Registration and permissions

Example 1 Who and which drones are ready on 16 November 2026?

The company has three pilots and three drones. Check readiness on the mission date and find documents expiring within 90 days after it (hypothetical data).

from datetime import date

mission = date(2026, 11, 16)
pilots = {                                   # pilot rights expiry dates
    "P01": date(2029, 3, 31),
    "P02": date(2026, 11, 10),
    "P03": date(2027, 6, 30),
}
drones = {                                   # (registration expiry, policy end date)
    "D1": (date(2027, 1, 20), date(2026, 12, 31)),
    "D2": (date(2026, 11, 30), date(2026, 11, 15)),
    "D3": (date(2026, 10, 1), date(2027, 5, 1)),
}

def ok(d):
    return d >= mission

good_pilots = [p for p, exp in pilots.items() if ok(exp)]
for d, (reg, ins) in drones.items():
    problems = [n for n, v in (("registration", reg), ("insurance", ins)) if not ok(v)]
    print(f"{d}: {'ready' if not problems else 'NOT ready: ' + ', '.join(problems)}")
print("pilots ready:", good_pilots)

soon = [(k, (v - mission).days) for k, v in pilots.items() if 0 <= (v - mission).days <= 90]
for k, (reg, ins) in drones.items():
    soon += [(f"{k} {n}", (v - mission).days) for n, v in (("reg", reg), ("ins", ins))
             if 0 <= (v - mission).days <= 90]
print("expiring within 90 days of the mission:", soon)

D1: ready
D2: NOT ready: insurance
D3: NOT ready: registration
pilots ready: ['P01', 'P03']
expiring within 90 days of the mission: [('D1 reg', 65), ('D1 ins', 45), ('D2 reg', 14)]

Drone D2’s registration is still valid, but its policy ends one day before the mission. D3’s registration has already expired. Pilot P02’s rights ended six days before the mission. The usable pairings are therefore P01 or P03 with D1, and renewal of D2’s registration and D1’s documents should start today. Advance warnings must allow for the time authorities take to process renewals.

Example 2 Every waypoint is outside, but the route still passes through

A survey route has five waypoints, and a four-sided restricted area lies in its path. Using local coordinates in metres, check with ray casting and segment intersection tests (hypothetical data).

zone = [(400, 200), (900, 150), (1000, 600), (550, 700)]   # hypothetical restricted area (m, local coordinates)
route = [(0, 0), (300, 100), (1100, 300), (1200, 750), (500, 800)]  # route waypoints

def inside(p, poly):
    x, y = p
    c = False
    for (x1, y1), (x2, y2) in zip(poly, poly[1:] + poly[:1]):
        if (y1 > y) != (y2 > y) and x < x1 + (y - y1) * (x2 - x1) / (y2 - y1):
            c = not c
    return c

def cross(a, b, c, d):
    def o(p, q, r):
        return (q[0]-p[0])*(r[1]-p[1]) - (q[1]-p[1])*(r[0]-p[0])
    return o(a, b, c) * o(a, b, d) < 0 and o(c, d, a) * o(c, d, b) < 0

edges = list(zip(zone, zone[1:] + zone[:1]))
for i, p in enumerate(route):
    print(f"waypoint {i} {p}: {'INSIDE zone' if inside(p, zone) else 'outside'}")
for i, (a, b) in enumerate(zip(route, route[1:])):
    hits = sum(cross(a, b, c, d) for c, d in edges)
    print(f"leg {i}-{i+1}: crosses zone boundary {hits} time(s)")

waypoint 0 (0, 0): outside
waypoint 1 (300, 100): outside
waypoint 2 (1100, 300): outside
waypoint 3 (1200, 750): outside
waypoint 4 (500, 800): outside
leg 0-1: crosses zone boundary 0 time(s)
leg 1-2: crosses zone boundary 2 time(s)
leg 2-3: crosses zone boundary 0 time(s)
leg 3-4: crosses zone boundary 0 time(s)

Checking only the waypoints would wrongly conclude the route is safe, but leg 1–2 crosses the edge twice, meaning it goes in and comes out. In real work, restricted areas should be expanded by a margin before checking, using the correct coordinate system of the source data. Many flight-planning tools check this, but planners must know what their tools do and do not check.