Pilotless Passenger-Carrying Aircraft

: Can We Safely Buckle –Up and Sip Champagne and Coffee???

Article By : Odadie Kwasi Okatakyie Adjekum

The passengers and crew of Malaysia Airlines Flight 124 were just settling into their five-hour flight from Perth to Kuala Lumpur that late on the afternoon of 1 August 2005. Approximately 18 minutes into the flight, as the Boeing 777-200 series aircraft was climbing through 36 000 feet altitude on autopilot, the aircraft—suddenly and without warning—pitched to 18 degrees, nose up, and started to climb rapidly. As the plane passed 39 000 feet, the stall and over speed warning indicators came on simultaneously—something that’s supposed to be impossible, and a situation the crew is not trained to handle.

At 41 000 feet, the command pilot disconnected the autopilot and lowered the airplane’s nose. The auto throttle then commanded an increase in thrust, and the craft plunged 4000 feet. The pilot countered by manually moving the throttles back to the idle position. The nose pitched up again, and the aircraft climbed 2000 feet before the pilot regained control. The flight crew notified air-traffic control that they could not maintain altitude and requested to return to Perth. The crew and the 177 shaken but uninjured passengers safely returned to the ground. The Australian Transport Safety Bureau investigation discovered that the air data inertial reference unit (ADIRU)—which provides air data and inertial reference data to several systems on the Boeing 777, including the primary flight control and autopilot flight director systems—had two faulty accelerometers. One had gone bad in 2001. The other failed as Flight 124 passed 36 571 feet. (ATSB, 2006).

The preceding incident sets the ball rolling for this discussion on the future of pilotless commercial passenger carrying aircraft operations. In recent times, The ‘’noise’’ for pilotless commercial operation has reached its crescendo, with even demonstrated flight conducted in Britain and a lot of work done by the US military on remote piloted/unmanned aerial systems (UAS).The next bold step in how to actualize the idea and get the travelling public to accept the idea that computers and software, without any assistance from any human, in an aircraft will get them from New York to Tokyo safely.

Normally in the absence of failures, that would simply be a matter of switching modes from preflight to takeoff to climb to cruise to descent to landing to taxiing to the terminal (always done manually today) as the pilot does in today's complex aircraft. However, without a crew, there are too many contingencies to be pre-programmed. Engine(s), hydraulics, trim motors can fail, cabin pressurization can fail, etc. An example was the A-380 takeoff from Singapore when a blade separated from one of four engines and destroyed the hydraulics, much of the electrical system, the fuel jettison system, thrust reversers, the fuel transfer system from tank to tank, etc. It took five experienced senior pilots two hours to go through all the computer alarms to figure out what to do. They landed the damaged aircraft without injury.

A similar incident occurred for an aircraft in Iowa that landed without hydraulics thanks to the skill of the pilots. Also a recent Polish (LOT) Boeing 767 aircraft landed with retracted landing gear because a circuit breaker had tripped. The glide landing in the Hudson River by US Airways Flight 1549 is very fresh in our memory and the impact of the flight crew in averting catastrophe in the face of dire consequences cannot be shoved under the sheet. The loss of control of Air France 447 Airbus 330-200 out of Brazil ,in which the pitot tubes iced up and the flight crew had to battle with catastrophically degraded automation and flight parameters, resulting in a high altitude stall and subsequent loss of control, shows that even with a collaborative human –automation set up, there can be complexity. All passengers aboard died. There are too many contingencies to be pre-programmed. Lives and the cost of the aircraft make the cost of a crew member trivial.

The crash in February 2009 of Turkish Airlines Flight 1951 just short of Amsterdam’s Schiphol International Airport, which killed 9 people and injured 86 others, raised this concern anew. As the aircraft passed through 1950 feet, the left radio altimeter failed and indicated an altitude of –8 feet, which it passed on to the autopilot, which in turn reduced engine power because it assumed the aircraft was in the final stages of approach. The pilots did not initially react to the warnings that something was wrong until it was too late to recover the aircraft.

Will automation be powerful enough to do it all by itself? What about the social and economic acceptability of pilotless aircraft in civil transportation? How will it affect the human-machine relationship, with the apparent marginalization of the human input? Pilotless aircraft (Military) still makes use of human operators, where design challenges for successful co-ordination with automation especially under non-normal situation are no less than, when the operator sits in the cockpit. There is a substitution myth of whether computers can replace humans, without the further consequences for the higher human-machine ensemble. Those who argue for such substitution normally cite increased safety, lower operating cost, less requirement for manning and training etc (Dekker, 2004).In a complex, dynamic and non- deterministic world, the human component will always be part of the operation of highly automated systems. What matters at the end of the day is not absolute automation, but the degree to which automated systems allow team play and seamless inter face with human operators. This will allow for direction, especially under unusual and novel situations. As another economic argument, and one with implication for safety as well, automation is premised on the basis of accuracy of aircraft control, than humans. Let us analyze a scenario, where a pilotless aircraft derates thrust at an airport, by taking the prevailing weight, runway length, ambient temperature and humidity. This might save fuel while making exactly sure that the aircraft lifts off before it is out of the runway. But this can impede flexibility. The pursuit of accuracy may render the aircraft to become insensitive to unanticipated changes in real time scenarios ( Billings,1996).Higher thrust may not be available even when called for in an emergency during takeoff.

A proficient crew person is still needed and will be for the foreseeable future until software can anticipate contingencies, that is, acquire human-like intelligence and motor skills. With the present computing processors and capacity available, to match the human minds capacity at identifying, processing and making cogent decisions to ensure safety under unusual circumstances and flight profile will be a daunting challenge. The idea of replacing humans with machines and computers will surely be met with stiff resistance from pilot unions and pilots association, since it digs a deep hole into their very existence. The political ramification of accountability and responsibility for human lives on an aircraft in case of any mishap cannot be emphasized, when the aircraft is pilotless. Capt. Sullenberger, perhaps one of the most famous airline pilots in the US modern history, thinks that the idea of remote-controlled airliners triggers a lot of critical questions. He speculated about what might have happened to Flight 1549 after it collided with the geese if the plane had been controlled by a remote pilot.

"What if the geese damaged whatever forward viewing devices there were -- such as cameras or infrared or radar? What if the damage prevented the operator from seeing the river? Or seeing the plane's height above the river?" How would the operator be able to land the plane safely?

"On every airplane I've ever flown, I tend to use the technology to its full capabilities when it's appropriate," Sullenberger said. "But looking as far into the future as I can see, every airplane -- no matter how sophisticated -- really needs to be flown, and flown very well, by a human pilot."