Here is the full list of all 39 Piloteer achievements.
Do a backflip
Land in the water
Land successfully 10 times
Rank up to a Cadet
Do a front flip
Crash 10 times
Crash once
Land successfully once
Crash 50 times
Crash 100 times
Crash 500 times
Crash 1,000 times
Rank up to a Captain
Rank up to a Major
Rank up to an Aviator
Rank up to a Piloteer
Rank up to a Platinum Cadet
Rank up to a Platinum Captain
Rank up to a Platinum Major
Rank up to a Platinum Aviator
Rank up to a Platinum Piloteer
Do 10 backflips
Do 100 backflips
Hit 10 bird while in the air
Hit 50 birds while in the air
Hit 100 birds while in the air
Do 10 front flips
Do 100 front flips
Land successfully 50 times
Land successfully 100 times
Land successfully 500 times
Land successfully 1,000 times
Get hit by a plane's propellors
Land inside the back of the motor boat at The Pier
Land on a ferris wheel car, then let it take you around a full cycle
Get hit by a car while standing up
Fly as high as possible
Stay in the air for an entire minute
Fly between the basket and the hot air balloon