Process for the display of the attitude of an aircraft or spacecraft for aiding piloting or flying in space, which comprises the steps of:
- defining a spherical celestial canopy (C) centered on the center of gravity (G) of the aircraft (A), having a polar axis oriented towards the celestial north (N) and an equatorial plane (E) perpendicular to said polar axis and passing through a vernal reference marking point (.gamma. 50);
- defining reference marking parallels (M,P) and meridians on said celestial canopy;
- defining a reference mark (G,X,Y,Z) with orthogonal axes centered on the center of gravity (G) of the aircraft, a first axis (X) of said mark passing through the vernal point (.gamma. 50), a second axis (2) coinciding with the polar axis and a third axis (Y) being perpendicular to the first and second axes;
- defining a specific reference mark (G, X.sub.A, Y.sub.A, Z.sub.A) of the aircraft with three orthogonal axes, having for its origin the center of gravity (G) of the aircraft, a first axis (X.sub.A) directed along a longitudinal axis of the aircraft, a second axis (Z.sub.A) located in a plane of symmetry passing through the longitudinal axis of the aircraft and a third axis (Y.sub.A) perpendicular to the first and second axes of the specific reference mark;
- defining the attitude of the aircraft by calculating the cardan angles, (roll (.phi.), pitch (.theta.) and yaw (.psi.) ) of the aircraft with respect to the reference mark (G,X,Y,Z);
- using the values of the cardan angles (.phi., .theta., .psi.) for displaying, on a screen (1) of display means (2), the image obtained in a plane perpendicular to the first specific axis (X.sub.A) of a net formed from portions of meridians and parallels (M,P) of the celestial canopy projected onto said plane within a piloting or flying circle (B), displayed on a screen (1) and centered on the first axis (X.sub.A) of the specific reference mark;
- displaying a cruciform reticule (7,8,9) with two perpendicular segments (7,8) intersecting the flying circle, intersecting in the center (O) of the circle (B) and corresponding respectively to the second and third axes (Z.sub.A, Y.sub.A) of the specific reference mark, the position of the center (O) of the circle respectively representing the yaw and pitch angles referenced in longitude and latitude, respectively with respect to a meridian portion (M) and a parallel portion (P) of the net;
- and displaying the value of the roll angle (.phi.) in a scale (10) of numerical values, close to the intersection of the flying circle (B) with the segment (7) of the reticule corresponding to the second axis (A.sub.A) of the specific reference mark.