climbing through ice

[Ian_J]

The 91.500s apply to Large and Turbine-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft.

-mini

Right you are... my bad!

Actually no regs about flying into known icing for personal flights under part 91.

Check that flight manual though, guys... bet it has something about flying into known icing in there.

 

[jonny]

You obviously don't fly it in the midwest/great lakes.

I have 1500 plus hours in the van(2000+ in pa 31) and I had a VFR 135 pilot riding along that night who has pictures some where. We were at max continuous torque 1653 ft/lbs(600 hp) and in a 500 ft/min descent at 110 kts. I had to shoot an emergency approach to some airport in northern IL that I never saw the surface because it was 200 and 1/2, however we hit the freezing level about 6-400 agl and got enough off to remain airborne.

If you've never been to the edge then you are the one who doesnt know wtf you are talking about. When you get it that bad you point the nose over and do what you can, but you keep flying the plane.

Nice. Wow, did you file a pirep for severe icing? 5+"? I've had 1+" and no love holding 12K. This was a week ago and, to tell you the truth, you should have been at max cont. (ITT, NOT torque). I'm not gonna speak for models I dont know, but I will tell you that you shouldn't come off as a hot shot who can handle the 'van with 5+inches of ice. Because, unless it's shaped like the wing, you're in a world of crap. Like I said, if you have the a/s, than smile.

That and if you had boots, and it woudln't come off, why would you descend at 500fpm? Why wouldn't you increse your speed in the descent and blow it off with a higher speed?

 

[WalterSobchak]

Nice. Wow, did you file a pirep for severe icing? 5+"? I've had 1+" and no love holding 12K. This was a week ago and, to tell you the truth, you should have been at max cont. (ITT, NOT torque). I'm not gonna speak for models I dont know, but I will tell you that you shouldn't come off as a hot shot who can handle the 'van with 5+inches of ice. Because, unless it's shaped like the wing, you're in a world of crap. Like I said, if you have the a/s, than smile.

That and if you had boots, and it woudln't come off, why would you descend at 500fpm? Why wouldn't you increse your speed in the descent and blow it off with a higher speed?

With the inertial air seperator open depending on temp it might be a challenge to hap more than an inch at 12 in level flight depending on what IAS you are shooting for.

My cruise altitude was 5,000 ft and descending. Up high it would have been a different story because you IAS is less so you have to do more to keep the air flowing, but have more altitude. That is the nice thing about the midwest with bad ice you have flat terrain and most elevations are below 1,000 ft. The ice came off initially but once the airspeed went the boot effectiveness went down exponentially.

We were 40 miles from any airport and I had to fly in a way to minimize the descent while attenpting to get to an airport and preserve as much altitude to attempt an approach. If I would have descended at 130+ I would have hit the ground. It flew pretty well at 110 it buffeted a little and that was with zero flaps I wasn't going to change the configuration.

I'm not coming off as a hot shot that can handle 5 inches of ice in the van every single time. I would never want to do that again(Hence the reason I left flying general aviation airplanes in ice) What I am saying is the stall speed didn't double with even that much ice. My original post was partly in referrence to another post. My message is don't panic and fly the airplane.

 

[jonny]

I completely agree with the message. Fly the airplane. And you're lucky you're in the midwest with no 10000' mtns. to deal with. BUT, 5+inches of ice is no joke. 1+inches of ice is no joke. ICE IS NOT NICE. That is the point.

We can monday morning qb all day, I would have pitched down and blown the boots in MAN if I were you at 160-175. It may have given you more options, but you made the best decision you could have. For the youngsters on here, just realize that 1" of ice WILL cause a loss of at least 10-15 kts. Not so good if your a/c doesn't climb well. And any less than 110 at max cont. (in the van) you ARE descending whether ATC is able or not. Use your best judgement and do the best you can. Over and out.

 

[pwttogfk]

This is what I love about JC--I've learned a lot about icing from this thread, and my own personal minimums for ice have changed considerably! I'm extremely conservative on my go/nogo calls because of my relative lack of experience; hearing all of these stories makes me realize that my inexperience with ice led me to set my personal minimums for icing far too high.

 

[ppragman]

I completely agree with the message. Fly the airplane. And you're lucky you're in the midwest with no 10000' mtns. to deal with. BUT, 5+inches of ice is no joke. 1+inches of ice is no joke. ICE IS NOT NICE. That is the point.

We can monday morning qb all day, I would have pitched down and blown the boots in MAN if I were you at 160-175. It may have given you more options, but you made the best decision you could have. For the youngsters on here, just realize that 1" of ice WILL cause a loss of at least 10-15 kts. Not so good if your a/c doesn't climb well. And any less than 110 at max cont. (in the van) you ARE descending whether ATC is able or not. Use your best judgement and do the best you can. Over and out.

That's the problem, you can't say that ice will "do" anything specific. Sometimes you're lucky, sometimes you're not. I've had 3-4" of ice on the wings of the 1900 and only lost about 5kts, other times, depending on texture and density, its dropped off 25kts. There's no gaurantees. Wait for an inch, blow the boots, and try to find a way out if you need to. Remember, if the airplane is certified for it, there's no reason to be afraid of normal icing as you drive along, just don't be an idiot.

 

[sundog]

besides aerodynamic effects, ice is heavy. for example on a seneca with 207 ft^2 wing area, one inch of ice weighs over 800 lbs.

 

[ppragman]

besides aerodynamic effects, ice is heavy. for example on a seneca with 207 ft^2 wing area, one inch of ice weighs over 800 lbs.

Clear ice is nice and aerodynamic for the most part, why do you think its effect is so adverse? Weight.

 

[jtrain609]

Yes, in a caravan. I had more than 5 inches of mixed on and the stalling speed was less than 110 because that was all I could hold in a descent. That was about an inch a minute of of mixed ice. It would take more than 30 seconds to make a 99 stall at 150 kias and a ton more ice than I have gotten on the caravan. I have had Navajo's with 3+ inches several times and they flew pretty well. I obviously don't know what the lower limit was but it wasn't any were close to that high. Take ice seriously is very true especially in airplanes that don't have means of getting it off. I feel if you do have ice protection it's good to know what your plane can do pick it up and see how quickly your speed burns off, what your climb rates are etc. That way you are better prepared to deal with it instead of freaking out like its the boogie man.

It happened to one of the forum members here up in the mountains up here, just had dinner with him the other week and talked with him about it. He ended up fire walling hit PT6's and still couldn't maintain altitude.

 

[WalterSobchak]

It happened to one of the forum members here up in the mountains up here, just had dinner with him the other week and talked with him about it. He ended up fire walling hit PT6's and still couldn't maintain altitude.

I suppose up there you can catch a nasty up draft with a crap load of moisture. Was that out by CA?

 

[jtrain609]

That's all I can figure it was. He was in Utah when it happened, or there abouts. He could give you the details, but I think he's probably still too busy trying to pull that Beech 99 out of his colon.

 

[B767Driver]

I've had 3-4" of ice on the wings of the 1900 and only lost about 5kts, other times, depending on texture and density, its dropped off 25kts. There's no gaurantees. .

That's a lot of ice for an airplane with pretty good boots. I'm curious why you let the ice build up so much?

 

[Lee D]

My buddy, however, said that we would've been fine. Climbing through 5,000ft, we would've picked up some ice, of course, but by the time we got to 12,000ft, everything would've already been frozen. At 12,000ft, we would not pick up any more ice and the remaining ice that we did have would simply falll off, according to him.

What do you think?

I realize the thread is a few days old, but anyway . . . Just because you climb out of the ice doesn't mean it is going to simply fall off like your buddy suggested. I don't think I have ever seen ice fall off unless the temperature was above freezing. Even with boots I have flown through ice, climbed out of it and then watched the remnants just sit out there, barely sublimating at 26000 ft, not to come off til we decended to warmer, above freezing air. In a plane with no de-ice/anti ice, that ice is not going anywhere fast. Some may sublimate, but until you find warm air it is going to stick.

 

[Ralgha]

I have 1500 plus hours in the van(2000+ in pa 31) and I had a VFR 135 pilot riding along that night who has pictures some where.

Post 'em or it didn't happen.

 

[ppragman]

That's a lot of ice for an airplane with pretty good boots. I'm curious why you let the ice build up so much?

Ehhhhh back from vacation. The ice was accumulating too fast and even cycling it wasn't coming off fast enough, finally started to melt off on our descent into PAJN.

 

[riccochet]

i believe that scenario (van with a few inches of ice) considering it had to make an emergency descent and approach. a long time ago, back when Fed-Ex still flew them [vans] in the Rockies, a friend was holding over the Aspen vor at 14000ft waiting on an approach clearance. picking up a good amount of ice he realized soon that if he wasnt cleared it would be an emergency. eventually he was at full power (during winter) and without heat (conserving bleed air for more power), losing altitude. he was cleared just as he was about to call an emergency. fortunately the approach has steep stepdown fixes becasue he descended at full power and barely made the runway!!! after sevral accidents in the rockies companies realized the caravan had too many fat ice accumulating parts in the airflow and not enough power to overcome the drag and weight at these high altitudes. the lowest mea's i remember seeing in Colorado were about 14 or 15000 ft!!! i flew a king air all over Colorado and never picked up a whole heck of alot of ice. most of it occurs in the mid to high teens but i heard stories of some nasty stuff ont he same days i flew. ice is where ya find it. the FAA is vague or at the least is misinterpreted about "know ice" when it comes to regs. if you have an incident with ice and your not "certified into flight with known icing" when the FAA gets involved youre in trouble because they consider "known icing" to be any conditions suitable for icing. meaning temps at freezing and anything below and visible moisture!!! this is not my opinion or theory but, i know of someone who duked it out with the FAA in court and lost!!! the FAA is vague on alot of regs and you get away with all these things until an incident, then you are screwed!!!! Another EX: there is no reg that says you cant fly "IMC" in class "G" (uncontrolled airspace where atc has no jurisdiction) without an "IFR" clearance so, this is interpreted by pilots as legal if your instrument rated. i myself have done it. but, if you have a near mid air thats gets reported or some other "incident" that involves the FAA, theyll get you on that FAR 91.??? thats says you are careless, reckless or negligent, & a NASA form wont save ya! think about that.....

You obviously don't fly it in the midwest/great lakes.

I have 1500 plus hours in the van(2000+ in pa 31) and I had a VFR 135 pilot riding along that night who has pictures some where. We were at max continuous torque 1653 ft/lbs(600 hp) and in a 500 ft/min descent at 110 kts. I had to shoot an emergency approach to some airport in northern IL that I never saw the surface because it was 200 and 1/2, however we hit the freezing level about 6-400 agl and got enough off to remain airborne.

If you've never been to the edge then you are the one who doesnt know wtf you are talking about. When you get it that bad you point the nose over and do what you can, but you keep flying the plane.

 

[MikeOH58]

to tell you the truth, you should have been at max cont. (ITT, NOT torque).

If i'm flying the van and can't maintain altitude or min. icing speed (120 I believe) I could care less about ITT or torque. I am firewalling the power lever and doing whatever it takes not to become a hole in the ground. If its a matter of not coming back at all, or returning with a blinking ETM, i'll take the latter.

 

[ppragman]

If i'm flying the van and can't maintain altitude or min. icing speed (120 I believe) I could care less about ITT or torque. I am firewalling the power lever and doing whatever it takes not to become a hole in the ground. If its a matter of not coming back at all, or returning with a blinking ETM, i'll take the latter.

Turbines don't like the high ITTs though, you know that, they melt too quick.

 

[MikeOH58]

Your not going to melt a PT6-114 if you firewall for 20 seconds in the winter...And even if you do trash the engine, i'd rather be alive.

 

[minitour]

If i'm flying the van and can't maintain altitude or min. icing speed (120 I believe) I could care less about ITT or torque. I am firewalling the power lever and doing whatever it takes not to become a hole in the ground. If its a matter of not coming back at all, or returning with a blinking ETM, i'll take the latter.

Ditto. I'd hope most van drivers feel that way.

-mini