In Praise of Light Icing

Sulako · Post by **Sulako** » Fri Mar 05, 2004 10:09 am

Here's something I have been discussing with a couple of fellow pilots, and I wanted to bring it forward for discussion, or perhaps to get yelled at

I think a tiny bit of icing makes our airplane handle better, and fly faster. By tiny, I mean a quarter inch or so. Now hear me out for a couple of seconds before you yell at me and make me cry...

The aircraft I fly eschews heated leading edges in favor of boots, and the condition of most of the boots is, shall we say, rustic. I'm talking about patches placed on top of patches, etc. I have noticed that when we pick up light icing, before we blow the boots, the airspeed actually increases by about 5 knots. I think the reason for this is that the icing makes a nice smooth coat over the cracked and peeling patches, and the dents in the wings. I also notice that when we blow the boots, not all the ice comes off; we are left with plenty of chunks and bits still sticking to the leading edges.

It makes me not wanna blow the boots at all when we just have a wee bit of ice. Forget the arguments about 'bridging' of ice if we blow the boots too soon or whatever. It just seems to me that the airflow is smoother over a wing without chunks and bits of ice sticking off the leading edge.

Note that I'm not talking about icing thicker than a quarter inch.

What do you think? Am I totally out to lunch here?

Cat Driver · Post by **Cat Driver** » Fri Mar 05, 2004 10:15 am

Please go and get some sleep now because you are correct.

Cat Driver:

twinpratts · Post by **twinpratts** » Fri Mar 05, 2004 1:26 pm

Dents in the wings?

Aycarumba!

Right Seat Captain · Post by **Right Seat Captain** » Fri Mar 05, 2004 2:13 pm

Does that mean I should fly my C-172 with dented wings through ice to fly better?

Dockjock · Post by **Dockjock** » Fri Mar 05, 2004 3:27 pm

Kinda like how drinking 2 beers actually increases your ability to formulate cogent arguments?

ahh, maybe....

. . · Post by **. .** » Fri Mar 05, 2004 4:34 pm

and five beers helps with over all reaction time, and ability to drive?

cedarjet · Post by **cedarjet** » Sat Mar 06, 2004 7:58 am

doesn't beer make girls prettier?

Snagmaster E · Post by **Snagmaster E** » Sat Mar 06, 2004 8:10 am

I think that bridging only occurs with the early generation of boots - the modern ones bridge rarely (if at all).

Illusions created by draught - my favorite lesson. A precautionary approach follows, usually ending with Spins.

bezerker · Post by **bezerker** » Sat Mar 06, 2004 5:40 pm

It could also be that the reduced lift from the ice has a nice side effect of reduced drag, hence the increase in speed. You might want a few beers in you before you try the stall tests with ice

shankdown · Post by **shankdown** » Sun Mar 07, 2004 11:50 pm

I agree, Sulako. I'm with you in your trepidation and I understand why you'd wade so cautiously into the unknown waters of the 'icing-clean aircraft concept' conversations, because there are always a rash of people ready to tell you how unsafe you are when operating with even a frozen water droplet on you windscreen. But a quarter of an inch of ice changes your airfoil far less than a clean wing with your de-ice boots inflated. And those wings where there is 3000 dead mosquitos and patchwork dotting the boots like chicken pox? Some ice would have to make that go a little quicker. Interesting thought, though. I've never tried looking for an increase in airspeed... I've just looked for the decrease. Besides, the Navajo never seems to fly at the same indicated airspeed twice

But I will keep an eye on that from now on, in the event I see ice between now and next fall... I'm off to the equator for a while... leaving on Wednesday

SD

tip tank · Post by **tip tank** » Mon Mar 08, 2004 6:31 am

You put alot of thought into your posts Sulako. I've never before even thought of looking for that, as we have the same problem here. But, I would love to be a fly on the wall when you bring that argument up at your next annual renual GS.......... Argue And apparently, bridging is not an issue anymore!

ndb · Post by **ndb** » Mon Mar 08, 2004 6:43 am

Neither is "flicker vertigo" - it quietly disappeared.

Transport says lots of strange things, but I won't embarrass them by repeating them here.

Boeing Driver · Post by **Boeing Driver** » Mon Mar 08, 2004 7:18 am

I used to fly a Navajo with more patches than I cared to count. They rarely inflated properly, failed me numerous times, and over all gave me a false sense of security. I had a discussion with an AME and he told me that after a certain number of patches (not very many), the aircraft is no longer certified for known ice. It makes sense to me why it would be that way as I think boots are marginal at the best of times. Boots buy you barely enough time to get out of serious icing. Been there, done that, changed my shorts!

I realize Sulako was refering to just a bit of ice (assuming it stops when you've collected just the right amount), but during icing, I usually don't think about the resulting increase in airspeed.

As far as aerodynamics are concerned, if you have an uneven surface (like patched up boots), cover it in a thin layer of CLEAR ICE, than it would smoothen out. I would hope however, that you weren't at gross weight as this would rob you of even more performance, not to mention increased fuel flow.

I must be getting old, I'm starting to sound like TC. Somebody slap me!

Cheers!

Cat Driver · Post by **Cat Driver** » Mon Mar 08, 2004 8:54 am

Sometimes reading these topics makes me wonder if we maybe shouldnt just crawl in caves and hide.

Ice is a well known factor in flying airplanes and there are ways to deal with it and ways to avoid it. Ice is not some black magic that has suddenly appeared on the scene and will kill you if you fly into it.

However it can kill you and that is the secret, knowing how to deal with the different types of ice, not to mention having the brains to look at the weather and access the probibality of icing.

To even bring TC into the equasion and seriously consider their voo doo thinking only shows a lack of understanding of reality if you seriously quote these idiots.

George Morewood the pilot of the Fokker that crashed in Dryden was a very good friend of mine, we learned to fly together. That crash brought on all the nonsense that has come from TC needing to be doing something. The crash was more about mindset in the operation of that airline and circumstances surrounding that flight than just an icing problem...ice / wet snow, killed them but the chain that led there had far more links in it.

If we have another high profile crash , lets say caused by a pilot losing some cabin attendants panties in the cockpit and they somehow get under the panel and block some static sourse or something like that TC would immediatedly go into full fast foward on a study to prevent another lost pantie rule...hopefully they would accidently come up with a rule that none can be worn on the airplane...

Cat Driver: