Preferred ATC Routes
When you're planning an IFR flight, PlaneWX automatically looks up the FAA's preferred routes for your city pair and shows you which one has the cleanest weather — before you even open your flight-planning app.
What Are Preferred Routes?
The FAA publishes a database of preferred IFR routes — routings that ATC commonly assigns between busy city pairs. Filing one of these routes reduces the chance of a reroute after departure, because you're already on a path ATC expects.
Route types
- HHigh altitude — Class A airspace (FL180 and above). Shown when your cruise altitude is FL180+.
- LLow altitude — Below FL180. Shown when your cruise altitude is below 18,000 ft.
- TECTower En Route Control — Short-haul routes handled entirely within TRACON. Typically within a single ARTCC region.
Data source & coverage
PlaneWX uses the FAA's official NFDC Preferred Routes database — the same source ATC references for published preferred IFR routes.
You may see fewer routes here than in ForeFlight. ForeFlight supplements the FAA database with routes pilots have actually filed, building a proprietary dataset over time. PlaneWX only includes routes officially published by the FAA. Both are valid sources — they just draw from different pools of data.
If no routes appear for your city pair, that's normal — not every corridor has published preferred routes. Flying direct or using your own routing is perfectly fine.
How It Works in PlaneWX
No button to click. Once you set both an origin, a destination, and select IFR as your flight rules, PlaneWX automatically searches for preferred routes in the background. If any are found, a Preferred ATC Routes panel appears directly in the trip creation form.
- 1
Enter origin and destination
Type at least 3 characters in both the Origin and Destination fields. The lookup runs automatically once both are set and your rules are IFR.
- 2
Set your cruise altitude
Altitude filtering is automatic. High-altitude (H) routes appear at FL180+; low-altitude (L) and TEC routes appear below FL180. Routes that don't match your altitude band are hidden.
- 3
Review the weather signals
Each route shows six weather indicators evaluated along the actual route waypoints at your cruise altitude, timed to when you'll actually be at each fix. Green = clean, amber = watch, red = significant hazard.
- 4
Click "Select"
The route's intermediate waypoints load directly into your waypoints field. Airways and SID/STAR procedure names are stripped — only the resolvable nav fixes are kept.
Weather Signal Icons
Each route displays six icons. Weather is sampled along the actual route waypoints — not just a straight line between airports — and is evaluated at your cruise altitude and timed to your estimated arrival at each fix.
Convective
Active SIGMETs for convective activity (thunderstorms, embedded convection) intersecting the route corridor.
AIRMET / SIGMET
Non-convective SIGMETs and G-AIRMETs for IFR conditions, mountain obscuration, low-level turbulence, or strong surface winds.
PIREP
Recent pilot reports within the route corridor and altitude band, weighted by recency and proximity.
Icing
Icing probability from CIP (Current Icing Product) and IFI (Icing Forecast) evaluated at your cruise altitude and ETA.
TFR
Temporary Flight Restrictions intersecting the route at your cruise altitude.
Turbulence
GTG-Forecast (Graphical Turbulence Guidance) probability at cruise altitude along the route.
Best Weather badge — the route with the fewest and least severe hazards across all six factors receives a green "Best Weather" badge.
Icons are color-coded: green = no significant hazard, amber = caution, red = significant hazard.
Altitude Filtering
PlaneWX filters routes to match your planned cruise altitude automatically. You don't need to do anything — changing the altitude selector in the trip form triggers a fresh lookup.
| Your cruise altitude | Routes shown | Routes hidden |
|---|---|---|
| FL180 and above | H, NAR (high altitude, oceanic) | L, TEC (low altitude) |
| Below FL180 | L, TEC, SHD, SLD (low altitude) | H (high altitude) |
If only high-altitude routes exist for your city pair and your planned altitude is below FL180, the panel will not appear. This is intentional — showing routes that don't match your altitude would be misleading.
Route Notes and Restrictions
Some routes include an FAA restriction note below the route string — for example:
These notes come directly from the FAA database. Common abbreviations:
What the Panel Won't Show
Fewer routes than ForeFlight
PlaneWX uses the official FAA NFDC Preferred Routes database. ForeFlight also incorporates routes pilots have filed over time through their app — a proprietary dataset that PlaneWX does not have access to. This means ForeFlight may show routes for city pairs where PlaneWX shows none. If the panel doesn't appear, that's normal; it doesn't mean anything is wrong with your routing.
VFR flights
Preferred routes are an IFR concept. The panel only appears when your flight rules are set to IFR.
Waypoints vs. full route
Clicking Select loads the intermediate nav fixes into your waypoints field. Airways (J42, Q15, V23) and SID/STAR procedure names (PAWLN1, SNIDR2) are automatically stripped — these aren't individual waypoints and can't be plotted. Only the fixes that exist in the FAA navigation database are added.
One-way routes
FAA preferred routes are directional. A preferred route from KORD to KMIA may not have a corresponding route from KMIA to KORD — the return leg may use a completely different corridor.