Understanding Air France 447

by Palmer, Bill

  Training Matters

  Training and experience matters a great deal in producing pilots that can handle these or other unexpected situations.

  For these high performance airplanes, training exercises need to demonstrate and compare the stall margins and recovery techniques in both high and low altitude regimes.

  At low altitude, high angles of attack are required for stall, and power addition provides a quick recovery with minimal loss of altitude.

  Contrast that with the high altitude scenario, where the stall margin is very narrow, and power addition can be weak or ineffective in reducing the angle of attack, and in some cases may actually hamper the ability to pitch the airplane down. In this environment, altitude will have to be traded to gain airspeed. The performance physics simply do not allow the airplane to regain airspeed in level flight with the available power once it has gotten critically slow. Additionally, as the recovery progresses, and Mach number increases the airplane’s stall margin again decreases. Therefore, the recovery must be made somewhat gently to prevent a secondary stall encounter in the recovery.

  The idiosyncrasies of fly-by-wire airplanes must be demonstrated and understood, not just mentioned in a briefing. In this case the absence of angle-of-attack protection and low speed stabilities, the function of the auto-trim, and the fact that the airplane’s natural dynamic stability to pitch down was masked by the g-load demand system are key to understanding the handling of the airplane in these situations. For the airplane to pitch down, in situations where the fly-by-wire stabilities are lost, requires the pilot to push forward on the sidestick. These are key concepts of the airplane that should not be glossed over. Pilots do not intuitively know this. When I have demonstrated these factors to crews in training, numerous pilots stated that this was the most informative simulator session they have ever had.

  Training in these areas has improved since the accident, due in part to the findings of the accident, as it brought to light some areas of misunderstanding.

  The background of a pilot can also make a difference. First Officer Bonin came up through an ab initio program on the airline fast track. I am sure stalls were taught and demonstrated, but the training may not have been extensive. Most of his flight career was probably spent in cruise flight with a heavy use of automation. Despite almost 3,000 hours total time, his actual hands on time of actively flying the airplane may have been minimal.

  Contrast that with a pilot who worked as a flight instructor teaching stalls recovery or spin training. Graduates of military training programs also receive intense instruction in maneuvers and awareness of angle of attack and the effects of high altitude and high speed aerodynamics, as well as a very wide envelope of attitudes. Also skilled are pilots with many hours on airplanes where hand flying was required due less sophisticated autopilots or none at all.

  Pilots who have come up through ab initio programs may have missed much of this experience. Training programs and company policies need to be aware of this and include hand flying in initial and recurrent training, as well as support hand flying the airplane during routine operations where practical.

  An A320 Captain relates the following story of a pitot-static problem he encountered in an A320. The incident follows the probable contamination of the static ports during a washing, which was then addressed by maintenance before departure.

  We had just punched into the overcast and raised the flaps when the stall warning sounded and the flight control system went to alternate law indicated on the PFD. I had the first officer lower the nose immediately and cobbed the power. (we were above Point Loma by now and had nothing but ocean ahead of us-a stall recovery maneuver was not an option) There were no ECAM messages during this entire scenario. I immediately looked at the FO's airspeed to see what it said because the water in the system was still on my mind. I then checked the backup instruments to see what the airspeed was indicating. All three were within about five knots so the puzzle was raised a couple of degrees in my mind. What was the real airspeed? When we broke out on top about a minute later I could visually tell that we were hauling so I knew we were above stall speed and the attitude was nowhere near stall attitude. The warning stayed on till about 275K and we kept the airspeed there till we came up with a plan.

  He attributes his ability to maintain control, verify indications with the standby system, and successfully land the airplane in instrument conditions to his extensive hand flying experience in the Navy and on the DC-9.

  Good training helps to reinforce or strengthen those skills. But good training does not happen on its own. It takes a training program that is willing to provide the training needed, even if it means going beyond the regulatory requirements, and it takes good instructors to make it happen effectively.

  Good instructors can detect signs of pilot misunderstanding. The cues are often subtle: how students move the controls, what modes they select, how they plan their energy management on approach, when they change configuration and much more. Then, the instructor can try to fill in the holes in a pilot’s experience or understanding with exercises to improve his understanding an skill.

  A threat to this system is the increasing use of instructors with no experience in the airplane they are teaching in, especially in later stages of training. They set up the simulator as per the syllabus, perform the maneuvers listed in the lesson to the standards prescribed, but may lack the experience and ability to catch the hints of misunderstanding subtly displayed by the student. Their lack of actual line flying experience can sometimes allow them to miss the significance of certain items as it would apply to real life scenarios. Will their students be ready if real life strays from the cookbook procedure?

  Sitting and watching the autopilot fly the airplane, following flight directors with little awareness of what pitch attitude to fly should they disappear, are behaviors that despite adding hours to a logbook, add little to a pilot’s real experience and ability to be the defining factor between a failure and tragedy.

  The AF447 Final Report44 validates these assertions with the findings of Air France’s own internal safety report. Among the findings:

  The piloting abilities of long-haul and/or ab initio pilots were sometimes poor;

  A notable loss of good sense and general aeronautical knowledge;

  Weaknesses in terms of representation and awareness of the situation during system failures (reality, severity, danger level, induced effects …).

  It does not take a great deal of imagination to apply these findings to the crew of AF447. It is sad to consider that these are probably not the only three pilots incapable of handling this situation. Though the empirical evidence indicates they are the minority, as the dependence on technology and economics change the nature of pilot training, we must consider what the future will bring. Training departments at all airlines must take these factors into account.

  Chapter 11: Going Forward

  It would be easy to simply criticize the incompetence of the two first officers, but it is not as simple as that. The vast majority of accidents have multiple causes. Air France 447 is no exception.

  The loss of the autopilot, autothrust, and airspeed indications, occurring in turbulent weather at night was combined with degraded flight controls, and flight directors that provided inappropriate guidance. The situation was beyond the ability of the crew to:

  Recognize what had happened,

  Recognize what was happening, and

  Determine what actions to take to restore controlled flight.

  But, the skills of the two first officers were a product of their prior training and experience.

  Not long ago, hand flying was common. Operating today’s highly automated aircraft virtually 100% of the time with the automation engaged has allowed manually flying skills to erode to the point where they may not be sufficient to handle an emergency. We must also recognize that a generation of pilots have been trained on the techniques of following the flight director, and the development of high
-level manual flying skills have been de-emphasized.

  If we fail to train our fellow pilots to manually fly the airplane under the most challenging conditions then we have failed them, our passengers, and cabin crew. In the absence of this training, any significant loss of auto-flight systems or degradation of flight controls could result in a scenario for which they are not prepared. Which is a recipe for another disaster.

  Analysis of the factors involved reveals numerous areas of pilot misinterpretation and misunderstanding. This fact alone should make us resolve to do a better job in educating our pilot population. These factors include:

  How to properly operate the weather radar to account for the low radar reflectivity of storms in the ITCZ.

  The proper pitch attitude and power setting to maintain or reestablish cruise flight.

  That Alternate Law provided no protections, could maintain a dangerously high pitch attitude with no back pressure at all, and provided nearly double the normal roll response to sidestick input.

  That the synthetic voice announcing "STALL, STALL, STALL" meant that the nose must be pitched down, as it would not happen on its own.

  That insufficient power exists at cruise altitude to constitute a stall recovery.

  A misidentification of the stall buffet for a high speed buffet. Believing they had "some crazy speed" the pilot flying even deployed the speed brakes momentarily, unaware that the wing on this airplane made Mach buffet extremely unlikely or perhaps not even possible.

  Both first officers lost the discipline of accomplishing the abnormal procedure, and failed to identify who was flying the airplane. The synthetic voice announced "DUAL INPUT" while both pilots were trying to fly the airplane, sometimes with conflicting commands.

  But as egregious as all these error seem, and indeed were, we must realize that these pilots were the product of their training and experience, as are we all. Like the loyal family dog who lets in the burglar, one cannot truly be expected to effectively handle a crisis situation for which they have not been trained.

  However, even the skills of pilots with extensive manual instrument flying experience will erode over time when those skills are not maintained with practice.

  We must, therefore train our fellow airmen:

  To be able to handle the hand flying that the autopilot relieves them of,

  To be aware of the normal pitch attitudes and power settings that the flight directors and autothrust allow them to forget or never learn,

  To understand the weather they are surrounded by,

  To understand the aerodynamics that keep them aloft and,

  To understand the unique characteristics of their aircraft.

  We must not allow mastery of the Flight Management System to be confused with airmanship.

  It is our sacred duty to each other and to every passenger that ever climbs aboard.

  We have been warned.

  Appendix

  Recommendations of the Investigation

  The BEA released a number of safety recommendations in the various reports on the accident. These cover a range of subjects from airplane an simulator design to search and rescue. In the final report they are grouped primarily by which report the recommendations were issued in. I have arranged them below by subject.

  Flight Recorders

  Extend as rapidly as possible from 30 to 90 days the regulatory transmission time for Underwater Locator Beacons (ULBs) installed on flight recorders on airplanes performing public transport flights over maritime areas; make it mandatory, as rapidly as possible, for airplanes performing public transport flights over maritime areas to be equipped with an additional ULB capable of transmitting on a frequency (for example between 8.5 kHz and 9.5 kHz) and for a duration adapted to the pre-localization of wreckage;

  Study the possibility of making it mandatory for airplanes performing public transport flights to regularly transmit basic flight parameters (for example position, altitude, speed, heading).

  Ask the FLIRECP (ICAO Flight Recorder Panel) group to establish proposals on the conditions for implementing deployable recorders of the Eurocae ED-112 type for airplanes performing public transport flights.

  That ICAO require that aircraft undertaking public transport flights with passengers be equipped with an image recorder that makes it possible to observe the whole of the instrument panel; and that at the same time, ICAO establish very strict rules for the readout of such recordings in order to guarantee the confidentiality of the recordings.

  Today, the regulation requires recording of the flight parameters displayed on the left side. Some parameters essential to the analysis of the conduct of the flight are lacking, in particular those displayed to the pilot in the right seat: speed, altitude, attitudes, position of the flight director crossbars, etc. In addition, airplanes are equipped with complex systems whose functional analysis is limited and delayed by the absence of a recording of all of the data sources that they use.

  Consequently, the BEA recommends: that EASA and the FAA make mandatory the recording:

  of the position of the flight director crossbars,

  of the parameters relating to the conduct of the flight displayed on the right side, in addition to those displayed on the left side;

  And that EASA and the FAA evaluate the relevance of making mandatory the recording of the air data and inertial parameters of all of the sources used by the systems.

  That EASA and ICAO make mandatory as quickly as possible, for airplanes making public transport flights with passengers over maritime or remote areas, triggering of data transmission to facilitate localization as soon as an emergency situation is detected on board;

  And that EASA and ICAO study the possibility of making mandatory, for airplanes making public transport flights with passengers over maritime or remote areas, the activation of the emergency locator transmitter (ELT), as soon as an emergency situation is detected on board.

  Certification

  Undertake studies to determine with appropriate precision the composition of cloud masses at high altitude; and in coordination with the other regulatory authorities, based on the results obtained, to modify the certification criteria.

  That EASA and the FAA evaluate the relevance of requiring the presence of an angle of attack indicator directly accessible to pilots on board airplanes.

  Training for Manual Aircraft Handling

  That EASA review the content of check and training programs and make mandatory, in particular, the setting up of specific and regular exercises dedicated to manual aircraft handling of approach to stall and stall recovery, including at high altitude.

  That EASA define additional criteria for access to the role of relief captain so as to ensure better task-sharing in case of augmented crews; and that, provisionally, the DGAC define additional criteria for access to the role of relief captain so as to ensure better task-sharing in case of augmented crews.

  Search and Rescue

  ICAO ensure the implementation of SAR coordination plans or regional protocols covering all of the maritime or remote areas for which international coordination would be required in the application of SAR procedures, including in the South Atlantic area.

  The DGAC, in concert with the other services responsible, develop a homogeneous framework for training and for approval of operators responsible for search and rescue activities in France.

  ICAO define the framework for the training of SAR operators in its standards and recommended practices.

  Within France: the DGAC designate a point of contact at ICAO for the ARCC that has adequate means to accomplish his/her missions.

  ICAO ensure each Member State has a national point of contact and makes his/her contact information available.

  ICAO amend Annex 12 on search and rescue operations so as to encourage contracting states to equip their search aircraft with buoys to measure drift and to drop them, when these units are involved in the search for persons lost at sea.

  Air Traffic Control

&
nbsp; The Brazilian and Senegalese authorities make mandatory the utilization, by airplanes so equipped, of ADS-C and CPDLC functions in the zones in question.

  ICAO request the involved States to accelerate the operational implementation of air traffic control and communication systems that allow a permanent and reliable link to be made between ground and airplane in all of the areas where HF remains the only means of communication between the ground and airplanes.

  Pilot Training

  EASA ensure the integration, in type rating and recurrent training programs, of exercises that take into account all of the reconfiguration laws. The objective sought is to make its recognition and understanding easier for crews especially when dealing with the level of protection available and the possible differences in handling characteristics, including at the limits of the flight envelope.

  More generally, EASA ensure that type rating and recurrent training programs take into account the specificities of the aircraft for which they are designed.

  EASA define recurrent training program requirements to make sure, through practical exercises, that the theoretical knowledge, particularly on flight mechanics, is well understood.

  EASA review the requirements for initial, recurrent and type rating training for pilots in order to develop and maintain a capacity to manage crew resources when faced with the surprise generated by unexpected situations.

  EASA ensure that operators reinforce CRM training to enable acquisition and maintenance of adequate behavioral automatic responses in unexpected and unusual situations with a highly charged emotional factor.

  EASA define criteria for selection and recurrent training among instructors that would allow a high and standardized level of instruction to be reached.