Many of the aids available to modern pilots such as DME (Distance Measuring Equipment), GPS, Weather Radar on so on hadn't even been dreamt of during WW2. The standard wireless fit in most British heavies was the T1154 HF/MF transmitter coupled with the R1155 Receiver; various marks of the equipment denoting the frequency bands available. Being a HF set, a long wire aerial was required, unlike the VHF sets for short range use, and this trailing aerial wire was usually stowed on a reel on the side of the Wireless ops desk so that he could wind it out when it was needed. Of course, one major drawback of having a long length of wire dangling out of the bottom of the fuselage raised its ugly head when the aircraft was forced to fly low, such as coming in to land. One must wonder at how many trailing aerials found themselves wrapped around the aerodrome perimeter fence. In the latter years of the war, many of the navigation/bomb aiming aids; GEE, Oboe and especially H2S were still regarded as too sensitive to allow them to be flown over enemy territory without some way of protecting those secrets should an aircraft be forced to land and the equipment remain intact. To this end an air presure (altitude) sensitive barometric fuse attached to an incendiary device inside the case designed to incinerate the contents was armed at the start of the mission and disarmed prior to landing back at home. Yes, you’ve guessed it … how many operators forgot to disarm the thing and had to go cap-in-hand to the ground crews to get a new set. No doubt they only did it once!