Operational necessity - ORM Corner

Approach, Dec, 2002 by Tony Allou

My crew just had completed a mid-cycle night launch from USS John F. Kennedy, and the butterflies that always accompany me until the "Passing 2.5, kilo" call had settled down. It was time to prepare for our Operation Enduring Freedom mission and let the air conditioning work after sitting in a closed, hot, humid cockpit for 30 minutes. The mission, including transit and tanking time, was a 6.5-hour flight and a 0230 recovery. We briefed the standard emergencies and airborne contingencies, concentrating on areas that required a non-standard recovery.

About 10 minutes alter launch, the crew noticed a burning smell in the cockpit. It cleared quickly, and a cockpit-security and circuit-breaker check indicated nothing out of the ordinary. The transit to the tanker track was uneventful. An hour into the flight, we completed our check-in with AWACS and rendezvoused with our tanker. As we approached port observation, I heard a slightly high-pitched whine coming from below my seat.

After tanking, we slid over to starboard observation, detached, and proceeded on mission. The pilot asked ECMO 1 to cool the cockpit as we climbed to our transit altitude. I felt the air blowing out of the vents beside my left console, and it was hot. Alter 15 seconds, ECMO 1 reported no change in air temperature, despite his holding the switch to full cold. We were concentrating so much on the mission that it took a few minutes for the wheels to turn in our brains, and we started to troubleshoot the problem.

The air was hot, but it was not hot enough to trigger the EA-6B emergency procedure. A full-cooling failure would have allowed unregulated 12th-stage bleed air into the cockpit. This condition would have been intolerable, requiring the execution of the boldface procedures and shutting down all bleed air in the aircraft. We continued to head toward station and began to execute our mission while we discussed our situation.

We decided not to shut off the bleed air, since there were no smoke or fumes. The hot air was bearable. We verified all the environmental-control-system-related circuit breakers were in. After descending to our mission altitude, we discussed what could be done to make the cockpit more comfortable. If the cockpit became too hot, we would continue with the steps outlined in the EP, without actually shutting down our aircraft bleed air. Following the EP would involve shutting off the cockpit air and opening the ram-air valve to let in the outside air. With ram air providing the only source of air pressure, the cockpit and ambient air pressures almost would be equal, instead of having the 8,000-to-9000-foot differential that was normal at our operating altitude.

As we discussed our condition and whether to continue with the mission or return to JFK, we focused on how necessary it was to have a Prowler on station. If this had been a normal sortie around the ship, or if another Prowler could have taken our tasking, the decision would have been all easy one: RTB. Conditions did not warrant returning to base.

We were supporting a direct-action mission on the ground ill progress, confirmed by the flash of supporting fire on the ground. To solve the dilemma, we had to think outside established patterns. We had determined it was not a full-hot condition, but the heat was severe. Our mission started with a lot of sweating, and now we were in for more than four hours of dehydration before heading to the carrier for a night recovery. We discussed everyone's mental state, our fatigue factor, and our Water supply. The food we had brought was no good to us; the ham-and-cheese sandwiches at 100-plus degrees were not very appealing. I played devil's advocate while the mission commander, one of the squadron's senior pilots, sorted out the situation and weighed our options. In the end, operational necessity dictated we remain on station.

Fortunately, the failure that caused our current condition happened after we had cold soaked the interior of the cockpit, which allowed us to tolerate the hot air for some time. As we headed back to our second tanker of the mission, we finally cried "uncle" and let the ram air take over. We watched the cabin pressure rapidly climb to several thousand feet below aircraft altitude. We continued to monitor the pressure as we climbed.

We approached 25,000 feet and switched to cockpit air to minimize the chances of extreme cabin-pressure altitude and the threat of a physiological episode. Once off the tanker, we continued the mission. We switched to ram air on the descent, and every 10 minutes or so, we turned on the defog to maintain forward visibility. When we were 10 minutes off the second tanker, we received information our relief was going to be an hour late to station. Groans emanated from the crew, and we reassessed our situation. Everyone still was positive and motivated, despite our condition. "Adapt and overcome" was the catchphrase running through my mind as I took another long draw from my water bottle. A third trip to the tanker should have sent us home, but, instead, it saw us heading back to station.