View Full Version : AOA for Best Rate of Climb

10-11-2010, 10:51 PM
I saw a post on the old forum asking about the AOA for best rate of climb. I understand that best angle is indicated at L/D Max, but have never read anything in the manuals about what to look for at Vy. Any thoughts?

Craig Schwartz
Santa Rosa, CA

Trevor Conroy
10-13-2010, 12:52 PM
From our manual...

Total Drag Curve
As indicated in Figure 2, adding both induced drag and parasite drag together forms a "U" shaped total drag curve. At the airspeed where induced drag equals parasite drag, the total drag is at a minimum, and the ratio of lift to drag produced is at a maximum. This is referred to as "L/DMAX".
Ignoring propeller effects, L/DMAX generally has great significance for high performance aircraft. If drag is at a minimum and thrust equals drag, then the fuel flow will also be at a minimum; therefore, the aircraft has maximum endurance at this airspeed. Maximum climb angle (Vx) is achieved at L/DMAX because thrust available in excess of drag is at a maximum. This is not the case with maximum rate of climb (Vy). In case of a flameout or engine failure, maximum glide range is also obtained. If L/DMAX equals 15:1, then the glide ratio is also 15:1.
Ignoring propeller effects:
• Maximum Endurance occurs at L/D max.
• Maximum Climb Angle occurs at L/D max.
• Maximum Glide Range occurs at L/D max.