Turbine Pilot

Workload management skills for pilots of single-pilot light jets

There is a wise expression that those who fail to study history are condemned to repeat the mistakes of the past. With all of the excitement in the industry about the new "very light jets," perhaps this is a useful time to look back at the lessons learned from the previous generation of single-pilot business jets. I looked through the files of the NTSB, as well as the reports from the equivalent agencies in Great Britain, Canada, Australia, and New Zealand, for accidents involving entry-level light jets flown by single pilots for business or personal purposes.

Overall, the accident record is really quite respectable, but I think a lot of the credit goes to the engineers who purposely utilized easy-to-read "tape" instruments, relatively user-friendly flight management systems, wide cockpit windows, and straight-planform wings with thick airfoils and relatively slow approach speeds to produce rather forgiving aircraft. A total of 58 accident records from the period from 1991 through 2002 showed up in this category, but as most of you realize, serious accidents are only the tip of the iceberg. Usually there are many more incidents, and these close calls are just as important to learn from. Some deeper digging found 95 incidents in the FAA's database that also give us insight.

So what events are creating the most fatal accidents, serious accidents, and close calls for single-pilot entry-level jets? By far the one category that stands out from all others is the approach and landing accident. Eight fatal accidents, 25 nonfatal accidents, and 48 incidents fall into this category. Almost two-thirds of these resulted in runway overruns. Undershoots, runway excursions, and losses of control filled out the remaining third.

Were there any consistent causes among these 81 accidents and incidents? Yes! More than two-thirds involved failure to fly a stabilized approach. In many of the cases, the single pilot was working under the adverse condition of high workload and failed to detect an unstabilized approach early, or failed to make adequate corrections and tried to salvage a bad approach. Since jets fly at much faster speeds and don't tend to bleed off their energy as quickly as propeller aircraft, pilots flying these faster, sleeker jets really need to learn workload management skills to help them manage their time, attention, and the aircraft's energy. For example, a successful technique used by airline and corporate crews flying into busy terminal airspace is to set up for the approach during the low-workload period of cruise flight, thus greatly decreasing their workload during the critical approach and landing phases so they can pay more attention to monitoring the aircraft. Such workload management skills and techniques are especially vital for pilots of single-crewmember light jets.

Turbine-aircraft operators have used the stabilized-approach criteria for many years. In fact, a safe landing in a turbine transport really requires a stabilized approach. An unstabilized approach drastically increases the chances of mishap. The stabilized-approach criteria mean the aircraft's energy state is within limits (in terms of airspeed, sink rate, and glidepath), but there is more to the concept than that. It also requires the aircraft to be in the proper landing configuration with the engines at a normal power setting (to avoid problems with spool-up time common in older turbine engines). There is one final element that has been added recently and deserves special mention. It requires the pilot to be sufficiently caught up on all of the cockpit tasks so that attention can be solely devoted to executing the approach.

In today's world, it isn't uncommon to get the infamous slam-dunk approach, which often begins the whole unstabilized-approach error chain. Pilots who fly into the same airport regularly have the advantage of anticipating the slam-dunk and can take preemptive actions such as slowing down and getting the aircraft configured early so they can effectively bleed off the excess altitude.

Too fast, too slick

All of the runway overrun accidents involved aircraft operating under FAR Part 91 landing-distance requirements, which basically allow a pilot to try landing on a runway as short as the aircraft manufacturer's test pilot was able to land on. Of course we all know that the test pilot had optimal conditions in his favor at the time he established the landing-distance numbers. In the Part 135 nonscheduled air-carrier world, pilots aren't allowed to risk the safety of their passengers on such performance. Instead, they are required to have sufficient runway so they can land and stop within 60 percent of the usable runway. Not surprisingly, this rule is quite effective at minimizing the number of runway overruns, and you would be well advised to adopt the same risk-management philosophy.

There were some other noteworthy common trends among this data. The most common mistakes involved in the runway overruns were the pilot's failure to adequately evaluate the effects of runway conditions, precipitation, and adverse winds on the aircraft's ability to land and stop within an adequate distance. Many of the overruns involved contaminated runways. While rain was the most common precipitation cited for causing the contamination, snow was a close second. Landing a fast-moving jet on a contaminated runway is a situation that demands attention, and proper planning and procedures. While a Cessna 172 touching down at 55 knots on a contaminated runway is a tricky situation, touching down a sleek jet at 110 knots is a far trickier task. Manufacturers have added antiskid brakes, spoilers, and thrust reversers on some jets to help as braking devices, and those are effective under normal circumstances. However, like any system, they have their correct operational procedures and limitations, and when used improperly, they can quickly slew you off the side of the runway before you can correct. Poor runway conditions are cause enough for concern, but this becomes even more problematic for light jets because so many of the destination runways lack surfaces specifically designed to minimize the effects of runway contaminants. Inadequate airport and runway markings, inadequate lighting, or poor surface conditions were common contributing factors in accidents.

The granite approach

The second biggest killer involves controlled-flight-into-terrain (CFIT) accidents, which shouldn't be surprising. These aircraft are commonly flown into airports surrounded by adverse terrain seldom served by terminal approach radar and which usually have only a nonprecision approach. The Flight Safety Foundation's studies have found that the lack of a precision approach can increase the chances of a CFIT accident by eight times, and the lack of approach radar can increase it three times. Additionally, many of the common light-jet destinations are not served by a full-time air traffic control tower or full-time weather reporting services. In short, the operating environment for very light jets is going to present a number of unique hazards that the airlines seldom venture into.

The second leading category of incidents involved mechanical failures. While the first light jets were purposely designed to be relatively simple to operate, they are more complicated than your average light twin. Type rating training exposes you to the proper operating procedures for these systems under normal, abnormal, and emergency circumstances. However, these systems aren't 100-percent reliable and sometimes fail. Roughly one-quarter of the mechanical incidents were caused by a malfunctioning pressurization system requiring an emergency descent. This is a maneuver you will practice several times in the simulator so that your reactions will be nearly automatic should the cabin suddenly lose pressurization.

One down...

Engine failures during flight were the cause of roughly one-quarter of the incidents. The good news is that most of the engine failures were handled without further damage to the aircraft or injury to the occupants. You will find during type training that more than half of your simulator time will be spent flying around in a single-engine condition. The good news is that an engine failure doesn't cause the rather marked control problems that failure of an unfeathered propeller causes. The bad news is that not only have you lost a lot of performance, but also most of these jets just don't climb very well on a single engine. Simulator training will definitely expose you (ad nauseam, in fact) to the engine-failure-on-takeoff situation and you'll become adept at physically handling that. Simulator training is excellent for instilling the proper reactions to such emergencies, but there are some limitations to the fidelity of simulator training. For example, it still isn't the same as standing on the ramp at Aspen amidst some low weather and thinking, "Gee, if the engine fails at rotation, what am I going to do?" In the real world, you'd better have sufficient climb-performance margins to ensure adequate obstacle clearance. The type of decision-making process involved with gathering and adequately assessing the aircraft's performance given the climb gradients and other environmental factors isn't going to be learned in just a couple simulator sessions.

Earning a type rating is an assurance that you've demonstrated a rudimentary level of performance of aircraft handling and system procedures, but let's face it, that isn't the same as operating in the real world. In the real world we get slam-dunk approaches into fields with poor radar services and maybe only a nonprecision approach into a runway that doesn't have good approach-light aids, and it probably doesn't have grooved runway surfaces for draining precipitation. In the real world you'll be operating in the flight levels, which means a whole new world of high-altitude meteorology, flight planning, and physiological considerations. These are the type of real-world situations that put a premium on your workload management skills, your management of the aircraft and its systems, and your judgment.

The key to minimizing accidents with the new very light jets will be a comprehensive "systems safety" approach. That first means reducing the risk whenever possible. What are some of the decisions we can make to lessen unacceptable risks? It's too much risk trying to land on runways without extra margins of length. Excessive runway contamination, combined with other hazards such as adverse winds, is a definite high-risk situation that is best avoided. Operations into areas of adverse terrain served by limited approach and runway facilities are also high-risk events. The second step in the systems-safety approach is the use of safety devices in the design, such as forgiving airfoil and wing designs. The third step involves the implementation and proper use of warning systems such as the equivalent of ground proximity warning systems and traffic alert and collision avoidance systems. Finally, it will be crucial for the industry to develop a thorough training and mentoring program to help pilots stepping up into this high-performance environment. Type training will be just a small part of that process.

Patrick R. Veillette of Park City, Utah, is a commercial airline pilot.

Links to additional information about very light jets may be found on AOPA Online ( www.aopa.org/pilot/links.shtml).

Accidents and incidents involving single-pilot light jets flown for business purposes (1991 through 2002)