Airline tailwind limits are usually about 10 knots (performance calculations account for 150% of TW component versus only 50% of HWC)
Landing with a moderate tailwind is an option if sunlight (or physical features of a strip) preclude another direction.
Be aware that very often, tailwind approaches 'feel' very much faster than the few knots of TW add to ground speed.
Other aspects that should be considered are:
- that faster 'feel' can cause the pilot to inadvertently reduce airspeed in order to restore the normal 'look' of the approach.
- Higher rate of descent in order to achieve a given approach slope can also feel unfamiliar and can cause a bit of 'ground shyness/early flare'.
- Any excess speed is amplified in terms of touchdown point
- Obvious performance calculations apply (see the first paragraph)
Finally, crosswinds that shear to a tailwind in the touchdown zone (you can monitor your GPS groundspeed/IAS difference as a rough guide) can wipe out precious airspeed just at the flare and surprise the pilot. Most common where the crosswind is 90 degrees from the left due to backing of the wind close to the ground. This also provides a fantastic excuse when you pile it in ("Oh yes, well, shearing tailwind, you see. Tricky!"). Don't use this as a reason to carry excess speed all of the time 'cos I get really wound up by the add-some-for-mum brigade!!!
Hope this is useful.