Friday, June 15, 2007

ADS-B-Cool



You may have noticed all the stories in the press for the last few days about our “outdated” air traffic control system. It’s “outdated” for a reason. But we’ll get to that in a minute. Let’s take a look at the stories themselves. I’ll pick on MSNBC but in reality, it could be virtually any of them because they’re all saying the same thing. They’re doing little more than reading off the FAA’s press release.

That fact alone ought to concern you. Before you spend 40 billion dollars you might want to do a little thinking. Let’s pick the news story apart a little, shall we ?

”Using ADS-B, separations between aircraft can be reduced, airplanes will be able to fly more direct and efficient routes and the increase in U.S. air traffic will be accommodated.

That is a mighty broad statement. What “separations” -- exactly -- can be reduced ? Well, over the oceans (where there is no radar) seems like a likely place. Okay. Is that a 40-billion-dollar problem ? Let’s say the current separation standard (at the same altitude) over the ocean is 100 miles and ADS-B can cut that down to 10. What happens when they get to JFK ? Do all those other aircraft using JFK suddenly disappear ? Nope. The overseas guys have to get in line just like all the other aircraft. (Please note the phrase “get in line.” We’ll come back to that, too.)

Still, being able to cut your separation standard by 90% would be a good thing, right ? Well, not necessarily but we’ll let that slide for the moment too. The key argument in the above excerpt is “...the increase in U.S. air traffic will be accommodated.” How’s that ? You can cram 10 times as many airplane in the sky but where are they going to land ? You didn’t increase the capacity of JFK airport ten times. ADS-B is some pretty cool magic but it can’t defy the laws of physics.

”It (ADS-B) has produced a 40 percent drop in Alaska's traditionally high accident rate.”

That statement morphs a little more each time I see it. I think it’s more than a little bit fishy but suffice it to say that the rest of America isn’t the Alaskan bush. And I don’t think we’re going to spend 40 billion dollars just to make it safer to fly into the back country of Idaho, Wyoming or Georgia.

”A big part of the problem is that the U.S. air traffic control system is based on ground-based radar technology that is increasingly incapable of handling the growing volume of traffic — particularly in bad weather.

I’ll grant them this. Satellites are sexier than “ground-based” radar. No doubt about it. But are they better ? Look on any U.S. warship. Does it have radar ? You betcha. What about all that “Star Wars” stuff ? How do they get one missile to hit another missile (which you have to admit, is a pretty amazing feat) ? Oh yeah, that would be with radar. And speaking of “bad weather”, how do we know that “bad weather” is coming ? Yep, that would be (weather) radar. “Ground-based” weather radar.

ADS-B (that’s Automatic Dependent Surveillance-Broadcast by the way) is a pretty neat system with a few neat advantages. One advantage is that it’s cheap. Well, cheap to the taxpayer anyway (after the first $40 billion or so -- maybe.) It’s cheaper because a lot of the cost is off-loaded to the airplane owner. The owner has to pay for a piece of equipment that sends out a signal with all the neat information that controllers and other pilots will use to keep everybody separated. Of course, if he doesn’t want to send that information out all he has to do is turn it off. Or have an electrical failure. So terrorists, drug-runners and an aircraft (say your aircraft) that suffers an electrical failure (otherwise known as an emergency) will disappear. That seems to be what no one wants to say. ADS-B won’t replace radar. It can supplement it but it can’t replace it. Where are we saving all the money if we have to run two systems ?

I know. We’ll save it by being able to run airplanes closer (reduced separation) and airplanes will be able to fly more direct routes and everybody will save fuel. Or not. Let me ask you a couple of questions. If we put some whiz-bang contraption on your car and you could reduce the “separations” between the cars you see flying down the interstate, would you want to ? Do you really want that 18-wheeler looming in your rearview mirror to get closer ? How about when you pull into the parking lot ? Can you get any closer to the car in front of you ? Would it get you into a parking spot any faster if you could ?

These things don’t change when you’re talking about airplanes. Increased spacing equates to reaction time. You know the rule -- an extra car length for every additional 10 mph of speed. There’s a heck of a difference between 55 MPH and 550 MPH. And keep in mind -- airplanes don’t have brakes (once they leave the ground. ) To get into the garage (the airport) they do the same thing that you do. They “get in line.” And instead of stretching down the block, their line stretches a couple of hundred miles.

Tell me again where those fuel saving are ? You were calculating your fuel savings for your car when you were reading the above weren’t you ? What’s that ? You were thinking about your safety ? Safety over money ? Surely you jest. Get with the program. You were supposed to be thinking “more like a business” just like the current Administrator of the FAA is telling you to think. What’s wrong with you ?

Oh, I was supposed to get back to the “outdated” part wasn’t I ? The air traffic control system doesn’t run on the latest version of Microsoft Vista. I was reading a thread on a BBS I visit and it had a perfect explanation of the FAA’s software. In answer to the complaints about the bugs and security flaws found in virtually all of the modern software it was noted that you actually can have nearly perfect software. It’s extremely expensive, enhancements come very slowly, it isn’t the least bit sexy and it is always “outdated.” We don’t use unproven technology (including software) in air traffic control. That’s a good thing. And the folks calling it “outdated” know it.

Don Brown
June 15, 2007

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