Definition
A stall that begins at the wingtip of an airplane rather than at the wing root, causing the outer portion of the wing to lose lift before the inner portion. Tip stall is undesirable because it tends to occur near the ailerons, reducing roll control at the moment the pilot most needs it, and it can produce an abrupt wing drop that may develop into a spin.
Plain English
When a wing stalls, you want the part near the fuselage to stop flying first so the ailerons (out near the tips) still work. A tip stall is the opposite: the wingtip gives up first, which can cause the airplane to roll sharply with little warning and reduces the pilot's ability to fix it.
Context Anchor
Encountered in stall training and in discussions of wing design features that help an airplane stall more predictably.
Derivation
Tip means the outer end of something. Stall, in aviation, does not mean the engine has stopped; it means the wing is no longer producing normal lift because the airflow over it is no longer smooth enough. Together, tip stall means that loss of normal lift starts at the wingtip.
Why Pilots Care
Tip stalls can produce an abrupt roll toward the stalled wing and increase the risk of entering a spin if recovery is delayed.
Grounding Statement
Picture the outer end of one wing losing lift first; that side can drop even though the rest of the wing is not fully stalled yet.
Intuition Check
Do not read stall here as an engine problem. In tip stall, the engine may be running normally; the problem is that the outer part of the wing is no longer lifting normally.
Example Sentence 1
Designers add washout to the wing so the root stalls before the tip, reducing the chance of a tip stall and preserving aileron control during the stall.
Example Sentence 2
Adding washout to the wing helps prevent tip stalls by ensuring the root stalls first.