Captain must notify dispatch of which scenarios?

• A. Holding, altitude changes greater than 6000' below FL310 or altitude changes greater than 4000' above FL310, route changes greater than 100 miles
• B. Only route changes greater than 50 miles
• C. Only altitude changes above FL350
• D. Only holding

Answer: (A)

When the flight crew must keep dispatch in the loop is about keeping the operation coordinated with fuel planning, timing, and routing changes. Holding, for example, changes how long you’ll be aloft and how much fuel you’ll need, so dispatch needs to know to adjust fuel reserves and arrival estimates. Significant altitude changes are also important to report because they alter fuel burn and exposure to winds; the thresholds you’re given reflect when a change is large enough to impact those calculations: below a certain cruising level, a change of more than 6,000 feet is sizable, while above that level a change of more than 4,000 feet is considered large enough to affect fuel planning and meteorological considerations. Route changes matter too when they exceed about 100 miles, since a longer detour or re-routing can change fuel requirements, diversion options, and ETAs. In short, the captain should notify dispatch whenever holding is involved, when a substantial altitude change occurs, or when a long route change occurs, because these events directly influence fuel planning, timing, and overall mission viability.