Weekly News Summary - May 17, 2006

In a nearby story, the FAA's top safety official, Nicholas A. Sabatini, reflected on the extraordinary safety record of modern commercial aviation and noted the contribution made by technology. Without any way of diminishing Mr. Sabatini's important and appropriate observations, Wingman would offer some examples of other technologies that are important not only to commercial aviation safety, but to non-commercial and some military aviation as well.

First let's review what causes most airline accidents, using the latest available annual summary provided by Boeing in its "Statistical Summary of Commercial Jet Airplane Accidents Worldwide Operations, May 2005." (See first graph below.)

Keeping in mind that these data span the period of 1987 through 2004, the 56 accidents caused primarily by CFIT might be somewhat misleading, because as Mr. Sabatini pointed out, new technology such as TAWS (terrain awareness and warning system), or EGPWS (enhanced ground proximity warning system) as it's more commonly called in the U.S., have dramatically affected this potential safety hazard in a positive way in recent years.

Nevertheless, the graph indicates that pilot errors related to aircraft control and awareness of position continues to be major factors related to fatal accidents, along with power-plant and other aircraft system failures.

Source: Boeing “Statistical Summary of Commercial Jet Airplane Accidents Worldwide Operations, May 2005

When the accident causes are aggregated still further as represented in the chart below, it can be seen that pilot situational awareness of the aircraft's position relative to the runway and other surroundings, as well as proper control usage, is still a major area for improvement. System failures are an important second place to put more attention. Together these two categories have caused more than nine out of ten fatal accidents between 1987 and 2004.

Based on Boeing Statistical Summary of Commercial Jet Airplane Accidents, May 2005

Happily, there are a number of new technologies that should be able to ameliorate all of these causes - and over time, substantially reduce those related to so-called pilot error. Some of these technologies are still expensive, and aren't widely available on all aircraft types. And a few have unresolved certification issues that would increase their operational usefulness and economic attractiveness. But if history is a valid guide, their capabilities will likely expand over time, and their costs will enviably go down.

Each of the technologies listed below can be related - often very directly - to the causes depicted in these charts:

Modern HUDs (head-up displays) that give pilots highly intuitive approach and flare guidance, speed control and trend, and angle-of-attack, unusual attitude and windshear escape if needed. These tools likely could have prevented many accidents related to poorly executed approaches and landings, as well as takeoffs and some inflight upsets.

Enhanced vision systems (EVS), used with or without HUDs that allow the pilot to see hazards including terrain and other obstacles as well as runways that would otherwise be obscured or invisible.

Synthetic vision systems (SVS) that accurately depict an aircraft's position relative to a desired flight path, and to surrounding terrain and known obstacles, using comprehensive databases.

Modern displays of horizontal and vertical flight paths that depict important situational and performance information that is calculated by modern flight management systems.

GPS position navigation, which when augmented by external or onboard systems and supplemented by new procedures, such as RNAV (area navigation) and RNP (required navigation performance), gives pilots new approach capabilities, including vertical guidance, to many more runways.

New mapping, including ground position moving maps, to help maintain situational awareness while taxiing.

Honeywell's RAAS (runway awareness and advisory system) uses GPS position information and EGPWS (enhanced ground proximity warning system) databases that alert the crew if they should attempt to takeoff or land on a wrong runway, prevent an unauthorized taxiway takeoff, and provide distance remaining callouts, among other things.

The graphical depiction of weather delivered via datalink in real time that clearly shows the pilot, his position relative to metrological hazards, such as thunderstorms, with a 360 degree field of view.

Improved weather radar systems that provide the pilot with more turbulence detection and range capabilities, and lighting detectors that can be used alone or to supplement weather radar.

Datalink that makes communications more reliable and accurate, and virtually anywhere in the world with satellites. (The single most deadly accident in aviation history, the runway collision of two B-747s at Tenerife, begin with a "stepped on" voice transmission.)

ADS (automatic dependent surveillance) that can be used in a broadcast mode as an automated position report to vastly increase surveillance to locations where radar couldn't physically or economically be deployed.

Ground position detection systems using radar, but now supplemented or supplanted by ADS-B, multilateration techniques and other sensors.

Aircraft parachutes that can literally float a distressed aircraft to the ground in such a way as to allow the pilot and passengers to be unharmed from various inflight mishaps are now being credited with a number of saved lives.

This list is more representative than complete, and certainly leaves somethings out. Furthermore, the list could be organized and combined in a manner that would show the significant synergism that exists between many of these technologies that makes them even more valuable for purposes that serve both safety and operational effectiveness.

Wish List

This list is impressive and very encouraging in Wingman's view. Yet there is even more that might be possible, and even quite feasible. Here are some safety systems that Wingman wished we had, but aren't yet developed or haven't appeared on the scene. (If they are, please let us know):

A takeoff performance monitoring system. Such a system would alert or warn the pilot that the aircraft isn't accelerating properly on takeoff. Simply put, the system would use an aircraft's inertial sensors to compare its actual acceleration rate with what is required based on inputted environmental factors and runway information from a database. Alerting and warnings should occur as early as possible in the takeoff roll while the aircraft is at a low energy state.

The system shouldn't try to be too smart in determining either the cause of lacking performance or what the pilot should do; it should only alert and warn. The pilot's action should be procedural as it is with TAWS: abort the takeoff as quickly as possible, when the ground speed is low.

The system would be able to detect inadequate performance from many causes: too much weight, too little thrust, runway clutter, and even a dragging brake.

A landing performance monitoring system. This system would alert or warn the pilot that the aircraft has too much kinetic energy (ground speed) or potential energy (height) to safely continue, relative to the anticipated touchdown point and runway remaining. Many air transports and business jets already have the necessary sensors (GPS, inertial, and maybe radio altimeter) that could be correlated to a runway database to make the needed calculations.
A degraded wing-lift detection system. While such a system may be considerably more challenging - both in terms of capability and economics - its successful development might someday save many lives. In theory it would monitor the elements that make up an airfoil's lift potential early enough to warn the pilot to discontinue a takeoff prior to liftoff, if it is deemed inadequate.

Perhaps the most obvious benefit of such a system would be its ability to prevent accidents that have resulted from wing ice or frost contamination, but it might usefully work in conjunction with other sensors that detect improper flap configuration, over loading, or even improper balance. 05-17-2006. (Top)