For closely spaced RNAV SID departures, what separation combination is specified for less than 2,500 ft apart?

• A. 1 mile; 10 degrees
• B. 2 miles; 15 degrees
• C. 0.5 mile; 5 degrees
• D. 3 miles; 20 degrees

Answer: (A)

When two RNAV SIDs are very close to each other, keeping them apart relies on both how far apart they are laterally and how quickly their paths diverge. If their initial positions are less than 2,500 ft apart, the standard way to maintain safe separation is to require one mile of lateral separation plus a ten-degree difference in their track or course. That combination gives enough offset right at departure and then causes the flight paths to diverge fairly quickly as the airplanes proceed, reducing the risk of encroachment.

This is chosen because it thoughtfully balances practicality and safety: the one-mile lateral gap is the minimal, achievable separation at the outset, and the ten-degree course change ensures the routes fan apart promptly. The other options either under- or over-estimate the separation needed for closely spaced SIDs, which could either fail to prevent close proximity or impose unnecessary maneuvering.