November 12, 2007
A highly successful manufacturer of personal airplanes displayed a big banner at AirVenture last summer that read, "Life without flight delays or cancellations." Obviously this company was marketing to people who fly for business or long-distance personal transportation. Since I travel frequently by airline to train pilots fortunate enough to own their own airplane, the slogan's strike directly against airlines' on-time record certainly hits home with me. What a great idea, it sounds ... at least at first: Buy one of these high-performance airplanes and avoid the scheduling hassles of commercial travel.
But what sort of message is that sending to pilots, really?
Delays And Cancellations
|U.S. airlines' on-time performances, March 2007 (top; larger version here) and August 2007 (bottom; larger version here). Source: U.S. Bureau of Transportation Statistics.
The airline industry suffers terribly from a reputation for late flights. No wonder a general aviation (GA) manufacturer would market against this perception. The U.S. Department of Transportation's Research and Innovative Technology Administration (RITA) includes the Bureau of Transportation Statistics (BTS). Among many other things, BTS tracks and reports on the rates and causes of scheduled airline flight delays.
A flight is considered "delayed," by BTS' definition, when it arrives 15 or more minutes later than scheduled. A sampling from the BTS Web site reveals that, by this definition, over 70 percent of all airline flights arrive on time -- bucking the reputation, but still revealing that nearly one out of three airline flights runs late. Reasons for the delays include:
- Extreme Weather: Significant meteorological conditions (actual or forecasted) that, in the judgment of the carrier, delays or prevents the operation of a flight. Examples: tornado, blizzard or hurricane.
- National Aviation System (NAS): Delays and cancellations attributable to the national aviation system that refer to a broad set of conditions, such as non-extreme weather conditions, airport operations, heavy traffic volume and air traffic control.
- Late-arriving aircraft: A previous flight with same aircraft arrived late, causing the present flight to depart late.
- Security: Delays or cancellations caused by evacuation of a terminal or concourse, re-boarding of aircraft because of security breach, inoperative screening equipment and/or long lines in excess of 29 minutes at screening areas.
Avoiding Flight Delays With GA
Against this record, can GA provide a "life without flight delays?" Let's look at the major causes of airline delays and whether they would have a similar impact on GA scheduling:
Weather, often considered the most common cause of airline delays, is cited as a distinct delaying factor in only about 1 percent of all airline flights. Dig a little deeper into BTS and you'll find that this figure represents the "extreme" weather delays, i.e., tornado, blizzard or hurricane" in the terminal area or flight path of the airliner. Other weather delays (winds, fog, low clouds, thunderstorms, ice) are included in the roughly 8 percent of all airline flights included in the National Aviation System Delay category -- averaging 60 percent of those flights, or about 5 percent of the total. All told, then, weather is reportedly responsible for delaying about six percent of all airline flights, or roughly 10 percent of all airline delays.
|Weather factors such as airframe ice are at least as likely to delay GA flights as they are the airlines. (Click here for larger version.) Source: NOAA's National Weather Service Aviation Weather Center.
Can GA do better? Hardly. Of course the "extreme" weather events that ground airliners do (or at least should) ground GA airplanes as well. Although weather slows operations at the major hub airports (that most GA airplanes avoid), the fact is GA airplanes are often grounded in conditions the airlines can still fly. Consequently, there are few weather conditions that would delay airline flights that would not delay GA flights in the same geographic area as well. Put another way, it's the rare GA airplane that has weather dispatch reliability exceeding that of the airlines -- attested to in part by the relative accident rates of light GA and air carrier aircraft.
What about the latest generation of technologically advanced airplanes (TAA)? Glass cockpits with GPS moving maps overlaid on uplinked weather synched to powerful autopilots should improve the TAA airplane's weather capability. Unfortunately the record doesn't support this. The AOPA Air Safety Foundation's Technologically Advanced Aircraft Safety and Training Special Report (2.1 Mb Adobe PDF file) summarizes that while "TAA hav[e] proportionately fewer accidents compared to the overall GA fleet" and "TAA have experienced reductions in the percentage of takeoff/climb, fuel management, and maneuvering accidents," they have shown "increases in landing, go-around and weather crashes, as compared to the [rest of the GA] fleet" (my emphasis added). The report states that weather contributed to 45 percent of all TAA aircraft in the study period, compared to 16 percent of the GA fleet overall. ASF executive director Bruce Landsberg observes, "TAA are neither as good as proponents say nor as bad as detractors contend. These aircraft provide situational awareness tools that have dramatically improved aspects of GA safety. But those tools are not enough to overcome a pilot's faulty decision-making or a lack of experience in how those aircraft are operated."
In part the much greater rate of weather-related accidents in TAA aircraft may be due to the fact that these new, capable and expensive airplanes are more frequently acquired for serious cross-country business and personal transportation, thus more often exposed to weather that becomes a causal factor in a mishap. The record shows, however, that even highly capable TAA equipment is not a panacea for weather-related flight delays in GA airplanes.
Crew Duty Time
If you've flown by airline much, you know that flights are often delayed (or even cancelled) because the flight crew has reached its duty time limit. These delays would be part of the roughly 7 percent of flights categorized as "air carrier delays."
We don't have to worry about that in general aviation, do we? Except for a limit on the total amount of in-flight instruction a CFI can provide in aircraft in a 24-hour period (the limit is eight hours), there are no stated duty-time limits on GA pilots. This is a good thing because it permits individuals to determine their own fatigue-related fitness for flight. People vary significantly in their ability to get up before dawn and safely fly, or to launch after ending a long work day.
But the effects of fatigue on transportation (including GA) are only just beginning to be studied in depth. There is growing evidence that performance may be significantly degraded after a pilot has gone 12 hours since the last sleep. Award-winning aviation fatigue researcher Dr. Mark Rosekind said at the recent Bombardier Aerospace Safety Standdown that NTSB "used to investigate [pilot fatigue issues] back to 72 hours before the crash," but that now they "go much farther back than that" and often find in the case of a fatal mishap that the pilot "had not had two consecutive nights of eight-hour sleep in the last 30 days."
How will fatigue and sleep deficit affect you in the cockpit? You won't know until your performance begins to decay in flight. Individuals can (and must) consider not only whether they are alert enough to begin a flight, but more importantly what their likely fatigue state will be at the end of a contemplated trip. Pilots who honestly evaluate themselves may find safe GA as frequently limited by duty time as is the airline industry.
Another frequent cause of airline cancellations and "air carrier delays" is aircraft maintenance. Airliners work hard and often. Commercial air carrier requirements are often such that many seemingly insignificant items must be in working order for the airplane to be dispatched. The result is that a broken airplane almost always delays tightly scheduled airline turn-arounds, and frequently causes the flight to be cancelled altogether.
If you own your own airplane and are very proactive with maintenance (as opposed to repairs after something has broken), chances are you'd get great dispatch reliability (being in mechanical condition to go when planned) out of your airplane. If you use someone else's airplane, or rent, you don't have that control and dispatch reliability may suffer as a result. In other words, unless you ...
- own the airplane;
- continually inspect and maintain it to exacting standards; and
- prioritize inspection and maintenance schedules over travel plans
... you are still subject to the practices and whims of somebody else when it comes to avoiding aircraft maintenance-related delays.
The biggest single advantage GA has over the airlines is the almost complete lack of traffic congestion. Despite very public claims that airline delays are heavily influenced (if not caused) by GA traffic, the reality is that airline traffic delays are the result of air carriers scheduling more flights at peak hours than airports have capacity to handle, especially in adverse weather, and the limiting factors of available runways and terminal gates.
For example, recently I rode on a United 737 from Wichita to Chicago. UAL is the only airline I know that pipes ATC audio over the cabin entertainment system, and of course I was listening in. After a ground hold of about 40 minutes at Wichita because of traffic saturation at O'Hare, we were released, only to have the airplane's climb and even en route speed limited to fit into the O'Hare sequence. We were even given several "vectors for spacing into O'Hare" while still over Kansas. Once we were on Chicago Approach frequency, we heard that airliners were being vectored and even put in holds. Meanwhile corporate jets and light GA airplanes sharing the supposedly crowed airspace were given unimpeded access to reliever and outlying Chicagoland airports. It was airliners at O'Hare, not GA airplanes, that caused the delays.
If you're traveling to a destination served by a general aviation airport, and especially if you can go nonstop by GA when an airline routing requires you to change planes at a hub airport along the way, then GA has a clear scheduling advantage over the airlines.
Life Without Delays And Cancellations?
The reality is that most flight delays and cancellations are caused by factors that would delay owner-flown GA airplanes as well. The only true benefit of personal aviation over the airlines in terms of scheduling comes when your destination is far removed from a non-airline airport but is served by a general aviation airport, or when your destination is within nonstop range of your departure point but would require a change of planes to travel through the airlines' hub-and-spoke system.
Instead of a slogan that strongly suggests GA airplanes avoid the delays and cancellations common to one out of every three airline flights, I suggest GA manufacturers proclaim, "Take personal responsibility for your scheduling decisions." This acknowledges that GA is subject to most of the same delays and cancellations as the airlines, while emphasizing that the decision is in the hands of the traveler, not a nameless airline employee. That level of empowerment makes me wish I could buy an airplane. It probably appeals to you, too.
Fly safe, and have fun!
Thomas P. Turner's Leading Edge columns are collected here.