Ditching

Ditching (Emergency Landing on Water)

Ditching = a controlled emergency landing on water. The last resort when no suitable landing area is reachable. Rare in GA, but relevant for island flights, coastal flights, or over-water cross-country.

Source: FAA-H-8083-3B Chapter 17 Emergency Landing on Water; FAA-H-8083-25B Chapter 18; ICAO Annex 12 Search and Rescue; ICAO Annex 10 Vol III (ELT).

Before approach — preparation

1. Mayday and squawk 7700.
2. Position to SAR (Search and Rescue).
3. Life jackets for all occupants — donned, but NOT inflated before ditching (movement restriction in cabin).
4. Life raft prepared (if available).
5. Sea chart checked, wave direction observed.

Approach plan — wind and waves

Sea state / wave pattern analysis:

• Distinct waves (>1 m): land parallel to the wave crest (along the wave), possibly with slight wind offset.
• Few waves, strong wind: land into wind.
• Best: pick a wave-crest (between crests).

Special case: close to shore

• If the shore is in reach and suitable (beach, flat meadow): fly to shore and land on land.
• If the shore is in reach but NOT suitable (steep cliff, dense buildings, strong surf): ditch parallel to the shore — not perpendicular but along the coastline. This keeps the pilot within visual and reach distance of rescuers on land, and avoids impact with rocks/surf.

Touchdown speed and configuration

• Vstall + 5 KIAS — minimal above stall, as slow as possible.
• Full flaps (POH) — lowest stall speed, lowest touchdown speed.
• Nose up at touchdown — avoid nose-first immersion.
• Wings level — for a fixed-gear aircraft (e.g. Cessna 172) all three wheels should touch the water simultaneously → no asymmetric braking, no roll tendency.
• Power: leave residual power with engine running if possible (controlled touchdown); without power on engine failure.

Sequence at impact

1. Tail wheel (or tail cone) contacts first (nose-up attitude).
2. Tail drop into water → strong noise and deceleration.
3. Main body splashes through water, can flip.
4. Stop typically after 50–150 m.

Damage pattern

• Fixed-gear high-wing (Cessna): wheels dip first → strong braking moment, possible nose-over. → All three wheels simultaneously on water for symmetric deceleration.
• Low-wing: wings decelerate, often better controlled.
• Retractable gear: gear RETRACTED for ditching recommended (POH) — extended wheels pull the aircraft nose-down into the water.

Egress (exit)

Before touchdown:

• Doors unlatched (not open!) — impact pressure could jam them.
• Seatbelts tight.
• Brace position.

After touchdown:

1. Master OFF.
2. Door open immediately after stop.
3. Quick release seatbelt.
4. If submerging: cockpit fills with water in 30–60 sec — speed matters.
5. Inflate life jacket OUTSIDE the aircraft (not in cabin — entangles in tight spaces, blocks doors, hinders diving out). The vests are inflated only after exiting the aircraft — this is a critical detail.
6. Activate life raft.
7. Gather and keep distance from the sinking aircraft.

Survival time in water (cold/warm)

Cold water is killer #1 — hypothermia (see Subject 040).

• 0 °C: unconsciousness after 15–30 min, death after 30–90 min.
• 10 °C: unconsciousness after 1 h, death after 1–3 h.
• 20 °C: hours to days.

Water temperature Central Europe: Lake Constance winter 4–6 °C, summer 18–22 °C; North Sea 6–18 °C.

ELT (Emergency Locator Transmitter)

Meaning: ELT = Emergency Locator Transmitter — a beacon that transmits a radio signal after an accident, received by satellites and ground stations to locate the accident.

Activation:

• Automatically on mechanical impact (G-sensor, typical threshold 4-5 g) — standard equipment in modern aircraft.
• Manually by the pilot — cockpit switch (pre-crash during controlled emergency landing).

Frequencies:

• 121.500 MHz (analog) — historic emergency frequency, low power (~100 mW), signal not coded.
• 406 MHz (digital) — modern emergency frequency, 5 W transmission power, coded distress signal with unique aircraft ID and (with built-in GPS) position data.
• 243.0 MHz (military) — historic, mostly retired.

Mandatory equipment: per EASA NCO.IDE.A.170 an ELT is required for flights over sea/remote areas.

COSPAS-SARSAT system

COSPAS-SARSAT is the international satellite-based SAR detection system. It consists of two satellite constellations:

• LEOSAR (Low Earth Orbit SAR): polar satellites in low Earth orbit (~850 km altitude). Receive ELT signal, determine position via Doppler calculation at overpass.
• GEOSAR (Geostationary SAR): geostationary satellites at ~36 000 km altitude. Receive ELT signal instantly at activation (continuous coverage), but provide no Doppler position — only the GPS position from a 406-MHz ELT.

Data flow on triggered ELT (406 MHz):

1. ELT transmits coded signal with aircraft ID and (if GPS-capable) position.
2. Satellites (LEOSAR + GEOSAR) receive the signal.
3. Reception and control centres (LUT — Local User Terminal; MCC — Mission Control Centre) process the signal, determine position.
4. SAR coordination centres (RCC — Rescue Coordination Centre) receive position and aircraft ID, coordinate search and rescue.

→ Response time typically < 1 hour in Central Europe, often minutes near the coast.

Source: ICAO Annex 10 Vol III; COSPAS-SARSAT International Programme official documentation (https://www.cospas-sarsat.int).

Life jackets — mandatory

EASA Part-NCO: for overwater flight beyond 50 NM from shore, life jackets for all occupants are mandatory (NCO.IDE.A.175).