Yes, this is strange "floating" bug.

It can be fixed in two ways:
- download and install the new hotfix 1004

or

- open aircraft.cfg
- add this string
light.4=13,0,0,0,void
to [LIGHTS] section

It should looks like:

Code (]
[LIGHTS):

light.0=1,  19.35, -0.90, 11.30, cs1011_bcn light.1=1,  16.35,  0.30, 11.30, cs1011_bcn light.2=1,   5.46, -4.26, -8.62, cs1011_bcnb light.3=1,   5.46,  4.26, -8.62, cs1011_bcnb light.4=13,0,0,0,void