Definition
An informal name for the inverted black triangle containing a white 'T' that appears on instrument approach charts and Takeoff Minimums and (Obstacle) Departure Procedures pages. The symbol indicates that the airport has non-standard takeoff minimums, non-standard alternate minimums, or a published obstacle departure procedure that pilots must consult before flying the procedure.
Plain English
A small black triangle with a white T printed on an approach chart. It is a warning flag telling the pilot, 'Stop and check the takeoff or departure rules for this airport before you go — they are not the standard ones.'
Context Anchor
Seen on FAA instrument procedure charts, usually near the airport or procedure information, when takeoff minimums or departure procedures need special attention.
Derivation
Called the 'trouble T' because the letter inside the triangle is a T (for Takeoff) and because the symbol flags potential trouble — something non-standard that could catch a pilot out if missed. The nickname is informal pilot shorthand, not an official FAA term.
Why Pilots Care
Using standard minimums when the Trouble T is present can result in inadequate obstacle clearance during the initial climb.
Intuition Check
The trouble T does not mean the aircraft has a problem. It means the chart is flagging special takeoff or departure information that must be checked.
Example Sentence 1
During the preflight briefing, the captain pointed to the trouble T on the approach plate and pulled up the takeoff minimums page to check the required climb gradient.
Example Sentence 2
Even with good visibility, the trouble T required us to follow the steeper climb gradient listed for that runway.