Prop pitch, IFR clearance, icing, WX decisions

[Mr. Cole]

Wow! There were some pretty sobering posts regarding flight in IMC, particularly Avbug's. As a fairly new instrument pilot who loves the technical nature of instrument flying and IMC, I'm still very leery about my first true solo foray into the soup. I came out of the IR with about 11 hours of actual and have flown IMC without an instructor since my checkride, but with other pilots. Having another instrument pilot next to me was certainly a big help and I see the benefits of good CRM. In both cases the ceilings were about 2000'. I still fly with my instructor every few months for proficiency and have a standing order in with him to call when it's good IMC and he doesn't have any students. I plan to keep my minimums fairly high and maybe fly with another pilot for a while and slowly ease myself into solo IMC. Although I have access to fairly capable 172s, I understand the risks in both IMC and night flying. This thread really drove it home.


Dave

 

[Vector4fun]

Cooper,

You've gotten some good info in the above posts. I'll only comment on two points.

Regarding an IFR clearance, you're almost always going to get a clearance to the airport, and it's seldom going to include an IAF. In a Radar environment, you're most often going to get Radar vectors to the approach in use. In fact, every STAR at my airport ends at a fix, or at the VOR, and says "Expect Radar Vectors" or some such. Every approach plate says "Radar Required".

What about NORDO? (no radio) Carry a hand-held, or carry a cell phone. And always carry a second headset or have a second mike and working speaker. Two nav-coms just don't often quit on the same flight, and if they do, (elec failure) you most often don't have any reliable navigation to shoot an approach anyway, unless you're using that hand-held GPS, which is not certified for such.

In a NON-Radar environment, you can expect to be re-cleared to an IAF at some point as you near your destination. Which one will depend on which approach is in use.


I also think your instructor was wise. 600' looks like a lot from the ramp. It's **CENSORED****CENSORED****CENSORED****CENSORED** little when you're feeling for a runway at dusk on a non-precision approach.

 

[wheelsup]

To go with the IFR question, I like to look at the destination weather a pick an approach that I'll most likely be doing. Then, in my flight plan I make sure to include the IAF or feeder fix from which that approach begins.

9 times out of 10 I'm "cleared as filed" or with minor changes mid-route. That way most of my thinking is completed on the ground should I lose my radios.

~wheelsup

 

[apcooper]

Vector4fun,


Had another ATC question. I reas an article on the FAA aeromedical website http://www.cami.jccbi.gov/aam-400a/FASMB/FAS/34.html that mentioned that 30% of all ATC transmissions are repeated. This sounds way too high to me. Could this actually be true? Let me know. Thanks.

 

[C77MD80]

What? Could you repeat that last question please?

 

[nosehair]

...uh, was that for me??

 

[Vector4fun]

Vector4fun,


Had another ATC question. I reas an article on the FAA aeromedical website http://www.cami.jccbi.gov/aam-400a/FASMB/FAS/34.html that mentioned that 30% of all ATC transmissions are repeated. This sounds way too high to me. Could this actually be true? Let me know. Thanks.

I chuckle every time I see this guy's work. When I started in ATC, and for years later, one of the things we were graded on was "Combines transmissions". In other words, why make three transmissions, when you can make one? Now they realise we (ATC) do that all too well.

I think the number could be as high as 30% at times. I certainly try to stay under that. I probably have to repeat around 10% of the time on average.

 

[wings421]

The question about the 172 in ice.

I would say 2 inches of ice in a 172 and you'd be coming down, at a moderate pace. Thats A LOT of ice in any aircraft let alone a 172 with no boots, and the pitot tube that MIGHT get to room temp. I think that IMC in a "light" single in winter time is a gamble (in geographic areas). Ice is almost always forcasted in the clouds.

As far as the question about dual in the soup.

You only have 55 hours TT. I'm sure that, like others have said, you'd be along for the ride. Once you get close to your checkride, going up in the clouds is a GREAT idea. Perhaps not as low as what it was that day, but you NEED to get some actual before you go it alone in the clouds. Its much different than the hood. As far as your CFII's decision, always go on the side of cautious. Respect his/her decision and rest assured that they did what was best for you.

As for the other replies on this thread. You guys make me feel better about not wanting to go up in moderate to low IFR in a single again. I though I might be the only one. As I've moved up to more advanced equipment in my short career, I look back and think about things that could have gone wrong. Flying down to ILS mins in an Archer is crazy. Two wig wags and equipment that is all older than me. Great experience, but I don't want anymore of it.

 

[HMR]

Ice on the 172: Do you mean two inches on the wing? Remember, the ice forms in an inverse proportion to the size of the surface it's collecting on (I can't remember the exact formula). If you have two inches on the wing don't look back. There will be more on the horizontal stab. The tail will likely stall before the wing. If you've never stalled the tail before (maybe doing unusual attitude training) it's a creepy feeling. The prop in a 172 will most likely stop long before two inches can build on the wing. The prop is the first surface to ice up and performance drops significantly with just a small amount of ice. The performance drop from two inches on the wing would be far greater than full flaps. Add in the weight of the ice and you have a lawn dart.

I still have a twitch from an icing incident in a 182 a few years ago when I was a CFII. The plane stalled at 100kts. in the clouds as we were executing a 180 to get out of there.

 

[apcooper]

HMR,


My goodness! Tell me more about the 182 ice incident. While certainly the 182 stall speed in ice is a lot higher than Vso I'm amazed it was 100kts! I'd have thought maybe 75-80kts clean. Did you have the flaps deployed? If so that actually would INCREASE the stall speed! I am amazed at 100kts because in you've ever watched the NASA research video "Icing for GA pilots" if the beginning they show a Bonanza with a student and CFI that is at full power and 110kts and desc at 200fpm!! The plane seemed to fly OK at 110kt eventhough it was desc and later after they safely landed there was about 3-4 inches of ice on the wings in a nasty horn shape.