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Chapter VIII

T-CAS and Mode C

Tuesday, September 20

“What did you find out?”

Deputy Administrator Evans’s tone made the remark sound more like an accusation than a question. It was ten o’clock, and the sixth-floor conference room was fast becoming the central meeting place for the FAA’s higher echelon.

Gary Dennison, Air Traffic System Effectiveness Director, answered.

“Our accident investigation team arrived at the New England TRACON early Monday afternoon. They’re still out there interviewing the controllers and supervisors. They made transcripts of the radio communications and copies of the voice tapes. The transcripts were emailed last night. Copies of the voice tapes were FedEx’d yesterday. We should receive them before noon today. I’ve placed a copy of the transcript on the table for everyone here. We also know from our C-D-R tape that the Brasilia’s Mode C altitude readout showed him at ten thousand, exactly where he was supposed to be. C-D-R stands for Continuous Data Readout. It allows us to reconstruct the flight paths of all the aircraft on the controller’s scope along with their altitudes provided those aircraft are equipped with transponders that have Mode C capability.” Dennison assumed Evans would not know what C-D-R meant, so he threw in the explanation. He was right. Evans had not known.

“Anything else?” Lawrence Evans still sounded like an inquisitor.

Dennison continued. “Seems the controller, her name’s Melissa Jason, was pretty busy, but she had things well under control—nothing out of the ordinary, really. A few of her words on the tape can’t be deciphered, but that’s all.”

“How the hell do you know that some words can’t be deciphered if we don’t have the tapes yet?” Evans was being his usual obnoxious self.

“The transcript has the word ‘unintelligible’ written on it in two places, which means the Quality Assurance Specialist transcribing the tape couldn’t understand what was being said.”

It was clear Evans was not happy. “What two places?”

Dennison placed his finger on the transcript in front of the Deputy Administrator and pointed. “Here at zero four four zero one six coordinated universal time and…”

“In real-life time, Gary.” Evans made no attempt to hide the sarcasm.

“Seven-forty and sixteen seconds pm eastern standard time, she’s talking to a Beech Baron being vectored around weather. The transcript shows that she said…” Dennison moved his finger over the words on Evans’s copy of the transcript as he read. “Six three pop ‘unintelligible’ weather twelve o’clock, six miles. The ‘unintelligible’ word doesn’t seem important. The Baron was nowhere near the Brasilia and Centurion.”

“Sounds okay,” remarked Evans.

Dennison shook his head from side to side as he spoke. “Actually it’s sloppy. She didn’t precede the numbers of the call sign with the word ‘November’ or the type of aircraft. The phonetic pronunciation for the letter p is ‘papa’, not ‘pop,’ and she’s supposed to use the phrase ‘precipitation returns’ or ‘cells,’ not the word ‘weather’ when issuing that kind of information. She made similar errors on her initial contact with the Centurion, including not identifying the station reporting the altimeter setting or advising him as to type of approach to expect.” Dennison hadn’t spent two years in the evaluations division for nothing, and he wasn’t about to pass up the chance to show the Deputy Administrator he knew his business.

“Did those phraseology errors cause or contribute to the crash?” Evans practically growled the question.

“Hardly.” Dennison suddenly wasn’t sure he should have said anything.

Evans continued the growl. “Make sure the on-site team we sent to New England briefs our Ms. Jason as to proper phraseology and make damn sure she doesn’t have an attitude. The last thing we need in a videotaped deposition or in a courtroom is a controller coming across as flippant or arrogant, especially in this situation.”

Evans scanned the transcript. “What the hell is this!?”

Dennison’s eyes went to the spot on the transcript indicated by Evan’s finger. “Oh, that. The Brasilia pilot thought he was on the PA system when he transmitted the welcome-aboard spiel to the passengers. Actually, he was on frequency. Jason, of course, heard it and decided to yank his chain a little by letting him know he had transmitted over the frequency instead of the PA system.”

“Great, just ‘fuckin’ great! The press is gonna love that. I can see the headline now, Controller Yanks Pilot’s Chain Then Runs Two Airplanes Together.” The Deputy Administrator was clearly irritated.

“There’s nothing to indicate she ran them together.” Dennison spoke quietly, trying to keep the conversation productive and civil.

Evans shook his head. “That won’t stop the press from making us look like bumbling idiots if they get their hands on those transcripts and tapes and decipher those smart-ass comments. That transmission makes us look like clowns even though it had nothing to do with the crash. Don’t release any information until you have to. If the media files an F-O-I-A request for the transcripts, delay it to the maximum time limit. If you get any questions from the press, tell them we’re gathering information and that we will not speculate about anything. Where’s the other unintelligible word on this transcript?”

Dennison’s eyes scanned his transcript. “It’s here, “pointing to the same spot on Evans copy. “Just after she kidded the Brasilia pilot, she made a transmission to the Centurion pilot. I spoke with the Quality Assurance Specialist at New England approach. She told me the tone of Jason’s voice on the tape indicates that Jason was still kidding with the Brasilia pilot when she did it; kind of a second shot, if you will. We’ll get to hear it for ourselves as soon as the tape arrives.” Dennison knew Evans was going to explode. He didn’t have long to wait.

It was a minor eruption. “Terrific!” The sarcasm really dripped from the Deputy Administrator. “And just what did our ace-of-the-base controller say to the Centurion pilot?”

“According to the transcript, she said, ‘Cessna four niner Romeo “unintelligible” one one thousand,’” replied Dennison.

Evans responded. “That means it was unintelligible to the Cessna pilot also. Okay, things are looking up. There’s only one word that’s unintelligible, and one one thousand is clear. We know the Cessna hit the Brasilia at ten thousand since we have the Brasilia’s Mode C altitude readout showing him at ten. There’s no such thing as a one-word clearance, so the dummy flying the Cessna obviously descended out of eleven thousand without authorization.”

“We don’t know what the Cessna pilot heard,” corrected Dennison. “The transcript is prepared from the tape. The tape and tape recorder equipment are old. What’s recorded on the tape can be distorted for a variety of reasons. What the pilot actually heard through his headset could have been C-A-F-B.”

The look on Evans’s face told Dennison the Deputy Administrator didn’t get the mnemonic. Dennison enlightened him. “Clear as a fucking bell.”

Service Director Eric Jarutz stole a quick look at Sharon Doell. She never flinched. Jarutz and Doell had already told Evans that there was nothing in their investigations that presented a problem. Eric Jarutz had reviewed the New England TRACON’s airspace and determined it was designed according to all the appropriate specifications, although he made a mental note that it did look like a jigsaw puzzle. He kept that revelation to himself. Sharon Doell had read the results of the facility’s two previous full evaluations, and with the exception of them noting a few minor administrative “bookkeeping” errors, there was nothing in either report that pointed to something that contributed to the accident.

Evans pressed on. “What about some kind of warning indicating that these two planes were on a collision course? I thought we had equipment that gave us that kind of information. Do the words ‘Conflict Alert’ ring a bell?” Evans was still being sarcastic.

“We do,” said Dennison, “but the Mode C altitude reporting equipment must be working on both aircraft in order for our Conflict Alert equipment to tell us if something is wrong. The Mode C portion of the Cessna’s transponder was inoperative, therefore, our equipment could not compare the altitudes of the two aircraft and had no way of knowing their altitudes were starting to conflict.”

The look on Evans face was not a happy one. “Does that mean the Cessna pilot was flying without proper equipment and we didn’t catch it?”

Gary Dennison repressed the urge to exhale slowly. He wondered how Evans got to be Deputy Administrator with so little knowledge of the system, but then again, he was a political appointee.

“No, sir. The Mode C altitude readout in the Cessna failed while en route. A controller has the discretion to allow a flight to continue with Mode C inoperative, even if it’s above ten thousand. Boston Air Route Traffic Control Center approved that operation for the Cessna and passed the information on to the New England TRACON by placing it in the remarks section of four nine Romeo’s computer generated flight progress strip. Every controller who was going to be in contact with the Cessna received the aircraft’s revised strip showing that its Mode C altitude readout was not working. The Cessna pilot reported in at eleven thousand on initial contact with New England, but when he descended out of that altitude, the controller had no way of seeing it since the Cessna’s altitude readout was not being generated on the scope.”

Evans continued his probe. “What about T-CAS? Wasn’t the Brasilia equipped with that?”

Dennison replied. “The Terminal Collision Avoidance System works off of the aircraft’s onboard computer comparing its Mode C readout to that of another aircraft’s Mode C readout. If the computer thinks the two altitudes are in conflict, it generates an alert directly to the flight crew. The problem was that the Brasilia’s T-CAS equipment had no way of comparing the Cessna’s altitude to its own altitude since the Cessna’s Mode C was not operating. It was the same problem our ground computer had. It did not have two altitudes to compare because it wasn’t receiving one from the Cessna. Our computer had no way of knowing that the two planes were in conflict, consequently, no conflict alert. Additionally, with all the rain in the area, it’s more than likely the Brasilia crew never saw the Cessna’s radar return on their weather radar because the target blended in with the precipitation returns. The same was true for the Cessna pilot. I doubt he ever saw the Brasilia’s radar return on his weather radar for the same reason. It’s highly unlikely the Brasilia crew knew the Cessna was closing in on them or that the Cessna pilot knew the Brasilia was closing in on him.”

“Why the hell don’t we have better equipment?” snorted Evans.

Dennison took a chance. “Ask Senator Alread.”

Evans glared at him then continued. “We’re going to have to move very cautiously. I know that Alread has already made some calls and that these transcripts and a lot of other information are already in the hands of some high-powered Boston law firm. Normally, it takes a lot longer to get those things, but obviously, the senator has connections. On the plus side, he doesn’t have copies of the voice tapes from the New England TRACON or from the Brasilia’s cockpit voice recorder—at least, not yet. I’ll keep it that way for as long as possible. That will give us the time we need to feed the press what we want them to know. By the way, what exactly does TRACON mean?”

“Terminal radar approach control.” It was Dennison. Dennison felt very uncomfortable. He wasn’t the only one.