No a pilot’s monthly salary is not strictly fixed by the airline it’s based on a more complex structure.
Airlines typically use a base pay model, which blends an hourly rate with a guaranteed minimum number of flight hours per month. For example some airlines guarantee around 70–75 flight hours per month, ensuring pilots take home a predictable income even if actual flight time fluctuates because of weather delays or scheduling changes. The airline pays for those guaranteed hours regardless of whether the pilot flies them, making the salary relatively stable.
However many pilots especially line holders (those with assigned monthly schedules) often exceed the guaranteed hours turning them into actual earnings based on hourly flight pay. So while there’s a baseline the actual monthly earnings can vary.
Additionally pilots may receive various extras such as per diem allowances for time away from base, bonuses (sign-on, retention performance-related) and profit-sharing or premium flight pay.
For instance, at budget airlines like Spirit Frontier or Allegiant in the U.S. pilots have base salaries set via contractual monthly guarantee (line) plus per diem holiday pay, and premiums—so their actual pay can considerably exceed the baseline.
summary
while there is a minimum guaranteed monthly salary, a pilot’s true monthly earnings are not fixed—they fluctuate based on actual flying hours allowances bonuses and other incentives.