Tips For Flying in ICE

[avbug]

Sublimation (which is a form of evaporation whereby the solid bypasses the liquid state and becomes a gas)will help erode any ice in clear, colder temperatures aloft...

Don't count on that. Ever. The ability for that to happen is largely proportional to the relative humidity at altitude, but it may never sublimate. If it does, nice for you...but don't ever count on that. I spent nearly three hours one day last week working in and out of weather in conditions very conducive to ice formation. I had nearly three inches on unprotected areas, and didn't shed any until descent to lower warmer temps in the clear. Even then, we were still shedding ice on final...in the middle east. It's dry here, too. Very dry, with a very wide temp/dewpoint spread at altitude, but outside the cloud, we didn't see any effects of sublimation.

 

[time builder]

Anyone else have much experience with prop anti-ice affecting their DG/Compass? I'm sure that's another good topic for discussion with icing conditions.

 

[avbug]

Why would propeller ice affect your gyro or compass? Are you talking about electrical boots interfering with the compass? That's possible, as will electric NESA type windscreens, hotplates, and all sorts of other electrical devices...but the ice shouldn't have any effect.

Flight in dry ice crystals can cause st. elmos fire and static discharges, which can affect your compass, but should have no effect on your gyros...especially air driven uncompensated gyros.

I don't think I've ever heard of ice on a propeller affecting a gyro or compass. Can you provide some detail?

 

[time builder]

Right, it isn't the ice, but high electrical loads in the vicinity of the cockpit throwing off the magnetic field of the compass. Now that you mention it, I believe the electric windshield heat threw it off too.

 

[avbug]

The compass should be calibrated with everything on, or at least everything that is expected for most phases of flight. Having the wiskey compass go to la-la land when electrical fields are introduced around it is normal, because all electrical fields produce magnetic fields, and the compass responds to magnetic fields. This will occur when you turn on the systems, without regard to the presence of ice.

Your gyro should not be affected in any way.

You'll likely see the compass moving around, not just in error by a certain amount, because with electric blankets and electric prop boots (and to some degree, windscreen protection), will cycle on and off in stages. One element will be energized for so long, then it goes off and another is energized, and so on. You can see it cycling on your ammeter, and you will probably see changes in the compass that coincide with the spikes or movements on the ammeter.

 

[Hook 'Em Horns]

Nothing to add about flying in ice, but when I was at AirNet we were to cycle the boots and all other anti/de-ice equipment before the first flight during the run-up. This was done all year long to prevent the boots from becoming brittle due to lack of use. A good idea.

 

[sleddriver71]

I know "new research" says that we're supposed to cycle the boots continuously when in icing conditions and that ice bridging is a myth. I would listen to people who fly in areas conducive to icing and those that basically have a lot of experience flying in ice. I flew out of the Seattle, WA area for several years, crossing the cascades frequently. I can't tell you if ice bridging is a myth or not but it doesn't matter at all. What I can tell you from my experience is that blowing the boots with a very thin layer of ice will not get rid of the ice. They teach at SIMCOM that ice bridging is a myth and that waiting to accumulate ice before blowing the boots is not necessary anymore because of the way boots are designed. That is bull loney! I should have known not to listen to someone in Orlando, FL telling me how to deal with ice, all his knowledge came out of a book and mine came from the pacific northwest and the ice machine known as the cascade mountain range. I don't care what the "latest" research says, I know what works and so does anybody who has a good deal of experience flying in icing conditions. Of course it is a good idea to get out of the icing conditions as soon as possible, but it is a BAD idea to immediately cycle the boots as soon as you get the first indications of ice. I flew Chieftains, Senecas, and 400 series Cessnas, and I would never blow the boots until I lost 10-15 kts of indicated airspeed.

 

[avbug]

Ice bridging is definitely not a myth.

I don't know about looking for a performance decrease, but at least a quarter inch or more of ice ought to be present...and you need to consider the type of ice. If it's soft ice that lends to bridging, more is needed before breaking it free. If it's hard glaze ice, then you may be able to crack it sooner. The rate and way in which it's accumulating is also important; if you're briding it out by popping the boots, and it's accumulating rapidly while the boots are out, you can develop a bridge that the next boot cycle won't break.

We ended up yesterday with a couple inches we couldn't get rid of after only three passes through a relatively benign level 2 cell...and it most definitely didn't sublimate in the clear air outside the cell (even with extremely dry air). We had to descend to get rid of it.

 

[Lead Sled]

As per the norm, Avbug nailed it. However, you're probably not going to follow his advice so I'll add another suggestion - get a hold of a copy Weather Flying by Robert Buck and read it cover to cover a few times. You will probably be able to find it at one of the larger book stores and it may even be in your local library.

Icing is one of those things that can kill you. I had a good friend of mine get killed in a known-ice certified light twin while "playing in the snow". Respect it.

LS

 

[sleddriver71]

As per the norm, Avbug nailed it. However, you're probably not going to follow his advice... Icing is one of those things that can kill you. I had a good friend of mine get killed in a known-ice certified light twin while "playing in the snow". Respect it.

LS

Thanks for the information on the book, I will get a copy of it when I can. I am wondering about your comment, "However, you're probably not going to follow his advice..." What are you referring to? If you read earlier posts in this thread you might notice that Avbug and I are not in disagreement, so I'm not sure what you're referring to.

 

[DirkkDiggler]

Ice bridging is definitely not a myth.

NASA disagrees with you, but what would they know!

 

[avbug]

Apparently not much.

They do know how to blow up and melt their equipment, spend ungodly sums of money, and transform the simple hammer into a five hundred dollar gadget.

Anybody who has any semblence of icing experience in boot equipped aircraft and is honest knows that ice briding is no myth.

I've seen it personally on numerous occasions, and couldn't give too hoots about what any organization has to say on the subject...I've seen it, experienced it, know it becasue I saw it with my own two eyes.

NASA and the FAA condemn the concept via the holy hallowed halls of science...which is much like the scientist and the fly.

The scientist sees the fly, and removes it's wings, which makes it...a walk. The scientist tells the walk (no longer a fly) to walk, and the walk walks. The scientist uses tweezers to remove one of the wingless fly's legs, and again commands it to walk. The scientist takes notes. He does so again, and again, until only two legs remain. The scientist removes one of the two legs, and commands the wingless fly to walk. The pathetic creature drags itself along by it's one remaining leg, straining to make headway. The scientist takes notes.

At length, the scientist does the inevitable. He removes the wingless fly's remaining leg, tearing it heartlessly from it's body, and commands the fly, "Walk!"

The fly lays there, not moving at all. Again the scientist barks, "Walk!" But the fly does not move. So, the scientist picks up his pen and notebook, and pens the conclusion to his experiment...

"Removed six legs from wingless fly, commanded walk. It has become apparent that removing legs from a fly negates fly's ability to hear. Further research required."

I don't need a scientist to tell me about ice bridging when I can look out at the wing and see it happen, time and time again. Presently I'm flying in a LOT of ice. I had to abandon my flight two days ago due to the ice buildup. I'm flying with bleed in the leading edges, and no boots...but other aircraft here are boot equipped, and are susceptible to ice bridging. Two of the pilots here are quite possibly some of the most experienced weather pilots alive, with a substantial part of that involving ice in boot equipped aircraft. One of them has done substantial meteoroglogical flying and atmospherics research for a number of organizations, including NASA...including holding the record for the most microburst penetrations...he was the one who garnered a great deal of the data that's available today. He has been there and done that, especially with respect to weather penetration and icing...and he's a staunch believer in ice bridging, because he has seen it his entire life.

Same here.

But what the heck...NASA says it doesn't exist....believe at your peril.

 

[BushwickBill]

Rule #1 Neither you, nor your airplane, were ever meant to fly in ice. When was the last time you saw a bird flying with iced wings?

Rule #2 There are two types of ice protection; anti-ice, and de-ice. Anti-ice is primarily intended to prevent ice...you are primarily intended to prevent ice. Avoid ice, prevent ice. There's a connection. De-ice is designed to remove ice. Often, it cannot. You cannot. There's a connection. Therefore, de-ice is really best handled as anti-ice.

Rule #3 You'll hear rumors that ice bridging is myth. It isn't.

Rule #4 Ice and frost affects your aircraft performance more than you think it will. Act accordingly.

Rule #5 When your airplane is iced, it is no longer your airplane. It is another airplane, and does not necessarily respond to the same airspeeds, control inputs, or expectations that your former, uniced airplane did.

Rule #6 Your anti-icing equipment is subject to failure. Plan accordingly.
This is never a matter of if. It's always a matter of when.

Rule #7 Know your environment. Know what's above you, below you, ahead of you, and just as importantly, what is behind you. Never fail to consider what is behind you, and don't let something be behind you force you into having to accept what lies ahead of you.

Rule #8 On a slick runway, always slow enough on landing that you must add power to taxi clear of the runway.

Rule #9 Anti-skid is not anti-slide. Reverse may not be rearward in nature. If you don't like where you're going when you apply brakes, reverse, or any other control input, then put things back where they were when life was good.

Rule #10 You have the right, the responsibility, and sometimes the obligation to say NO. Respect it.

Word....

 

[labbutt]

didnt bother reading 3 pages of responses:

1: ALT= Options
2: dont blow the boots till you feel your ahole pucker, because you are scared shtless!

3: if in AK over oceanic waterways, descend to 10 ft above the water, ice will melt!
good day

 

[ubpilot]

i used to fly freight near the great lakes area, i must say that those tips above are pretty good. just remember that never ever take off in the freezing rain, drizzle, or fog. I almost got killed once when i took off in the freezing drizzle, just for a few boxes of checks!