How is the MEA/MSA for a diversion determined?

How is the MEA/MSA for a diversion determined?

• A. Ignore obstacles until touchdown
• B. Use the published IFR minimum enroute altitude
• C. Assume MSA equals 2000 ft above airport elevation
• D. Plot the diversion on a VFR chart, then within a 5-mile radius check for height obstacles; if over non-mountainous terrain, add 1000 ft to that elevation to determine the MSA

Answer: (D)

The key idea is to ensure you have safe clearance from terrain and obstacles around the diversion point. For a diversion, the MSA is determined by looking at the terrain near the diversion and setting an altitude that guarantees obstacle clearance in that local area, rather than relying on the route’s MEA or airport-based figures. You plot the intended diversion on the chart, then examine obstacles within a close radius (about 5 miles) of that point. Find the highest obstacle within that radius and add 1000 feet if the surrounding terrain is non-m mountainous. That gives you the MSA for the diversion. If the terrain is mountainous, you would add 2000 feet to provide the necessary clearance. So, this approach directly ties the MSA to local terrain around the diversion, ensuring you have a safe buffer as you rejoin a route or proceed to a diversion airport. Ignoring obstacles, using only a published enroute minimum, or simply basing it on airport elevation would not guarantee sufficient nearby clearance.

The key idea is to ensure you have safe clearance from terrain and obstacles around the diversion point. For a diversion, the MSA is determined by looking at the terrain near the diversion and setting an altitude that guarantees obstacle clearance in that local area, rather than relying on the route’s MEA or airport-based figures.

You plot the intended diversion on the chart, then examine obstacles within a close radius (about 5 miles) of that point. Find the highest obstacle within that radius and add 1000 feet if the surrounding terrain is non-m mountainous. That gives you the MSA for the diversion. If the terrain is mountainous, you would add 2000 feet to provide the necessary clearance.

So, this approach directly ties the MSA to local terrain around the diversion, ensuring you have a safe buffer as you rejoin a route or proceed to a diversion airport. Ignoring obstacles, using only a published enroute minimum, or simply basing it on airport elevation would not guarantee sufficient nearby clearance.