Professional Pilot, July 2020

Embraer Phenom 300E with Prodigy Touch avionics based on the Garmin G3000 suite Crew and passengers are protected by EDM as standard equipment PROFESSIONAL PILOT July 2020 19 Automatic descent equipment In reality an automatic system to fly an aircraft down to thicker air is not magic at all It exists today and is in widespread use on business jets Called Automatic Emergency Descent Mode AEDM Automatic Descent Mode ADM or Emergency Descent Mode EDM by various manufacturers the system debuted in 1997 on the Gulfstream V The magic system is an AP feature which safely flies the aircraft from physiologically impairing altitudes to altitudes where both life and consciousness can be maintained thus mitigating the risk of occupant injury due to depressurization Dassault Falcon On Dassault Falcon aircraft ADM activates when sensed cabin altitude climbs above 15000 ft while the aircraft is at or above 30000 ft pressure altitude Normal cabin altitude at cruise flight levels is less than 7000 ft Falcon ADM assumes the pilots have become unconscious Once activated it turns on the autothrottles if they were not already on and retards the engines to idle thrust AP then varies the descent attitude to maintain MMO V MO until reaching 15000 ft where the aircraft will level off and decelerate to 250 kts This maneuver allows the flightcrew to regain consciousness and assume control of the aircraft While descending the aircraft will automatically use half bank to turn left 90 degrees and then hold this new heading The 90 degree heading change serves to alert air traffic controllers that there is something unusual about the aircraft that needs their attention as well as serving as a way to get the descending aircraft off a particular airway or oceanic track If the pilots are receiving sufficient oxygen through their masks to remain conscious they can disengage ADM with a push of the AP quick disconnect on the yoke or deselect AP on the guidance panel ADM is available on all EASy Falcon models Gulfstream Gulfstreams AEDM system works as described above except that the aircraft must be flying above 40000 ft for AEDM to trigger According to Heidi Fedak Gulfstreams director of corporate communications and media relations Gulfstream introduced AEDM on the GV in 1997 because its max altitude was 51000 ft requiring us to develop a method of addressing rapid depressurization All in production Gulfstream models are equipped The G500 G600 and G700 all go a step further than earlier AEDM implementations in that the airbrakes will open when AEDM activates Textron and Embraer ADM is standard on Textrons Cessna Citation Sovereign Latitude and Longitude and its an option on the Caravan and Grand Caravan says Christina Walser communications specialist at Cessna Citation Business Jets Textron aircraft that are not outfitted with autothrottles are equipped with EDM which is similar to ADM but lacks the ability to automatically reduce engine power Current production aircraft that feature standard EDM include Cessna Citation M2 CJ3 CJ4 and XLS Embraer delivers its Phenom 100EV 300E Legacy 450 500 and Praetor 500 600 business jets with ADM as standard equipment Garmin Garmins take on ADM is part of the companys Autonomí suite of autonomous flight solutions and is called EDM Autonomí pronounced as autonomy is an overarching term that encompasses layers of safety EDM is built into Garmins integrated flightdecks those containing both Garmin avionics and Garmin AP and its typically standard in pressurized turboprops and jets Interestingly the non pressurized Cirrus SR20 SR22 light singles also have EDM In non pressurized cockpits the Garmin avionics monitor pilot consciousness If no avionics interactions are sensed for a set time the avionics will prompt the pilot If this prompt goes unacknowledged EDM will activate and the aircraft will head down to thicker air According to Bill Stone Garmins senior manager of aviation business development the companys work on EDM and its new Emergency Autoland mode predates Payne Stewarts accident but that tragedy solidified the need for autonomous flight solutions What ADM wont do As with any airplane system it is important to understand its limitations as well as the capabilities Most ADM systems will not engage while the aircraft is being hand flown With a few exceptions ADM will not automatically deploy airbrakes nor change the transponder code to 7700 nor transmit Mayday on either the radio frequency or data link The system will not change altimeter setting as the aircraft descends through transition level nor will it keep the aircraft from impacting terrain that happens to poke above the designed level off altitude