Comments by "Sar Jim" (@sarjim4381) on "The Drydock - Episode 063" video.

  1. To be fair, one of the reason why almost all scouting and scout bomber aircraft were two place is so the observer could use a pretty good set of optics to give them more details than the Mark I Eyeball. As Drach pointed out, in less than ideal conditions, accuracy of identification deteriorated rapidly. The RN not only recognized this problem earlier than other major navies, they treated finding a solution as an emergency. Consequently, they used Identification, Friend or Foe (IFF) systems on their ship and aircraft earlier than other countries. As usual, you can identify the pioneers by the arrows in their back. The original IFF system depended on a passive system using a vertical dipole, and the only receiver sensitive and wide banded enough was a superregenerative type. I won't get into all the technical detail since I'm sure most you don't really care about them, but the super regen receiver was extremely difficult to tune sitting at a desk on dry land. Doing so in a Swordfish, while being buffeted by rough air and rapid changes in altitude, required an observer that was both skilled and lucky. The passive dipole system was unreliable even if the receiver was working correctly. Yet another British invention allowed the radar signal itself to actively interrogate a receiver on a ship or another aircraft. The IFF was then transmitted as a coded part of the radar return. That meant no fiddling with receivers on an aircraft, and it was also more difficult for the enemy to compromise the system. By the second half of 1944, about 75% of RN ship and aircraft and nearly 100% of US ships and aircraft were equipped with IFF. The extremely time consuming teaching of ship and aircraft recognition from models, photos, and drawings became much less important. A pilot merely had to interrogate the IFF receiver on a ship. If it was one of ours, a spike on the radar screen would show a positive return. In later iterations, the return could even tell a pilot the name and type of a ship or the type of aircraft being interrogated. While this greatly reduced blue on blue attacks for a time, it didn't eliminate them. Imagine seeing an unidentified ship, interrogating on the correct IFF channel, and getting no return. Enemy ship, attack away...except what happens if the IFF on the ship was broken and not working? With pilots given less recognition training and early electronics subject to frequent failures, the number of mistaken attacks on friendly ships actually increased for a short period of time in late 1944. A crash program to make IFF more reliable and getting pilots trained in better visual recognition reduced the blue on blue attacks to much lower levels by early 1945 than those seen earlier in the war. IFF systems in use today, although much more sophisticated and reliable, are still based on the same principles as used in the late WWII systems.
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