A physical model of triggered lightning strikes to aircraft is applied to interpret the initiation of intracloud flashes depicted with the French UHF-VHF interferometric system. It is shown that both intracloud discharges and triggered strikes are initiated in a qualitatively similar way: the simultaneous bi-directional development of the negative stepped leader and the positive leader-continuous current process. The airborne visual observations and electromagnetic waveform records during the junction stage of intracloud flashes reveal (1) the presence of continuous current during the entire period, and (2) a ''multistroke'' feature, observed as variations of the low-frequency (continuous) current with current pulses superimposed, which occurred only during periods of rising continuous current. It is shown that airborne measurements of lightning strikes to aircraft provide an opportunity to recognize recoil streamers in time domain data and the determine their characteristics (duration and amplitude), which are not obtainable, with other techniques. Tortuosity of two scales, tens of centimeters and several meters long, has been observed in visual images of lightning channels at close range with video cameras aboard the NASA F-106B airplane. The hypothesis is advance that high-rate pulse bursts in VHF and UHF bands associated with recoil streamers are radiation pulses attributable to reflection processes at kinks of the highly tortuous channel traversed by a current pulse. ¿ American Geophysical Union 1989