Definition
A NOTAM contraction indicating that a piece of aviation equipment, facility, navigation aid, or service has been permanently taken out of service and is no longer available for use.
Plain English
It means the equipment or facility has been retired for good. It is gone, switched off permanently, and pilots should not plan to use it.
Context Anchor
Seen in NOTAMs, which are official notices that tell pilots about changes affecting airports, routes, procedures, or equipment.
Derivation
From the prefix 'de-' meaning 'remove' and 'commission,' which in service use means 'put into active duty.' To decommission something is to formally take it out of active duty. In aviation, it signals a permanent retirement, not a temporary outage.
Why Pilots Care
Attempting to use a decommissioned aid can cause navigation errors or regulatory violations.
Intuition Check
Do not read DCMSND as simply broken or temporarily closed. It means the item has been officially removed from service.
Example Sentence 1
The NOTAM showed that the VOR at the nearby field was DCMSND, so the pilot replanned the route using a different navaid.
Example Sentence 2
After the old VOR was DCMSND, charts were updated and pilots relied on newer waypoints for routing.