Xoar International LLC PJP-T-L 40x10 Precision Pair Carbon Fiber

The Xoar PJP-T-L 40x10 is a two-blade carbon fibre propeller from Xoar International LLC (USA) from the PJP-T-L range for very large heavy-lift multicopters. It measures 40 in in diameter with a 10 in pitch and, like the smaller sizes of the range, is supplied as a precision pair in which both propellers are matched to each other.

The 10 in pitch is a quarter of the diameter: very flat, laid out for hovering with a large load at low rotational speed. The weight of 380 g is the average weight per propeller, with a tolerance of 15 g. The bore is 10 mm, and the round hub measures 65 mm by 30 mm. As the recommended upper bound for speed Xoar gives 4,000 rpm; the value is comparable only within this manufacturer. The propeller does not fold.

At 40 in blade-tip speed governs noise and losses; it grows with diameter and rotational speed, which is why the upper bound is so low. Legally the aircraft counts: heavy multicopters operate at the edge of the open category, which ends at 25 kg take-off mass including payload; above that the specific category applies, with a risk assessment of the operation. In both cases the geographical zones in which flying is restricted or prohibited have to be observed.

A spinning 40 in blade demands distance from people and a de-energised drive before any work at the propeller. On selection: the 10 mm bore must fit the motor shaft or the driver. Frayed edges, nicks at the tip and leading edge and dull-sounding areas point to delamination and are reasons to replace. At this length imbalance loads the motor bearings and structure particularly; the matched pair is replaced together.