No Aircraft
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Confusion; Situational Awareness
No Specific Anomaly Occurred All Types
General None Reported / Taken
Chart Or Publication; Human Factors; Procedure
The OLM ARRIVAL in SEA has had mandatory crossing altitudes and speeds changed multiple times in the last several years by NOTAM. Some of the NOTAMs have lasted well over a year. Several weeks ago the mandatory crossing altitude at ARVAD was again changed by NOTAM. Now it has been changed back.We have been told the reasons for the changes were to see how the new altitudes and speeds worked to help the flow of traffic. While this in itself is good; I feel it is extremely dangerous to be changing altitudes and speeds on arrivals and departures in order to see how the traffic flow works. The NOTAMs for these things are buried in amongst many other NOTAMs and can be difficult to find. Additionally; not all arrival NOTAMs are grouped together but can be spread out between FDC NOTAMs or hidden in between other unrelated regular NOTAMs. This is a huge threat; and I believe an invitation for an accident. If an altitude or speed needs to be changed for some urgent reason; then issue a NOTAM. Other than that; revise the approach plate! There should never be an altitude or speed change on an arrival or departure by NOTAM unless it is an emergency change. In all other cases changes should be made only by issuing new approach plates. Changing a speed; or especially a mandatory altitude; by NOTAM is unacceptable and is a huge threat.
An air carrier Captain reported his displeasure at what he believes to be unnecessary NOTAMed changes to crossing altitudes on the OLYMPIA STAR to SEA. He believes that anything other than emergency changes to airways procedures should be introduced via a chart revision.