# Is there a name for change in attitude with respect to time?

I'm in the process of writing a flight-dynamics software program, but I'm not sure what to call the derivatives of the aircraft attitude. If it was in one dimension, they would be the "angular velocity" and "angular acceleration" respectively.

In aviation, is there a special name for these vectors?

• I love a programmer who's serious about naming his symbols. Thank you :) – Steve Apr 14 '16 at 17:04
• @Steve you're welcome. IMHO it's the most important part of the whole business. – Nicolas Holthaus Apr 14 '16 at 17:07
• In general 3d physics contexts, "angular velocity" is typically understood to be a 3-vector. I think what you have in mind would better be understood as "magnitude of angular velocity". (In one dimension, I'm not sure how to define rotation ;) but I think I understand what you mean.) – Praxeolitic Apr 15 '16 at 5:12
• @Praxeolitic Angular speed? – user253751 Apr 15 '16 at 6:53
• @immibis That phrasing would feel unusual to me but the intent would be obvious. I don't know if I'm in the minority there. – Praxeolitic Apr 15 '16 at 8:11

The components of attitude vector are called:

• yaw (or heading) is the angle of longitudinal (x) axis in horizontal plane,
• pitch is angle of longitudinal (x) axis from the horizontal and
• roll is angle of lateral (y) axis from the intersection of the yz (orthogonal to longitudinal axis) plane with horizontal.

And their derivatives are usually yaw-rate, pitch-rate and roll-rate. Second derivative names probably vary.

Regarding coordinate system, the first axis, called x, is always longitudinal and positive direction is forward. The second axis, called y, is usually lateral one, but positive direction is right in some systems and left in others. And z completes a right-handed coordinate system (so your vector products work the usual way), so z down if y points right.

Edit: I thought u,v,w is sometimes used as alias for the axis, but actually they are usually rather used for the velocity vector components.

• so extrapolating from this, attitude-rate would be a plausible name for a vector consisting of the changes in yaw, pitch, and roll? – Nicolas Holthaus Apr 14 '16 at 11:58
• @NicolasHolthaus, yes, you could call it that. – Jan Hudec Apr 14 '16 at 11:59
• I've never heard it called that, but it would make sense. The closest I've seen is "Rate of attitude change" or "Rate of change of attitude" - or specific to each eg "Yaw rate", "Rate of change of pitch", "Roll rate" etc. They tend not to be combined into "attitude rate", but I don't see why they couldn't be - semantically it makes sense. – Jon Story Apr 14 '16 at 12:48
• "Pitch rate", "roll rate" and "yaw rate" all seem logical for their derivatives. – StephenS Oct 16 '19 at 22:16

I know this is an old question, but I wanted to throw quaternions (and quaternion rates) and other non-Euler angle attitude (and rate) representations into the mix.

While yaw, pitch, and roll are frequently used for aircraft, quaternions are also used for aircraft and inertial guidance systems. Other attitude representations include principle rotation vectors, direction cosine matrices, classical Rodriguez parameters, and modified Rodriguez parameters. There are also a lot of other Euler angle representations available. All have their pros and cons including existence and type of singularities in the equations.