In various forms, a practice called SLOP (strategic lateral offset procedure) has been utilized. The practice is now highly recommended. The procedure has been standardized to require a one- or two-mile offset to the right of the clearance route. The theory is that current navigational technology for most participating airplanes is highly accurate. A flight that needs to descend from its assigned track because of an emergency might very well create a traffic conflict with airplanes at lower altitudes. The offset provides for a lateral safety margin.
As was done before the days of GPS and inertial reference systems, SLOP is used simply as a courtesy. A flight on the same track that is trailing behind another airplane may experience wake turbulence. Knowing that this possibility may occur, the leading airplane will offset, pending wind direction. Of course, it isn’t always apparent that another airplane will actually be affected by wake turbulence. More often than not, the trailing airplane will initiate the procedure.
Not too long ago, I answered a call from a brave soul ferrying a Cessna 172 across the pond from France. It seemed that the type of airplane didn’t quite register with the other airlines that day. The pilot’s request was for current weather in Gander, Newfoundland. I gladly put our printer to work. After I read back the metars in the area to the pilot of the 172, we had a brief discussion regarding his status. All was proceeding well. I made a few inquiries as to the technical details of his equipment. It was a newer 172 with a Garmin G1000 system. I wished him a safe flight.
Without saying, emergencies command immediate attention from our metal neutral club. Although satcom and CPDLC (controller pilot data link communication) are superb communication tools, another cockpit can sometimes help. And on some occasions, assistance has been rendered just by virtue of another pilot’s previous experience with a similar emergency.
As I mentioned in a previous column, my declaration of a medical emergency was greeted with numerous offers of assistance. So much so that I had to make an assertive request that the other airplanes stand by. My colleagues quickly understood that our cockpit was becoming a busy place. They refrained from further comment. I am thankful for a Lufthansa flight that had us in visual contact. He stated his position, indicating that no conflict would occur. It must have been disconcerting to observe a contrail dash almost 90 degrees across the tracks. I am also thankful for an Icelandair flight that volunteered to alert Keflavik ATC as to our diversion.
On a lighter note, the metal neutral club participates with brief snippets of discussion involving contact with old friends. Commentaries and commiserations of a particular airline’s state of affairs can sometimes be heard on the air-to-air frequency. The occasional info regarding the particulars of a given layover is conveyed for the benefit of the next crew. If it’s an especially mundane crossing — with no adverse ride conditions — the silence might be interrupted by a few quick refrains of a rock ’n’ roll song from an errant iPod.
One of the more visually pleasing benefits of the metal neutral club is the spectacular view of another airplane. The close proximity of 1,000-foot vertical separation allows for some great photos. The opportunity to capture another airliner in flight, contrail included, is a way cool experience. Digital cameras make their way out of flight bags. Pilots exchange e-mail addresses in order to share the suitable-for-framing moment.
The negative connotation of metal neutral will probably never quite dissipate from our airline pilot psyche. To consider our job as part of one homogenous global airline seems contrary to the competitive spirit. In addition to having a sense of loyalty, my colleagues take pride in their respective companies. But pride comes from within. In that regard, I am proud and privileged to be a member of a club that is always prepared to assist its fellow professionals regardless of what may be painted on the aluminum.