F3K Gear

As a minimum you will need:-

If you want to compete seriously at national or international level, you will need:-

Some extra gliders - it is not uncommon for you to need to swap over to a second or third glider during a competition due to damage or failure or preference (if you have a particular model suited to specific flying conditions).

In the wold championships, for example, you need a minimum of 3 models to enter with most pilots entering the maximum of 5 models.
For local competitions, two models should suffice, unless you have bad luck.
In most serious competitions, it is not uncommon for one of the pilots to sustain damage to their model. But this is part of the game and a risk we happily fly with. The sources of damage / failure include loss of control due to radio failure, due to pilot error or due to gear failure.
Pilot error may be due to flying the wrong plane - it sounds silly but it happens to the best of us, getting disoriented - this happens to the less experienced pilots more often than not, mid-air collisions, heavy landings and hitting obstacles.
Gear failure may be due to a servo, battery or radio may failing. Some times a servo, rod or horn comes adrift in flight too.

Ballast for your models - ballast are weights which you put into your model to make it heavier, to fly in stronger winds.
Model repair tools and materials

It's useful to carry a small kit to the flying field for quick repairs
For bigger repairs back at your 'workshop' (assuming you are going to undertake plane repairs yourself) you will need to stock up on some tools and materials like epoxy, resin, fibreglass, carbon fibre, etc.

F3K South Africa