit the master prior to startup or if working on something in the hangar (maybe an override switch?).
 
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I used a Radio Shack piezo type buzzer (cheap around $7).. Similuar to their # 273-075..Small & light......Mounted on a bracket behind the panel on the bottom with the horn pointing down... They have various tones, and loudness models... The one I used had 2 inputs... a steady tone and a pulsing tone.. The steady tone I used for the engine instrument alarms..the pulse tone input for the 'master on' alarm...which also has an red light on the panel.. The 'master on alarm' circuit is keyed via the low oil pressure switch (that also runs the Hobbs when pressure is up)... The horn is loud enough just to be annoying and can be heard while the headset is on.. Works for me...never left the master on yet...
 
Buzzer or 'idiot light' is a good idea. My 'idiot' light is my NAV lights. They are LED's so they don't use much power when I forget my master for a couple minutes. I just leave my NAV light switch on all the time. Master on = NAV lights are glowing (very bright).

Scott
RV-8 Fastback (flying)
 
My strobes have an "off", "belly" and "all" positions... Unless doing maintenance, the belly is "always" hot if the master is on just to prevent this problem. No way to walk away from that!
 
Kyle, for sure you remember to pull the mixture to shut the engine down. Consider establishing a flow procedure that moves your hand to the mag switches and master at the same time. Once that habit pattern is imbedded, you won't feel comfortable climbing out of the airplane until it is done. It's one, two, three or it does not feel right. (or something like that)

I don't say this critically. It's just a suggestion to fix the problem.

I hate leaving the master on, and have done it, but it has not happened since going to a flow pattern to get it and the mags OFF. It is an old method of getting things done in an airplane and used extensively before the check list became mantra. The engine has to be shut down, it is a good starting point for a pattern that ends with the master coming off.

This is not to suggest a flow pattern is better than a check list. But doing it both ways does insure the job gets done just in case one forgets to whip out the check list. :)
 
Keyswitch!

I have a keyswitch for the master (and aux), just like in car. To be able to take the key of the switch it must be turned off. I am not flying yet, but I guess with the car keys on the same ring, it will be very hard to leave the plane with the master on. And nobody will be able to turn the master on when I am not there, either.

Regards, Tonny.
 
David-aviator said:
Kyle, for sure you remember to pull the mixture to shut the engine down. Consider establishing a flow procedure that moves your hand to the mag switches and master at the same time.
Click to expand...

I have always flipped off the master with left hand as I pull the mixture with right hand. Works great and never left the master on. (I think I just jinks myself so I will be stopping by the hanger on my way to work to check the master!)
 
I saw an idea here on VAF that I plan on stealing.

Have a ?Low Oil Pressure? warning light installed. That way, this light will be On if the Master Switch is On and the engine is shut down, and as such it serves as a ?Oops! You left the Master Switch On with the engine shut down.? warning light as well.
 
audio AND light

The standard low oil pressure/master on circuit that crossbow mentions can also be modified to work with the Dynons to come on if there is an alarm so it acts as a master caution light. That is what I did however I have still left the master on a couple of times at fly-ins when it was a bright sunny day and I did not notice the light. Integrating a audible buzzer into the circuit should be fairly easy and would alert you when exiting the cockpit, I think I will add this to my "mods during annual" phase that is coming up.
 
After ten years....

Kyle Boatright said:
As someone who has accidentally left the master on occasionally, I've been "saved" two or three times by my electric T&B continuing to whine after I climbed out of the airplane. "Hmm, what's that whine... Oops, the master is on."

Now that I don't have a T&B, I'd like to install a replacement noisemaker to wire to the master. If the master is on, I'd like there to be a 60DB (?) whine under the panel. Enough to hear, but not enough to be bothesome.

Any suggestions?

And yes, I did get to the airport this morning to find a stone dead battery with the master "on"...
Click to expand...

Well Kyle.........I did it. :eek:

There was a very rare break in the rain yesterday afternoon, I arrived at the hangar primed and ready to fly only to discover the moron who taxied my plane back to the hangar after a fly-in lunch on the ramp ten days ago overlooked turning off the master. This in spite of the big red oil pressure light.......

In my defense, the shut-down was out of the routine since I was just taxiing the plane, not returning from a flight. But, non-routine events happen...

Think I've been converted to the camp of noisemaker.

As a datapoint, the 3 1/2 year-old PC680, even though discharged to a stone dead condition, came back to life after having a 2 amp charger on it overnight. Don't know if the ultimate life of the battery has been compromised, but it cranked the plane normally this morning.

Plan is to wire an alarm in parallel with the oil pressure light and put a switch on the tip-up canopy that will inhibit the alarm when the canopy is closed. Hmmmm...or make the alarm real loud, wire the switch straight to the master and I'll also have a "canopy unlatched" alarm.

Getting old is, well, getting old................ ;)
 
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I also would want a noise alarm

When I was in Grand Cayman I taped up the canopy and sides and then had my obsessive compulsive thought "Did I turn off the master?"

I had to remove all the tape just to verify that the master was off.
 
Good ideas all ...

Lotsa good ideas here, at least one of which I will incorporate in my Nine-A to assure I don't forget the master. To date I have NOT had that problem in the Cessnas I fly because my flight training included the pneumonic "SLIM" as shutdown procedure .... shutting down in order: Switches, Lean, Ignition, Master. That's my mantra when I shut down. Once
my instructor beat that into me, I never forgot it. :)
 
Kyle

I put a 3 dollar Radio Shack beeper on my Motorcyle turn signal as a minder.

Could easily cut it into the oil pressure light.

U can get a 80 Db or a 125 Db. I used the 80, its not enough to overcome the m/c engine noise.
 
carguy614 said:
Guys..
Check this out...

http://www.aircraftspruce.com/catalog/avpages/masternag.php

Regards,
Chris
Click to expand...

This device will work if you have a hobbs meter or oil pressure switch on the plane. Many newer RVs have neither since those items have been superceded by digital engine monitors.

I have a digital engine monitor but also an oil pressure switch to run an independent indicator light. I bought a 12v audio transducer and a pack of "normally on" pushbutton switches from Radio Shack and intend to install the beeper and a canopy switch in parallel with the oil pressure light.
 
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