The scare begins.
We were scheduled to refuel about five hours into our flight on track 636 off the coast of Norfolk. The rendezvous would be with a KC-10 at FL210. They told us of a cloud layer at FL210, and moved the rendezvous up 1,000 feet to FL220 to get above the layer. The join-up with the tanker went smoothly; it was a nice night for air refueling.
Fifteen minutes before completion, another tanker (a KC-135) checked in with Giant Killer (VACAPES). It would be next to refuel with our tanker. The KC-10 told the KC-135 they would coordinate a rendezvous after refueling with us. The KC-10 was scheduled as the receiver in the next refueling evolution.
With the refueling complete, we descended to the bottom of the air-refueling block, FL210, and stayed in contact with the tanker until MARSA (military assumes responsibility for separation of aircraft) was cancelled. After the post air-refueling checklist was concluded, the seatbelt sign was extinguished and our Mercury crew resumed their duties. With clearance established with Giant Killer and MARSA terminated, we proceeded on a westbound heading at FL210.
The KC-10 coordinated a rendezvous with the KC-135 and climbed to FL230. All three jets were approximately on a heading of 280 degrees toward Norfolk. We entered a thick cloud layer and entered IMC. We also encountered moderate icing, with about a quarter of our windscreen getting rapidly covered with ice. We told Giant Killer of the icing and requested a climb as soon as possible, including the need for a new heading to remain clear of track 636 and the two tankers. We increased speed to 280 knots to limit icing exposure and to prepare for our climb. Giant Killer responded with a new assigned heading of 230. Once heading 230, Giant Killer cleared us to FL260. We initiated an immediate climb at 2,300-feet per minute.
Unbeknown to us, shortly after we initiated our climb, the two tankers began a left hand turn within the air-refueling anchor to aid in their rendezvous. Fifty-five seconds after beginning our climb, while passing FL230, Giant Killer radioed us to stop our climb at FL220. I quickly reported that we already had passed FL220. Giant Killer requested a level-off at our current altitude, now FL232. At that moment, we received a resolution advisory (RA) from our terminal-collision-avoidance system (TCAS) to "climb." We quickly responded by pushing the throttles up and climbing in adherence to the RA. The climb call was followed shortly by a TCAS, "monitor vertical speed" call. We were still in IMC. I immediately told Giant Killer that we'd heard the RA and that we were climbing.
After receiving the TCAS "clear of contact" call, we asked for an assigned altitude and were given FL300. Still observing the tanker frequency, I told the tankers what had happened and requested feedback. They were monitoring Giant Killer and had heard all the radio transmissions. The tanker formation thanked us for adhering to the RA, because they were in the process of rendezvousing.
Poor timing nearly caused a mid-air collision on that night. The tanker's left hand turn and our clearance to climb, compounded with IMC, resulted in a situation in which two aircraft almost inhabited the same piece of sky at the same time.
Being monitored by ATC and separated by radar does have flaws. Being in close vicinity with multiple aircraft, regardless of atmospherics, demands attention to detail and clear communications.
LT. PUTMAN AND LT. FUNK FLY WITH VQ-4.