Difference between ICE and SEVERE ICE detected ECAMs on Airbus
 

Hi ladies and gents,
Would anyone shed any light on the different triggering conditions for ICE DETECTED and SEVERE ICE DETECTED on the Airbus? Is there a similar distinction on the Boeing? Thank you.

On 737 there is no ECAM/EICAS nor system which detect ice conditions.

For A320 ICE DETECTED, you can check under Abnormal - ANTI ICE. Regarding the SEVERE ICE DETECTED, there is some info on Getting Grisps Cold Wx Ops. Hope that helps.

The 777 gives an EICAS alert if the system is off, and ice is detected.

The difference between ice detected and severe icing is in the actions required - see #3, check the specific actions for the aircraft.

Getting to Grips with … https://www.skybrary.aero/bookshelf/books/3404.pdf

The usual advice is that according to the aircraft type certification limitations, is that for ‘normal icing’ ** the flight can continue in the conditions, but remain observant.
For severe icing, aircraft type specific - e.g. rate of accumulation, location, effects, then the conditions should be exited, change of course and/or altitude.

Note that the met icing definitions do not relate to the inflight conditions experienced by aircraft, and that inflight icing PIREPS only relate to the reporting aircraft, but can be a useful guide.

I do not know about the airbus specifically, but would expect a detector to differentiate between rates of accumulation, clever physics. However, the crew must always check where the ice is forming, and remember that what can be seen on the wings may not be the same on the tail / fin which could have greater effects, (finesse ratio).

** No such thing as ‘normal’ ice; only good ice, bad ice, and hazardous ice.
Good ice is in the galley.

That’s assuming you can see the wings… which in most airliners, you can’t.

Ice det equals about . 0.5mm ice accretion. It holds the signal for 60secs. if after 60 sec no ice detected it resets. Once it detects it heats the probes and sheds the ice. If it does this 7 times in a row / Then Sev ice det. = about 5mm ice.

the ice changes the oscillating frequency of the probe. Just like a quick dip in a frosty pond one could say.

something like that.

when you select Wai on resets the counter.

ice det is NAI on. Sev is NAI and WAI.

detected from the vibrating ice det on the lower part of the nose (2 of them).

or you can look at the horn on the window centre pillar

Thank you all!

‘That’s assuming you can see the wings…’

Perhaps that’s why Airbus have taken the initiative to provide the crew with more information. But even with this information the crew actions and continued reassessment is vital.
So for Severe Icing detected, both anti icing systems are used; but do not forget that there still are conditions, intensity, duration which could affect systems and engines, beyond the tests and assumptions in certification.

The OP ask about other aircraft; so if you cannot see the wings in B or any other type of aircraft, how might the crew detect the difference in icing intensity, and how is this related to other parts of the aircraft.

Check the Icing indicator
 

dont trust it 100%

Keep checking the lighted icing indicator, in icing its a the best visual indication!

“The A320 detector vibrates at a rest frequency of 40.000 Hz.
A shift of 133 Hz represents an ice thickness on the probe of approximately 0.020 inch and lead to the ice signal which remains active for 60 seconds.

For the A320Fam a ice "detector" is only an option.
Normally there is only a lighted icing indicator between the windshields.”