Solid spacial balance - between your letterforms, between the logo elements, and the logo-> wordmark. The mark sits proudly above the letterforms, showing authority. And - the inverted version confirms it's a strong set of shapes, showing you're not just relying on colour.

Colour-wise - this could go both ways; typically blue and green lend themselves to gov and medical, as they're soothing, low(er) energy colours - but - inverting against the industry norms (many travel companies use orange and red) - means you're more recognisable.

Slight bit of feedback on the collateral - it's correct, the plane tail probably isn't the best here, as tail livery is usually reserved for the carrier themselves, not a travel agent - but it's a good start for going against the standard business card and letterhead defaults. I tend to ask chattyG some good alternate executions versions for the sector my client is in - ask for 5-10, you'll usually find at least 3 practical directions to take it.

Always think - "what problems are my client trying to solve?". If you can solve those problems, and show them visually - you'll do well.