
Creating a Diversion (Part One)
By Owen Zupp
In aviation, as in life, things do not always go to plan. Despite one’s best efforts, intentions and preparation, events can still unfold that call for a change in strategy. When these events take place aloft, pilots need to be able to adapt without undue delay and exercise the options available to them. Under the high workload environment of the cockpit, there is a certain skill set required to successfully execute an in-flight diversion.
Be Ready for Anything.
I recently had cause to divert to an alternate airport in a Boeing 737 as the weather at the destination deteriorated rapidly mid-way through the flight. Only a week earlier, an aircraft had become disabled on the runway, also forcing the thought processes to consider the available options and ready the aircraft to divert elsewhere. Fortunately, in this instance the aircraft was cleared away and our flight arrived as planned, if not as scheduled. Obviously, operating an airline transport category aeroplane has the benefits of auto-pilots, flight management computers (FMC) and multi-crew to alleviate the workload. However, in both cases, it was striking how the principles and considerations of planning these diversions were common to those basic pilot training exercises so very many years ago.
The first thing to consider is that diversions are extremely varied in their nature. Everyone is familiar with the copybook flight-test diversion to the degree that you can almost guess where and when the change in plan will take place. In the real world of the VFR pilot, the cause is not always so clear-cut. Deteriorating weather is the traditional foe, while a passenger’s deteriorating health may offer far less warning. An aircraft serviceability issue may call for an expedient landing or a ‘wheels up’ landing by another aircraft may take out the only available runway at the destination. Perhaps the diversion is not to a new destination, but a divergence from the planned track to avoid some isolated weather.
As with all aspects of flight, a great deal can be achieved with thorough pre-flight preparation, before the workload of the cockpit has even started. A simple diversion consideration can relate to the destination airfield, should it only be serviced by a single runway. In these cases it is always worth having the required fuel to reach an alternate airfield as any number of occurrences could render it out of action. For the greater part of the journey, consider the planned route and then expand the perspective to include nearby airports. The level to which this consideration is detailed can be matter of personal choice and available time. At the very least, draw a reasonably sized circle around each airfield as this will enhance situational awareness and offer a ready appreciation of the distance from any particular airport at any particular stage of the flight. Some choose to draw a compass rose on the circle, while others will include basic facts such as elevation, runway direction and radio frequency; it’s your choice.
In pre-flight planning, review the weather and NOTAMs for these proximal airports to guard against a worthwhile diversion to an unavailable airfield. Similarly, consider the location of controlled airspace or active restricted areas in this planning phase. Highlight any significant restrictions in your planning notes so that are at the ready should an in-flight change of plans take place. Similarly, organise your cockpit, charts, pencils and plans before you taxi as this equipment will all be needed to be accessed without fuss in flight. Even without concerted effort, these simple measures will begin to formulate an enhanced appreciation of the route you are to fly, which is a definite advantage when the unexpected takes place enroute.
Decisions, Decisions.
Often the most difficult part of the diversion is the initial decision to go elsewhere. The pressure to ‘push on’ beyond a safe point can often be exacerbated by pride or the desire not to disappoint the passengers. Alternatively, some folks, even pilots, can tend to procrastinate and forge on aimlessly rather than taking action. Whatever the circumstances, the safe conduct of the flight rests squarely on the shoulders of the pilot-in-command and any operational decision must be made in a safe, timely and measured manner.
Firstly, consider why diverting is an option. Is the weather progressively reported as worse than the forecast or is there rising suspicion that the fuel in the tanks will not be enough to arrive safely with reserves? Overall, if the facts are enough to evoke genuine concern, then there is a solid reason to divert to another available airfield, get on the ground and sort out the issue on the safety of Terra Firma. While conservative, an early decision is generally a good decision. And always remember that an early radio call to the Flight Service facility is a wise move if the situation, particularly weather, is starting to cause a degree of doubt.
Even so, all decisions should be made on the foundation of fact, so gathering in the available information may take a little time. It is here that the pre-flight observance of alternate airfields starts to pay dividends in the workload stakes. Consider your options in a measured way, but never ignore flying the aeroplane; it must always remain the first priority. Distraction can pose a real threat in these situations and the flying conditions may already be ideal by virtue of the weather necessitating the diversion. Stay in control, ensure there’s adequate fuel in the tanks and maintain safe clearance with the terrain; these are three potential killers that stalk the pilot under pressure.
The speed with which the decision is made may ultimately be determined by the circumstances on the day. A wall of water falling from the heavens ahead, or an incurable rough running engine will call for action without delay. However, if the issue is a disabled aircraft at the destination on a fine day with hours of fuel in reserve, the decision may not have to be so time critical, such that the diversion takes place from overhead the destination. Whatever the time frame may be, once the decision is made get the plan into action without further delay.......
Check back soon for the conclusion of "Creating a Diversion".
















