Protecting your landing against overruns 4th annual Safety Forum 2016 Captain Wolfgang Starke General intro and greetings
What is being done Dispatch calculation prior route initialization Determination of maximum masses prior to flight Actual T/O and LDG-performance calculation before and in-flight Assistance from Safety Nets Overview how take-off and landing performance is calculated and which calculations have been done until landing First calculation prior route opening by the company. Average weather conditions are used, 60-70% depending on prop or jet of the runway is used for calculation. Second calculation is done by the crew or dispatch during preflight using actual or forecasted weather. Determination of actual maximum landing and take-off mass is done. Third calculation by the crew immediatelly prior take-off or landing is done using actual weather and mass. Speeds, thrust reduction and actual performance is calculated. -> T/O and landing should be safe as it is calculated three times and done using proper SOPs. Safety Nets assist pilots after performance was assured to be safe.
Reason for Safety Nets Protection against daily slips and errors Increase of flight-crews‘ awareness If the T/O or LDG is safe, for what do we need safety nets to protect us? -> daily slips and errors: attempted take-off or landing on taxiways Line-up with wrong runway Incursion awareness -> Awareness Runway length (if it is short) Incursion and correct runway
Runway Safety Nets two examples Two examples of Safety Nets implemented in flight decks.
Runway awareness and advisory system (RAAS) -> protection against excursions and incursions -> aural information and alerts to flight crew Example No.1 the RAAS RAAS gives pilots aural information and warning against runway incursions and excursions. Such information can be annunciation of the runway, warning if speed on taxiway is too high. Warning when approaching runways on ground and in air, remaining runway length information.
at Düsseldorf, RWY 23R Looking at DUS, approaching RWY23R. Clearance is to land and vacate at the end via L9.
Alerts from RAAS RAAS will provide following alerts In Air one alert, approaching RWY23R plus LDA available On ground roll: 5 alerts if speed is above 40kts (1200, 900, 600, 300, 100) On ground roll, end of runway: 9 alerts at the end (90, 80, 70, 60, 50, 40, 30, 20, 10) One alert before crossing RWY23L -> 14 (!) alerts on the runway for a NORMAL landing?! Flight crews may inhibit RAAS on the runway as it is disturbing and noisy. Chances are high they do not reengage RAAS after landing or RAAS is not getting operational quick enough to protect against incursion of RWY23L.
How does it look? Apron directly behind the runway. No turns, wide taxiway (as it was a crossing runway years before). Guard lights are located at high distance from centreline, easy to produce a runway incursion. RAAS is generally a good system. TUNING makes the difference! Number of nuisance alerts should be kept at a minimum to not tempt flight-crews to inhibit system or get used to alerts. Number of nuisance alert is big topic at ICAO GBSNSG DO NOT THROW SYSTEMS IN FLIGHT DECKS BUT TUNE AND DESIGN THEM WELL, TRAIN FLIGHT CREWS!!!
Runway length warning Long haul aircraft arriving at European airport for scheduled flight Airport regularly used by this aircraft type Two runways available, both in excess of 3000 meters LDA Weather was windy but flyable Setting the scene, describing the general situation (not mentioning it was Emirates Flight EK-19 from Dubai to Manchester on March 26th 2016)
What happened Three missed approaches from around 1000ft AGL within one hour Diversion to an alternate airport Flight from alternate to destination about two hours later with successful landing Caused by „runway too short“ alerts The aircraft approached the airport, went around from about 1300ft AGL due to „runway too short alert“. Second approach same runway, again same alert and go-around. About one hour of holding then approach to second runway of the airport, again missed-approach due to same warning. Diversion to alternate airport with safe landing. About two hours later flight to destination and landing with about four hours of delay. Weather and runway about the same upon 4th landing, obviously the runway was not too short. Question is how mandative should these systems be? -> Remember: Landing was calculated to be safe three times before actual landing occured! Should there be a possibility to inhibit alerts if they are deemed faulty (after careful consideration of the crew)? What about even more dangerous situations like the A350 automatic rejected take-off?
Issues with current SNETs Tuning of SNETs remains an issue Who is in command? SNET vs. pilot We have seen in Düsseldorf that tuning is a real issue when talking about SNETs. Too many alerts may tempt flight-crews to inhibit the system. By this, protection of the system is degraded. The second example revealed the question about how mandative these systems should be. Well trained pilots can evaluate the situation and decide whether an alert is apropriate or not. Do we want pilots surrounded by little robots that tell the pilots what they have to do? SNETs should be ASSISTANCE to pilots, not DIRECTIONS or ORDERS.
Conclusions Safety Nets can help preventing accidents Careful tuning and implementation which includes training for crews is a prerequisite Safety Nets should assist pilots, final decision should remain with the pilot in command Generally SNETs are good and welcome! To be effective they need to be properly tuned and implemented. Training to crews is essential. When tuning these systems crews should be involved! Once properly implemented chain of command must be clear. SNET is assisting but responsibility for safe outcome of flight must remain with the PIC. - > in case of nuisance alerts there should be an inhibit possible to enable crews to „override“ their SNET after careful consideration and evaluation of the situation.
THANK YOU for your attention ! ! ! Wolfgang.Starke@VCockpit.de