Tag-Archive for » air traffic control «

GE Aviation: Paths of Flight

Via the Ghost of a flea, a short but fascinating video illustrating the complex aerial ballet that is modern air navigation.

GE Aviation designs engines, flight paths, and advanced aircraft systems. And we wanted to share the intricate choreography of flying in all its glory. So we captured all the take-offs and landings that happen over the course of one day and combined them into one short film. Watch, and see the hidden beauty of flight reveal itself.

More details—including a “making of” video—at the GE Show site.

Category: Aeronautics  Tags: ,  Comments off

Port-au-Prince, before and after

Len, 767 captain and author of Views From The Left Seat, has crafted a pair of posts that amply illustrate some of the problems with Haiti’s aviation infrastructure.  Haiti’s weak national government and longstanding social malaise are well-known and well-documented, but it is informative to see that the lack of rigour extends even into the highly disciplined arenas of air traffic control and airside management.

The first, written on December 4th, 2009 (before the earthquake) paints a picture of what we in North America might generously call “relaxed” operational and security discipline.

The climb up to FL 370 was uneventful. 600 miles later and approaching Haitian airspace, we said “goodbye” to Miami Center and gave Port Au Prince Control a call.

No response.

Five more calls and they finally answered. Had they not answered we would have been forced to hold at the boundary of their airspace. Glad they answered since we had a small thunderstorm to contend with right along our route.

While descending, we passed an opposite direction outbound airliner 1000 ft below us and wondered why we weren’t advised? A call to Approach Control about that went unanswered.

…We parked, set the brakes and once the ground crew had positioned the boarding stairs, the cabin crew opened two cabin doors. Out flooded the passengers onto the ramp with wild abandon! They all knew where to go but it was almost comical to see so many unattended people on an airline ramp with absolutely no security concerns whatsoever!

—  Len.  “Third World Operations.” Views From The Left Seat, 4 December 2009. [Emphases are mine]

The second post, written on March 20th, 2010, illustrates what air traffic control services were like after the quake—and after Haiti’s own controllers took over from the combat controller services provided by the US Air Force.

It was business as usual until we had to switch over to Port-au-Prince tower.

Descending in, we were cleared for an ILS to runway 10 with a circle to land on runway 28. But we were only given a clearance to descend to 5000 ft and to report inbound on the ILS. OK fine…So we continued on in and reported inbound but the controller was apparently too busy or distracted to hear us. We kept calling until he finally answered us and asked where we were? “We’re overhead the field at 5000 ft” was our answer! He seemed surprised and promptly cleared us back to the initial approach fix and gave us instructions to hold and await further clearance.

20 minutes later he cleared us for the same approach and for us to call the field in sight and to enter a downwind for runway 28. So we did all that and set up for the landing. Meanwhile he cleared a Canadian Air Force C-17 to back-taxi for takeoff on runway 28. As we turned final, the tower amended the C-17’s enroute clearance which resulted in them not being ready for takeoff. With us now on short final and the C-17 still on the runway, we had to execute a go-around and get back in the pattern.

So now we’re back on final and the tower has cleared the C-17 for takeoff. It all was looking good until the C-17 aborted their takeoff with some sort of mechanical issue. We had no choice….another go-around!! We broke off to the right and started a climb. Just then we received a traffic alert on our TCAS with instructions to “CLIMB, CLIMB”. I looked out and saw a Cessna Caravan doing a steep turn to avoid us as we were climbing and turning in the other direction. That was close!

We asked the tower for instructions and all he could tell us was “go hold east of the airport somewhere”. He was completely flustered and not in control of his airspace. Now a clearance like that in the real world is just unheard of! We were clearly on our own this day.

After several minutes of us circling low over the city, he told us to come on in and land. By then we had lost sight of the airport so we had to rely on some basic VFR skills and dead reckoning to re-acquire the airport.

—  Len.  “Port-au-Prince (After The Quake).” Views From The Left Seat, 20 March 2010. [Emphases are mine]

Now to be fair, aircraft convergence conflicts are not entirely uncommon.  Close calls with little (or not forceful enough) warning from air traffic controllers can happen anywhere—in fact a similar incident involving a United Boeing 777 and an Aeronca 11AC occurred near KSFO on Saturday.  Planes travel at hundreds of miles an hour, so you may have only seconds to identify that little dot at your 11 o clock before it ends up in your lap.  This is why large aircraft have onboard radar and TCAS systems, and smaller “pocket” versions (using transponder signals) are available for GA pilots.

The more worrisome aspect is that the controllers (before the quake) were lackadaisical about answering calls from aircraft; this says something unkind about their professionalism even under ideal circumstances.  In the “after the quake” situation, the controller got overwhelmed, lost the picture, and did not give proper radar vectors (i.e. “turn left heading 060, maintain 8,000, follow published missed approach procedure and hold”).  That could have had disastrous and fatal results, especially if the converging aircraft lacked TCAS equipment.  Fortunately, Len survived to blog about it; not every pilot is so lucky.

The problem isn’t just that Haiti has lax standards, or even lax enforcement of rigorous standards (whether in aviation, building codes, or otherwise).  As Publius at Gods of the Copybook Headings pointed out some months ago, Haiti had no economy to speak of, even before the quake.  It is the poorest country in the Americas; with GDP per capita running at a paltry USD $1,300—or three and a half bucks per person, per day.  Government corruption is rampant, which lead the United States (among others) to end aid in 2000.  The BBC reported in 2004 that “that some 70% of assistance [to Haiti] found its way into the pockets of corrupt officials”.  It’s important to note that without foreign aid, the government of Haiti would literally cease to function.

Haitians themselves need to understand how institutionalised corruption (and social tolerance of it) retards their country’s economic and social prospects; if they cannot bring about significant political reform, all the money in the world cannot drag their country out of entropy and into modernity.

RELATED: Robert Kiltgaard of AEI offers a prescription for tackling corruption in Haiti’s government.

Category: Aeronautics, Foreign Affairs  Tags: , ,  Comments off

The FAA does not share your sense of humour

On February 17th, someone at JFK Tower had their child with them, and subsequently let the child issue instructions to aircraft.  (The instructions were takeoff clearances and then handoffs from JFK Tower to the New York TRACON controller, not issuance of any radar vectors or changes in assigned altitude.)  As you can hear in the audio clip below, pilots communicating with the child seemed to take in it a humourous spirit, but that was evidently not the case with the FAA, which has suspended those involved from ATC duties pending the outcome of an investigation.

Before we go any further, it’s worth remembering that first, a fully-qualified controller was looking over the kid’s shoulder at all times (just they would for ATC trainees), and second, aircraft entering and exiting busy Class B airspace like New York follow pre-planned departure and arrival routes.  These are known as SIDs (Standard Instrument Departures) and STARs (Standard Terminal Arrival Routes).  Here is one of the SIDs for John F. Kennedy Intl. Airport:

KENNEDY ONE (JFK1.JFK) Standard Instrument Departure. Click image to enlarge. (This example not for use in actual flight operations—get current charts from officially approved sources.)

The destination and enroute routing of your flight will determine which transition your aircraft flies, but as you can see, the routes are not random, they are well-defined.  The SID is assigned while the aircraft is still on the ground, so the pilots have ample time to look it up and familiarise themselves with it.  The runways in use will also be obvious (via automated ATIS, listening in on TWR’s freq, or simply asking the clearance delivery controller while he’s examining your flight plan).  By the time of your handoff from tower to the departure controller, where you are headed and how you will get there is no great mystery.

Aside from the violation of federal aviation regulations—no small matter, to be sure—my only (minor) beef is that the kid’s handoff call didn’t include the next facility’s full name and frequency.  It should have been something like “JetBlue 171, contact New York Departure on one-three-five decimal niner, good day.”  Still, for an amateur, it was a fairly creditable job.

As highly regimented a creature as aviation is, it is still staffed and run by human beings, with all of the virtues and foibles that entails.  In my younger days (pre-September 11th), I had dated a woman whose father was a very senior controller at Nav Canada.  When the young lady flew from CYYZ to various destinations abroad, she would inevitably get called to the cockpit to chat with the controllers on duty—friends of the family—who had known her from the time she was a child.  If there were delays in departing, these controllers would subsequently prioritise her flight’s departure above all others (excepting medevacs), which was no doubt a pleasant surprise to the captain of said aircraft.

We live in a human world, and humans—by nature—are going to deviate from the script every now and then.  Determining the difference between harmless and harmful deviations is not always easy (especially when inflexible bureaucracies become involved), and one hopes the controller and supervisor at the heart of the matter don’t lose their jobs over this.

RELATED: Ars Technica has a terrific article on the science and technology of air traffic control.

ALSO RELATED: Kent Wien, Gadling.com’s resident 757/767 driver, notes that this is why IFR flights require detailed readback of instructions, so that there is no mistake about what the aircraft is expected to do in the airspace.  The pilots departing JFK did read back the kid’s instructions, and those instructions were not incorrect, otherwise a duly-qualified controller (i.e., the tyke’s dad, or the tower supervisor) would have leaped in and corrected it.

USAF takes charge at Port-au-Prince airport

Airport Arrival, originally uploaded by The Fang.

AFSOC teams arrived at Toussaint L’Ouverture International Airport (MTPP) on Wednesday night and began the process of bringing order out of chaos at Port-au-Prince’s primary airfield.  Elements of the 23d Special Tactics Squadron (23 STS) and 720th Special Tactics Group (720 STG) are providing air traffic control and airfield services, medical support, and weather observation/forecasting.  (More information available via yesterday’s DoDLive Bloggers Roundtable interview (embedded below) with Lt. Col. Brett Nelson (USAF), 23 STS Commander and Maj. Jason Daniels (USAF), director of operations for the 720th Operations Support Squadron.

Some noteworthy items mentioned in the interview:

  • The airport is open 24 hours; airfield lighting is operational and USAF brought additional portable lighting as well.
  • Traffic flow at the airport is constrained primarily by ramp space and fueling equipment.  There are only 12 ramp spaces, 2 fuel trucks and 2 tow bars.  One foreign aircraft (identified as Chinese in other reports) required 6 hours to refuel, which is considered a significant delay.
  • Peak capacity seemed to have been when there were 44 aircraft on the ground; the more aircraft there are crowding into the small ramp, the harder it is to download cargo and upload evacuees.
  • USAF is working with the FAA to try to prioritise air traffic and try to get the most urgent cargo and equipment to the airfield at the time they are needed.
  • Due to the limited logistics capability at the airfield, USAF would prefer that aircraft arriving at Port-au-Prince have enough fuel to depart again.
  • Status of the petro tank farm is not known.
  • USAF looked at using an additional airfield (Cap-Haitien International Airport, MTCH) to facilitate traffic flow, but determined that its potential throughput is “not that significant”.

RELATED: CNN producer Larry Shaughnessy was present on the call and has penned a pretty good summation of the effort at MTPP.

Delhi airport loses ATC systems for an hour

365 Days – Day 63, originally uploaded by konrad_photography.

Last night, Delhi’s Indira Gandhi International Airport (VIDP) and its enroute air traffic centre (Delhi Center, VIDF) lost radar data and had to revert to the old-fashioned method of separating air traffic:

“With no radar available, the radio system was the only way of knowing their position,” said a senior air traffic control officer, refusing to be identified, about the situation in the tower.

The radar shows to air traffic control the exact coordinates of planes in the air, or those waiting to take off, their altitude, their speed and the distance between them — it can get bumper-to-bumper up there.

Air control switched to something called a “manual” process: traffic controllers obtain the position of each plane from its pilot on radio, put it down on a chit of paper and stick it to a scrabble kind of a board.

“We knew the exact position of the aircraft and had to segregate them further so they stay away from each other,” said the traffic control officer, admitting a small human error or an oversight could have proved disastrous.

— “Airport radar crash: 60 mins on brink of disaster.” Hindustan Times, 14 January 2010.

Needless to say, nothing went horribly, fatally wrong or you’d be seeing it on the news this morning.  The procedures for dealing with communications or radar failure are well-known and part of pilot and ATC training.

The Hindustan Times is sort of overselling the risk factor, given that 1) Delhi was able to switch seamlessly from the old, crashed Raytheon AutoTrack II system to the brand-new AutoTrack III, which was conveniently already installed and being-shadow-trialled for six months; and 2) most commercial airliners these days fly with their own onboard traffic collision avoidance systems (TCAS).

Indian Express has a less breathless and saner account of the goings-on.

V Somasundaram, executive director (air traffic management), Airports Authority of India, told Newsline: “The computer system that provides all aircraft-related data to the Delhi ATC failed at 5.44 pm on Thursday. The system was rebooted and put in place by 7.30 pm. But the controller used other channels of communication with pilots and aircraft in this period.

“Aircraft that usually maintain a distance of five nautical miles from each other in the air were forced to fly 12 to 15 nautical miles apart as a precautionary measure,” the official said. “This led to a delay in landing, and the subsequent chaotic situation.”

— Gupta, Geeta.  “Software crash grounds IGI for 2 hrs.” Indian Express, 15 january 2010.

Category: Aeronautics, Foreign Affairs  Tags: ,  Comments off

Coming again, to save the motherf*!#ing day

When a major disaster occurs, the world rightly leaps to respond as fast as possible.  Owing to their speed, aircraft are usually designated to carry in the first wave of relief supplies and personnel, with the much greater capacity of sealift following up in the days afterward.  For example, Canada has sent strat- and tac-lifters full of relief supplies, light utility helicopters and personnel to beleaguered Haiti.

But what happens when local air traffic control services are also out of action?

The earthquake that devastated Haiti also rendered its highest-capacity aerodrome (Toussaint L’Ouverture International Airport [MTPP]) unservicable by causing severe damage to its control tower.  Aircraft enroute to Haiti were diverted to other airfields within the region, and, as usual, the United States stepped up to conduct the initial damage assessment and air traffic control triage.

Initial assessments of damage were made in overflights by a U.S. Navy P-3 Orion.

…A member of the U.S. State Dept. Haiti Task Force said the U.S. Coast Guard was operating flights into the airport that were controlled from a USCG cutter operating in the bay outside the city. A U.S. government team was expected to arrive later on Wednesday to begin air traffic control in place of the tower.

— Ott, James.  “U.S. Provides ATC Support To Haiti.” Aviation Week, 14 January 2010. [Emphasis mine]

UPDATE 140100Z JAN 2010: USAF has taken over air traffic control duties with the arrival of AFSOC units—23d Special Tactics Squadron (23 STS), 720th Special Tactics Group (720 STG).  They are focusing on ATC and airfield services, medical support, and weather observation/forecasting.  More details are available through the DoDLive Bloggers Roundtable recorded yesterday (and embedded below).

Category: Aeronautics  Tags:  Comments off

A 380,000 pound, 4-engine airliner will be zipping around the Statue of Liberty at 1500 feet, but you have to keep it a secret

vc25_f16_nycImage: VC-25 and F-16 escort over lower Manhattan yesterday.
From istolethetv‘s Flickr photostream.

….from who?

Jim Peters, an F.A.A. spokesman, said “the photo op was approved and coordinated with everyone.” Notification was made in advance to the mayor’s office, “including its 911 and 311 operation centers,” the New York City Police Department, the New Jersey State Police, the United States Park Police and other agencies, he said.

The Police Department confirmed that it had been notified about the event but said it had been barred from alerting the public. “The flight of a VC-25 aircraft and F-16 fighters this morning was authorized by the F.A.A. for the vicinity of the Statue of Liberty with directives to local authorities not to disclose information about it but to direct any inquiries to the F.A.A. Air Traffic Security Coordinator,” the Police Department said in a statement.

— A. G. Sulzberger AND Matthew L. Wald.  “White House Apologizes for Air Force Flyover“, New York Times [City Room], April 27th, 2009.

Certainly not very secret from the bystanders on the ground.

I’ve been trying, without much success, to find an FAA or DoD NOTAM regarding this event—anyone else have any luck?  It’s typical to keep presidential flights hush-hush and not issue a NOTAM until the last minute, but this wasn’t a presidential flight, we’re told.

(Via Castle Argghhh!)

UPDATE: As BillT asks in the comments at Argghhh!, where were the photographers?  The majority of F-16 Fighting Falcons are single-seaters, unless they specifically chose to fly a two-seat B/D/F-model trainer for this mission.

UPDATE 281902Z APR 2009: The authorities have reportedly cancelled a second VC-25 photo op, over Washington D.C.  That’s a shame.  The lesson you should have learned, fellas, is not that big planes + big cities = oh my G-d, run for your lives, it’s that unusual (but planned) events + no prior warning = what the hell are you thinking?  Next time, just let people know ahead of time.  It’s that simple.

TOO MUCH TIME ON MY HANDS UPDATE: Currently reviewing LiveATC’s recorded traffic from yesterday, to try and isolate the VC-25 chatter to ZNY ARTCC.  It’s a lot less exciting that one might imagine.  A lot of traffic advisories from New York Approach (CAMRN) to the VC-25 (which is using 89th Airlift Wing’s “house” callsign, VENUS, as VENUS 1 HEAVY).

Here is some of the chatter as excerpted by John Croft (Americas Editor for Flightglobal.com).  Keep in mind neither the controller nor the pilots have any idea of the mayhem being generated around the Goldman Sachs Tower, for example:

UPDATE 290400Z APR 2009: Major X, an anonymous F-16 driver, makes some good comments over at Joey deVilla‘s blog, especially regarding the use of the Falcon as a camera platform.  He also asks the readers to note which other units (besides 89AW) are located at Andrews AFB.  If you listen to the LiveATC feed above, you will note that the VC-25 (Venus 1 Heavy) refers to its chase aircraft as Capital 92—which would mean an F-16 from 113FW, also based at Andrews.  That explains how the F-16 was selected as the camera platform.  Other than the execrable decision to try and keep this under wraps from the public, it looks like a very ordinary pilot currency mission gone horribly awry.

The other interesting thing the Major notes:

This whole furor is driving me a little crazy. FWIW, I actually spoke to the F-16 pilot yesterday…we go way back. As far as I know, he was the only F-16 flying chase with the photog in back. He was on a conference call THAT MORNING with about 30 different agencies, including the DHS, FBI, NYPD and others. This photo op has been in the works for THREE months. THREE! The idea that Obama or Bloomberg didn’t know is ludicrous.

I can’t say I’m too surprised that the pols appear to be hanging the military out to dry on this one.  There’s plenty of precedent for that.

One note about callsigns. I think it’s safe to say that this definitely wasn’t some kind of super-secret passenger-carrying flight, where the truth is being obscured so as to prevent a politician from being embarassed.

When the VC-25 is carrying the President, its callsign—as we all know—is Air Force One.  When they are carrying VIPs (Cabinet officers, senators and the like) their callsigns are SAM [for Special Air Mission] 28000 and SAM 29000, depending on the tail code of the aircraft being flown.  When they are carrying relatives of VIPs, the callsign will be Executive [tail code].  And finally, when they are just doing the day-to-day proficiency and currency flights, the front-office callsign will be Venus 1 (for aircraft 28000) and Venus 2 (for aircraft 29000).

Venus, incidentally, is the “house” callsign for 89th Airlift Wing.  Plenty of other aircraft types also use that callsign: the C-20s use Venus 2x, the C-37As use Venus 4x, the (now retired) C-9A used Venus 8x, and the C-32As use Venus 9x.

Finally, because the VC-25’s gross take-off weight is over 255,000 lbs, they will have the “Heavy” suffix appended to the callsigns.  And because the front office that day was using “Venus 1” (as opposed to “SAM 28000”), we can assume there were no VIPs or relatives of VIPs aboard.

UPDATE 051716Z MAY 2009: The folks at Potomac Current and Undertow (a blog from/for/about/to the air traffic controllers at the Potomac TRACON) have published the text of a memo from Mr. James Johnston, head of the National Capital Region Coordination Center, which I will reprint here.

FROM: FAA Air Traffic System Operations Security (AJR-2)

SUBJECT: Flight Notification- New York City -Statue of Liberty Photo Op, Upper New York Bay / Newark Bay on April 27, 2009, 10:00L. (amended 4/23)

The information in this document is considered FOR OFFICIAL USE ONLY, and should only be shared with persons with a need to know. Information in this document shall not be released to the public or media.

1. The Department of Defense (DOD), in coordination with the Federal Aviation Administration (FAA), will conduct a flying photo op in the New York City Area on April 27, 2009 involving a transport and fighter aircraft. Below are the details regarding the operation.

• Date: Monday April 27, 2009 (Primary), April 28 or April 30 (weather backup dates)
• Number / Type Aircraft: 1 VC-25 and 2 F-16s. Actual photo op will only have VC25 and 1 F16.
• Callsign: VENUS01
• Departure point: ADW
• Arrival point: ADW
• Flight Plan: Crews will file two separate IFR flight plans:
Requested altitude FL190B210

• Planned Departure Time: 0930 approximately
• Planned Time On Photo Op Location: 10:00 -10:30L.
• Planned Photo Op Altitude: 1000-1500ft
• Number of Passes: 2, possibly 3

The aircraft will depart ADW via IFR clearance as a three (3) ship formation to Sea Isle (SIE). At SIE one (1) of the fighters will leave the flight and return to ADW IFR via SIE ATR V308 BILIT ADW.

The VC25 and 1 F16 will proceed IFR to CAMRN intersection south of JFK. In the vicinity of CAMRN intersection the aircraft will cancel IFR and proceed VFR with New York TRACON (N90) towards the Verranzano Bridge. N90 will hand the aircraft off to Newark Tower (EWR) for the flight in the Upper NY and Newark Bay. Upon completion of the final pass the aircraft will be treated as a EWR departure and pickup an IFR clearance back to ADW.

The photo op portion of the flight will be VFR in accordance with the specified ground track as per the attached map (Attachment 1). On the northbound flight segments the fighter aircraft will be offset to the east by approximately ½ mile. During the southbound flight segment the fighter will re-position to remain offset to the aircraft within the depicted box.

The operation will be monitored by FAA Air Traffic Security Coordinators (ATSC) at the Domestic Event Network at FAA Headquarters from start to finish. Any questions or issues can be directed to the FAA ATSC at the DEN. The FAA ATSC can be reached at (202) 493-5107.

The Public Affairs posture for this effort is passive. No media or press releases are planned. Please direct all media inquiries to the FAA Air Traffic Security Coordinator at (202) 493-5107. Due to the possibility of public concern regarding DOD aircraft flying at low levels, coordination with Federal, State and Local law enforcement agencies, emergency operations centers and aviation units has been accomplished.

AJR-2 System Operations Security
Comm: [redacted]
Cell: [redacted]

In the words of that blog’s author, “This is the type of  stupidity that FAA management creates for air traffic controllers at Potomac TRACON everyday.  We’re glad we could share our experiences with the rest of the country.”

Air France 358 crash was avoidable

First published 03 October 2005.

But lazy, half-assed reporting was not.

Sunday’s Toronto Star had a nice three-page story about the September 2nd incident involving Air France 358 (web version here).  As citizens of this city are no doubt aware, the A340-313X arrived at Toronto Pearson’s Runway 24L in the midst of a severe thunderstorm.  The aircraft did not touch down until almost halfway down the 9,000ft runway, and it did not manage to stop, but ran off the end of the runway and went careening down into the Etobicoke Creek ravine.  The plane caught fire and the composite-based fuselage was almost completely destroyed, although no passengers were killed.

The Star leads off its coverage with a splashy front-page colour photo of the burning aircraft, with the bold headline “THIS COULD HAVE BEEN AVOIDED: An exclusive investigative report into this summer’s Air France crash at Pearson“. CTV News also summarized the story in their web edition here.  Naturally, I was eager to see what Star reporters Scott Simmie, Kevin McGran and Catherine Porter had to say about it.  I thought I was going to hear interesting anecdotes from current A340 pilots, runway design enhancements from GTAA staff, a discussion of the typical decision tree when flying in severe weather, and speculation on what might have occurred in the cockpit during the event itself.

What I got instead was at least one full page devoted to the detailed story of two particular passengers, some idle speculation from lawyers handling the class action suit, quotes from exactly two pilots, four specific recommendations for field improvements to the airport, blasé rebuttals from a GTAA official that at least one of the runway improvements may not be effective in winter, and some very, very sloppy reporting.

I am disappointed in the Star‘s coverage for a number of reasons:

1) Focusing exclusively on airport safety measures and not pilot decision support systems.  Here are the Star‘s four recommendations:

A) Terminal Doppler radar.  Doppler radar allows meteorologists to see inside the storm structure and determine where wind shear is likely to occur.  This predictive function can be automated, with alerts passed to air traffic controllers when wind shear has been detected (or likelihood of it is very high).  ATC would then pass on the warning to inbound aircraft, who would then make decisions about the wisdom of an approach into such conditions.  Pearson International does not have its own Doppler radar but instead relies upon the Environment Canada doppler system based in King City, Ontario.  While this is a great suggestion and Pearson ought to have its own terminal Doppler radar in any event, it does not take rocket science to predict the occurrence of unsafe wind shear within a thunderstorm.  That assumption is routine for GA pilots whose smaller aircraft do not carry their own weather radar.  Although large commercial aircraft regularly fly into severe weather conditions, private pilots in smaller aircraft generally do not.  Why?  Because there are certain life-threatening risks associated with doing so, and you learn that in ground school before they ever let you near your very first prop-driven, piston-engined aircraft.  You don’t need Doppler radar to figure out that thunderstorms are inherently dangerous to flight.

B) Grooved runway surfaces.  Cutting small 6mm grooves, spaced 24-38cm apart, into a runway’s surface can help drain water and prevent hydroplaning.  The grooves are perpendicular to the runway’s direction of travel.  The FAA requires grooving of concrete and asphalt runway surfaces, but Transport Canada does not.  Pearson’s concrete runways were grooved at the ends in the 1970s, but its current asphalt runways are not.  Transport Canada believes the grooving technique may be effective in the summertime, but results in increased maintenance and marginal effectiveness during the winter.  Note also that TSB lead investigator Real Lavasseur has publicly cast doubt on speculation that hydroplaning was a decisive factor in the AF358 incident.  This did not stop the Star’s crack team of reporters from quoting a retired pilot and other experts who speculate that hydroplaning did occur and was in fact a decisive factor in the erosion of AF358’s braking performance.

C) Engineered Material Arresting System (EMAS).  ICAO recommends a 1000ft overrun area and the end of each runway, but not all airports have enough real estate to accomodate large overrun areas.  EMAS mitigates that limiting factor to a degree.  It is special, crushable concrete placed at the end of a runway in the overrun area, designed to crush under the weight of an aircraft, but support the weight of emergency vehicles.  EMAS slows down an overrunning aircraft rapidly by absorbing the aircraft’s inertia while denying its wheels traction, much like a car trying to drive on loose sand.  Airports whose runways end in a body of water have been most of the early adopters for this technology, and it is credited with some impressive saves.  Since the EMAS concrete is very porous, the GTAA has questions about its effectiveness in winter.  In wintertime, the EMAS concrete is likely to fill with water and freeze, increasing its structural strength slightly and raising its weight threshold.

D) Covering over the Etobicoke Creek.  Putting any kind of effective overrun area (EMAS or otherwise) on the 06-24 runways would involve covering over a portion of the Etobicoke Creek ravine.  What the Star doesn’t mention is that covering the ravine and installing a 1000ft overrun area without EMAS would be a big-ticket Bad Idea, as Highway 401 angles northward west of the runway end.  Any aircraft travelling fast enough to have a significant overrun on Rwy 24L may just end up on the 401 westbound collector lanes.  If we install any kind of major overrun area on the 06-24s, it has to have some kind of inherent decelerative properties, like EMAS.

In the Star‘s world, the installation of these four technical solutions at Pearson International would have saved this flight.  And to its credit, the paper’s discussion of the possible field improvements is informative, largely factually accurate and relevant.  But these systems (with the exception of Doppler radar) are essentially a last-minute fail-safe.  Technical means provide some buffer from bad decisions made in the cockpit, but on their own they are utterly inadequate to prevent future tragedy.

For these fail-safe systems to come into play, your flight crew must already have shown questionable judgment and landed under marginal weather conditions… on a very wet runway… without enough room to stop.  With all due respect to the Star, air travellers generally want the avoidance of disaster to consist of more than last minute, on-the-ground airport and runway improvements.  There is no ground-based system which can definitively prevent errors in judgment.  The best flight management systems in the world are up there in the airplane with you, housed inside the skulls of the flight crew.  Getting the right information into that grey matter, at the right time, is critical to flight safety and the best way to avoid screwups.  If your flight crew makes a series of bad enough calls, even the world’s best weather detection systems and a three-mile runway with a thousand-foot EMAS overrun zone can’t help you.  You have to catch each little questionable decision long before they collectively add up to something approaching disaster.  This is generally well ahead of the point where the flight crew is staring at the rapidly approaching opposite end of the runway.

And what about other safety measures, like distance-to-go markers.  In addition to grooving the runway and installing this EMAS overrun zone stuff, wouldn’t it be a whole lot easier and cheaper to give pilots the tools to know what’s left in front of them?  Then they can make their own decisions about whether a full stop or touch-and-go is viable.  Why make them guess and wait for the concrete embrace of Nanny GTAA’s overrun zone?  They are pilots for heaven’s sakes, trained and accustomed to multi-tasking — talking to ATC, maneuvering the aircraft, fiddling with the FMS and avionics all at the same time.  They are not your typical poorly-trained civilian driver who can barely manage to safely maneuver his or her commuter vehicle down the highway while talking on a mobile phone.

2) Non-explicit accreditation of the two quoted pilots.  Neither were Air France pilots, and neither were credited as being currently or formerly rated to fly the A340.  I’m going to excuse the first pilot because he was quoted in context as the head of the Canadian safety branch of the Air Line Pilots Association, and he was speaking about weather detection capabilities at Pearson.  Although he only flies regional jets and turboprops, he has additional knowledge and a role dealing with air safety in a professional pilots’ organisation.  That’s a reasonable linkage.  The second pilot, however, is credited only as being retired from Air Canada, and he was speaking about this particular landing incident.  Look, guys, I know you’re just mere reporters but not all pilots are created equal.  Different airlines have slightly different operating procedures, even for the same type of aircraft.  Not all pilots are qualified to fly every aircraft in the airline’s inventory.  Some pilots are captains and some are FOs (first officers).  Some have additional training duties, like checkrides and pilot qualification.  All of these things have a bearing on the relevance of their commentary to a news story like this.

For instance, my own experience in single and twin piston-engine general aviation aircraft does not make me an expert witness in terms of multi-engine turbofan-powered commercial air transports.  I know what I know, but more importantly, I know what I don’t know.  If you want to know about a particular aircraft’s performance limitations, then talk to someone qualified in that aircraft type, plain and simple.  Don’t find the first off-duty guy with a uniform and ask him to comment about flight systems, avionics and procedures he’s not familiar with.

What made the retired Air Canada pilot worth talking to?  Special training?  Involvement in a similar accident?  Familiarity with Air France’s training doctrine and procedures?  Similar tastes in the choice of neighborhod pub?  His kids play with yours in day care?  Where does his expertise, aside from being a generic ATP-rated commercial pilot, bear relevance to this incident and your story?  Anyone?  Anyone?  Bueller?

3) Failing to follow up on obvious questions.  Leave the fluffy human interest crap at home.  I’m not interested in the devout Iraqi Christian woman who prayed through the whole flight and busted her femur getting out of the burning plane.  Thrilling to some, no doubt, but leave the Reader’s Digest “Drama in Real Life” tear-jerkers for Oprah.  The whole article is supposed to be about how THIS COULD HAVE BEEN AVOIDED, remember?  Where was your editor when the three of you decided to phone in this under-researched story?  Ask some real frickin’ questions for a change:

  • The Star mentions the unsourced Figaro story I mention here, and then goes on to say that the twelve-second delay in reverse-thrust deployment may have been “software related”, even though Airbus’ safety circular after the incident noted no software problems.  This is the simpleton’s method of saying that all of the thrust reverser interlock conditions (wheel rotation speed, main gear compression, throttle setting, radio altitude) may not have been met.  Airbus would not have indicated any software problems because the software is not at fault — even if hydroplaning occurred, no one is going to recommend disabling the interlock criteria for wheel rotation speed — it was operating properly as designed.  Disallowing reverse thrust because not all interlock criteria are present is not a fault with the software (which can not detect a hydroplaning condition) — but with the pilots, who are supposed to assess the risk of hydroplaning long before touchdown, and adjust their landing and rollout procedures accordingly.
  •     * What’s really important is not whether or not the reversers engaged twelve, ten, or even two seconds after touchdown.  Reversers will slice off, at most, 11% of the landing distance on a very wet runway.  Other conditions, such as weather and runway contamination (water, oil, etc.) can totally nullify any landing distance reduction from operational thrust reversers.  Significant tailwinds, for instance, can increase the landing rollout by as much as 24%.  Didn’t any of your pilot sources tell you?  Perhaps none of them were rated to fly the A340, were they?  So I guess they wouldn’t be able to approximate the landing weight of an A340 flying a transoceanic LFPG-CYYZ route with 309 souls (and luggage) aboard, nor estimate precisely how runway and weather conditions affect the length of the A340’s landing rollout.  You know what remedies lack of personal knowledge? Research.  Where the hell was yours?  You could at least find the last reliable METAR, and figure out how much of a tailwind there was.  Would reversers (delayed or otherwise) have made any impact at all, given the late touchdown, tailwind and poor runway conditions?
  • Why did the crew elect to execute an approach when there was significant storm activity on the field?  Significant convection activity (like cumulonimbus clouds [CBs] and lightning) are reliable indicators of the presence of wind shear — i.e. rapid wind direction or velocity changes.  Wind shear is not exactly a new phenomenon to pilots, especially those with enough experience and training to hold an ATP rating and type-certification on multiple varieties of turbofan-powered airliners.  GA pilots are generally advised to stay away from an airport that is showing cumulonimbus (CB) activity within 15 nautical miles of the field.  What sort of restrictions or advisements exist for commercial aircraft?  Were any of these in effect at the time?  What are Air France’s guidelines for approaches into marginal weather.  What, if any, are the decision criteria for diversion to an alternate?
  • Newer A340s, like the A340-600, carry enhanced weather radar with predictive wind shear detection capability.  These systems warn pilots as much as a minute in advance of expected wind shear activity.  Was the A340-313X fitted with these systems, or not?  What sort of weather detection capability (besides the aircrew’s Mk I Mod 0 eyeballs) does it have?  How would these systems have helped or hindered the aircrew in their decision to divert or execute a full-stop landing?
  • The retired pilot indicates that landing with 40% of the runway behind you is a classic “Don’t do it” situation.  The preferred solution to a rejected landing is applying power (TOGA or take off/go around thrust), executing a touch-and-go followed by the missed approach procedure.  Since an aircrew cannot see how much runway lies behind them, how do they know how much runway remains in front?  At what point does the landing become rejected and TOGA thrust applied?  What decision factors lead an aircrew to make this call?  Does Air France include these scenarios in routine simulator drill?  Do any other airlines?  How frequently do they practice it?  How many flights, on average, ever execute a touch-and-go?
  • One of the lawyers suing the airline speculates the plane was low on fuel and had to land or risk fuel exhaustion.  What is the basis for this claim?  Has the lawyer ever heard of a thing called “reserve fuel”?  Does the laywer even know the regulations for flight and fuel planning for commercial transoceanic flight?  Has Air France or any of its aircrews violated any of these fuel planning or must-divert regulations in the recent past?
  • The Star mentions the loss of the anemometer, which gives wind speed and direction information to air traffic control (and hence also to the pilots).  Did air traffic control pass on the anemometer failure to Air France 358, and how would this have affected the aircrew’s land-or-divert decision?  What level of equipment failure is sufficient to jeopardise flight safety and/or shut down the runway?  What are Air France’s regulations for landing at fields in severe weather that have non-operational weather detection gear?

I am just a plebian, non-ATP-rated civilian but I have managed to answer a few of these questions on my own, here on this blog.  I could literally write volumes about this stuff.  If I somehow — horror of horrors — looked upon blogging as a journalistic effort I might even be motivated to write more, but I’m not paid to do this and frankly the idea of being a reporter does not and never will excite me.  I like to do things, not write stories about other guys doing things.  Most of my pilot pals fly GA (general aviation), and the commercial guys I know mostly fly Boeings.  And none of them work for Air France, so I will never be able to answer all the airline-specific questions.

But some folks do get paid to write stories, and among those people are the ones who forgot to ask all sorts of pertinent questions in the course of this so-called investigation.  In the Star‘s case, it took not one but three J-school grads to forget or avoid asking all of these questions.  Yet they still managed to milk this weak article in a major Canadian daily for a full three pages, and many other media outlets picked it up and ran with it — without asking questions of their own.

I stopped reading the Star a while ago, because sometimes while scanning a half-baked, poorly-researched story I could actually feel a net loss of brain cells.  News coverage is supposed to inform the public, not make us dumber for having read it.

Category: Aeronautics  Tags: , , ,  Comments off

Front Office Politics

First published 15 September 2005.

In the aviation world, the cockpit is often referred to as “the front office”.  And just like any ordinary ground-based office, if it is to function well, the people in it need to communicate effectively, with unity of purpose and effort.  In the case of Air France 358, it appears that the captain and co-pilot may have had a relatively minor but hugely consequential disagreement during their landing rollout.

Montréal radio station CJAD (AM 800) cites an interesting story in Paris daily Le Figaro, “Crash de Toronto: les mystères du cockpit” (poor BabelFish translation to English here).  The French newspaper reports it has somehow obtained details of the Air France 358 crash, gleaned from the plane’s FDR (flight data recorder).  The crash was previously discussed here in posts “Good Landing?” and “How Long Is Too Long?”  The FDR, incidentally, remains in the custody of Canadian officials and they do not expect to publicise the data, along with the CVR (cockpit voice recorder) transcript, until October 4th.

According to Le Figaro, the FDR shows that twelve seconds elapsed between AF358’s touchdown and the application of reverse thrust.  Normally, reverse thrust is manually engaged by the pilot seconds after an aircraft touches down.  The onboard computers have a series of interlocks comparing variables like compression of the main gear struts, wheel rotation speed, throttle setting and radio altitude.  When all of these requirements are met, the computer will allow the pilot to move the throttles into the reverse thrust setting.  The twelve-second delay is not in itself damning, because thrust reversers do not contribute that much deceleration; the main gear brakes contribute the most to slowing a landing aircraft.  If you look at the landing distance modifiers chart below, you can see the effect that the reversers have under various landing conditions.

Figure 1. Corrections to Actual Landing Distance

A340_Landing Distance_Corrections

(click to view larger image)

On dry runways, thrust reversers contribute the least amount of braking power (-3% landing distance), because the landing gear wheels have maximal traction and grip on the runway.  As runway conditions change and become wet, the wheels have less traction, and reversers contribute more to the deceleration of the aircraft (-7 to -10% landing distance).  Under icy conditions, of course, the wheels have very little traction and reversers contribute greatly to aircraft braking (-28% landing distance).

Reviewing our earlier data, we know that Air France 358 touched down on Runway 24L with 5,000ft remaining of the 9,000ft landing distance available.  AF358 decelerated from its touchdown speed of 148kts to 120kts, and in that time it travelled 2,296ft (700m) without maximum braking (thrust reversers, spoilers and main gear braking), but the FDR shows it did at least use the main gear brakes.  As Le Figaro points out, loss of twelve seconds and 700m (2,297ft) on a normal 3,000m (9,843ft) runway is not a big deal under normal (dry) conditions, but that changes when heavy rainfall enters the equation.  Wheels have less traction, and therefore brakes have less effectiveness.  Can the thrust reversers, spoilers and main gear brakes take an A340-300 from 120kts to 0 in 2,703ft on a wet runway?  AF358 was travelling at about 80kts (150km/h) when it ran off the end of Rwy 24L, so apparently the answer is “no”.  [But if you throw in another 656ft (200m) and a heavily wooded ravine, the answer is a qualified “yes”.]

What might cause that twelve-second delay?  The article says it could be attributable to the pilot (PNF, handling radio communications and FMS) and copilot (PF, landing the aircraft) disagreeing over the proper course of action.  The reporter doesn’t say whether this is the case, because the CVR (cockpit voice recorder) transcript has not been released.  But I will bet anyone right now that the delay was caused by the aircrew disagreeing over whether to apply takeoff thrust and go around, or apply maximum braking and commit to a full stop landing.  That is the sort of decision that needs to be made and executed very quickly and very early in the landing roll, otherwise you will find yourself in a position of having too little runway to safely do either.  And that’s when things end badly.

Remember how I talked about crew resource management in this post?  Good CRM is critical to good flight operations.  If one of the flight crew detects something amiss, but doesn’t mention it forcefully enough, or is ignored or overruled by the other pilot, things can go wrong.  It is important that both the PF (pilot flying) and PNF (pilot not flying) respect each others’ judgment, and that one unambiguously submit to the authority of the other, even if opinions differ on the proper course of action.  Reaching a balance between opinions of two highly-trained, highly experienced pilots, and doing it in a moment’s notice, is tricky work under the best of circumstances.

Some other interesting tidbits from the Figaro article:

  • I asked in my original post whether it might have been better to use the adjacent longer (9,697ft) Rwy 24R under low-vis conditions, instead of the shorter (9,000ft) Rwy 24L that AF358 used.  According to Le Figaro, Rwy 24R’s ILS (instrument landing system) had been disabled by lightning on the day of the accident.  Air France regulations quite sensibly require the aircrew to use ILS guidance under marginal weather conditions, so 24R was not an option.
  • Pearson Tower communicated weather conditions of moderate winds (11kts) to AF358, but the A340’s black box indicates 23kt winds to touchdown.  Apparently Pearson’s anemometer and windshear detector were also inoperative that afternoon.  No word on whether the Arrivals or Tower controllers were aware of the weather detection problems.
  • The captain’s seat failed (“ruptured” is the word they use) at some point during the crash, and he sustained spinal injuries.  Only three years from retirement, he will probably not fly any more.  The copilot will resume flying at the end of this month, after a routine simulator checkride.

Another problem is that Pearson does not have distance-to-go markers on its runways.  These are indicators that tell a pilot how many feet of runway remain in front of him.  These markers are standard on U.S. and Canadian military airfields, and many of the United States’ large civil airports, but they are not present at high-traffic civil airports in Canada.

Overall it’s not a pretty picture, if all of these unsourced assertions are true.  An airport (and air traffic control) whose weather detection capabilities were impaired, and may not have known about it.  A key runway unusable because its ILS equipment was disabled.  The busiest airport in Canada, without appropriate flight safety markings on its runways.  An experienced aircrew that failed, at one of the most critical moments of flight, to commit to a go-around or full stop.

I think one can call this as “pilot error” under the circumstances, but note that there were a lot of mitigating factors.  Perhaps ATC should have been more circumspect in routing and traffic flow, in light of 24R’s incapacity.  Certainly the absence of reliable wind indications and windshear detection should have forced AF358 to an alternate, assuming that ATC was even aware of the problem.  The go/no-go decision should absolutely have been made prior to touchdown — AF358 had already floated down 40% of the runway before the wheels made contact.  If Pearson had distance-to-go markers on its runways, the Air France aircrew would know whether they had enough room to go around or fully stop.  They, in turn, would have less cause for disagreement because numbers would be right there in front of their windshield.  Delaying a critical decision for twelve seconds in the rollout might have cost people their lives.  We are all are extremely lucky that no one was killed, given the circumstances.