  We present a detailed spectroscopic study of line broadening in the A7IV-V
star Altair. In a wavelength region covering 690AA we reconstruct the overall
broadening profile taking into account more than 650 spectral lines. From the
broadening profile we determine the projected rotational velocity vsini, derive
an upper limit for the equatorial velocity v from the shape of the profile and
search for signatures of differential rotation. Our redetermined value of vsini
is (227 +-11)km/s. Measuring the first two zeros of the Fourier transformed
broadening profile yield no signatures of differential rotation. We derive that
Altair is seen under an inclination angle higher than i=68deg and it rotates at
v<245km/s or slower than 53% of breakup velocity on a 1sigma level.
