How should you phrase a clearance to instruct an aircraft to depart via a SID?

How should you phrase a clearance to instruct an aircraft to depart via a SID?

• A. <Callsign>, depart via <SID name>, climb/descend as assigned, maintain <altitude>.
• B. <Callsign>, fly via <SID name>, climb/descend as assigned, maintain <altitude>.
• C. <Callsign>, fly via <SID name>, climb/descend as assigned, maintain <heading>.
• D. <Callsign>, fly via <SID name>, climb/descend as assigned, maintain <altitude> and speed.

Answer: (B)

The key is to have the pilot execute the published departure route from the start. Saying “fly via” the SID name tells the pilot to follow the exact published SID path, including any initial altitude steps, from brake release onward, unless you assign different altitudes. The rest of the clearance—“climb/descend as assigned, maintain altitude”—ensures the flight adheres to the SID’s vertical constraints and keeps you in control of the flight level while the SID is in effect. Using a heading would ignore the published vertical and lateral path, and adding speed is only appropriate if you’ve explicitly assigned a speed. So the clearest, standard way to issue a SID clearance is to say: fly via the SID name, climb/descend as assigned, maintain altitude.

The key is to have the pilot execute the published departure route from the start. Saying “fly via” the SID name tells the pilot to follow the exact published SID path, including any initial altitude steps, from brake release onward, unless you assign different altitudes. The rest of the clearance—“climb/descend as assigned, maintain altitude”—ensures the flight adheres to the SID’s vertical constraints and keeps you in control of the flight level while the SID is in effect. Using a heading would ignore the published vertical and lateral path, and adding speed is only appropriate if you’ve explicitly assigned a speed. So the clearest, standard way to issue a SID clearance is to say: fly via the SID name, climb/descend as assigned, maintain altitude.