The Gaia Radial Velocity Spectrometer ( RVS ) provides a sample of 7 224 631 stars with full six-dimensional phase space information .
Bayesian distances of these stars are available from the catalogue of Schönrich et al .
( 2019 ) .
We exploit this to map out the behaviour of the velocity ellipsoid within 5 kpc of the Sun .
We find that the tilt of the disc-dominated RVS sample is accurately described by the relation \alpha = ( 0.952 \pm 0.007 ) \arctan ( |z| / R ) , where ( R,z ) are cylindrical polar coordinates .
This corresponds to velocity ellipsoids close to spherical alignment ( for which the normalising constant would be unity ) and pointing towards the Galactic centre .
Flattening of the tilt of the velocity ellipsoids is enhanced close to the plane and Galactic centre , whilst at high elevations far from the Galactic center the population is consistent with exact spherical alignment .
Using the LAMOST catalogue cross-matched with Gaia DR2 , we construct thin disc and halo samples of reasonable purity based on metallicity .
We find that the tilt of thin disc stars straddles \alpha = ( 0.909 - 1.038 ) \arctan ( |z| / R ) , and of halo stars straddles \alpha = ( 0.927 - 1.063 ) \arctan ( |z| / R ) .
We caution against the use of reciprocal parallax for distances in studies of the tilt , as this can lead to serious artefacts .