Chap 3: Aircraft's Nationality and Registration Marks

Annex 7: Aircraft nationality and registration marks

01 Definitions

1.1 Classification

• Aircraft

  • Lighter than air

    • Non-powered: Free balloon, Captive balloon

    • Powered: Airship

  • Heavier than air

    • Non-powered: Glider

    • Powered: Aeroplane, Rotorcraft (Autogyro, Helicopter), Ornithopter

1.2 Definitions

• Aeroplane: Power-driven heavier-than-air aircraft deriving lift mainly from aerodynamic reactions on surfaces fixed during flight conditions.

• Aircraft: Any machine deriving atmospheric support through air reactions, excluding ground reactions.

  • Lighter-than-air aircraft: Supported mainly by buoyancy.

  • Heavier-than-air aircraft: Supported primarily by aerodynamic forces.

  • Remotely piloted aircraft (RPA): Unmanned aircraft piloted remotely from a control station.

• State of registry: The state where the aircraft is officially registered.

02 Nationality marks, common marks, and registration marks

• Nationality/Common Marks: Letters/numbers assigned by states or international agencies. Selected from radio call-signs assigned by the International Telecommunications Union (ITU). States must inform ICAO upon selection.

• Common aircraft marks:
  Assigned by ICAO to international operating agencies for aircraft registration. These marks come from the nationality call-sign series designated by ITU. Common marks precede registration marks.

Examples of nationality marks:

• Angola → D2

• China → B

• Finland → OH

• Liechtenstein → HB

• Nationality marks must follow ITU call-sign allocations and precede the registration mark.

• If the first character of a registration mark is a letter, it must be preceded by a hyphen.

  • Example: OH-LZA, B-3429

• Registration marks can consist of letters, numbers, or both, assigned by the state of registry or a common mark registering authority.

• Marks must not resemble:

  • 5-letter International Code of Signals

  • 3-letter “Q” codes

  • SOS (distress)

  • XXX (morse urgency)

  • PAN (urgency)

  • TTT (safety)

03 Marks location

• Nationality, common, and registry marks must be painted or affixed to the aircraft using reliable, durable methods.

• They must remain clean and clearly visible.

3.1 – Lighter than air aircraft

• Airship:
  Marks should be either on the envelope or tail-unit.

  • If on the envelope: placed horizontally on both sides and on the upper surface of the vertical meridian.

  • If on the tail-unit: placed on both vertical and horizontal surfaces.

• Balloons:
  Marks should appear on both sides near the equator of the balloon.

  • Exception: unmanned balloons → marks placed on identification plate.

3.2 – Heavier than air aircraft

3.2.1 – Wings

• Marks should be painted on the lower surface of one wing.

• Preferably on the left side, equidistant from the leading and trailing edges.

• The top of the letters should face the leading edge.

• 

3.2.2 – Fuselage (or equivalent structure) and tail-unit

• Marks should appear on both sides of the fuselage, between the wing roots and the tail-unit, or on the upper halves of both sides of the tail-unit.

• If the tail-unit includes multiple vertical stabilizers, the marks must be on the outermost stabilizers' external surfaces.

04 Mark Dimension

4.1 – Lighter than air aircraft

• Except for unmanned balloons (where dimensions are determined by the state of registry), the minimum letter height must be 50 cm.

4.2 – Heavier than air aircraft

4.2.1 – Wings

• Minimum letter height on wings: 50 cm

4.2.2 – Fuselage (or equivalent structure) and tail-unit

• Minimum letter height: 30 cm

4.3 – Type of writing

• Letters must be in ROMAN BLOCK style; numbers must be ARABIC numerals without decorative elements.

• Width of each character and hyphen length must be 2/3 of the character height.

• Line thickness must be 1/6 of character height, in a color contrasting sharply with the aircraft's skin.

• Characters must be spaced by gaps at least equal to 1/4 of their width.

• A hyphen is counted as a character

05 REGISTER AND CERTIFICATE OF REGISTRATION

• Each ICAO member state or common mark registering authority must maintain an up-to-date register of all aircraft, containing the information from the certificate of registration.

• According to Article 29 of the Chicago Convention, all aircraft used for international navigation must carry their certificate of registration on board.

• The format of the certificate is determined by the registering state or authority. If not written in English, an English translation must be included.

For unmanned balloons, the register must include:

• The date, time, and place of launching

• The balloon type

• The operator’s name

06 IDENTIFICATION PLATE

• Every aircraft must have an identification plate that displays at least the nationality mark (or common mark) and the registration mark.

• The plate must be made of fireproof metal or equivalent material.

• It must be affixed in a visible, accessible location, typically near the main entrance of the aircraft.

• For unmanned balloons, it should be placed visibly on the outside of the balloon.