Library · Destination briefing · Sion (LSGS), Valais, Switzerland
A 6° glide path that ends in a visual turn between mountains, an approach that is closed to crews without a specific qualification, a military training area that can reject the flight plan before it is filed, and 2,000 m of runway at the bottom of a valley. What a business jet operator needs to know before committing to LSGS. Written in English.
Orientation
Plenty of European airports sit in valleys. Sion is unusual because the terrain does not just raise the minima — it changes the shape of the procedure. The instrument approach to RWY 25 is flown on a 6.0° glide path, roughly double the standard, and it does not continue to the runway: it ends at D7.0 ISI, after which the pilot flies visually at 4.0°, offset from the runway axis, turning final over the town.
On top of that geometry, three things decide whether a flight to Sion happens at all: the qualification held by the crew and the operator, the military activity above the valley, and the weather, which here changes faster than a nine-hour TAF suggests.
This briefing is written for operators and crews planning a first visit with a mid-size or large business jet. It summarises how the operation works. It does not replace the AIP, the NOTAMs, the airport's own qualification material or the aircraft manuals — every figure below must be verified against the current publications.
Access
IFR approaches and departures at Sion are restricted to pilots, operators and aircraft holding the Sion airport qualification (AIP LSGS AD 2.22). The level held by the pilot in command decides which procedures and which minima are available.
| Level | How it is obtained | What it allows, in broad terms |
|---|---|---|
| Type A | Online exam | Day only, and only with substantially higher decision altitude, visibility and ceiling requirements |
| Type B | Ground briefing plus a check flight in the aircraft type, with a qualified instructor | Decision altitude driven by aircraft performance, lower visibility, and — with the high-performance departure and RWY 25 in use — night operations |
Recency matters: the qualification is tied to the operator and to the aircraft type, and it lapses if the airport is not flown for an extended period. Plan the qualification process weeks ahead of the trip, not days. Simulator credit is accepted for some renewals; the current rules are published by the airport.
A short-notice charter request for Sion, from an operator without the qualification, is not a scheduling problem — it is a no. The realistic alternatives are Geneva, Bern or Milan, with surface transport into the Valais.
Arrival
The approach is an IGS: an ILS-like installation whose localiser is deliberately offset 6.5° from the runway centreline, because the valley does not allow a straight-in path. The arrival is flown via the RNAV STAR to GRANA, then the procedure descends on the 6.0° glide path to D7.0 ISI, about 5.9 NM from the threshold.
From D7.0 ISI the flight continues visually on the offset track, passes abeam St-Léonard about 3.9 NM from the runway, and turns left onto the extended centreline just south of the Sion hospital, following PAPI 25 at 4.0° to landing. The PAPI beam is itself aimed 5° north of the runway axis, towards that offset path, so it is not seen from a conventional straight-in position.
Most transport-category jets have a maximum autopilot- or flight-director-coupled glide path well below 6°, and an approach-angle limit around 4.5° for the certified landing technique. In practice the steep segment is hand-flown, with a plan for the configuration, the rate of descent (roughly 1,300–1,700 ft/min at typical approach speeds) and the stabilisation gate. Check the figures in your own AFM and operations manual before accepting the approach.
Circling to RWY 07 exists, but it is limited to categories A and B, with a speed limit, special training and no night circling. A category C jet therefore plans on RWY 25 or diverts. Landing on RWY 07 is possible when the conditions allow it, but the runway is short for a heavy jet and there is no separate published missed approach — the low-performance departure profile serves as the visual reference.
Departure
At Sion, "performance" is not a certification class. It describes whether the aircraft can meet the climb gradient of the steep departure out of the valley, all engines operating.
| High performance (HP) | Low performance (LP) | |
|---|---|---|
| Climb requirement | About 13.3% to 10,100 ft, all engines | About 3.7% to 12,500 ft, after a visual segment |
| Runway | RWY 25 only | RWY 07 and 25 — from RWY 25 restricted to CAT A/B |
| Day / night | Day and night | Day only |
| Character | Instrument departure, no visual segment | Initial visual segment in the valley before joining the SID |
For a category C jet this usually resolves to the HP departure from RWY 25, or the LP departure from RWY 07 — which in turn is the limiting case for take-off weight, because the usable length and the terrain ahead are far less forgiving in that direction.
Airspace
The IFR procedures cross Swiss Air Force training areas. When those areas are active, the restriction is applied at flight-plan level through the non-standard planning zone LSNPZ1: IFR flight plans to Sion are rejected for that period, with a message pointing at a forbidden route — not merely delayed by a slot.
Check the AUP the evening before every flight, and the UUP again before departure. On a long sector, this is the single item most likely to change while the aircraft is airborne.
Weather
Runway de-icing at Sion is carried out by the military base rather than by the airport administration. Expect delays and build them into the slot and crew duty planning. For the aircraft itself, a heated hangar is available and is often the better option: it removes contamination without fluid and keeps the departure independent of the de-icing queue — subject to hangar availability, so it must be requested early.
On the ground
Sion has a business-aviation FBO with a private terminal, customs and immigration on site, crew and passenger facilities, and hangarage large enough for heavy business jets. Outside parking and heated hangar space are both available, as are the usual ramp services, lavatory and water servicing, GPU, cleaning and catering coordination.
Before every flight
Sources
Everything here is a summary. The authoritative documents are free of charge and should be consulted directly for every operation.