I have been mostly a Cessna guy throughout my years of flying. The Citations I flew had the Com #1 antenna on the bottom of the fuselage so we used Com #1 as the inflight radio. The Com #2 antenna was on top of the fuselage, so we used Com #2 as the ground radio.

I had assumed that the Cessna arrangement was industry standard. But now I have learned that most King Airs have the opposite layout: Com #1 antenna on the top of the fuselage (Com #1 is ground radio) and Com #2 antenna on the belly (inflight radio).

With modern radios, does anyone still worry about matching ground/flight com selection to the antenna locations?

Having used Com #2 for ground control for all of my flying (perhaps incorrectly during my Bonanza and King Air 200 hours), it will be a shock to my habit pattern if I need to use Com #1 for ground control. It even has me considering swapping the com antenna coaxs to put my King Air in a Cessna configuration. Heresy?

On my Baron (16 wt xmtr) , it seems the wrong way around also. Very rarely has it made any operational impact though.

I have never seen a performance difference based on antenna location.

My habit is to do ATIS & Ground on Com 2 and setup Com 1 for Tower and Departure freq. That way I test both radios on the ground.

Allen,

That is my procedure exactly.

I hope we hear from the King Air crowd on its procedures.

In the air it never makes any difference which one you use.

On the ground the bottom antenna performance can be compromised if it is too close to the ground.

On the B200 I flew I swapped the antenna leads so the #2 was on the top antenna. There were times when the #2 was useless on the ground at some airports in some positions, until the antenna lead swap.

On my '76 A36 both COM antennas have always been on the roof. They work fine on the air or ground.

As for COM 1 vs. COM 2, I've gotten into the routine of using COM 2 exclusively for ATIS, Clearance Delivery and Ground. I do that so I can set up COM 1 with Tower and Departure (for IFR departures) prior to taking off and so I can set up COM 2 for ATIS and Ground prior to landing.

Just a small time saving mini-process to keep me from having to enter frequencies at otherwise busier flight moments.

Both of my COMs (IFD 540 and CNX 80) have flip flop COM frequencies so I can pre-load and have visible 4 frequencies at once. The GMA 340 audio panel also allows me to monitor COM 2 while listening to COM 1 so I can check arrival ATIS without missing any radio calls.

PS.

We replaced our flying vee antenna with a Comant GPS/COM antenna which I really like. For the VOR's we added a small cat's whiskers to the bottom of the empennage under the rudder that works nicely and was easy to install.

I've been so happy with the Comant GPS/COM antenna that if our other GPS antenna or COM antenna quit working I'll just get another Comant. I really like the 2 in 1 concept.

Jim

I cannot recall ever noticing a difference in the air or on the ground, although logically I do think No. 1 bottom and No. 2 top makes more sense.

We almost always fly two-crew and use No. 2 as primary since, with the older Pro Line II radio tuning heads, it simply keeps the copilot's left hand closer to his own side rather than reaching across to the No. 1 and blocking the MFD/Radar display. No big deal, of course, but we like it.

So for the Primary com, be it No. 1 or No. 2, as has been stated, I use it for Tower and other ATC communication. The Secondary gets ATIS, Clearance, Ground, and monitors 121.5 when not being used for those others.