I understand that Bond Helicopters have fitted Honeywell TCAS II to their Super Puma helicopters. It took them
six months including flight trials and certification etc. MoD plan on installing Honeywell TCAS II to the Tornado GR4 aircraft, and so far it has taken them
six years.
http://aerospace.honeywell.com/~/med...Bond_TCAS.ashx
As a retired aircraft engineer who has been involved in engineering new fits and and carrying out flight trials testing I believe that the Bond time frame is the more realistic,
if there is the will.
DV