Which GPWS modes produce a "whoop whoop, pull up" alert?

• A. Mode 1 and 2
• B. Mode 3 and 4
• C. Mode 5 and 6
• D. Mode 6 and 7

Answer: (A)

The alert pattern “whoop whoop, pull up” comes from the GPWS warning logic that watches for the most urgent threats to terrain proximity. The two modes that trigger this two-tone warning are the ones that monitor how fast you’re descending and how quickly you’re closing on terrain ahead. If the airplane is losing altitude rapidly or closing on terrain at an unsafe rate, the system sounds the distinctive two-tone cue and issues the “pull up” command to prompt an immediate climb. Other GPWS modes look at different situations and produce other warnings, so they don’t use this same urgent two-tone alert.