Ditching procedure
Ditching = emergency landing on water. Always consider possible over water. Handbooks usually carry type-specific ditching instructions (TC AIM AIR 2.11.2).
Decide early: allows powered, stabilized approach with low descent rate and low airspeed, not an unpowered arrival.
Read the water:
- Primary swell: easiest to see from altitude. Can vanish behind secondary swell and wind chop on descent.
- Wind effect: shows only much lower, as whitecaps.
- Waves: move downwind except near shore. Swell direction unrelated to wind direction.
- Wind lanes (streaks): clearest looking downwind. Gusts ripple a smooth surface.
- Water looks calmer from the air than it is. Fly low, read drift for true wind.
Choose the heading:
- Never land into the face of the primary swell unless winds extremely high.
- Best heading usually parallel to the primary swell (TC AIM AIR 2.11.2(a)).
- Strong wind: compromise, more into wind, slightly across swell (2.11.2(b)).
| Water state (TP 1102) | Land |
|---|---|
| Smooth water or long swell | Into wind |
| Large waves or short-spaced swell | Parallel to swell, across wind (nosing into swell more dangerous than landing crosswind) |
| River | Downstream, unless strong wind dictates otherwise |
Gear:
| Gear | Effect |
|---|---|
| Retractable | Retract if able. Generally lands faster, greater deceleration forces |
| Fixed | Digs in on impact, stops the skip. Rapid deceleration, nose burrows only slightly |
Flaps (unless AFM says otherwise):
| Wing | Flaps |
|---|---|
| Low-wing | Retracted or extended only slightly |
| High-wing | Full |
Prep:
- Fasten seat-belts.
- Secure loose items.
- Keep flotation and hypothermia gear at hand.
- Brief passengers on post-impact roles.
Communicate:
- Broadcast on last frequency in use.
- Switch to 121.5 (many high-altitude carriers monitor it).
- Transponder 7700 (coastal radar picks it up at long range).
Cold water: lengthy exposure after ditching causes hypothermia (TC AIM AIR 2.11.2).
After impact:
- Expect double impact. Second (nose hits) is the greater one.
- Aircraft may swing if one wing touches first.
- Release seat-belts only once certain aircraft has stopped, then evacuate quickly.
- Doors open only after water entering cabin equalizes pressure.
- Unless badly damaged, aircraft will not sink immediately.
Trap: flap rule easy to reverse: low wing little or no flap, high wing full flap.
References
- TC AIM AIR 2.11.2
- TP 1102 (Emergency Procedures: Ditching)