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Ice and Laminar Flow Wings


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I've never picked up more than trace ice on my wing so I have ever noticed an effect on lift or airspeed--nor do I ever want to. However, I am fascinated by how a little ice can take down an aircraft. 

I am interested to hear stories from anyone who has picked up moderate ice on their non-FIKI Mooney. How did the plane perform? What did you do? And i've heard/read that icing on the prop is more critical than the wing--any first hand accounts? Any photos? Videos?

 

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When I had my J I was over the Bay across from Norfolk, started to pick up some ice asked for higher and was told standby, in 3-4 minutes and ready to declare I had about 1/2 inch my airspeed went 155 to 130, I climbed 2000 feet to clear air, the ice did not shed until my descent into Myrtle Beach sounded like someone was beating the plane with a hammer, never again, if ATC would have acted promptly I would have had no problem, we must avoid or get out of the junk ASAP.

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5 minutes ago, Danb said:

When I had my J I was over the Bay across from Norfolk, started to pick up some ice asked for higher and was told standby, in 3-4 minutes and ready to declare I had about 1/2 inch my airspeed went 155 to 130, I climbed 2000 feet to clear air, the ice did not shed until my descent into Myrtle Beach sounded like someone was beating the plane with a hammer, never again, if ATC would have acted promptly I would have had no problem, we must avoid or get out of the junk ASAP.

Dan...was the beating sound the prop shedding ice? Was your climb rate anemic? Amazing that 1/2 inch would make that much of a difference--you must have been shitting bricks.

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Was in a pa-28 with 1/2 inch of ice on it and thought I was done for. Some hot shot instructor flying. Idiot. Put 1/2 of ice on my J and it slowed maybe 10-15kts. Not a huge deal but not a situation I would want to loiter in. Now take 15kts off a pa-28 and it's barley flying. The slipperiness of a mooney might allow for more ice carrying but don't push it.


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On 2017-03-17 at 10:39 AM, Danb said:

When I had my J I was over the Bay across from Norfolk, started to pick up some ice asked for higher and was told standby, in 3-4 minutes and ready to declare I had about 1/2 inch my airspeed went 155 to 130, I climbed 2000 feet to clear air, the ice did not shed until my descent into Myrtle Beach sounded like someone was beating the plane with a hammer, never again, if ATC would have acted promptly I would have had no problem, we must avoid or get out of the junk ASAP.

Icing is scary.  I'm a little surprised that the request to get out of ice took several minutes.  Did you clearly state that the reason for higher was because you were picking up ice?  On the one occasion I started to get ice, I asked for an altitude change due to icing and got a clearance in moments not minutes.  I think I'd give it just a minute before declaring.   I'm far more concerned about my own skin than trying to reduce a controllers workload.

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Just now, Cyril Gibb said:

I'm a little surprised that the request to get out of ice took several minutes.  Did you clearly state that the reason for higher was because you were picking up ice?  On the one occasion I started to get ice, I asked for an altitude change due to icing and got a clearance in moments not minutes.  I think I'd give it just a minute before declaring.   I'm far more concerned about my own skin than trying to reduce a controllers workload.

I would guess the speed of giving the clearance had something to do with whether or not there was crossing traffic. I am sure the controllers want to get you out of the ice, but they also don't want you to crash into an airliner that might be crossing right above you.  I presume if you declare an emergency and say you are climbing then they would immediately move the airliner if possible.

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13 minutes ago, aviatoreb said:

I would guess the speed of giving the clearance had something to do with whether or not there was crossing traffic. I am sure the controllers want to get you out of the ice, but they also don't want you to crash into an airliner that might be crossing right above you.  I presume if you declare an emergency and say you are climbing then they would immediately move the airliner if possible.

Yup, I understand the issues.  I was just wondering if DanB stated clearly that the request was due to icing. 

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Icing is scary.  I'm a little surprised that the request to get out of ice took several minutes.  Did you clearly state that the reason for higher was because you were picking up ice?  On the one occasion I started to get ice, I asked for an altitude change due to icing and got a clearance in moments not minutes.  I think I'd give it just a minute before declaring.   I'm far more concerned about my own skin than trying to reduce a controllers workload.

I would request immediate altitude change and tell controller I'll accept a heading change. Without the latter the controllers may wait for traffic.
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12 hours ago, aaronk25 said:

Was in a pa-28 with 1/2 inch of ice on it and thought I was done for. Some hot shot instructor flying. Idiot. Put 1/2 of ice on my J and it slowed maybe 10-15kts. Not a huge deal but not a situation I would want to loiter in. Now take 15kts off a pa-28 and it's barley flying. The slipperiness of a mooney might allow for more ice carrying but don't push it.


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The high wing loading and laminar flow makes a Mooney wing a lot less suitable for ice accumulation than a big fat winged Piper.  The speed loss is reflective of drag and noticeable.  What isn't always very reflective with ice is the loss of lift and increase in stall speed.

To look at it another way a thin layer of frost on the wing can cause you to crash. It isn't drag or weight related.  It is the airflow disruption causing enough loss of lift that the plane won't fly. 

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The high wing loading and laminar flow makes a Mooney wing a lot less suitable for ice accumulation than a big fat winged Piper.  The speed loss is reflective of drag and noticeable.  What isn't always very reflective with ice is the loss of lift and increase in stall speed.
To look at it another way a thin layer of frost on the wing can cause you to crash. It isn't drag or weight related.  It is the airflow disruption causing enough loss of lift that the plane won't fly. 



I wouldn't dispute that the laminar flow wing would lose a proportionally more lift for a given amount of ice when compared to a relatively high drag design wing, but there is the advantage of less drag to start out with which is shown in a faster true airspeed.

With about 1000 hours of seat time in the J and about 750 in a pa28 I've seen on multiple occasions less loss of airspeed with the same amount of ice on a j as a pa28-2.

Ice is never good. The mooney flys like it does with rain going over the wing 5kts gone immediately.


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13 minutes ago, aaronk25 said:

With about 1000 hours of seat time in the J and about 750 in a pa28 I've seen on multiple occasions less loss of airspeed with the same amount of ice on a j as a pa28-2.

 

 

Probably a true statement it isn't relevant though.  Frost causes almost no loss of speed and is more deadly than ice.  The loss of speed is a symptom but it isn't what kills you, loss of lift is.  

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I did a lot of IFR flying my M20F in the 80s before they changed the rules from known to forecast icing. I left early in the morning so I was the guy who found the icing and let it be known.

I've never had more than 1/2 inch of rime or 1/4 inch of clear with some minor horns. (except for the last item below) I never had a controllability problem or lost more than ~10 kts of speed.

On my plane the first 1/8 inch of rime makes the plane go faster.

Be super careful flying into icing conditions with a strong tail wind. If your only out is a course reversal it will take you a lot longer to get out than it took you to get in.

Whenever you start picking up ice you should do something, go up, go down or turn around.

If you extend your gear to get down fast in icing conditions, don't put them back up. At the very least you will probably bend your gear doors.

The worst icing encounter I ever had was in a Cessna Cutlass RG. This all happened between the FAF and the runway. I tough place to make a decision.

Contrary to popular lore, I think the Mooney caries ice very well.

I was descending once with about 1/2 inch or rime and the ice shed from one wing  and not the other for about 30 seconds. The plane almost rolled over. It took a considerable effort to hold it level. It was about twice as hard as one speed brake up.

I was on an IFR flight plan over Wyoming in VFR conditions once in about 86. There was a single dark dense cumulous up ahead and the OAT was ~-5. I wondered how much ice was in there. Being young and stupid I flew right through it. It was small enough I could have deviated without even asking. I was in that cloud for 20 seconds and picked up almost an inch of ice. That one incident changed my life forever. I don't think the plane would have made it for a full minute. The plane still flew fine. It was a bright sunny day and the ice sublimated before I landed in Casper.

BTW That hot glycol the airlines use to deice there planes is EXPENSIVE! I landed with ice and had to get it off before I took off a few times. If they are fast you might get away with $50. The trucks have a meter like the gas trucks and it is literally coming out of a fire hose!

 

Edited by N201MKTurbo
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post-8069-0-68001300-1383915306_thumb.jpgpost-8069-0-25699900-1383915297_thumb.jpgpost-8069-0-87884800-1383915522_thumb.jpgpost-8069-0-87569400-1383915532_thumb.jpg

 

 

I was not onboard and this was not my plane. The pilot did add quite a bit to his approach speed, but otherwise noticed no adverse handling. IIRC this was a C model. Yes, ice is bad for all wings. Laminar flow or not it will likely take a lot more than any of us are comfortable with. If you find yourself in icing conditions, don't panic, just take steps to exit said conditions immediately. It's really that simple.

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5 minutes ago, Shadrach said:

post-8069-0-68001300-1383915306_thumb.jpgpost-8069-0-25699900-1383915297_thumb.jpgpost-8069-0-87884800-1383915522_thumb.jpgpost-8069-0-87569400-1383915532_thumb.jpg

 

 

I was not on board and this was not my plane. The pilot did add quite a bit to his approach speed, but otherwise noticed no adverse handling. IIRC this was a C model. Yes, ice is bad for all wings. Laminar flow or not it will likely take a lot more than any of us are comfortable with. If you find yourself in icing conditions, don't panic, just take steps to exit said conditions immediately. It's really that simple.

Those are quite the scary pictures!

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When I had my J I was over the Bay across from Norfolk, started to pick up some ice asked for higher and was told standby, in 3-4 minutes and ready to declare I had about 1/2 inch my airspeed went 155 to 130, I climbed 2000 feet to clear air, the ice did not shed until my descent into Myrtle Beach sounded like someone was beating the plane with a hammer, never again, if ATC would have acted promptly I would have had no problem, we must avoid or get out of the junk ASAP.

I had a very similar situation in my 261. I was picking up (unexpected) ice at a huge rate at FL190. And I could see light coming through the clouds above. I knew the worst place to be for ice was near the cloud tops, so I asked ATC for higher. His response was he would have higher for me in five minutes. That was not going to work for me so I answered "unable", and "if I don't get higher immediately I would declare an emergency". His reply was to give me an immediate climb to FL 210, and I was soon out of icing conditions, but it took a good half hour to sublimate the ice already on the wings. The heated prop shed the ice on it with "bangs" against the aircraft. I always went with extremes to avoid ice, but still had more ice encounters than expected. Frankly ice scares me. Please read about the TBM that was lost to severe icing about two years ago.

 

 

 

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6 hours ago, Cyril Gibb said:

Yup, I understand the issues.  I was just wondering if DanB stated clearly that the request was due to icing. 

There was no question on my part, it was with Pauxtent approach, her boss came back before my handoff and kinda apologized  stating she was in training. I was close to declaring, I requested higher or lower 3-4 times before he got on and gave me my choice.

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10 hours ago, Bob_Belville said:

Bob Kromer talked at Mooney Summit about ice tests they did at Mooney years ago. Perhaps Mike_Elliott or someone else can provide more details.

An article discussing some aspects of Mooney airframe icing by Bob Kromer was posted here: http://www.mooneyevents.com/flying5.html. It focuses on tail stalls.

From the article:

"... But as you can imagine, we also learned a lot about structural icing on the Mooney airframe during thest tests. Lots of important information came from those tests, but I want to pass along what I think was the most important for your consideration. 

Most of the airframe ice I accumulated at altitude was brought to the approach and landing. It was just too cold at lower altitudes to melt anything. And what we learned that I think was so very important was this - WITH AIRFRAME ICE ON A MOONEY DURING APPROACH AND LANDING, CONSIDER LIMITING FLAP DEFLECTIONS FOR THE LANDING. 

Here's the reason. We all know the amount of nose up trim required in our airplanes is pretty substantial to retrim when the flaps are extended - especially the M20K, M20M, M20S and M20R airplanes. Retrimming our airplanes causes the entire horizontal stabilizer to move and significantly changes the angle of attack of the horizontal tail's leading edge (nose up trim is leading edge down). With a substantial amount of ice on the horizontal tail (1/2 inch or greater), we found that the airflow could seperate over the horizontal tail and the horizontal tail could begin to stall when retrimming the airplane nose up for the landing with anything greater than 15 degrees of flap deflection. 

The buffeting started around 85 KIAS with the flaps at the takeoff setting (15 degrees) and got worse as we got slower. Buffeting was felt through the control column and elevator effectiveness was greatly diminished. With ice on the M20K prototype while landing, I learned to make my approach and landings at 90 KIAS with the flaps up. This completely avoided the retrimming/tail buffeting/stall situation. We felt so strongly about this (limiting flap deflection for landing with ice on the airframe) that we immediately added this recommendation to the Pilot Operating Handbook for the 1985 model M20K when we got back. 

The aerodynamics of the airplanes we all fly are very similar. I suspect that what we experienced on the M20K prototype in Canada you will experience in your airplane. So think about limiting flaps to minimize retrimming the tail when landing with airframe ice on your Mooney. Keep the speed up on the approach (85-90 KIAS) and carry that extra speed to the landing flare (just make sure the runway is long enough to handle the extra speed and landing distance). Stalling the horizontal tail is something not to be reckoned with, especially close to the ground."

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19 hours ago, N201MKTurbo said:

I was on an IFR flight plan over Wyoming in VFR conditions once in about 86. There was a single dark dense cumulous up ahead and the OAT was ~-5. I wondered how much ice was in there. Being young and stupid I flew right through it. It was small enough I could have deviated without even asking. I was in that cloud for 20 seconds and picked up almost an inch of ice. That one incident changed my life forever. I don't think the plane would have made it for a full minute. The plane still flew fine. It was a bright sunny day and the ice sublimated before I landed in Casper.

This sounds so familiar.   For me, it was near Colorado Springs.  I don't know what I was thinking when I entered that could.  I was near the top of a very tall cloud.  I could have called for a small deviation like I had done 20+ times that day.  --But it was a small cloud and I could see a way out (to the right)....  The plane was instantly covered with ice.  It was like being in a snow cone machine.   Splat, and the window was totally covered.  My next call to ATC was "Mooney needs immediate right turn."  I had already started the turn as I called ATC.  There was no waiting for approval.  Continued flight would have been an emergency.   A minute later I let ATC know everything was ok.  ATC was very accommodating.   --I will think long and hard before I do that again.

Anyway, since I was over the plains, I asked for lower and the ice melted away fairly quickly.

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My instructor and I were forced to do an approach in my J model thru a thick layer just below freezing from 4,500 msl down to about 2,000 which was about 400agl when we broke out on the ILS. The same layer was present for about 200 miles and no ice forecast, but we got what we got.  We kept up the speed, kept the gear and flaps up, and entered the soup at 150kts established on the ILS, and used throttle to slow as we descended.  Broke out at 400-500agl and chopped the power, drop the gear, and used a good portion of the runway.  No way were we gonna go missed because we picked up 1/2 to 3/4 inch of rime on the leading edges which fell off on the rollout.  No issues with flight characteristics, but we both agreed on no-flap landing.

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This is from about 8 minutes in the clouds on an approach in Jamestown, NY on Sunday evening to drop the plane off for a annual.  After a flight in ice, I always check the surfaces to make sure the tks was working everywhere and observe the ice on the unprotected surfaces. 

'As others has said, keep speed up and limit flaps.   Except for landing, minimum speed in a TN with ice is 120 kts and you are limited to T/O flaps for the landing.  

Sorry for the sideways pictures :wacko:

 

Brad

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