PA.X.A.K4FAA-S-ACS-6C · Nov 2023Knowledge
Importance of drag reduction, including propeller feathering, gear and flap retraction,...
Importance of drag reduction, including propeller feathering, gear and flap retraction, the manufacturer's recommended control input and its relation to zero sideslip.
Bottom line
Drag from a windmilling propeller, extended landing gear, flaps extended beyond optimum, or any sideslip will reduce or even eliminate any modest single-engine performance that may exist. After the flaps and landing gear have been retracted and the propeller of the inoperative engine feathered, a key element in extracting best climb performance is minimizing sideslip.
Key numbers
| Number | What it means |
|---|---|
| approximately 2° toward the operative engine | Zero-sideslip bank |
| one and one-half to two and one-half degrees, varies among airplanes | Bank range |
| one-third to one-half of a ball width toward the operative engine | Ball position |
| 8–10° bank toward the operative engine | Ailerons alone |
FAA references
- FAA-P-8740-66, Flying Light Twins Safely — FAA-P-8740-66
- AFH ch. 13 (pp. 13-28–13-30) — FAA-H-8083-3C
- PHAK ch. 5 (p. 5-12) — FAA-H-8083-25C (2023)
Build understanding you can use
Unlock the full lesson and continue studying this element.
- Full teaching sections: What it is; Key points; Rules and numbers; How it is done
- Check your understanding with answers you can reveal
- Common mistakes paired with the FAA facts that correct them