Definition
Standard Instrument Approach Procedures published specifically for helicopter use. Copter SIAPs are designed around helicopter performance and may be flown only by helicopters. They typically feature reduced visibility minimums, lower minimum descent altitudes or decision heights, and shorter or differently shaped final approach segments compared with fixed-wing approaches. The maximum airspeed on a Copter SIAP final approach is 90 knots unless otherwise specified.
Plain English
These are instrument approach charts made just for helicopters. Because helicopters can fly slower and maneuver in tighter spaces than airplanes, the rules and minimums on these approaches are different — usually allowing the helicopter to get lower and continue in worse weather than an airplane could on the same approach.
Context Anchor
Seen on helicopter instrument approach charts and during planning for approaches to airports or heliports in low clouds or poor visibility.
Derivation
Copter' is a clipped form of 'helicopter,' itself from Greek 'helix' (spiral) and 'pteron' (wing). 'SIAP' stands for Standard Instrument Approach Procedure — 'standard' meaning it is published, charted, and approved for general use, not improvised by the pilot.
Why Pilots Care
They allow helicopter pilots to complete approaches to destinations that lack suitable fixed-wing procedures and often provide lower landing minimums suited to helicopter capabilities.
Intuition Check
Do not read “Copter” here as casual slang. On a procedure title, “COPTER” means the approach is specifically designed and approved for helicopter operations.
Example Sentence 1
The pilot briefed the COPTER ILS RWY 18 approach, noting the lower decision height available because it was a Copter SIAP.
Example Sentence 2
Copter SIAPs frequently permit lower decision altitudes than the corresponding airplane approaches to the same airport.