Premium On Safety - Issue 9, 2012 - (Page 7)

ASI mESSAGE Excursions (continued from page 6) Interference from the cabin By BRUCE LANDSBERG Our intrepid crew could be in trouble. Have they updated dispatch calculations with a predescent assessment to determine a factored landing distance for current conditions? How did the passing heavy rain impact the runway? Is it grooved? Aircraft limitations aside, has accepting the tailwind sacrificed too much safety margin for this wet runway? Have the pilots specifically identified a latest acceptable touchdown point, and is the pilot monitoring (PM) empowered and expected to call a go-around if wheels aren’t on the ground by then? Are both pilots in sync on planned use of ground deceleration devices, specific duties to assure prompt deployment, and the point after which they’re committed to stopping? All these factors matter. If this crew falls back on “muscle memory” from frequent use of longer runways and mismanages the flare in hopes of a “greaser,” that slightly hot and high tailwind approach will put pavement they need behind them. If any delay or confusion on deceleration technique is experienced after touchdown, especially if contaminated runway segments are encountered, look out. The fact the setup appeared perfectly stable just seconds earlier will be no consolation. An FAA study following several serious excursion cases estimated only 50 percent of operators have adequate policies to drive systemic assessment of expected aircraft landing performance at time of arrival. Considerations such as grooved versus un-grooved runways, wet versus contaminated surfaces, interpreting braking action reports, and tail/crosswind effects may not be properly accounted for unless an operator’s policy triggers and guides the process. Does your company policy identify excursion hazards and standardize evaluation of the risks? In cases where the result is “acceptable, but with reduced error margin” what defenses are available? The High Performance Landing is offered as a flight crew tool to focus a precision flying mindset, apply risk controls, and sustain them until the aircraft is stopped. Pre-identifying a latest acceptable runway touchdown point is vital. Simply landing within the touchdown zone offers no assurance of stopping on the remainder, especially if the surface is not clear and dry. Most AFM landing performance tables are based on test pilots touching down 1,000 feet from a dry runway’s threshold using techniques not typical in operations (i.e., max flaps and brakes, Vref with no speed correction, and 50’, power-to-idle, flare). AFM tables are extrapolated from flight test data using mathematical models, and often include wet runway estimates. They are only as accurate as the modeling applied and the degree to which the landing point and braking technique used resembles those on which the tables were based. Landing distance figures include air distance (the transition between crossing the threshold and touchdown) and ground/braking distance. Maximum deceleration occurs in the latter, so unnecessarily extending air distance must be avoided. When the conservatively assessed runway required is within 80 percent of runway available, a High Performance Landing protocol can increase safety by elevating landing preparation and execution by the pilots flying and monitoring (PF/PM) with these elements: • Pre-briefed—Pilots specifically identify the tasks required for the stabilized approach, crew performance in the touchdown zone, and the deployment of all available stopping devices. • Go-around prepared—Review procedure and specific situational considerations. • Stabilized approach—Review and follow specified stabilized approach criteria. • Latest acceptable runway touchdown point identified—Conduct a purposeful touchdown, prior to this specific point, avoiding unnecessary float that extends air distance. I’ve been somewhat skeptical about electronic device interference with avionics, but a NASA ASRS report on the subject caught my attention. A CRJ flying at 9,000 feet received an EFIS COMP MON caution message: “Flight Manual directs pilots to slew compass to reliable side. It was apparent neither side was correct with the Captain’s mag compass, and First Officer’s headings all different. We were cleared direct to a fix. Multiple attempts were made to match the headings with only temporary results. The First Officer made a PA announcement asking everyone to check their cellphones. Sure enough, there was a phone in standby mode—not airplane mode. As soon as the phone was secured, all the avionics worked perfectly.” I’ve spent a fair amount of time on GA aircraft with passengers whose phones, laptops, or iPads/ tablets were most surely not secured, and there have been no anomalies. However, it probably just means all the links in the electronic accident chain weren’t quite in alignment. As we learn more about the hardware and its interference profile, there’s the opportunity to either provide better shielding, or just shut the thing off! Has anybody else had a problem with electronic device interference? Share your thoughts below in the “Leave a Comment” tab. Safe Flights… Bruce Landsberg President, AOPA Foundation (continued on page 8) 7 

Table of Contents for the Digital Edition of Premium On Safety - Issue 9, 2012

Premium On Safety - Issue 9, 2012
Contents
Wide Awake
Accident Prevention: Safety Hang-Ups
Flight Vis: SMS and the Need for Innovation
Safety Brief: Runway Excursions
ASI Message: Interference From the Cabin

Premium On Safety - Issue 9, 2012

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