Practice Bore-Sight IFR for Descents on the Angles

Classic descent planning usually includes a time/distance/rate algorithm worthy of space shuttle re-entry or a that-looks-about-right guess. The latter often results in a screaming, idle path that ends with, Ahhh, Center, were gonna have a little trouble crossing STING at 3000.

Editorial Staff

Wednesday, December 03, 2014 at 12:00 AM ET

Verified

Key Takeaways:

The article introduces a "Flying Tigers gun sight" method for descent planning, advocating the use of the attitude indicator (AI) as a simple protractor to visually set descent angles, rather than complex algorithms or rough estimates.
For a standard 3-degree descent, pilots can calculate the required distance by tripling the altitude to lose, then set their pitch 3 degrees nose low on the AI, verifying the descent rate by halving their groundspeed and adding a zero.
For scenarios requiring different descent angles, the AI can be used to set a pitch by relating the altitude to lose to the distance (e.g., 50% of the 10-degree scale for 4000 feet in 8 miles equals 5 degrees nose low).

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Classic descent planning usually includes a time/distance/rate algorithm worthy of space shuttle re-entry or a that-looks-about-right guess. The latter often results in a screaming, idle path that ends with, “Ahhh, Center, we’re gonna have a little trouble crossing STING at 3000.”

Wouldn’t it be neat if you had a ring-and-bead gun sight like the old Flying Tigers P-40s to point the nose and smoke your descent target? In a way, you do.