One of the main problems faced by fast-growing airlines is the challenge of 'parking full.' As the demand for air travel increases, airlines are adding more routes and increasing their fleet size to meet the demand. However, this puts pressure on airport infrastructure, and finding available gates and parking spaces can be a challenge.

• Limited airport infrastructure: Fast-growing airlines may not have access to enough gates or enough ramp space to park their aircraft. This can lead to delays, increased fuel consumption, and scheduling problems.
• Increased competition: With more airlines competing for limited airport resources, fast-growing airlines may struggle to secure the necessary gate space and parking space, particularly during peak travel times.
• Cost: Parking an aircraft at an airport for an extended period can be expensive, leading some airlines to search for alternative locations to park their planes. However, the cost and logistics of moving aircraft to other airports can be prohibitive.
• Operational challenges: When airports are at or near capacity, air traffic control systems can become overwhelmed, leading to air traffic delays and increased congestion on the ground.

Overall, the 'parking full' challenge faced by fast-growing airlines is a multifaceted, complex problem that requires cooperation between airlines, airports, and government agencies to find workable solutions.