Related Clues:

• Change fourth dimension within height-measuring instrument
• Duration's covered by other pilot's gauge
• A highly informative device
• Skydiving device
• Moment to change clothes for bit of pilot's kit
• Change round what may be shown on dial for cockpit instrument
• Change over years, say, in flying instrument
• Climbing gadget
• Change round hours and minutes perhaps in measuring instrument
• Change round hour and position indicator
• Instrument measuring height above sea level
• Change outside of one meteorological flight instrument
• Plane’s instrument’s date shown during change
• Aircraft's height indicator
• Pilot needs this to be highly accurate