Lingering in icing

[carusoam]

Great additional insight Victor!

Thanks for sharing it.

and… Good Morning! 

Best regards,

-a-

[Mooney in Oz]

4 minutes ago, carusoam said:

Great additional insight Victor!

Thanks for sharing it.

and… Good Morning! 

Best regards,

-a-

Thanks and G”day Anthony  on a cold and wet (low freezing level) Aussie winter day!

[Scott Dennstaedt, PhD]

7 hours ago, hais said:

 thanks for http://avwxworkshops.com/ ! 

Thanks...however, that domain is being retired at the end of the year.

[Scott Dennstaedt, PhD]

10 hours ago, M016576 said:

...icing has taken down airliners.

Actually we don't see in flight icing taking down airliners (e.g., turbofan aircraft). Sure, there have been *ground* icing issues (e.g., Air Florida in D.C.) and aircraft sliding off of slick runways, but given the bleed air systems on these aircraft, it's hard to find an icing environment that is problematic while in flight. The in-flight issues have been with smaller twin turboprop commuter aircraft such as the one in Roselawn, Indiana in 1994 and Monroe, Michigan in 1997.  

[aviatoreb]

1 hour ago, Scott Dennstaedt, PhD said:

Actually we don't see in flight icing taking down airliners (e.g., turbofan aircraft). Sure, there have been *ground* icing issues (e.g., Air Florida in D.C.) and aircraft sliding off of slick runways, but given the bleed air systems on these aircraft, it's hard to find an icing environment that is problematic while in flight. The in-flight issues have been with smaller twin turboprop commuter aircraft such as the one in Roselawn, Indiana in 1994 and Monroe, Michigan in 1997.  

Haven't there been more?  I can remember at least also Colgan 3407 in Buffalo in 2009.  Also a large turbo prop not a turbo fan.  Still, a good reminder of the dangers of ice.  And that one had a good lesson in the difference in tail stall vs main wing stall recognition.

[1980Mooney]

21 minutes ago, aviatoreb said:

Haven't there been more?  I can remember at least also Colgan 3407 in Buffalo in 2009.  Also a large turbo prop not a turbo fan.  Still, a good reminder of the dangers of ice.  And that one had a good lesson in the difference in tail stall vs main wing stall recognition.

Icing did not overwhelm the control or flyability of Colgan 3407.   Mismanagement of the aircraft by the pilots brought it down.  The icing did alter Ref Speeds but the stick shaker automatically adjusted for it.

"The National Transportation Safety Board determines that the probable cause of this 
accident was the captain’s inappropriate response to the activation of the stick shaker, which led 
to an aerodynamic stall from which the airplane did not recover. Contributing to the accident 
were (1) the flight crew’s failure to monitor airspeed in relation to the rising position of the lowspeed cue, (2) the flight crew’s failure to adhere to sterile cockpit procedures, (3) the captain’s 
failure to effectively manage the flight, and (4) Colgan Air’s inadequate procedures for airspeed 
selection and management during approaches in icing conditions."

[Scott Dennstaedt, PhD]

40 minutes ago, aviatoreb said:

Haven't there been more?  I can remember at least also Colgan 3407 in Buffalo in 2009.  Also a large turbo prop not a turbo fan.  Still, a good reminder of the dangers of ice.  And that one had a good lesson in the difference in tail stall vs main wing stall recognition.

Hi Erik,

Yes, there have been more twin turboprop icing accidents...I just listed two of them that created the need for better icing forecasts.  But for turbofan aircraft, you just don't see in flight issues as it relates to airframe icing.  High ice water content (HIWC) yes (e.g., Air France), but not airframe ice.

I had a chance to visit the NASA ice house in Cleveland about 7 years ago. In talking with Kurt Blankenship who is a research pilot and deputy of aircraft operations at the Glenn Research Center, the Colgan Air accident had little to do with icing. In fact, on March 25, 2009, NTSB investigators indicated that icing probably did not contribute greatly to the accident.  Kurt said that, “the plane basically trimmed itself to a stall. It had a stick pusher on it which he [the captain] fought against and pulled back and held it until the plane finally went over and it was too late.”

Could it be that the captain thought he was experiencing an ice contaminated tailplane stall (ICTS) even though he said nothing on the tape? In Kurt’s opinion he thinks “the pilot simply panicked.” Kurt further commented that “he was low to the ground and it [pulling back on the controls] was a natural reaction.” Other mistakes were made such as the co-pilot retracting flaps without it being called and not having a sterile cockpit during the approach to land.

From Kurt’s view, this accident “was a low-speed awareness issue and that should be the focus of the training...and recognizing where you are at in the [power curve] regime. They were slow, it was a wing stall, clearly.”

[GeeBee]

Turbo jets get by with a lot because their exposure to icing conditions is a lot less, usually only climb and descent. Most the time after -40 you can turn off all anti-ice even in visible moisture. As an example the HS125 TKS tank is half the size of a Mooney..  

There is not massive amounts of thermal bleed air. In fact the DC-9/MD-80 tail flies for 15 minutes before 2.5 minutes of heat is applied when the airfoil icing is on, and why you have that white switch to divert heat to the tail right before landing. It simply lacks bleed capacity to do both surfaces at once. 737 just uses raw power to overcome tail icing and why you have a 14K pound penalty for landing in condition below 46 degrees to secure go-around performance. 

Add to this the operational control that involves dispatchers carefully routing through icing conditions. If jets spent their time in the lower altitudes with their turbo-prop brethren you would see a lot higher accident rate.

[M016576]

14 hours ago, Scott Dennstaedt, PhD said:

Actually we don't see in flight icing taking down airliners (e.g., turbofan aircraft). Sure, there have been *ground* icing issues (e.g., Air Florida in D.C.) and aircraft sliding off of slick runways, but given the bleed air systems on these aircraft, it's hard to find an icing environment that is problematic while in flight. The in-flight issues have been with smaller twin turboprop commuter aircraft such as the one in Roselawn, Indiana in 1994 and Monroe, Michigan in 1997.  

It’s a valid spear- but when I said “airliners,” I was referring to part 121 (scheduled air carriers) specifically with the thought of the multiple turbo props that have succumbed to icing.  Most people I know (including Webster’s dictionary) would consider a part 121 short haul carrier as an airliner, but I should have been more specific and said “turbo-prop commuter air carriers.” 

our de-icing procedure in the F-18 and F-15 were both “go faster”, which just melts the ice off the skin of the airplane due to friction.  Easy to do with overpowered turbofans complete with augmentors.  Even without them, though, there’s an abundance of power (thrust… but also bleed air and electricity) available on most, if not all jets to handle icing.

the engines are sensitive to FOD though- and while icing may not necessarily bring down a jet, it can certainly do millions in damage to the compressor and fan sections of the engines.

[GDGR]

Here’s the simple reason:

https://aviation-safety.net/wikibase/277600
 

 

[Scott Dennstaedt, PhD]

10 hours ago, M016576 said:

Most people I know (including Webster’s dictionary) would consider a part 121 short haul carrier as an airliner, but I should have been more specific and said “turbo-prop commuter air carriers.” 

Back in March 1997, the FAA changed the rules for the classification of major airlines so that air carriers with 10 or more seats, which previously were handled under Part 135 operations, would now be handled under Part 121 operations.

12 hours ago, GeeBee said:

Turbo jets get by with a lot because their exposure to icing conditions is a lot less, usually only climb and descent.

Yes, certainly agree that excess thrust, fast climb rate through icing conditions and spending most of the time in temps of -50°C or colder limits exposure. 

 

12 hours ago, GeeBee said:

If jets spent their time in the lower altitudes with their turbo-prop brethren you would see a lot higher accident rate.

Possibly, but not likely.  While none of these aircraft are certified into SLD, they operate under a waiver so they are allowed to fly through large drop icing environments.  Again, the biggest threat for these aircraft are ground icing.  

[Schllc]

20 hours ago, GLJA said:

Here’s the simple reason:

https://aviation-safety.net/wikibase/277600
 

 

Was this an icing incident?  I don’t see any conclusions in the link?

[GDGR]

20 hours ago, Schllc said:

Was this an icing incident?  I don’t see any conclusions in the link?

100% icing. No conclusions yet, but I’m close with the plane owner and the circumstances of the accident. 

[hais]

Anyone ever considered SLD guard?

https://www.cav-systems.com/sld/

[kortopates]

5 hours ago, hais said:

Anyone ever considered SLD guard?

https://www.cav-systems.com/sld/

Consider for what? They advertise it as a new factory install option on top of TKS. Doesn't look like its available yet either.

[moosebreath]

On 7/13/2022 at 7:56 PM, Schllc said:

Anyone who has had a real encounter with icing, has no desire to relive the experience. 
Even asking the question seemed somewhat crazy to me, but then I realized not everyone has had the experience.

Those who have not are probably pretty sure, as I was, that there was some embellishment, and/or exaggeration.

My experience took all of about 3-5 seconds to go from completely clean to accumulating 3”+ on the wings, enough to completely block the windshield, and cut my rate of climb by two thirds. I saw rain drops on the windshield, looked at the wings, looked back at the windshield which was completely covered in ice, looked back at the wings to see the 3”+. It took me longer to type this than it did to actually happen. 

I can honestly say it was the scariest experience of my life, and the thought of “lingering” in conditions that could reproduce that experience is just unfathomable. 
I would NEVER intentionally take a single engine piston, with or without FIKI knowingly into icing conditions. 
But to each their own….

+1