if(!AliExternalTrackParam::PropagateTo(p, covyz, covxyz, bz)) return kFALSE;
if(IsStartedTimeIntegral())
{
Double_t d = TMath::Sqrt((GetX()-oldX)*(GetX()-oldX) + (GetY()-oldY)*(GetY()-oldY) + (GetZ()-oldZ)*(GetZ()-oldZ));
if (GetX()<oldX) d=-d;
AddTimeStep(d);
if(!AliExternalTrackParam::PropagateTo(p, covyz, covxyz, bz)) return kFALSE;
if(IsStartedTimeIntegral())
{
Double_t d = TMath::Sqrt((GetX()-oldX)*(GetX()-oldX) + (GetY()-oldY)*(GetY()-oldY) + (GetZ()-oldZ)*(GetZ()-oldZ));
if (GetX()<oldX) d=-d;
AddTimeStep(d);