Whether Boeing or Airbus, the observation is the same: the so-called "services" trades in the aeronautical sector such as maintenance, aircraft repairs, spare parts, support to airlines are key vectors of growth! Indeed, it was for one or the other, these activities represented only a very small percentage of their activities: they had devoted themselves until now on their core business i.e. the design and production of planes. But new entrants made their appearance and came to shove the two mastodons. To keep one step ahead, the niches listed above are now strategic. The engine manufacturers had already understood it well and ensured comfortable margins. To make up for their delays, manufacturers use several methods; Repurchase of existing structures and also creation of department/Services in-house to respond to these new requests. The battle has begun, to follow!