Monday, April 30, 2007


Well, it's all the American pilots' fault, as they keep insisting in Brazil. It must be, it just must!

[The photo, by the way, is from the Kansas State Historical Society and, except for its use of the terms "aerial insanity" and "dip of death-spiral dive-steep banking," has nothing to do with the case in Brazil.]

So far, though, evidence that is not in dispute shows that the Sept. 29 accident was caused by a series of misfunctions, malfunctions, screw-ups and maybe outright malfeasances at and by air traffic control, on the ground -- abetted in small part by a transponder that malfunctioned for some reason on the Legacy.

For 55 minutes before the crash, Brazilian air traffic control overlooked the fact that the Legacy transponder wasn't signaling. It is, as I have said here before, part of their job to notice such fairly important things.

Meanwhile, as the Brazilian authorities nervously await the reaction from the 134-page report on the cause of the accident submitted to the Federal Police by ExcelAire, the Long Island charter company that owned and operated the Legacy, Brazil's largest newspaper, Folha de S. Paulo, timidly broaches the subject of whether just maybe the Air Force will have a look at training Brazil's air traffic controllers better -- not that they were in any way at fault, mind you.

Also, you real buffs on this saga will enjoy the section below ("Altitude Error") in which it is again mentioned that "large oscillations in altitude" by the Legacy preceded the collision. In fact, the large oscillations recorded on the busted-valise of air-traffic control technology in Brasilia were figments of the radar system's crazed technological imagination, not actual depictions of altitude changes being made by the Legacy, which flew steadily at 37,000 feet under prior ATC orders.

Remember, the oscillations were seized upon by the Defense Minister Wonderful Waldir Pires and others to charge that the Legacy pilots were doing performing illegal stunt maneuvers over the Amazon at the time of the collision to show off the plane?

Turns out "in reality," as Folha now says and as everyone in world aviation has known practically since day one, and as I have been reporting since October, the oscillations were caused by a technical failure in the radar. Back in early October, I mentioned well-known faults in Brazil's radar system that every international pilot is aware of. Wonderful Waldir practically had a stroke rushing to denounce this calumny.

The tone coming from Brazil now seems so say, well, we'll get around to looking at maybe making some corrections in this broken system .. manana, or should that be amanha in Portuguese?

Meanwhile, I'll be posting the full 22,000-word ExcelAire report, in English, properly translated by our Sao Paulo bureau chief Mr. Pedicini ... manana.

Here's Folha's blurb on Page One to an inside story:

"Seven months after worst airplane disaster, Air Force still has not implemented security measures

The Brazilian government has still not implemented safety measures that should correct flaws in the air traffic control system, seven months after the country's worst airplane accident, in which 154 people died.

One of the principal initiatives waiting for implantation is the change in the software that "translates" the radar data into screen information. According to the FAB, it could have confused the controller.

The controllers should also have been trained in flight clearances (authorizations), hand offs to to other centers and procedures for communications losses. No classes have taken place.

The Air Force says that it is studying alterations in the control software and that the controllers' training should only change after the accident investigation.

Of the announced measures, the only ones that have been taken are the changes in the manual, and English classes. Page C1

And from C1:

Folha de São Paulo

FAB analyzes changes in air traffic control

other side


Questioned by the Folha about the implementation of changes in air traffic control software because of the preliminary results of the investigation into the Flight 1907 accident, the Air Force Command informed that there is a "list of suggestions" under analysis and still not approved. On the training of controllers, it said that suggestions will be adopted only after the conclusion of the Air Force investigation.

Without citing the recommendation to add an audio or visual alert, on the screen, in case of the loss of a plane's transponder signal, the FAB affirmed only that software changes may be contracted in the future, but did not say when.

"These suggestions are in analysis at Decea [Department of Air Space Control] so that, if they are approved and after the necessary details are determined, they can be included in the next version of the software to be contracted to be applied in future modernizations", said the FAB's official note, signed by brigadier Antonio Carlos Bermudez. No forecast was made about possible training for controller, nor the topics to be covered.

"After the conclusion of the accident investigations, if there is any recommendation relative to controller training, Decea will promptly adopt it, always with the greater objective of increased safety in air activities", the text said.

The FAB did not respond to the questions about the updating and application of rules about loss of communication with aircraft on the part of air traffic control. It said that, in this case, it it up to the pilot to activate the emergency code on the onboard equipment and follow the flight plan.

The FAB also said that Cenipa and Decea "are unaware of" the preliminary suggestions of the NTSB (National Transportation Safety Board), which officially participated in the aeronautic investigation in conjunction with Brazilian authorities. "It is worth emphasizing that all the suggestions of a preventative nature are opportune and will be evaluated", the note said. (LS)

Radar image showed transponder failure

Brasilia Bureau

On the day of the accident, the Legacy's transponder became inoperative after passing Brasilia and impeded the triggering of the anti-collision system and left air traffic control without an altitude reading.

Instead of warning of this, the data on the controller's screen were automatically exchanged for imprecise altitude information, calculated by the primary radar - which doesn't use data sent by the aircraft.

In the Legacy's case, the controller received information which varied from 33,700 feet to 38,300 feet, without the jet having left 37,000 feet, as shown by radar images obtained by the Folha.

The controller had presumed that the flight plan was being observed because this information was also automatically updated on the screen. According to the NTSB, this should be revised. For them, this cannot happen without the "clearance" (confirmation or authorization) of the controller who is monitoring the flight.

Series of images shows failures in air traffic control system

First picture shows radar shot with "370=370 ", may be Figure 5. Graphic has overlay identifying it as "29 Sep 2006 - 18:51:33" Note that "Sep"is English, not Portuguese. To right, badly done map - Legacy doesn't pass through Brasilia and Legacy's planned flight from accident site is "to USA", not to Manaus.

  • Radar Functioning Without Problems
  • Before arriving in Brasilia, the radar read the Legacy correctly.
  • The cross sign with a circle around it indicates the position and the radar coverage
N600XL Legacy
370=370 Height reading and altitude programmed in flight plan
46 S077W Heading

Loss of coverage
  • Image shows exact moment of loss of Legacy by secondary radar, at 19:02 (16:02).
  • There is no longer a circle around the target
  • Altitude reading is imprecise, modified with a "Z"
  • N600XL Legacy
    46 S077W Speed and Heading
Altitude Error

  • At this point, the large oscillations in altitude begin. In little more than 10 minutes, at least three different altitudes were registered before the moment of the accident.
  • Legacy continues without transponder and primary radar makes incorrect altitude reading of 33,700 feet. In reality, the plane was at 37,000 feet.
N600XL Legacy
46 S077W Speed and Heading "


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