For an instrument departure (SID) what is the procedure design gradient (PDG)?

• A. 3.3%
• B. 2.5%
• C. 3.5%
• D. 5%

Answer: (D)

The main idea is that the procedure design gradient (PDG) is the climb gradient used when designing an instrument departure to guarantee obstacle clearance along the SID. It is expressed as a percent, meaning vertical gain per horizontal distance. A PDG of 5% translates to about 304 feet gained per nautical mile (roughly 50 feet of climb per 1,000 feet of forward distance). This value provides a safety margin for obstacle clearance and engine-out performance early in the departure.

Therefore, 5% is the standard PDG used for instrument departures, making it the best choice. The other options represent smaller gradients that do not meet the typical SID design standard.