GPS -- right at the right time

Someone commented as follows on our post about the "Quieter Skies" article in the Seattle Times:

Didn't you people advocate for GPS system during the planning period for the third runway? And now you seem to be against it. Come on!

That's a fair comment, & deserves an answer.  We & others advocated GPS technology for Sea-Tac Airport as a way of avoiding the need (supposed need) for a third runway.  With the use of that technology, the Airport would have been able to handle the traffic projected for many years into the future.  

At the very least, a third runway could have been built on the existing Airport campus, which would have made quite a difference in terms of noise impact, as well as saving a billion or so in costs..  This was pointed out to the Port Commission as long ago as 10 July 1996 by none other than Frank Hansen, member (& sometime mayor) of the City of SeaTac.

Now, we are looking at a different situation.  Instead of handling traffic at levels of 1996 - present, the planners are looking at a huge new volume of traffic.  The concern is that even with the third runway, the Airport won't be able to handle future traffic.  As compared to 1996, we are at overload now in terms of Sea-Tac noise, & no relief in sight.  Adding even MORE overflights by means of GPS technology or anything else would simply make a bad situation a lot worse.

For its intrinsic benefits, YES, to GPS technology.  As to more traffic at Sea-Tac, a resounding NO !  What is needed is a new airport, somewhere else.

Quieter skies? Or noisier?

Will new avigational equipment reduce noise from Sea-Tac?  We're skeptical.

The Seattle Times, in a front-page story in its issue for Sunday, 30 August, touted a new avigational system, under consideration for Sea-Tac Airport.  The Times said, "It promises to save airlines big money on fuel while cutting overflights, noise, and carbon emissions for people on the ground."  

The article reports on a recent test flight of an Alaska Airlines airplane equipped with what is called "NextGen" avigational gear.  According to the Times, Alaska Airlines projects reduced overflight noise for 750,000 Seattle-area residents, along with annual savings at the airport of 2.1 million gallons of fuel and 25,000 tons of carbon-dioxide emissions.

The paper quotes the text pilot, Mike Adams, as saying "There is nobody who loses here".

An interesting side note:  Alaska admits that overflight noise affects 750,000 Seattle-area residents.  This is a distinct deviation from the FAA's "party line", which insists that overflight noise only affects a handful of people very very close to Sea-Tac Airport.

On to the main point:  The Times does not explain why this system is projected to reduce arrival delays at Sea-Tac, or elsewhere.  We know, though, that this & other systems based on GPS technology provide much more accurate data as to where a plane is than the present radar-based system.  Knowing where everyone else is allows pilots to fly closer together, & thus more arriving aircraft can be landed in any particular time slot.  The pilots know where they are, they don't have to rely on the air traffic controllers' interpretations of radar -- often obscure.

That sounds good. More plans arriving without more runway construction.  Less reliance on air-traffic control.  Much greater assurance for flight crews as to where they & the other aircraft (& the ground) are.  And, we are told, at a cost of not much more than $1 million per plane.

In the case of the Seattle metropolitan area, it would be possible to design better noise-abatement corridors for arriving aircraft.  The Times ran a map (not shown on the website), with possible corridors for planes arriving from the north.  These planes might come into their landing patterns not up in Snohomish County (as at present) but essentially over downtown.  In other words, over fewer people.  The map suggests that noisy arrivals would not be heard north of, say, the Ship Canal.  Could be.

More importantly, the paper, & Alaska Airlines, are overlooking two vital equations:

(1)  More planes in = More planes out

(2)  More planes = More noise

This will be particularly true for folks under departure overflights (generally regarded as creating more noise for more folks than arrivals).

Areas now receiving more noise from the new third-runway flight patterns would experience even more noise when the NextGen system is deployed.  This is not the same as the Quieter Skies that the Times is promising.

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URL for Times story (not a live link -- paste into your browser):

http://seattletimes.nwsource.com/html/businesstechnology/2009772140_seatac30.html