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Sunday, April 6, 2014

Austrailians And The Search For Malaysian Flight 370

On reports that possible “pings” from flight data recorders, Retired Air Chief Marshal Angus Houston, head of the Australian agency coordinating the search operation, briefed the press.  "We are treating each of them seriously. We need to ensure before we leave any of those areas that this does not have any connection with MH370,"

It is very encouraging that there is some hard data to report in the search for Malaysian Flight 370.  It’s only fitting that the Australians are assuming a leadership role in the hunt for the missing Boeing 777.  It’s not just because of the proximity to the search location nor the vital role of the Australian vessel Ocean Shield or Air Chief Marshal Houston.  It is because an Australian, Dr. David Warren, invented the flight data and cockpit voice recorders that have become the “holy grail” of this investigation. 

Dr. David Warren was born in 1925 in the remote Northern Territories of Australia.  To receive a better education he attended 12 years of boarding school in Sydney.  His father’s last gift to him before an untimely death in a plane crash in 1934 was a crystal radio set.  David hoped to pursue radio telephony and electronics, however, the war efforts were inconsistent with “radio hams” and he turned to his other hobby chemistry.  Chemistry took his career path into the fuels industry, but he became famous for his contributions in electronics.

David was involved in the accident investigations related to the mysterious crash of the world’s first jet-powered aircraft, the Comet, in 1953.  He theorized that the cause of the accident would be obtained much easier if they knew what statements, if any, about the aircraft’s malfunctions the crew might have made in their last moments. He proposed a device to record cockpit conversations.  Aviation had little interest for such a device at that time.  However, Warren built a prototype based on a miniature wire recorder he had purchased.  Voice and sound could be recorded on this pocket-sized device.  He built two prototypes, one for voice and one for recording aircraft parameters such as speed, altitude, heading, etc.

There was little acceptance of the devices in Australia, however, a British company bought the manufacturing rights and began to produce cockpit voice and flight data recorders. Dr. Warren liked to share how his devices, which in fact are bright orange for better visibility, became known as the "Black Boxes".  Warren says, “It was called a black box because in the records of my meeting in London when it was first demonstrated and they were so keen, one of the people in the discussion afterwards said, ‘This is a wonderful black box.’   And a black box back then was a gadget box.  You didn't have to understand it but it did wonderful things.”

Coincidentally, the first government to make the flight and voice recorders mandatory was Australia.  The step was taken after the investigation of a Fokker F27 crash in Queensland did not have enough information to reach a definite conclusion in the probable cause of the accident.

Dr. Warren’s “Black Boxes” and the information they've provided have contributed more to aviation safety than any other single device.  They are the only way we will ever know the fate of Malaysian Flight 370.

Friday, March 28, 2014

What Could Possibly Go Wrong?


The FAA is soon to implement “Climb Via” procedures and phraseology into SID (Standard Instrument Departures) clearances.  On the surface it doesn’t seem like a big deal.  “Descend Via” clearances have been around for some time.  What has been learned, mostly through the non-punitive data collection efforts of the FAA, pilot unions, operators and LOSA (Line Operational Safety Audits) is that tactical reprogramming of the FMS (Flight Management System), particularly with respect to the vertical path, creates many threats.  When real time adjustments are made to the FMS with LNAV (lateral navigation) and or VNAV (vertical navigation) engaged, the associated threats are increased many fold and their consequences are much greater.  The vast majority of these threats involve communication.  The remaining threats involve the pilot’s ability to effectively monitor the aircraft.  There is a very critical communication process, especially in FMS equipped aircraft that must be precisely followed in order for an ATC clearance to be effectively consummated. 

First and most important, the clearance must be clearly communicated.  It must be understood and correctly read back by the pilots.  The pilots must make the necessary inputs to the aircraft’s flight controls, either manually or through the auto flight systems.  Those inputs must be crosschecked to ensure their compliance and accuracy.  Finally, the crew must identify any inconsistencies between the acknowledged clearance and the aircraft’s current and anticipated speed, course and vertical path must monitor the aircraft.  This communication process between ATC, pilots and aircraft is simple, but at the same time very complex.  This is especially true of FMS equipped aircraft that, once programmed, have the “capability” to completely control speed, course and vertical path with no pilot input or supervision. 

The final and most pernicious component of this communication process is time.  During periods of time compression, i.e. when either the controller or pilots are rushed, are the most fertile territory for error.  Generally this time compression is initiated by the controller’s need to make a tactical change to the SID or STAR (Standard Terminal Arrival Route).  The dynamic environment air traffic controller must deal with drives the time critical changes.  These tactical changes are usually communicated to the crew with minimal notice.  Hence, the introduction of time compression into the communication paradigm between pilot crew, air traffic control and the aircraft.  When this tactical change is received the crew is asked to rapidly understand it and transmit the changes to the aircraft.  Most often this is done through the FMS and auto flight systems.  This reprogramming of the FMS as well as time compression introduces many threats, i.e. potential for error.  Time compression often causes the crew to abbreviate verification protocols.  Just when extra scrutiny is needed most, crews short cut valuable error mitigation steps to try to expeditiously comply with the clearance. 

When short cuts result in an error, a deviation from the clearance, it is often labeled as intentional non-compliance by the crew.  That is a gross over simplification.  More often than not the error comes from the crews attempt to respond the actual or perceived time compression introduced by ATC.  Sometimes it feels like we’re at a “ho down” and the faster ATC fiddles the faster we need to dance.  I have seen this time compression many times, often at Denver International Airport (KDEN).  When a “Descend Via” clearance is modified the reprogramming of the flight guidance systems ranges from simply adjusting the altitude selector to reprogramming the entire arrival.  This happens every day at KDEN when the crew is given a completely new arrival at, just prior to or even after the aircraft has begun its descent.  This can be extremely challenging to do correctly and in a timely manner.

A solution to these threats includes a better understanding by air traffic control of the complexities of managing the sophisticated flight management systems on today’s modern aircraft.  In September 2001 the predominant aircraft types were MD-80s, B-727s, DC-10s and older models of the B-737. There was also a number of FMS equipped aircraft, but not the large number of RNAV arrivals in use today.   In over 12 years since 9/11 I have only had one air traffic controller ride in the flight deck.  I know why, but that doesn’t eliminate the fact.  My guess is that very few air traffic controllers working today that have ridden on the flight deck on modern airliners and observed crews manipulate the flight management systems in “real world” operations. 

Another solution would be for ATC to use less off course vectoring for spacing arrivals. This would reduce the need to amend and reissue “Descend Via” clearances.   RNAV arrivals are designed to minimize the amount of off course vectoring.  London’s Heathrow airport (EGLL), one of the busiest in the world and equipped with only two runways, has a very efficient arrival without all the complexities of the typical RNAV arrival in the United States.  The EGLL arrivals have only a couple of step down fixes and one speed limit point and ends at a holding fix adjacent to the airport.  When the arrival rate exceeds capacity, the holding pattern acts as a buffer and eliminates the need for vectoring.  Planes always leave the holding fix on a downwind heading.  Speeds have been 220 knots on downwind, 180 knots on base and 160 knots on final since the days of the B-707.  It’s very predictable and ATC issues very few amendments.

Another solution to communication problems between ATC and pilots would be for everyone to talk more slowly and clearly.  The objective should not be the number of words spoken in the shortest amount of time, rather the amount of information effectively communicated.  Pilots could do their part by using proper radio phraseology.  Controllers need to speak clearly and deliberately.  Talking fast and using jargon may sound cool, but is not the most effective way for controllers and pilots to communicate.

I do not expect any of these solutions to be adopted anytime soon.  However, more “Descend Via” and now “Climb Via” clearances are coming next week.  Be careful.  Every crew should recognize these clearances are loaded with threats from communication as well as execution.  Make sure you understand the clearance and ask for clarification if necessary.  Make sure you fly the airplane first and reprogram the FMS when you can.  Don’t be in a hurry!  Just because the controller is talking fast doesn’t mean you have to react faster than you’re comfortable.  Accurate compliance with a clearance is the goal not rapid sloppy non-compliance.  Get verification from the other pilot(s) even if it takes a little longer.  Make sure the airplane is doing what you want after it is reprogrammed.  Ron Popeil’s “Set it and forget it!” doesn’t work here.  Watch what the airplane is doing and make sure it is what you want it to do.  When the airplane is climbing or descending in LNAV and VNAV it actually takes more focus, not less.  It’s like telling someone else how to do something and then watching them do it.  You have to stay engaged because you don’t know when they might make a mistake. Either because you told them wrong or because they made a mistake, you have to be ready to intervene.  Finally, if you don’t have the time, distance or understanding to effectively comply with a clearance you simply need to use the word “unable”.  The controller’s expertise is facilitating air traffic, not flying airplanes.  Because a controller issues a clearance doesn’t always mean it is appropriate for the environment.  The Captain’s first responsibility is the safety of the airplane and always has the authority to meet that responsibility.