Airfoil Data
NPL9615
NPL 9615 AIRFOIL
Wing Geometry Simulator
The NPL 9615 AIRFOIL is a thin 6.6% chord-thickness airfoil with a maximum camber of 3.3% at 32% chord, suited to high-speed UAVs, sailplane tip sections, and propeller blade design. At zero angle of attack the cambered geometry generates positive lift, giving an estimated zero-lift angle of -3.3°.
Thin airfoil theory predicts a stall angle near 11.9° and a peak lift-to-drag ratio around 54 at typical UAV and light-aircraft Reynolds numbers — useful benchmarks before running a full XFOIL or NeuralFoil polar. The slim profile minimises pressure drag at higher speeds but leaves limited spar depth for structural integration.
The NPL9615 appears in the wing design of at least 3 documented aircraft — notably by Westland. Its proven track record across rotorcraft designs makes it one of the more field-validated profiles in the UIUC database.
Designers evaluating the NPL9615 typically compare it against profiles of similar thickness: NPL 9660 AIRFOIL, AH21 7% version (Andrew Hollom), EPPLER 818 HYDROFOIL AIRFOIL, GOE 563 AIRFOIL, RG 14 10% AIRFOIL. The E487 is another reference profile frequently considered alongside it.
Aircraft Using the NPL9615 Airfoil
Westland 30 | Westland | NPL 9615 | NPL 9660 |
Westland Lynx | Westland | NPL 9618 | NPL 9615/9617 |
Westland Lynx (early blades) | Westland | NPL 9615 | NPL 9660 |
Wing lofting: 3 of these aircraft taper from NPL9615 at the root to a different tip section. Use the Tapered filter to isolate them, then click any tip airfoil link to compare geometries.
Related Airfoils
Engineers evaluating the NPL9615 frequently compare it against profiles with comparable geometric constraints. Below are the closest matches based on maximum thickness (6.6%) and max camber (3.3%).