Definition
The greatest weight that a helicopter's external rescue or cargo hoist is certified to lift, as established by the manufacturer and approved by the certifying authority. This limit accounts for the strength of the hoist mechanism, cable, and supporting structure, and must not be exceeded during any hoisting operation.
Plain English
The heaviest load the helicopter's hoist is allowed to lift. Going over this weight risks damaging the hoist, breaking the cable, or causing structural failure.
Context Anchor
Seen in helicopter hoist operations, rescue planning, aircraft operating limits, and hoist equipment placards or manuals.
Derivation
"Hoist" comes from the Middle Dutch hijschen, meaning to lift or raise. "Permissible" comes from the Latin permittere, meaning to allow. Together they describe the highest weight allowed to be raised by the hoist.
Why Pilots Care
Prevents structural failure or loss of control during lifting by enforcing a safe operating limit that includes built-in safety margins.
Analogy
It is like the weight limit posted inside an elevator. The elevator may move with more weight for a moment, but that does not make the extra weight safe or approved.
Intuition Check
Do not read maximum permissible as “whatever the hoist can manage.” Here it means the published limit the crew must not exceed.
Example Sentence 1
Before the rescue, the crew confirmed the survivor and rescue swimmer's combined weight was within the maximum permissible hoist load.
Example Sentence 2
During engine removal the maintenance team stayed well below the maximum permissible hoist load to maintain safety margins.