The Air Force checkerboard

Checkerboard

A checkerboard or chequerboard is a board of chequered pattern on which English draughts is played. It is an 8×8 board and the 64 squares are of alternating dark and light color, often red and black....

is a national marking

Military aircraft insignia

Military aircraft insignia are insignia applied to military aircraft to identify the nation or branch of military service to which the aircraft belongs...

 for the aircraft of the Polish Air Force

Polish Air Force

The Polish Air Force is the military Air Force wing of the Polish Armed Forces. Until July 2004 it was officially known as Wojska Lotnicze i Obrony Powietrznej...

, equivalent to roundel

Roundel

A roundel in heraldry is a disc; the term is also commonly used to refer to a type of national insignia used on military aircraft, generally circular in shape and usually comprising concentric rings of different colours.-Heraldry:...

s used in other nations' air forces. It consists of four equal squares, of which the upper left and lower right are white, and the other two – red. These are surrounded by a border of inverted (counterchanged) colors 1/5 the thickness of a single square. Until 1993 the colors were reversed (ie red in the upper left).

Initially Polish military aircraft used varied signs in national colors (red and white), most frequently shields party per bend, pale, or red letter "Z" in a white square. The four-field, red-white checkerboard, was first used as a personal insignia of the Polish fighter pilot Stefan Stec. It was adapted as the Polish national roundel

Roundel

A roundel in heraldry is a disc; the term is also commonly used to refer to a type of national insignia used on military aircraft, generally circular in shape and usually comprising concentric rings of different colours.-Heraldry:...

 on 1 December, 1918.

In 1921 contrasting red and white border was added, but without specified dimension. In 1930 the ratio of border to fields was fixed at 1:5. According to current regulations, an additional gray border can be added, 1:6 the size of the field, if the insignia is on white or red background.

Between 1960s and 1980s the checkerboard (usually rotated 45 degrees) was also painted on turrets and hulls of Polish Army's tanks and APCs. The tradition was however discontinued.

In 1993 the color order was changed from red-dominant (red in the upper left) to white-dominant, to conform to heraldic

Heraldry

Heraldry is the profession, study, or art of creating, granting, and blazoning arms and ruling on questions of rank or protocol, as exercised by an officer of arms. Heraldry comes from Anglo-Norman herald, from the Germanic compound harja-waldaz, "army commander"...

 rules, though ignoring the 70-year old tradition. The first white-dominant checkerboard was used in 1940 in France.

Heraldic rules

In heraldry

Heraldry

Heraldry is the profession, study, or art of creating, granting, and blazoning arms and ruling on questions of rank or protocol, as exercised by an officer of arms. Heraldry comes from Anglo-Norman herald, from the Germanic compound harja-waldaz, "army commander"...

, the color of the charge

Charge (heraldry)

In heraldry, a charge is any emblem or device occupying the field of an escutcheon . This may be a geometric design or a symbolic representation of a person, animal, plant, object or other device...

 (in this case the white of the Polish eagle) takes precedence over the shield (red in the case of the Polish coat of arms

Coat of arms of Poland

The White Eagle is the national coat of arms of Poland. It is a stylized white eagle with a golden beak and talons, and wearing a golden crown, in a red shield.- Legal basis :...

). Because of this, white should be given the most "dominant" or dignified position in a heraldic design representing Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

. In the case of a checkerboard, this would be the upper left corner (Polish flag hung vertically should have white on the left for exactly the same reason). Note that this rule applies to the main color squares, not to the thin border, which is considered decoration.