What would be indicated if only one landing gear leg will go up?

If only one landing gear leg will go up, it suggests a mechanical issue within the landing gear system. A broken cross tube bolt would directly affect the connection between the landing gear legs. Since the landing gear typically operates using a system where both sides should move in unison, a broken bolt would cause the affected leg to remain stationary while the other side operates, leading to the situation described.

The importance of the cross tube is that it connects the two legs, allowing for coordinated movement. When one leg is not functioning, it indicates that there is a failure in the part that is essential for transferring motion from the crank mechanism to both landing gear legs, which in this case is a broken cross tube bolt.

This scenario can lead to significant safety issues, as one functional leg could potentially compromise stability and balance during landing or taxiing. Therefore, it's crucial for technicians to examine the landing gear thoroughly, focusing on the integrity of the cross tube and its associated components when faced with such an issue.