Pilot Paul's Travel Accessories and Travel News Blog

This all sounds like a great idea, but there is a major flaw in this system.

The data is not collected in an accurate (at least not at Southwest or some of the other "low-cost carriers) or fair manner. It is not a level playing field.

Here's why...

The legacy or major airlines all have equipment onboard their planes that automatically reports when a plane leaves the gate, takes off, lands and arrives at the gate.

This system, called ACARS (Aircraft Communications Addressing and Reporting system), data links the pilots to the company computer systems, the TV monitors in terminals, the dispatch and maintenance headquarters as well as providing updated weather information, and in some regions, to Air Traffic Control.

As an international captain at a major airline, I can't imagine ever being without ACARS. It would be like a business traveler having no cell phone, laptop or Internet access. It would be like having a library card for Internet access and a pocket full of dimes for phone calls. It limitation would have a great impact upon his effectiveness and ability to get critical and routine information.

I'm very glad I fly for an airline that has ACARS because it is a convenience and safety factor.

So how does this relate to the problem of the DOT on time performance ratings?

Airplanes with ACARS automatically report the plane's departure and arrival time and it is all synchronized to the official time in the airline's computer system.

At the airlines without ACARS, like Southwest, the pilot looks at one of the two clocks of two watches in the cockpit, makes a radio call to an agent, who then has to enter it into a computer. Who knows how many different time sources the agent has to choose from?

Remember, that these are all people who want their airline to do well and look good in the DOT on time ratings. I'm not saying that the times are always embellished or "adjusted" to be on time, but the vulnerability is certainly there.

For the DOT ratings, 14 minutes is a magic number. If you are within 14 minutes of the scheduled time, you are considered "on time". One minute over, and you're officially late.

Here's another factor that comes into play but is impossible to consider with the ratings.

Not all airliners fly at the same speed. Many of the new regional jets, as well as the Airbus 320's flown by Jet Blue and Ted, fly much slower than most of the other jets. With fuel prices as high as they are, airlines and pilots are motivated to fly at the most fuel-efficient speeds and altitudes.

That's fine in an isolated environment.

The reality is that planes are usually sequenced and spaced by Air Traffic Control. This is to space the arrivals into large airports with planes coming over specific points at specific speeds and altitudes.

This adjusting or "metering" sometimes begins over 1000 miles from the destination airport.

If there is a slow plane in the front of the pack, everyone behind must fly the slow speeds. Often you are not allowed to change altitudes or pass the slow guys (Jet Blue, Ted, regional jets).

Just last week, I was in a 757 with a normal cruise speed of .80 mach (80% of the speed of sound). For 1000 miles, we were slowed behind an Airbus 320 who could only go .75 mach. This cost us eight additional minutes flying time and we barely made our "on time" DOT criteria. The slow guy either couldn't of wouldn't speed up and we and an entire line of flights were delayed because of it.

It was also turbulent. In our 757, we are required to fly at .79 mach in turbulence. That is for a variety of aerodynamic reasons, and the Boeing flight manual limitations require this speed. The slow Ted flight had us at .75 mach. When I told the controller that we were required to operate at .79 mach, he gave us no relief.

Why the DOT puts such a big emphasis on something that they know has room for great inaccuracies is beyond me.
Because of this, the on time ratings should be taken very lightly.