What is this orange container labeled "Flight kit wheel"?
Short answer
Corsair is a small airline, with a limited number of aircraft, serving airports in remote islands from Paris. For their economical survival their aircraft must keep a high operational ratio. However:

The airline may not have a maintenance facility at destination, either a owned facility or an agreement for maintenance services from another company locally based.

The facility may not have a satisfactory stock of spare parts for their aircraft or the required tools, and no possibility to obtain them in a very short time, even from their main base.


A common solution is to bring parts aboard, in particular MEL components. It's a balance between the cost to carry the container and the cost of extra wait time (better said by FreeMan in a comment below: The weight penalty is much lower than the wait penalty.)
These containers marked Flight kit, Fly away kit (FAK), Do not unload, Do not offload, etc, contain components or tools intended to remain on board and be used at the next stopover in case of necessity.
It's relatively common to see FAK for spare wheels. One of the reasons is when the crew executes a rejected take-off just prior to V1 speed on a large aircraft, brakes are subject to intense heating propagated to the wheels. Tires inflated with nitrogen at about 1,300 kPa (that's about 13 bars or 200 psi) could blow out beyond a certain temperature, causing damages/injuries. To prevent such explosion, wheels are fitted with fusible plugs melting to allow tires to deflate safely.
After such event, the plugs (and possibly the tire) have to be replaced. A common option is to change the whole wheel and perform inspection and repairs later. The kit contains the necessary tooling and parts for this replacement. This might take 30 minutes or so.
As FreeMan also mentions, sometimes the mechanic who is going to replace the wheel is onboard. That was the case (at the time the photo was shot) for Corsair for certain destinations where there is no permanent maintenance team at the stopover.
Corsair, a small airline serving remote locations
And actually Corsair is a small French airline based at Paris-Orly (LFPO), which has a taste of holidays. Their 5 aircraft take people from Paris to beautiful beaches on islands where airports don't have large maintenance facilities (Fort-de-France, Pointe-à-Pitre, La Réunion, Saint Martin, Palma ...)
For a long time Corsair used Boeing 747 Classic, meaning also less common spare parts.
In such a small airline, when an aircraft is grounded the schedule of the others is indeed disrupted, the shorter, the better.
Flight kit

Loading a flight kit, source Linde

Flight kit, Air France (translates to &quot;Fly away kit, do not unload&quot;). Photo by A380spotter at Flickr

Flight kit wheels in cargo hold (Malawi elections inspection). Source
Secured content
Parts in the container are secured to prevent them from moving.

AKN FSK container for Air France (Source)

(source)
See also: Do any aircraft carry spare parts for making repairs?

Corsair, formerly Corse Air, comes from Corse island (the birth place of Napoleon Bonaparte). Their business has known ups and downs several times, they are now part of Dubreuil Group. Corsair 747 had over time famous tail numbers: F-GSEA, F-GSEX, F-GSUN, F-GSKY, F-HLOV, etc.

F-GSEA landing at Princess Juliana. Source: JetPhotos, photo by Rogier van der Velde