Why 2 Comm Radios?

[MauiLvrs]

Because one might break. So, our second is a handheld with vor hooked up to a wing tip antenna. If need be, it can be connected to the main belly mount antenna.

[RudiGreyling]

WOW! Thanks guys 40 posts in one day!

OK I think I get it, Having 2 radios is a convenience thing, just as I thought! If you agree that modern day radios are pretty reliable.

1) If you have the 2nd channel "listening in" and "channel swapping" capability like on a A210 or SL40 you are almost on par with the convenience of a dual radio setup.

2) The only other time a dual radio is helpful is if one fails. (This should NOT be life threatening) If you made provisions for backup NAV (in case 430/530 is your single Radio\NAV solution) and you can keep the airplane pointing the right direction and right way up, you should be OK. (Plane orientation and NAV is where I am going to spend my redundancy and weight)

QUESTION: I did not get a clear answer on the 430/530W query. I know it can do frequency swap, but can it do both frequency "monitor" like the SL40? (i.e. listening in on your standby frequency?) If it can then it seems to be my answer.

PS: I once flew with someone that had a duel 430 setup and a nice audio panel. Man even he got confused on which radio was linked through the audio panel connected to which mike. He often made a transmission then realised he was linked to the wrong radio/mike. So something should be said for simplicity as well.

Thank you
Rudi

[N941WR]

Originally Posted by Ironflight

I'm not sure I can personally agree with you on that one Bill. I would have no difficulty using a handlheld/portable GPS to help improve my SA and monitor an approach while being vectored in such an emergency (loss of all onboard IFR "legal" Nav), but I wouldn't want my first level backup plan to include operating no-Comm in the IFR system without IFR-quality Nav.

While I don't disagree with you that it is possible, I would consider that to be an emergency scenario. I think it prudent to design a system such that a single failure in your avionics lets you fall back on legal, reliable operations. A second failure might be an emergency.

I understand that others might have different comfort levels - I just wanted to flesh the thoughts out a little.

Paul

Paul,

I agree with you. The use of a hand held GPS for nav backup when flying IFR is for emergency situations only, like a total electrical or complete nav failure. Because of the hand held's internal battery, this is a natural.

For VFR flying, I have found the use of hand held GPS (496, in my case) to be all that you need. Actually, a lot more than you need.

Note: Neither I nor my plane are IFR, so this suggestion could be way off. Let me know, I'm trying to learn from all this as I'm thinking of upgrading both me and the plane.

[Captain Avgas]

I do quite a bit of night flying so I would not consider NOT having a second radio. When I get to my destination I want to be certain that I can switch on the PAL (Pilot Activated Lights) runway lights....even if I lose one radio.

It gets very lonely up there in the dark when you can't switch on the runway lights.

No-one has mentioned this so I thought I'd just throw it in.

[rleffler]

Originally Posted by RudiGreyling

QUESTION: I did not get a clear answer on the 430/530W query. I know it can do frequency swap, but can it do both frequency "monitor" like the SL40? (i.e. listening in on your standby frequency?) If it can then it seems to be my answer.

Unfortunately, the 430/530 doesn't have the standby monitor features of the SL30/40. The SL products were acquired by Garmin through an acquisition.

I have selected the SL30 to add a back up com and nav device in my RV-10.

[RudiGreyling]

Thanks Bob,

Ditto Captain Avgas: you've hit the nail on the head, it has not been discussed before. So if you do night flying and you're going to a place with Pilot Actived Runway lights, and there is no alternative Tower LIT airfield close by, then a single radio failure could be life threatening.

Rudi

[apkp777]

This discussion goes back and forth between WHAT IS SAFE and WHAT IS CONVENIENT.

Certainly 2 comm radios is convenient, no one can deny. Having an ability to monitor a standby freq, certainly mimics the second comm.

But I would have a hard time saying that a 2nd comm makes you "safer". A loss of a comm radio in most cases does NOT mean loss of communication. Unless you have a complete loss of power you sill have your transponder.

When the tower sees the 7600 squawk they know your radio is not functioning. (You should immediately select 7600 anytime you realize that you can't use your radio. You can switch back to 1200 or other if you get it back). Your transponder is a communication device. If you loose you all electric, yeah you loose your transponder and 2nd and 3rd comm.

Yeah, it sucks to lose your 1 radio, I have been there. Still no big deal. Over fly the tower, get a green light, enter the pattern and land. Call the tower on the phone tell them thanks! At night, choose a towered airport (if they are open) or find an airport with non-PAL. Remember your sectionals! L and L*. Heck my students hardly get to use any lights (theirs or the airports) "10 take off and landings at night". It's never a big deal. They LOVE landing in a black hole. I wish I could see there faces, but its too dark! Then we discuss the importance to taking care of their landing lights.

Personally, I don't care much for night flight. I avoid it as much as I can. Not because of loss comm, but because of loss of power. (both engine and electric). But if I need to go somewhere and leaving in the wee morning hours or get back late, I have no problem.

Still our little hobby is a safe way to travel. I am pretty sure it's safer to fly single comm than to drive my car instead.

Our safety responsibility as pilots is more centered on the ability to "see and avoid". That being said, the loss of NAV is a much bigger deal. This is where the IFR issue comes up. Should be a separate thread, "Why 2 Nav radios". I have a single SL30 going into my panel. Eventually more. But my "personal minimums" dictate that I don't fly a precision approach to below traffic pattern altitude without an autopilot and second approach capable nav device. So with a SL30, Skyview (no moving map yet) and a handheld GPS I am limited to enroute IFR. Which is great, I don't plan on descending to 100 feet off the deck in the soup, when all I wanna do is just have fun with my plane. Losing nav on an approach would be disastrous. No matter how reliable, a single SL30 won't provide the ability to fly the missed approach safely. But it is fine for enroute ops. in my configuration.

Now as a CFI I have to add this;

Steps to follow when you have radio failure

1. Establish a safe altitude
2. Squawk 7600
3. Get into cruise configuration
4. Start fiddling with the radio
5. Return to land.

Which step do most students do first? Yeah, step 4. Usually when there either on the runway or 200 feet off the deck. Yikes!

A comm failure is a HUGE distraction! Aviate, Navigate, Communicate. NO EXCEPTIONS!

[cleve_thompson]

A friend of mine was flying into his home field at night. The field had pilot controlled lighting and his single radio stopped working while in flight. He had to fly to a controlled field. Not a terrible situation but a backup radio would have been nice.
I have a little ICOM 20 as backup. I only have one VOR receiver that way though. I do have a panel mounted Garmin 396 in addition to my 430 so with failure of my 430 I do have that backup as well.
Isn't it fun! There is no end to what you can put in a plane with enough money
By the way, I was a surgeon at a Salvation Army hospital near Glendale in Zimbabwe for 3 years and surely do miss southern Africa. Those are some beautiful pictures of your trip!

[RV7Guy]

Convenience, redundancy etc..... I have a 430 and a SL40. I have ATIS and ground Freqs of the frequently used airports programmed into the 40. On long CC's I put 121.5 in the standby mode and monitor it.

Yes it is a convenience. But this means, ease of use and good cockpit resource management equaling improved safety. I use up to 7 frequencies on my short 15 minute flight to work in very busy airspace. That is a lot of work changing frequencies in a single 430. With the preprogrammed SL40 it is simple manner of hitting the swap button once.

In the scheme of the overall airplane the cost of a second comm, an antenna and some wiring is very minimal.

[N55CU]

Nothing screws up the ATC system more than a nordo! Install the extra radio! You will also find that the SL30 & King radios have a bit more performance than the Garmin. I can always receive a faraway ATIS sooner on my SL30 than I can the Garmin. And if one needs to go away for a repair you still can fly!
Randy Utsey
N55CU / RV-7 / 270 hrs.
Charlotte, N.C.