Emergency Descent Mode (EDM) Garmin Perspective

Emergency Descent Mode (EDM)

The Garmin Perspective G1000 glass cockpit, as is found in the latest Cirrus aircraft models, is equipped with an Emergency Descent Mode (EDM). EDM can kick in when flying at high altitudes like at FL 250 (25.000 feet).

Cirrus-FL250-4

At this altitude and without the pressure cabin found in larger jets or airliners, the time of useful conscience without additional oxygen supply is only about 5 minutes. In case you don’t touch any buttons on your displays (except for the radio button) the perspective system will initially show an alert “Are you alert? on your PFD display thinking that you might be unconscious. If you do not respond to this message and continue to fly without touching anything else on your display the system will eventually go into EDM mode and auto descend the aircraft initially to FL 140 and level off.

Auto descent

On the right side of the PDF, you see in red “AUTO DESCENT” as a red warning. At the top of the screen you see that the autopilot is in IAP (indicated airspeed) hold mode at a speed of 175 KT indicated. The set altitude is FL 140 (14000 ft). These settings were not done by me as pilot, but kicked in automatically by the system. At FL 140 the autopilot will level off the aircraft and hope for you to become conscious again. If that is not the case, then the auto descent mode will bring you further down to FL 125.

I have talked to several medical specialists and it seems plausible that an unconscious human becomes conscious again when the oxygen supply is restored.

Tryout on winter night above the North Sea

I tried out this EDM mode on a winter night while en route and of course only after getting permission from London Radar as we were flying inbound to London en route to our destination Calais. A little strange route, but it gave us the opportunity to try out this emergency mode. When we got permission from Radar we were flying over the icing cold North Sea at an outside air temperature of -40 Celsius.

Cirrus-FL250-5

Flying track up towards the Thames river.

Initially on our departure from Rotterdam (EHRD) we had to climb through a cloud layer with some ice in it, so we used the TKS Anti-Ice system in this aircraft to protect the aircraft from the ice as good as possible. This Cirrus is FIKI approved (flight-into-known-icing). The FIKI/TKS system cannot be operated at very low temperatures at which very low temperatures the icing risk is not that great anymore, but the remains of the TKS fluid on the wings will foam up and parts of its substance even flash evaporates due to the lower pressure up high.

Cirrus-FL250-3

It might look like ice here in this picture, which it is not. It is bubbles/foam of TKS fluid. Once you get down a little, the bubbles disappear almost instantly. The EDM mode that Garmin added to their Perspective G1000 system is yet another safety feature made available to pilots which I hope will never really have to be engaged for real.