Hello,

The MiG-29 and Su-27 have two displays: the ILS (windscreen indicator) and IPV (direct visibility indicator).  I would like to know: what is the difference?  Most photographs (very rare) show that the IPV is identical to the ILS.  Why two displays?

I believe there is an important difference.  Above the IPV, there is a box with two switches.  The switch on the left selects "Label" or "Line".  The switch on the right selects ""Tact." or &quotouble".  I believe that in the "double" mode, the IPV display is identical to the ILS, but in the "Tactical" mode, the IPV display is provided by radio datalink from the ground, and shows the positions of other aircraft.  Since most MiG-29s do not have the radio datalink, this has been very difficult for me to confirm.  Can anyone help?

Thank you, best regards

  -SK

P.S., I am also interested in the function of the "label/line" switch.  These functions are not described in the MiG-29 flight manual from Schiffer Publishing.