Answer:
The upward acceleration, a = 21.6 m/s²
Step-by-step explanation:
Given,
The mass of the helicopter, m = 5000 Kg
The net force on the helicopter, F = 59000 N
The net force acting on the helicopter is 
 F = ma + mg
Where, 
 mg - the force due to gravitation
 a - the upward acceleration of the helicopter
Solving the above equation for 'a'
 

Substituting the given values in the above equation
 

 a = 21.6 m/s²
Hence, the upward acceleration of the helicopter is, a = 21.6 m/s²