With blockchain, airlines can achieve the following:
Automate operations that repeat: with smart contracts – electronic agreements that self execute according to predefined rules – airlines can automate billing among airlines and travel agents, determine loyalty settlements, sell travel insurance, pay airport taxes.
With blockchain, airlines may also improve the customer experience, and deploy loyalty tokens that do not require a prior partnership agreements. Blockchain based loyalty points earned with one airline may become universal. Most notable project here is by SITA Labs.
With blockchain, airlines may also simplify payments reconciliation. Please read the whitepaper on blockchain adoption by IATA.
Blockchain based marketplaces are used to streamline supply chain and remove intermediaries. Thus airlines may reduce their dependence on travel agents. A distributed app may allow customers access air tickets directly from multiple airlines, with creating an online travel agent.