I have a friend who was a flight attendant for the oldest Mexican airline, and she indeed told me how sometimes, when there's a critical system malfunction before a flight, often managers call the pilots privately and offer a bribe to fly the plane with that malfunction. The pilot can refuse the offer without any problems or losing the job, but it's a bit scary to think that's there's corruption at that level.

Fortunately, planes are extremely robust and somehow Mexican airlines have an excellent safety record.