"runsim.py" script import error in HIL simulation

When I tried to run HIL with sim_vehicle.py script with parameter:
sim_vehicle.py -L KSFO -v ArduPlane -f quadplane --console --map --hil
This lead to run runsim.py and I got an error at line 8 when import fdpexpect.
output at JSBSim console
“import fdpexpect
ImportError: No module named fdpexpect”
I have tried with Python2.7 and 3.5 interpreter and got the same result.
Could anyone help me with this?

pip install "pexpect<3"