It wasn’t long ago that it was considered a mark of excellence to have a panel composed of all one brand. In a for-sale ad, the phrase “all Bendix/King IFR Silver Crown”was thought to have a cachet in the buyer’s mind and even if that wasn’t the case, it still sounded good.

These days, you can still build a panel entirely composed of one brand—Honeywell’s Bendix/King line, Garmin or UPSAT’s Apollo line and there are good technical arguments for doing it. But with the current avionics market being fragmented in terms of what various boxes will do—and won’t do—the savvy owner has to be increasingly concerned about avionics integration or,…