Dear L-188 -
With 2 GPS - you can continue with one GPS remaining if second fails, the one unit will provide sufficient update, to the INS in "T-Mix"... Our current configuration still gives full flexibility, i.e. in cas of one INS on MEL
... It was the least inexpensive upgrade, using these LTN
-92 type INS systems. Remember, DME
update requires DME
stations... not too many right in the middle of the oceans...
Happy contrails -