I flew the light-attack, single-seat jet the A7-E while stationed aboard the Nimitz. The landing gear position indicator indicated both up-and-locked as well as down-and-locked. That doesn't mean it got much attention on the takeoff though.
I was a new pilot attached to the squadron when one of the senior JO's left for a cross-country. He was climbing to altitude when he called maintenance to discuss a problem he was having. "There seems to be something wrong with the engine," he exclaimed. Maintenance asked him what the signs were and he replied that it just wasn't generating enough thrust. "I can't seem to get above 220 KIAS, and my climb rate is very low." A series of questions followed: What is your fuel flow? Turbine outlet temperature? Altitude? Throttle position? Any unusual noises?
His answers seemed to suggest that everything appeared normal. Nothing was out of the ordinary. As we listened to the radio conversation a pilot off in the corner, with a big smile on his face, suggested he look at his lading gear position indicator.
"Hey maintenance, I found the problem. See you in a few days."
In either position, down-and-locked or up-and-locked there was no audible tone. There was just a visible indication. One was expected to follow their checklists and look at the indicator.