Arch, AAD, flare, AFF: every skydiving term explained simply — your cheat sheet before the other guides assume you already know them.
"What on earth is an AAD, and why does everyone talk about the 'arch' like it's obvious?" If you're just getting into skydiving, you'll quickly trip over terms in the other guides that are simply assumed knowledge. That's why this glossary exists: the Skydiving ABC — every key term explained briefly and casually, so from now on every guide makes sense from line one, whether it's about your first tandem jump or later about freefly and wingsuit flying.
Main canopy (Hauptkappe): Your "normal" parachute, deployed first on every jump — nowadays almost always a ram-air canopy: air flows into cells and forms an airfoil, just like an airplane wing, generating real lift. It gets repacked after every jump and is your standard tool for the canopy ride and landing.
Reserve (Reserve): Your second, completely independent parachute in the same rig, packed by a certified rigger and officially inspected. It only deploys if the main doesn't open cleanly — your backup for the backup.
AAD (Automatic Activation Device): A small device that measures altitude and fall rate and automatically fires your reserve if you don't react in time yourself. Like a smoke detector that pulls the fire extinguisher itself in an emergency — this net has driven the sport's fatality rate down massively over the decades.
Harness (Gurtzeug): The carrying and connection system that links you to your main and reserve canopies — and, on a tandem jump, to your instructor too. Every carabiner gets checked multiple times before the jump.
Drogue (Drogue): A small drag chute deployed on tandem jumps that keeps the combined fall rate of two people in the normal range — without it, two people together would fall noticeably faster than one person alone.
Slider (Slider): A small piece of fabric on the main canopy's lines that cushions the opening — it slides slowly down during deployment, turning a hard jolt into a smooth transition.
Toggles (Toggles): The two handles on your canopy's steering lines. Pull one, and you turn that way; pull both evenly, and the canopy slows down — all the way up to the flare just before landing.
Freefall (Freifall): The phase between exit and deployment — roughly 50 to 60 seconds from about 4,000 meters. Statistically the safest part of the jump; almost all injuries happen later, during the canopy ride and landing.
Terminal velocity (Terminal Velocity): The constant speed you stop accelerating past, once gravity and air resistance balance out exactly — around 193 to 200 km/h in belly position. This constancy is exactly what removes the falling sensation, since that roller-coaster feeling comes from accelerating, not from speed itself.
Arch (Arch): The stable base position in belly flying — hips forward, chest and pelvis toward the ground, head up, arms and legs slightly back. This shape stabilizes you automatically, the same principle that makes a shuttlecock always fly cap-first.
De-arch (De-Arch): The most common beginner mistake in freefall — collapsing your arch under stress, hunching your shoulders, or curling up. That flips your stable shape and sends you into a tumble; the fix is always the same — come back into the arch.
Head-down / head-up (Head-down/Head-up): Two advanced freefall orientations — head-first (head-down) or upright (head-up), instead of the classic belly position. Far less body surface faces the wind, so speeds climb sharply — up to 240 to 290 km/h.
Opening shock (Öffnungsschock): The brief, forceful deceleration as the canopy opens, taking you from around 200 km/h down to canopy-ride speed. Modern canopies cushion this via the slider, so a clean opening feels like a firm tug rather than a hit.
Canopy ride (Schirmfahrt): The calm phase after deployment, gliding under your open canopy toward the landing area — about five minutes on a standard jump. The roar of freefall goes quiet, and you fly instead of fall.
Flare (Flare): The critical braking motion just before touchdown — pull both toggles down fully, lift briefly increases, speed drops off, and you set down softly. Timing is everything: too early, and you balloon up then drop; too late, and you're still fast. A mistimed flare is the single most common cause of landing injuries.
Landing pattern (Landemuster): The planned approach path that brings you into the wind cleanly over the landing area — like an airplane's landing approach, with a parachute instead of landing gear.
PLF (Parachute Landing Fall) (PLF): The fallback technique for hard landings — touch down with slightly bent joints and roll to the side to spread out the impact instead of dumping it all into your ankles. You learn this in training; on a tandem jump, you don't need it yourself.
Tandem instructor (Tandemmaster): The experienced, licensed jumper you're firmly attached to on your first jump, who handles the entire procedure — exit, freefall, deployment, landing. Your only job: relax and enjoy the view.
Dropzone (Dropzone): The airfield or club that jumps operate from — your go-to spot for tandem jumps, training, and later your own solo jumps, operating under the rules of a body like the DFV or USPA.
AFF (Accelerated Free Fall) (AFF): The modern standard path to becoming a solo skydiver. Unlike older methods, you jump from full altitude in real freefall starting with your very first training jump, accompanied by instructors flying alongside you.
Ground course (Bodenkurs): The classroom and practice-simulation training before your first AFF jump — about 1.5 days in Germany, covering body position, altitude awareness, and safety-critical procedures before you need them under real stress.
DFV / USPA (DFV/USPA): The governing bodies for training and safety standards — DFV in Germany, USPA in the US. Both certify drop zones, instructors, and licenses.
License (Lizenz): The official proof that you're cleared to jump on your own — in Germany the aviator's license for sport parachutes, in the US the USPA's A-license. Both require at least 25 jumps plus a passed written exam.
Wind tunnel (Windkanal): Also called a tunnel — a vertical facility with strong airflow where you can practice the arch safely with instant coach feedback, without ever jumping from a plane. Many drop zones recommend a few tunnel minutes beforehand.
Pin this one line to the wall: "Shape holds you, not strength." Whether it's the arch, the flare, or the landing pattern, almost every term here comes back to the same idea — hold a stable shape and stay calm in it, instead of fighting the wind or the canopy. If you hit an unfamiliar word in another guide, just come back here — this glossary isn't going anywhere.
### What is the arch position in skydiving? The arch is the stable base position for belly flying: hips forward, chest and pelvis toward the ground, head up, arms and legs slightly back. It automatically keeps you stable belly-to-earth, the same principle that makes a shuttlecock always right itself in flight.
### What does AAD mean in skydiving? AAD stands for Automatic Activation Device, a small unit that measures altitude and fall rate and automatically fires your reserve if you don't react in time yourself. It's part of the dual safety net that has driven the sport's fatality rate down over the decades.
### What is a flare when landing a parachute? The flare is the braking motion just before touchdown: you pull both toggles down fully, lift briefly increases, speed drops off, and you set down softly. A mistimed flare is the most commonly documented cause of landing injuries in the sport.
### What's the difference between the main canopy and the reserve? The main canopy is your standard parachute, deployed first on every jump. The reserve is a completely independent second canopy, packed by a certified rigger, only used if the main doesn't open cleanly — your backup for the backup.
### What is AFF and how is it different from a tandem jump? AFF is the standard training path to a solo license: after a ground course, you jump solo from your first training jump, accompanied by instructors. A tandem jump instead attaches you to a tandem instructor who handles everything — the ideal first experience with zero prior knowledge.
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