VFR-descent planner

Advisory route planning

Suggest a route that keeps a VFR-reporting airport within range at every point — ETOPS planning with a live-weather suitability predicate.

This tool suggests a route and shows margins. It never asserts that the weather will hold or that the route is authoritative. Stale or missing weather makes an airport unusable (fail-safe). Advisory / planning use only — not for navigation.

Plan a VFR-descent route

Range defaults to a 40 nm distance disk. Time-at-speed (range_min + speed_kt) and glide (glide_ratio + altitude_ft) modes are available as query parameters — see /v1/plan. Plans are capped at 600 nm great-circle — farther than that, use the trip planner.

No fully-covered route exists under the HARD constraint. Reason: disconnected. The origin reaches 998 node(s) over covered edges; the destination is reachable if coverage is ignored (a weather wall, not a missing connection).

Showing the SOFT minimal-exposure route below — the out-of-coverage segments are highlighted in red and quantified in the diversion table.

Local equirectangular projection, north up. Green fills are range rings (radius R) around suitable, VFR-reporting airports — their union is the covered region. 78 suitable airports in the region. Red segments are out of coverage. Coverage is tested by sampling the great circle every sampleSpacingNm; a covered verdict is exact only to ±sampleSpacingNm/2. An uncovered sliver narrower than the spacing can be missed. Advisory, not a defended claim.

Route · 20 legs · 605.0 nm · 117.5 nm exposed

#	From	To	Via	Dist (nm)	Coverage
1	KCDW	SLYNG	join	16.0 nm	covered
2	SLYNG	FJC	corridor	38.1 nm	covered
3	FJC	SLATT	V6	10.5 nm	covered
4	SLATT	SNOWY	V6	12.7 nm	covered
5	SNOWY	SEG	V6	41.9 nm	covered
6	SEG	COVOB	T356	14.0 nm	covered
7	COVOB	SWISS	T356	16.5 nm	covered
8	SWISS	FAVUM	T356	12.5 nm	covered
9	FAVUM	SCAAM	T454	17.5 nm	covered
10	SCAAM	WEVEL	Q186	22.3 nm	covered
11	WEVEL	MIGET	Q186	18.5 nm	covered
12	MIGET	TEESY	Q186	56.7 nm	covered
13	TEESY	SPYDY	Q186	59.0 nm	covered
14	SPYDY	DORET	Q29	40.2 nm	covered
15	DORET	ZORBO	J190	62.3 nm	covered
16	ZORBO	MUGOE	corridor	34.2 nm	covered
17	MUGOE	ERI	corridor	19.0 nm	exposed 4.4 nm
18	ERI	DOGGS	corridor	41.7 nm	exposed 41.7 nm
19	DOGGS	KNOOK	corridor	48.8 nm	exposed 48.8 nm
20	KNOOK	KPHN	join	22.6 nm	exposed 22.6 nm

Great-circle A→B is 388.1 nm; the planned route is 605.0 nm.

Diversion table (ETOPS-style)

Leg	Nearest suitable	Bearing (°)	Dist (nm)	Best cover	Margin (nm)
KCDW→SLYNG	KCDW	082°	0.0 nm	KMMU	29.9 nm
SLYNG→FJC	KABE	247°	4.5 nm	KDYL	2.2 nm
FJC→SLATT	KABE	129°	4.5 nm	KABE	27.7 nm
SLATT→SNOWY	KABE	108°	12.3 nm	KXLL	15.7 nm
SNOWY→SEG	KXLL	106°	24.3 nm	KLNS	▼ -8.3 nm
SEG→COVOB	KRVL	248°	28.3 nm	KRVL	5.5 nm
COVOB→SWISS	KUNV	248°	26.7 nm	KRVL	10.8 nm
SWISS→FAVUM	KUNV	218°	26.3 nm	KUNV	12.5 nm
FAVUM→SCAAM	KUNV	187°	21.4 nm	KUNV	12.5 nm
SCAAM→WEVEL	KFIG	221°	11.7 nm	KFIG	18.1 nm
WEVEL→MIGET	KFIG	140°	12.2 nm	KFIG	14.9 nm
MIGET→TEESY	KFKL	274°	1.2 nm	KFKL	▼ -5.2 nm
TEESY→SPYDY	KFKL	099°	11.6 nm	KYNG	2.9 nm
SPYDY→DORET	KPOV	202°	21.4 nm	KYNG	2.9 nm
DORET→ZORBO	KFKL	176°	20.8 nm	KFKL	▼ -1.3 nm
ZORBO→MUGOE	KFKL	210°	27.1 nm	KFKL	6.2 nm
MUGOE→ERI	KFKL	163°	30.5 nm	KFKL	▼ -3.0 nm
ERI→DOGGS	KFKL	143°	43.0 nm	KYNG	▼ -30.3 nm
DOGGS→KNOOK	KYNG	154°	70.3 nm	KPOV	▼ -61.8 nm
KNOOK→KPHN	KPOV	155°	101.8 nm	KPOV	▼ -76.9 nm

Per leg: the nearest suitable airport (bearing from the leg midpoint) and the single airport that best blankets the leg, with margin = R − its worst-point distance. A negative margin (▼) means no single airport covers the whole leg — the union still may; this is a per-airport lower bound, not an over-claim.

Snapshot & configuration

Nav cycle: 2607
Artifact: 66355e9d67a7
METAR reports used: 131 of 1036
Oldest observation: 2026-07-16T07:45:00.000Z
Range R: 40 nm → 40.0 nm
Weather minimum: VFR only · 75 min max age
Routing: mixed · corridor 30 nm
Constraint: hard
Min runway: 3000 ft
Coverage test: ±0.75 nm

This plan is reproducible from the values above: the same nav cycle, artifact, METAR observation times, and config yield the same route. Coverage is tested by sampling; a “covered” verdict is exact only to the tolerance shown. Weather is an ephemeral overlay — never merged into the navigation data.

Advisory / planning only · AIRAC cycle 2607 · not a certified navigation source.