Does the coriolis force have an effect on the direction in which an aircraft travels? Suppose an aircraft is flying from Kenya (which lies on the equator) to UK (which lies in the northern hemisphere). Does the Coriolis force veer the aircraft to the right? Do pilots have to correct their flight route because of this?
Yes, the effect is there, and (auto-) pilots have to compensate for it, but the direct impact of the Coriolis force is insignificant compared to the impact of any wind forces.

This has been discussed on Physics SE: Coriolis force on bullet vs airplane

On the other hand side, the Coriolis force (seemingly) deflects moving air masses and causes the global wind patterns as we now them. Through the resulting wind forces on aircrafts, the Coriolis force has a very significant indirect impact on aircraft travel.