Originally Posted by KC10 FATboy

The AWCAS was unstable (receiver's fault) and the boom operator initiated the contact when the receiver was unstable (tanker's fault). It looks like there was either an inner or upper limit disconnect (compressing the boom). However, after the disconnect, notice the AWCAS moves downward (too fast actually). This causes a low pressure between the airplanes. The tanker's autopilot senses that low pressure and assumes a climb (higher pressure down low, lower pressures up high) and starts trimming to counteract those forces. But the trim rate cannot keep up with what the autopilot is sensing and the autopilot abruptly disconnects. This causes an immediate nose down pitch change caused by the now out of trim tanker (remember the autopilot thought it was climbing due to the low pressure and was trimming nose down). The tanker then quickly dives into the receiver until the pilots can react. And as such, the receiver gets a very close and uncomfortable view of the tanker's tail. The KC-135 is very susceptible to this -- the KC-10 is not. Any large receiver moving up or down too fast most likely will cause the KC-135 autopilot to kick off. I have had it happen at night while in the weather. I was flying a KC-10 receiving gas from a KC-135. I could have sworn my co-pilot had yanked the controls and pitched us up into the tanker when in reality, it was the tanker coming down towards us. It was one of the more scarier moments I've experienced in flight.