{"id":20028,"date":"2022-10-18T10:21:23","date_gmt":"2022-10-18T14:21:23","guid":{"rendered":"https:\/\/ops.group\/blog\/?p=20028"},"modified":"2022-10-18T10:31:52","modified_gmt":"2022-10-18T14:31:52","slug":"winter-is-coming-updated-holdover-time-guidelines","status":"publish","type":"post","link":"https:\/\/ops.group\/blog\/winter-is-coming-updated-holdover-time-guidelines\/","title":{"rendered":"Winter is Coming: Updated Holdover Time Guidelines"},"content":{"rendered":"

Sorry, the GoT reference still hasn’t grown old. Anyway, every year the FAA & Transport Canada releases a new set of Holdover Time (HOT) guidelines for the winter season. The one for winter 2022 is available here<\/a>. So if you want to update your de-icing procedures, manuals, and training in line with the guidance from the feds, here’s what you need to know…<\/p>\n

What’s changed?<\/h4>\n

They’ve added some fluids and removed some fluids <\/strong>which are really good for middle speed aircraft.<\/em>\u00a0So basically, check what fluid is being used on your aircraft, confirm it is a good one for your aircraft Vr, and then make sure you use the right table.<\/p>\n

Standard Winter Ops 101.<\/p>\n

Type II generic holdover times have increased<\/strong>\u00a0(because they removed a fluid called Beijing Something or other\u00a0<\/i>that was holding them back). How much by? A few minutes here, a few minutes there, mainly in the -3 \u00b0C and above (27 \u00b0F and above) section.<\/p>\n

They also did a load of tests which means you now get HOTs for very cold snow<\/strong> (cold enough to turn your legs to ice blocks if you accidentally step into it because its colder than -14\u00b0C cold). This applies to a bunch of new Type II and IV fluids and is great because that’s the sort of stuff you’re going to want to escape from for sure.<\/p>\n

Double check those tables!<\/h4>\n

If you\u2019re heading into the generic fluid tables<\/strong> then that\u2019s fine but <\/b>you actually need to make sure the Type II or Type IV fluid is listed in table 55 or 57.<\/strong><\/p>\n

It might seem a little contrary to the point of a ‘generic table’ but there we go. If it isn\u2019t in the table, and if it doesn\u2019t have its own specific table, then chances are you\u2019re in some dodgy airport where they\u2019re spraying you with homemade, bootlegged moonshine and it might not be very safe.<\/p>\n

Freezing Fog.<\/h4>\n

There are changes to the HOTs for FZFG if it’s mixed with ice crystals or mist.<\/strong> Same for snow mixed with ice crystals.<\/p>\n

My opinion: <\/strong>You need some pretty trustworthy Met officer telling you exactly what is out there to start getting this specific. If in doubt, always go with the most limiting and then take a good look before taking off!<\/em><\/p>\n

A note on a note.<\/h4>\n

You can<\/strong> takeoff up to 90 minutes after the start of fluid application<\/strong> with a few conditions. This isn’t a new change, this has always been the case, but still worth mentioning.<\/p>\n

\"\"<\/p>\n

Small Hail.<\/h4>\n

This hasn’t changed but it is a confusing one so they’ve added a new note on it. It says this (give or take one or two inaccuracies):<\/p>\n