Design Flaw an Overlooked Factor in Malaysian Tragedy

WASHINGTON - March 20, 2014 - PRLog -- WASHINGTON, D.C. (March 20, 2014)  - Including a totally unnecessary in-flight-accessible "off switch" on the transponder appears to be an overlooked design flaw which contributed to the Malaysian MF370 tragedy, suggests public interest law professor John Banzhaf - an engineer as well as a lawyer - and it may well provide a basis for the families of the apparent victims to seek financial compensation from Boeing.

        While the finger of blame regarding Malaysian Flight 370 is being pointed at whomever turned off the ACARS system and the airplane’s transponder, apparently little attention is being focused on whether designing these two systems so they could both in fact be turned off so easily during flight is what lawyers call a "design defect," which may have contributed to what now appears to be a terrible tragedy.

        If so, Boeing may be liable for massive damages under legal theories of either negligence or strict liability, suggests Banzhaf, who, with a degree in electrical engineering from MIT, 2 U.S. patents, and a number of published technical papers to his credit, has both technical and legal expertise.

        Since a transponder is such an important safety feature, permitting it to be turned off during flight - whether by accident, by technically sophisticated terrorists, by pilots voluntarily or while being held at gunpoint, etc. - makes little sense unless there is a compelling reason to do so.

        Experts claim that pilots must be able to turn the transponder off (or at least to “standby”) to avoid cluttering the screens of ground control radar when the aircraft is moving on the ground at an airport, or when it is finally parked, but neither justification applies when the plane is airborne.

        Doug Moss, a former test pilot and aircraft accident investigator, explained that while pilots usually want the transponder on, it’s not the case at airports with surface radar movement equipment which gives air traffic controllers the precise position of aircraft on the ground.  At such airports, the transponder is unnecessary: it just "clutters up the radar screen for the ground controllers," Moss said.

        Also, the transponder is normally switched off or turned to “standby” when the plane is parked at a gate, and there is no longer any need for it.

        So, since it would be both easy and inexpensive to design the transponder system so that it automatically turns on and remains on whenever the plane is in flight (as indicated by an altimeter reading, lowered cabin air pressure, etc.), and such a simple design change would help deal with foreseeable events like hijackings by trained terrorists, malevolent acts by deranged pilots, or even simple pilot error, having a system where a crucial component can so easily be turned off when it is most needed looks like negligent design.

        Interestingly, some maintain that the ACARS system cannot easily be shut down.  However it, apparently like the transponder, can be rendered inoperative by throwing a switch or a circuit breaker to disconnect  it from the plane’s electric power supply.  Defenders of such an arrangement claim that, in the event of fire or other electrical system problems, the crew must be able to quickly disconnect the power.

        But, considering how critical both the ACARS system and the transponder can be, the inclusion within each system of a emergency backup battery would permit the systems to continue functioning at least for a while, even if aircraft power had to be cut in the event of a fire or other emergency.

        In short, the apparently inexpensive addition of a backup battery for the ACARS system, as well as for the transponder, would help insure that those on he ground would be able to receive information about the plane’s location, and the condition of its systems, at the most vital time - immediately following a fire or electrical emergency which forced the crew to disconnect the ACARS and the transponder from the aircraft’s power system.

        Would whoever diverted the plane have done so if they knew that the transponder - and even the ACARS system - could not quickly be turned off, thereby giving them the freedom to maneuver without detection during a crucial time period?  Possible, but probably not, suggests Banzhaf.

        If an operating transponder and/or ACARS system had alerted authorities that something was very wrong with the flight, could jets have been scrambled quickly enough to force the runaway flight down, or at least otherwise reduce the apparent loss of life?  Once again we may never know for sure, but a jury angry at Boeing for negligently not giving the passengers even this slim chance might well find that the design flaw was a significant factor in the loss of life, and order Boeing to compensate the grieving families, says Banzhaf.

        To these and other important related scenarios, we will never know the answer, because simple fail-safe principles of design, including providing backup batteries, simply were not followed.

        Perhaps, if nothing else, this tragedy will prompt authorities to require simple and inexpensive changes to get rid of the "off" switch on these crucial components while they are airborne, suggests Banzhaf.

JOHN F. BANZHAF III, B.S.E.E., J.D., Sc.D.
Professor of Public Interest Law
George Washington University Law School,
FAMRI Dr. William Cahan Distinguished Professor,
Fellow, World Technology Network,
Founder, Action on Smoking and Health (ASH)
2000 H Street, NW
Washington, DC 20052, USA
(202) 994-7229 // (703) 527-8418
http://banzhaf.net/ @profbanzhaf