What an Indoor Tunnel Removes From Wingsuit Risk

A wingsuit BASE jump gives a pilot somewhere between 20 and 90 seconds of actual flight, depending on the exit and the terrain. A mistake made in the first three seconds is often not correctable in the time that's left. There is no second attempt inside that jump — whatever the pilot does next has to be right the first time, because the ground is close and an instructor standing at the exit point cannot reach into the air and fix a bad line.

That is the arithmetic an indoor tunnel changes — part of it, honestly, not all of it.

1. The risk, stated plainly

The most carefully studied wingsuit BASE population — jumpers at Kjerag Massif in Norway, a well-managed site with experienced pilots — has produced a published fatality rate of roughly one death per 2,317 jumps. Broader studies across less controlled populations put the range considerably wider, from about 0.04% up to 1.67% of jumps ending in death depending on who is jumping and where. Wingsuits are involved in a disproportionate share of BASE fatalities relative to how many jumpers fly them, and the leading identified cause is not equipment failure — it is flight path miscalculation, misjudging where the body will actually go relative to the terrain.

Every number in that paragraph describes the same underlying problem: a wingsuit pilot builds the judgment that keeps them alive almost entirely from jumps that are themselves dangerous, at altitudes and closing speeds where a wrong decision is, by definition, unrecoverable. That is not a criticism of the sport. It is the reason a repeatable, correctable, indoor version of the same aerodynamics is worth building at all.

2. What repetition and correction actually buy

An indoor wingsuit tunnel does not simulate the jump — it isolates the one skill a jump can't teach safely in volume: body position and control response in a moving airflow, practiced enough times, with enough correction, that it stops requiring conscious thought under stress.

What that buys, concretely:

Instant correction instead of a post-mortem debrief. In the tunnel, an instructor is physically present in the same airflow, watching the same body position in real time, and can correct it before the pattern sets in — not review a helmet-camera video after the fact.
As many attempts as the skill needs. A wingsuit jump is, functionally, one attempt at whatever the pilot has practiced. A tunnel session is dozens of attempts at the same movement in a single hour, with the airflow held constant between them.
A tethered first exposure. New pilots don't fly free on their first sessions. They're on a leash — literally: a harness connected to the instructor by a line, so the airflow, the body position and the sensation of wingsuit flight are all real, while loss of control simply isn't possible yet.

3. What it doesn't buy — and why the honest answer matters

The tunnel does not teach terrain judgment, exit timing, canopy deployment under stress, or the decision-making that keeps a pilot alive when the flight path and the mountain are converging. Those skills only exist in the actual jump, and no amount of indoor practice replaces them. A facility, a federation or a training programme that claims otherwise will be caught out by the exact community it's trying to serve — wingsuit pilots know precisely what a jump asks of them that a tunnel session doesn't.

The honest claim is narrower and, for a serious buyer, more convincing: an indoor tunnel removes the part of the risk that comes from learning body control under jump conditions, while the pilot is still building that control. It does not remove the part of the risk that comes from the jump itself.

4. How the safety is actually built into the facility

Netting in multiple planes , not just below the flyer — a tethered or early-stage pilot who loses position needs a limit on displacement in more than one direction, not just a floor to land on.
A staged harness system , moving from a fixed, two-point tether to a longer working leash to fully free flight only once each stage is demonstrated — the same disciplined progression vertical wind tunnels use for skydiving students, adapted to the higher, more oblique airspeeds a wingsuit flight requires.
An entry and exit protocol into a moving airflow. Getting a pilot into and out of an inclined airstream safely, without a control-loss moment at the doorway, is itself a designed procedure, not an improvisation.
An instructor whose only job during that session is watching one flyer. Unlike the actual jump, where nobody can intervene once the pilot has left the exit point, the tunnel keeps a trained observer in continuous, corrective contact throughout.

5. What this means for your programme

Tell us who you're building this for — a federation training programme, a commercial facility, a hybrid of both — and we'll help you specify the netting, harness staging and airflow entry system that actually match the risk profile of the pilots who'll use it.

Sources and notes

Wingsuit BASE jumping fatality data (approximately 1 death per 2,317 jumps at the well-documented Kjerag Massif site; broader published fatality-rate range of roughly 0.04% to 1.67% per jump across different studied populations; flight path miscalculation as the leading identified cause of wingsuit BASE fatalities; wingsuits' disproportionate share of overall BASE deaths): consistent with Mei-Dan, O., Monasterio, E., Carmont, M., Westman, A., "Fatalities in Wingsuit BASE Jumping," Wilderness & Environmental Medicine, 2013, and subsequent published analyses of BASE jumping fatality statistics.
Indoor wingsuit tunnel training progression and safety systems (staged harness — an initial two-carabiner tether progressing to a longer tether line before free flight, netting, instructor-supervised progression through forward/backward/side-slide control before independent flying, typical progression time of 20 minutes to 2 hours before a first-time flyer is ready to fly free): consistent with a first-hand facility review of an operating indoor wingsuit tunnel (Skydivemag, "Review: Indoor Wingsuit Tunnel").
Related reading: our published articles on

engineering an inclined wind tunnel

and

the economics of an indoor wingsuit facility