What is the Vmo below 8,000 feet?

What is the Vmo below 8,000 feet?

• A. 305
• B. 320
• C. 270
• D. 350

Answer: (C)

Vmo is the maximum operating speed in knots indicated, set to keep the airframe within its structural limits. It isn’t the same at every altitude—the limit is intentionally reduced at low altitudes to account for the higher air density, which increases dynamic pressure for a given airspeed and gust loads. For this aircraft, below 8,000 feet the Vmo is 270 knots, providing a safe margin against those loads in dense air. Above that altitude, the limit typically increases (and eventually gives way to the Mach limit at higher altitudes). So, 270 knots is the appropriate low-altitude limit. The other numbers would apply to different altitude bands, not this below-8,000-foot case.

Vmo is the maximum operating speed in knots indicated, set to keep the airframe within its structural limits. It isn’t the same at every altitude—the limit is intentionally reduced at low altitudes to account for the higher air density, which increases dynamic pressure for a given airspeed and gust loads. For this aircraft, below 8,000 feet the Vmo is 270 knots, providing a safe margin against those loads in dense air. Above that altitude, the limit typically increases (and eventually gives way to the Mach limit at higher altitudes). So, 270 knots is the appropriate low-altitude limit. The other numbers would apply to different altitude bands, not this below-8,000-foot case.