“Heading and ALT Acquire please”
This callout from the pilot signals the transition to an autonomous flight director mode within seconds of initiating take-off. Thereafter, the complete flight till final approach to land is achieved by turning knobs and selecting modes on the flight director. If you think this happens only in a Boeing 737-800 or Airbus 320 Neo, think again. This is a helicopter – AW 139, the fully automated workhorse of the offshore industry.
Pilots like me who started their flying career 25 years ago would likely have seen the complete spectrum from “don’t you ever let go of the controls” on fully manual helicopters like the Alouette or Robinson to “what is it doing now?” – a comment commonly heard in automated cockpits. As more and more automation creeps into our cockpits, pure hand flying skills and system knowledge shouldn’t be allowed to atrophy. But it does. Journalist and former pilot William Langewiesche framed up the situation aptly in the wake of Air France 447 crash: “We appear to be locked into a cycle in which automation begets the erosion of skills or the lack of skills in the first place and this then begets more automation.”
Children of Magenta?
Back in 1997, American Airlines’ Captain Warren Van Der Burgh bemoaned the increasing dependence on automation that is turning pilots into what he called ‘Children of the Magenta’, the colour used for autopilot modes on flight displays. Twenty years on, there has been no let-up and what we see is even more automation. Automation is here to stay and has made the industry more efficient and safer. In fact, Airbus claims that their fourth generation fly-by-wire aircraft with flight envelope protection has halved the fatal accident rate of the previous generations. With increased airspace congestion and RNAV, PBN and RVSM coming into use, level of accuracy required to navigate through air corridors with reduced minima would test piloting skills and drive workload if not for automation. But it has also thrown up a new set of challenges that operators, trainers and the regulator must grapple with.
Levels of Automation
Automation in a modern helicopter has several layers. In the AW139 for example, starting from the basic ATT (attitude retention) mode, one can hold preselected airspeed, heading, vertical speed, altitude etc. or go on to fully autonomous vertical and lateral navigation (LNAV) modes. Captain Van Der Burgh made the case that we should use the level of automation that is appropriate to the phase of flight. Selecting the highest mode of automation may not always be the right thing to do. Sometimes, getting down to a lower level of automation may reduce workload or be more appropriate for the task at hand. Autopilots cannot spot birds. Or other aircraft. Neither can they understand ATC instructions or factor in uncharted obstructions that have come up after the last update. Glass cockpits today can bring together a wide variety of equipment that pilots earlier used to integrate in their minds, giving rise to terms like Pilot Flying and Pilot Monitoring (PF/PM). Even the best terrain, traffic or collision avoidance systems are no replacement for a good lookout or mental dead reckoning as many air accidents have shown us.
Terrain and Situational Awareness
Fully automated cockpits can easily lull the crew into a false sense of security. On 14th March this year, Rescue 116, a S92 helicopter operating for the Irish Coast Guard, flew into an outcrop called Black Rock Island that was uncharted on the aircraft’s Enhanced Ground Proximity Warning System (EGPWS). As per preliminary report issued by the Irish AAIB, a low altitude autopilot mode that reduces the warning boundaries and look-ahead distances was in use at the time of the accident. This VFR-only mode was used by night in weather that included patchy mist and fog, cloud base of 300-400 feet, occasional light rain /drizzle and gale force winds. The crew reportedly received an ‘Altitude Altitude’ aural alert 26 seconds before the crash while flying at 200 feet / 75 knots on an autopilot-FMS coupled mode. Initiating immediate recovery action by stepping down to a lower mode of automation or manually taking over controls would probably have saved the day. Instead, a heading change was initiated using the ‘Heading’ mode even as a rear crew member interjected with increasing urgency “Come right now, come right, COME RIGHT”. The helicopter with a host of new generation devices like EGPWS, FMS, Multi Missions Management Systems, Automatic Flight Control System (AFCS), Electro Optic / Infra-Red Camera System, dual radio altimeters, weather radar etc. impacted terrain and crashed into the sea with loss of four lives. Investigators will have to determine if the level of automation used was appropriate for a situation that required immediate manual intervention – something Captain Van Der Burgh had cautioned us 20 years ago. Even the most advanced FMS is but a shining example of ‘garbage in, garbage out’.
In the ill-fated transatlantic flight of Air France 447 (Jun 2009), the autopilot disengaged and the fly-by-wire system regressed to a mode that no longer provided stall protection after a pressure probe iced over. Unable to understand what mode the aircraft had gone into, the co-pilot applied backward pressure on the sidestick controller, raising the nose and putting the aircraft into an aerodynamic stall they could neither understand nor handle. The confusion about what the aircraft was doing continued 38000 feet down to the Atlantic Ocean, killing all 228 on board. This ‘mode confusion’ has had a hand in other accidents as well. If at any time, the autopilot or flight director behaves in an uncommanded or unusual manner, be prepared to either step down a level in the automation or take over controls till the confusion is resolved. Company procedures may also require that any change in flight parameters and mode select / deselect is done with standard callouts and acknowledgement. This must be respected.
Doing the Numbers
Today, sophisticated Flight Management Systems can compute the aircraft’s performance in a jiffy (provided the right data has been input). In a few keystrokes, you can get performance data that earlier came from unwieldy flight manuals. Yet there is no better safety mechanism than doing the mental math about distance, time and fuel consumption. It takes little effort and the results when correlated with the numbers churned out by FMS gives you a foreboding should something be amiss. Besides, it also helps keep those grey cells alive!
Learning from George
‘George (autopilot) flies best’ is a common belief in the community. So why not pick up some tricks of the trade from him? While using automated modes such as heading capture or ALTA (Altitude Acquire), notice what kind of roll/pitch/power manipulations are being made by the autopilot. These can, over time, give you reference values for flying manually. Wind vectors on the PFD correlated with track and heading can give you an idea of what offsets ‘George’ uses to maintain a required track. Pitch attitude while cruising automated at various speeds can be noted and used as reference while hands flying. As the aircraft turns to the next waypoint in LNAV mode, notice the rate of roll-in and roll-out. Observe what kind of power is used for climbs and descents and how the autopilot smoothens out each end by manipulating power for a return to level flight.
Utilize Hand Flying Opportunities
Fortunately, the industry still has some pilots left who have non-automated flying experience in their logbooks. But we are slowly reaching the point where ‘children of the magenta’ occupy both seats in the cockpit. Maybe we are already there. Today there are little, if any, opportunities or incentives to fly hands-on. For those who fly modern machines, ‘fly manually’ forms a miniscule part of the flight, usually reserved for take-off or landing. If your company manual allows it, go ahead and use bright and sunny VFR days to practice hands flying. Fly that DME arc manually, decrypt the three sectors and enter that hold manually, or fly that approach uncoupled. There are some windows for hands flying while some have to be created through regulations. But when you come up for your six-monthly line proficiency check, you will notice the distinct advantage. Ditto for that rainy day when the autopilot or flight director calls time on you. All equipment fail sometime or the other.
Knowing when to use automation is as important as knowing when not to. This starts from a deep reading of all autopilot modes / functions and their limitations, cross-couplings and useable envelope. Automation offers several combinations to achieve a desired flight condition. Regular use of all embedded functions will, over time, prepare you for options that you can select from. Long cruising flights and low workload situations offer windows of opportunity to gain deeper insights into different layers of automation. Automation can also be used to maintain a steady flight profile while handling emergencies. This again requires in-depth understanding of autopilot modes and a wrong mode chosen could further aggravate matters.
Knowledge-based Decision Making
Many of the issues discussed above were included by the NTSB as factors that contributed to the July 2013 crash of Asiana Flight 214 at SFO airport where a combination of manual flying and mode confusion resulted in the crew flying the aircraft into a sea wall short of the runway. Investigations into the Aug 2013 crash of a Super Puma in the North Sea also identified incorrect interaction between crew and automation to be among the causative factors.
Overconfidence in automation and reluctance to intervene when required – both can be costly mistakes.
Captain Ed Pooley summarises this best in his hard-hitting article ‘The Automation Problem’:
“A deeper background appreciation of the big picture – both how aeroplanes actually fly and how the automated interface between the pilot and his particular machine functions – is a fundamental part of competence. The focus needs to be placed firmly on effective knowledge-based decision making”.
If Captain Chesley ‘Sully’ Sullenberger and First Officer Jeffrey Skiles had relied on their FMS to fly US Airways’ Flight 1549 to the nearest alternate, ‘Miracle on the Hudson’ would have had a different, more painful outcome.
©KP Sanjeev Kumar, 2017. All rights reserved.