The "Silly" season is upon us!!

Doc · Post by **Doc** » Sat Oct 14, 2006 7:42 am

Here we go again. We have to sit and listen to not only RSC reports that call 95% bare and dry...but everybody that encounters even a trace of ice, has to pontificate like trained seals! Some of you are reporting "moderate to heavy" ice when the clouds are no more than a few feet thick. And the rest of us have to listen to this drivel. Ladies and gentlemen....it's winter...and in winter, when flying through a cloud...we usually encounter a light frosting on the leading edges...this is NORMAL! It is NOT "moderate to heavy" ice! The guy behind you is NOT going to come falling out of the sky like a "Baron full of lawyers"!
On the subject of inflight ice. IF you do encounter "moderate to heavy" inflight ice....do a one-eighty...NOW!

lost · Post by **lost** » Sat Oct 14, 2006 8:00 am

While I agree that alot of icing reports overstate the intensity of ice, on a day where there is icing forcast, a pirep saying its light or non-existant can be very helpful.

Cat Driver · Post by **Cat Driver** » Sat Oct 14, 2006 8:05 am

Can anyone here give us a definitive means to describe the level of icing observed in flight?

To a new age college grad from an aviation program what would be heavy icing to them would be insignifigant icing to an experienced pilot.

drifter · Post by **drifter** » Sat Oct 14, 2006 9:07 am

Does aircraft type not play a role in the severity of ice as well?

What would be severe for a caravan or mu-2 might be light to moderate for a navajo no?

Cat Driver · Post by **Cat Driver** » Sat Oct 14, 2006 9:18 am

So ice reports should be airplane specific?

U/S · Post by **U/S** » Sat Oct 14, 2006 9:48 am

When a PIREP is issued they always tell you the type that gave the report so I guess the pilot is responsible to draw his own conclusions. If a 47 reports heavy ice I would expect heavy ice if a caravan reports heavy ice, while heavy to the 'van it probably is light for many types.

Mostly Harmless · Post by **Mostly Harmless** » Sat Oct 14, 2006 2:53 pm

http://www.tc.gc.ca/CivilAviation/publi ... ET/2-0.htm

2.4 Airframe Icing
Report icing to ATS and, if operating IFR, request a new routing or altitude if icing will be a hazard. Give your aircraft identification, type, location, time (UTC), intensity of icing, type, altitude or flight level, and indicated airspeed. (See the suggested format on the back cover of the CFS.)

The following describes icing and how to report icing conditions:

INTENSITY ICE ACCUMULATION
Trace Ice becomes perceptible. The rate of accumulation is slightly greater than the rate of sublimation. It is not hazardous, even though de-icing or anti-icing equipment is not used, unless encountered for an extended period of time (over 1 hour).
Light The rate of accumulation may create a problem if flight is prolonged in this environment (over 1 hour).
Moderate The rate of accumulation is such that even short encounters become potentially hazardous, and use of de-icing or anti-icing equipment or diversion is necessary.
Severe The rate of accumulation is such that de-icing or anti-icing equipment fails to reduce or control the hazard. Immediate diversion is necessary.
*Rime ice: Rough, milky, opaque ice formed by the instantaneous freezing of small supercooled water droplets.
*Clear ice: Glossy, clear, or translucent ice formed by the relatively slow freezing of large supercooled water droplets.

Also... one of my pet peeves:

http://www.tc.gc.ca/CivilAviation/publi ... -1.htm#3-7
3.7 Turbulence Reporting Criteria Table
INTENSITY AIRCRAFT REACTION REACTION INSIDE AIRCRAFT
LIGHT Turbulence that momentarily causes slight, erratic changes in
altitude and/or attitude (pitch, roll, yaw).
Report as “Light Turbulence”.
OR
Turbulence that causes slight, rapid and somewhat rhythmic
bumpiness without appreciable changes in altitude or attitude.
Report as “Light Chop”. Occupants may feel a slight strain
against seat belts or shoulder straps.
Unsecured objects may be displaced
slightly. Food service may be
conducted and little or no difficulty is
encountered in walking.
MODERATE Turbulence that is similar to Light Turbulence but of greater
intensity. Changes in altitude and/or attitude occur but the aircraft
remains in positive control at all times. It usually causes variations
in indicated airspeed. Report as “Moderate Turbulence”.
OR
Turbulence that is similar to Light Chop but of greater intensity. It
causes rapid bumps or jolts without appreciable changes in aircraft
altitude or attitude. Report as “Moderate Chop”. Occupants feel definite strains
against seat belts or shoulder straps.
Unsecured objects are dislodged.
Food service and walking are difficult.
SEVERE Turbulence that causes large, abrupt changes in altitude and/or
attitude. It usually causes large variations in indicated airspeed.
Aircraft may be momentarily out of control.
Report as “Severe Turbulence”. Occupants are forced violently
against seat belts or shoulder straps.
Unsecured objects are tossed about.
Food service and walking impossible.

NOTES 1: Occasional: Less than 1/3 of the time.Intermittent: 1/3 to 2/3.Continuous: More than 2/3.

2: Pilots should report location(s), time (UTC), intensity, whether in or near clouds, altitude, type of aircraft and, when applicable, duration of turbulence. Duration may be based on time between two locations or over a single location. All locations should be readily identifiable.

3: High level turbulence (normally above 15 000 feet ASL) not associated with cumuloform clouds, including thunderstorms, should be reported as CAT (clear air turbulence) preceded by the appropriate intensity, or light or moderate chop.
Examples

1. Over REGINA 1232Z, moderate turbulence, in cloud FL310, B737.

2. From 50 NM EAST of WINNIPEG to 30 NM WEST of Brandon 1210 to 1250Z occcasional moderate chop, FL330, AIRBUS.

goldeneagle · Post by **goldeneagle** » Sat Oct 14, 2006 3:53 pm

Cat Driver wrote:Can anyone here give us a definitive means to describe the level of icing observed in flight?

To a new age college grad from an aviation program what would be heavy icing to them would be insignifigant icing to an experienced pilot.

I do not claim to be an expert on this subject by any means, but, when I'm flying with someone sitting beside me who has no real world experience with ice on the airplane, I'll offer them some guidelines for judging ice, and how it relates to THIS airplane. The symptoms on ours are very similar to those on a ho, but, our bird doesn't carry it quite as well as the ho. We are pressurized, so, the tendancy is go get higher asap if we bump into the sticky white stuff. If there is lots of it in the forecast, then we make every effort to end up between layers, even if that means asking for a wrong way cruising altitude.

insignificant - The leading edge of the boots turn white, from the mid section to the trailing edge of the boot remains black to the view from the driver seat.

trace - There is a little buildup on the leading edge. If you cycle the boots, you can see it break off, but, you dont feel anything. The entire boot turns white after a few minutes.

light - There is a definite accumulation on the leading edge. The right hand windshield (its plexi) gets frosty on the outside, you dont see much thru it. Left hand windshield remains mostly clear (its glass, defrost on hi, windshield heat is still off). You occasionally hear the tick on the side of the fuse when something comes off a prop. When you cycle the boots (every 5 to 10 minutes) you hear the distinctive noises of ice coming off in small chunks. On the radio, pilotely requesting higher.

moderate - You have accumulation on both sides of the windshield. The tic tic of stuff coming off the props is very regular. Cycling the boots once a minute, and you _feel_ the ice coming off the airplane. Airspeed is down 10 to 15 knots. Pilot has charts out, looking for options, and is on the radio demanding higher. Pilot is analyzing terrain vs freezing level in various directions and getting the contingency plan worked out. If it doesn't improve in short order (couple of minutes at most), the contingency plan will be executed. Normally a climb of 4 to 6 thousand feet will get us out of this, and it's rare ATC cannot give you the climb. Special case, if MEA/MOCA is below freezing level, we are headed down to the comfort of the rain, which will de-ice the airplane faster than any de-icing bay at the airport.

heavy - The chatter on the side of the fuselage is non stop. You feel the buffet firmly when you cycle the boots every 30 seconds. It's hard to see what's happening on the wings, the side window has glazed over. You are turning either back to the moderate you just came from, or in a direction where the terrain is below the freezing level. Conversation with atc has changed from 'asking' to 'telling'. The contingency plan from the previous phase is being executed. Higher is no longer an option.

severe - You dont wanna be here. You shouldn't be here. If you are here, you screwed up. You are descending on a trajectory very similar to that of the space shuttle, and throttles to the firewall are not stopping it. The only escape is to get below freezing level, which is coming very soon now. The only question left, where do you get first, impact or freezing level.

Doc wrote: On the subject of inflight ice. IF you do encounter "moderate to heavy" inflight ice....do a one-eighty...NOW!

Agreed to a point doc. Out in the flatlands, and in general, it's the best advice. The thing is, dealing with moderate to severe ice is more prevalent on the wet coast than in most other areas, and out here there is a special case overriding factor, cumulus granite that sticks WAY up, with prevailing winds off the ocean that push lots of moisture up along the coast range, creating bands of really sticky stuff. Of course, this is all airplane dependant too, i'm writing from the view of somebody driving a light twin around the west coast, i'm sure lear and boeing drivers will have a different perspective.

When you run into a lot of the sticky white stuff on the west coast, your absolute best option is always to descend below the freezing level. You will be amazed how fast a little bit of water clears the airframe of all ice. The problem is, descent thru freezing level is not always an option if you have cumulus granite below, and that's where the 'local knowledge' comes into play. 7 days out of 10 in the winter, you are inbound for yvr, fat and happy above the clouds, and you get cleared onto one of the various STARs for yvr. Each of those STARs has altitude restrictions at specific points. I'll use the KEINN as the example.

Typical winter day, blowing southeast, the 8's are active, and you've been sent to KEINN, which has an altitude restriction to get you down to 12 in an area where MEA is 9200. That southeast blow is pushing wet stuff into the north shore mountains, it's saturated, and the freezing level is anywhere from 2 to 5 thousand. Now you are fat and happy above the cloud at 17 thousand with a controller trying to get you to start a descent into that stuff. Nossir, not gonna happen. I'm going to advise the controller that I will accept a descent clearance when it takes me below freezing level, and not before. Until then, I'm fat and happy above the clouds, no ice on the airplane, and feeling quite comfortable. I'm really sorry if my attitude is going to screw up your arrival plan, but, that's how it works out here in the real world. I'm the guy that's driving this thing, and, my call trumps your clearance, thank you please.

The odd controller will get a little huffy when you say no to the descent, but, if you mention freezing level as the reason, most will just put you on a vector out toward the straits, and send you to the localizer. A few minutes later they will advise you now over the straits, and clear you all the way down, often with a request to expedite the descent if able. The same principles apply inbound from the east, but controllers will be a little more miffed, it's a lot harder for them to deal with a light twin coming down from flight levels over the fraser valley than it is when you are out over the straits. Again, my attitude is 'to bad'. When balancing my life against 'easy shift' for a controller, that scale tips pretty solidly my direction. If a typical west coast winter system is pushing up against the north shore mountains, and i'm above it, I will accept a descent if and only if it takes me all the way to the freezing level. Once you poke the nose down into the white stuff, consider yourself committed, you ARE going to the freezing level, and you must assume the ice accumulation on the way down is going to ensure that nothing else is possible. 180 back is no longer an option.

The same logic holds for departures. Assume a blast off headed for kelowna, with preferred routes that take you strait up over the north shore mountains. The southern lane takes you out over CILLI, and keeps you over the valley for the first 50 miles, with safe altitude underneath of 3000, vs the 10,000 and higher safe altitudes on the northbound departure lane. The trick, file it at 10 or 12 thousand so they dont stick you on the northern preferred route, but instead route you out the southern lane. Once you are airborne and outbound on the southern lane, then just keep asking for higher till you break between layers or even get on top of the stuff. If you are on the southern departure lane, the 180 back and descent to the freezing level is a valid option for the first 50 miles, more than enough time to find a good altitude away from the bad sticky stuff. And honestly, if you haven't found a good altitude free of ice by the time you are making the turn to princeton, you really do need to ask yourself if it's even worth going. That turn is going to take you out over some of the most unforgiving terrain on this planet, and it's not a place you want to be in an airplane battling ice.

The point I'm making in a long detailed manner Doc, altho your 'do a 180' is good sound advice when encountering ice, and it's always the first level contingency plan if you have no other plan already prepared, being aware of your situation and location is extremely important. Terrain is the deciding factor. The 180 may take you back to surviveable conditions, and is the only option for somebody not fully aware of the entire situation. On the coast, a descent below freezing level is always a better option than a 180 that points you back into the higher ground. If you know the sticky stuff is going to be there, and you can cruise above it, then just staying above it until you can blast thru it all the way down into the rain, you will turn what could have been the scariest airplane ride of your life into a non event. When departing the valley, you want to keep the descent down to freezing level as a valid option until you have crested the top of the bad ice, which normally means between layers or on top.

When you are flying in areas where ice is the norm in the winter, there are a couple of buzzwords that really apply. 'Situational awareness' and 'local knowledge' are the ones that matter. Dont leave home without it.

Cat Driver · Post by **Cat Driver** » Sat Oct 14, 2006 4:22 pm

Golden one, good post as usual.

However may I add one more type of icing that will be found out here in Lotus land?

Freezing rain ( Clear Icing ), that makes cloud icing look mild for catch rate and performance degrading time wise.

One day I had a Twin Otter on floats litterally fall out of the sky on me when I flew into freezing rain that had not been forecast.

We entered cloud just as we flew over the Lions Gate bridge cleared via present position, the Iona beacon, Active pass , the YYJ beacon at 4 T...

.... in the next couple of minutes we started to ice up in freezing rain and just passing the Iona beacon we were unable to maintain at max power and the heated windshield was frozen over.

All that saved us was a left decending turn into the river and the fact that the windshield blew clear in time to see to land the thing.

It happened so fast that we didn't even screw up the IFR's landing 08, having advised departure of our problem he switched us to tower and we just flew right through the 08 ILS between the arriving airliners.

So you never know when all hell breaks lose..aviate , communicate..and get down safe if you can.

Cat

sky's the limit · Post by **sky's the limit** » Sat Oct 14, 2006 4:39 pm

Worst ice I've run into is in the tropics.

Hitting a line of embedded CB's and you try to pick your way through, only to take a few lumps along the way. I'll swear until the day I die, I actually heard it ice up once....lol.(laughing now, not so much at the time)

The good news is, the freezing level is always very high, and out over the ocean, you just decend until she melts. Or you pop back out into the clear, and it sublimates off pretty quick.

STL

desksgo · Post by **desksgo** » Sat Oct 14, 2006 4:59 pm

GOLDENEAGLE...

Wow...I am going to save that, looks spot on. It is one of the most mis-understood topics in training and I appreciate the thoroughness of your response. You may have just educated a lot of people.

Hedley · Post by **Hedley** » Sun Oct 15, 2006 4:14 am

GE: Fantastic post about icing! I'm going to save that - it ought to be mandatory reading for any pilot doing IFR training in Canada, and I'm certain that less than 10% of the newly-minted IFR pilots would know any of that.

I would like to re-emphasize GE's point about the importance of delaying your descent through an icing layer, until you can get a clearance which allows you to descend through it.

Pop Quiz: leading edge temp rise, anyone?

Even though it may be tremendously convenient for ATC, DO NOT accept a clearance to fly level in an icing layer.

Same thing on the way up - if ATC wants you to level off on an icing layer on the way up, it's not going to help your climb performance any to pick up a load!

Rosedale, IN anyone? I'm sure it was very convenient for ATC for that ATR to hold in freezing rain, but perhaps the pilots should have said, "No, we ain't going there".

wallypilot · Post by **wallypilot** » Sun Oct 15, 2006 9:09 am

Great post GE. Thanks.

The Hammer · Post by **The Hammer** » Sun Oct 15, 2006 10:22 am

Hedley wrote:
Rosedale, IN anyone? I'm sure it was very convenient for ATC for that ATR to hold in freezing rain, but perhaps the pilots should have said, "No, we ain't going there".

Roselawn actually and maybe the pilot's should have followed the AFM and not held in icing conditions with flap down (they were helping the FA's by lowering flap to lower the deck angle) As well, ATC can only react to what you tell them. The forecast/reported icing in Roselawn wasn't extreme and that is what caused such a panic afterwards because the icing just wasn't that insane. Holding with flap allows ice to build up on non-protected surfaces. Roselawn just exemplified the importance of doing things right because if you don't you become a test pilot. I feel sorry for those who learn the hard way because it probably wasn't taught well before and now the rest of us benefit from their misfortune.

PS I luv the guy who holds for 30 minutes then decides to tell atc he has a fuel emergency.

bob sacamano · Post by **bob sacamano** » Sun Oct 15, 2006 6:36 pm

Thanks for the good post GE,

Instead or ranting about it, you actually took some time and did something usefull.

As for the originator of the thread, just a thought, but maybe tune down the volume?

Elessar_44 · Post by **Elessar_44** » Sun Oct 15, 2006 7:25 pm

Thansk for the post eagle, new CPL appreciates it