Lnewqban

These are questions for the full scale pilots out there.

Around the recent airliner crash in Buffalo, ice formation on the wings has been mentioned.

Why this happens?
What resources an airplane has to avoid it?
What pilots can do against it?

masonman

Super cooled water droplets make it happen........There are anti-ice bladers on the leading edges of the wings that air up an crack the ice lose so the wing does not get deformed an stop flying. There are Heated de-ice boots on the base of each prop blade to keep ice build up from happenin.............As for what happened..Not sure..The NTSB is doing there jobs to tell us........What do I think? Well I think the wings were deformed with ice. Cause it more less lost control with the flaps an gear down. So that tells me that the stall speed was moved way up with the wing not working properly. So I think it stalled. An I still can't figure out why that plane had 5K pounds of fuel on board for that short of flight. That pushs your stall speed up aswell............As I said before. I think it was Ice build up.

huck1199

I think they will find that it was a tail plane stall from ice build up on the tail plane. This causes problems when the flaps are deployed. People on the ground said the engines were at full throtle. This is the tactic to get out of a wing stall and will agravate a tail plane stall.

jetmech05

there is anti ice. and there is de-ice....de ice as mason man described..uses boots to break ice off the wings and tail once it has formed....the down side to this system is you have to let the ice form..you can bridge the boot with ice if you leave the de ice system on....then you have lost the abilitiy to de ice
then there is anti ice as used by most turbine powered aircraft..where you port off some bleed air from the compressor and route this heated air to the leanding edges of the wings and tail and the inlet of the engine..the downside to this system is you rob some power from the engines and have the plumbing and valves to route the heated air...
you can bridge this system as well if you have too much ice form before you turn it on....
de-ice removes ice once it has formed..anti ice keeps ice from forming..see the difference....
In the Buffalo case who knows, too many variables to guess..anything from a bad valve on the de-ice system to a hole in the boot to a bridged boot....

dhal22

i heard that there was 1000's of gallons of fuel on board. why? that is just dumb.

TFF

As the amount of fuel I am guessing that just for takeoff power at 5 minutes would use 150 gallons which is close to 1000# of fuel. It a takes a bunch to fly. You have to have enough fuel to fly to an alternate airport and then still have 45 minutes of fuel at the end of your flight.
You collect ice when the air is saturated with mosture and near freezing. The wings are moving at speed cools the water and freezes it the rest of the way. Put water on your hand and blow on it you can feel it cool. A wing going 250mph will cool the water a couple of degrees, easy. I dont remember if those planes have boots or heated leading edges which matters in teqnique to get rid of the ice. And if you fly in the winter in or near clouds or rain you will get ice it; happens on all the time.

Deadeye

It sure does sound like ice is the culprit. But just to be clear, wind chill affects nothing unless it has a heartbeat.

Villa

I believe that much more technology is needed to assist the flight crew during icing conditions. It seems to depend on just bad luck as to whether a plane goes down or not. The plane was already low and in the landing approach when the crew decided they had a bad situation and did their best to get some speed/control. What condition causes the crew to turn on the de-icing devices? The crew needed to abort the landing but did not have the information till it was too late to recover. If it is decided everything was working right and it appears the crew followed established procedures then I say do something to give the crew an earlier alert about icing occurring on THEIR plane. I am not a full scale pilot.

Flyfalcons

Tankering, alternate, and contingency fuel. Chances are it took off from EWR with 5,000 pounds, not arrived at BUF with 5,000 pounds. These things don't exactly have the fuel efficiency of a Prius especially at low altitude.

huck1199

Check out this video from NASA on ice. It is a pilot training video.

http://video.google.com/videoplay?do...59021331008391

Captainbob

My Feedback: (4)

Gentlemen,
The history of aviation safety clearly shows that ice buildup on an aircraft is not a problem for a professional crew that is alert and doing their job, problems like this are usually an indication of poor airmanship. All commercial aircraft are designed according to FAR Part 25 which specifically requires all aircraft certified for flight in icing conditions to meet certain criteria. Aircraft antiicing/deicing systems are designed to remove more ice than would ever be encountered in flight.

Aviation like sailing the high seas is a profession not very forgiving of inattention, carelessness or inexperience!

rc34074

My Feedback: (5)

We now know that the de-icing system was turned on 11 minutes after takeoff. So maybe there was something wrong with the de-icing system?

Ed

beenie

My Feedback: (9)

As has been said before, airplanes accumulate airframe ice when flying through water that is supercooled, that is at or below freezing and still a liquid. How can this happen if, as everybody knows, water freezes at 0C? I forget, but Wikipedia doesn't http://en.wikipedia.org/wiki/Supercooled_water . When it contacts a surface such as an airplane, it freezes instantly. The airplane moving through the air can actually heat up the leading edges due to air friction, the plane I currently fly gains 30C at cruise due to air friction. At Dash 8 speeds, the effect is less pronounced.

Planes certified for Flight Into Know Icing have a variety of ways to either keep the ice off (anti-ice) or remove it after it has accumulated (de-ice). There are the pnumatic boots, bleed air heated leading edges, TKS weeping leading edges, or electrically heated leading edges. They all work and they all have their advantages and disadvantages. Interestingly, all of them are anti-ice devices except for the pnumatic boots. The boots inflate and break the ice that is already on them, then the airstream blows it off the surface. Jetmech05, you have mentioned ice bridging. That is supposedly a phenomenon where the boot inflates and ice builds up on the inflated boot. It then contracts, leaving a growing shell of ice that the boot is unable to remove. The FAA has recently published guidance stating that ICE BRIDGING IS A MYTH. It simply doesn't occur. In modern aircraft, turbines especally, the boot inflation and deflation cycle is too fast (usually 6 seconds of inflation) for the ice to build on the inflated boot. I currently fly a Gulfstream 200, arguably the highest performance civilian plane ever built with pnumatic boots. Our procedure for encountering icing conditions is to turn the de-ice on. It cycles all the boots automatically every 1 minute. You don't look for 1/2" or 1" or whatever, you turn them on immediatly. We were in ice 3 times today, never had a problem.

Most (all?) jets have an ice detection system that alerts the crew to the airframe icing, usually before it begans to accumulate on the plane. There is a great article about this in thes month's issue of Flying. I don't know if the Dash8's have such a system, maybe someone who knows the type will come foward. This system along with visual inspections of the wings or windshields or windshield wipers or whatever is out there that collects ice lets the crew know that they are in icing conditions. Airplanes fly in icing conditions (sometimes severe) every day in every season and don't come falling out of the sky.

Huck 1199, that is a great video. Thanks for the link, I didn't know that it was on the internet. Everybody who operates an aircraft in the clouds (FIKI or not) should see that video. It is eye opening and goes against everything that we have been taught about stall recovery. Everybody is taught about wing stall indications and recovery but nobody is taught about tailplane stall indication and recovery. From what I have read, it certainly points to tailplane icing. The loss of control upon flap application is very indicative of such. Now it has come out that they were on autopilot until the stick shaker activated, which disengaged the autopilot. I'm sure that there will be a $h!tstorm over that given the current guidance to hand fly the airplane in icing to better feel the changes in pitch and roll required due to aerodynamic changes from the icing. Seems like they didn't know that there were getting into trouble until they were already well into it. I am very interested to see what they find out.
Ben

Lnewqban

Thank you all for the interesting responses and the link to the instructional video.

I have learned many things that I ignored.

Regards!

Captainbob

My Feedback: (4)

beenie,
Are you braging or complaining about the fact that your G-200 has rubber boots?

beenie

My Feedback: (9)

I am not sure, merely mentioning the fact. Many people hate the boots on it, so much so that Gulfstream got Goodrich to develop silver boots for the G150 and 200. That way they look like "real" jets, instead of pretend jets with their black boots. I liked the black ones better, it was much easier to see ice on them. Regardless of color, I like them. They do a very good job of getting rid of ice with NO preformance penalty. Also, since they are de-icing devices, I don't have to turn them on when the possibility of icing exists, only when there really is ice. So I guess I am bragging

Ben

Villa

As a none full scale pilot I am left with the impression that the pilots are not being given enough technical help in determining how close to a bad situation the icing is. The plane in Buffalo had the deicing system working since 11 minutes into the flight. It appears the thing stalled due to icing. If they had known the icing was above some dangerous point, they could have aborted the landing earlier, nosed down, speeded up, and looked for a better situation. Does the fact it was a T-tailed plane mean anything? Obviously they have to pass the same icing/stall recovery tests.

Villa

Most have probably seen this. A T-tail may make things different afterall. http://www.liveleak.com/view?i=560_1234634990

stuntflyr

Dear Captain Bob,

Your statements are clear and utter nonsense. There is NO requirement for certification that testing be done beyond the minimum requirements set down for the process. Icing conditions beyond the scope of those set down in certification tests are those in which pilots are required to access and avoid or escape after entering.

This is where the accidents occur and many pilots aren't knowledgeable about them. This is due to poor training from the administrator (FAA) where the pilot gets their initial training, to the operator (greedy airline owner) where the pilot is often neither trained nor is the attitude for survival promoted, the airline just wants a completed revenue event so the money can be collected.

The rate of accretion, ability of the de-icing system on a boot equipped airplane, and the weather ahead are all of importance to the pilot for a successful flight. The pilots of the Buffalo Q400 in my estimation had tail ice accretion that the de-icing system could not deal with for a normal configuration change at speeds flown. When the flaps were lowered to 25, the high wing flap position caused a nose up pitch excursion as the auto pilot tried to handle the requirements, when it slowly came to a point where the horizontal stab/elevator could no longer provide sufficient downward lift because of the ice accretion, the nose pitched down in a rapid excursion. During these pitch excursions, the wings control surfaces were upset, and/or the partially iced up wing stalled and produced roll excursions as well.

Since flying the older piston powered, propeller driven airplanes of the 40's in icing conditions for hire in the early part of my career, I was taught by older, more experienced pilots at the time to minimize speed changes, configuration changes, and try to keep a sharp eye on the rates of accretion, and escape routed during flight if performance drop-off made continuing impossible. In the Twin Beech 18 and DC-3, these performance figures were low, and thick wings with blunt leading edges made low speed controllability level high along with the fact they had traditional control manipulation through direct cable to flying surface horns. Control was always direct, big loads of ice were able to be carried, and configuration changes were minimal because approach speeds clean were very close to those with flaps extended.

In modern, high performance, high efficiency turboprop airplanes, the old boots are upgraded to high pressure, but the a boot is a boot. It is the same device as the DC-3 which flies at 140kts at cruise and lands flaps up at 90kts and less. The modern turboprop deals with icing with the same device, but the thin, high aspect ratio wing has high lift devices that cover a huge pecentage of the wing, and control surfaces that are flown by the tabs on the trailing edge of the flying surface and disruption of airflow in an unprotected area (which would be ever surface that doesn't have a boot) can cause the flyng surface to move uncontrollably no matter where the control yolk is positioned by the pilot.

These features make a modern turboprop unforgiving in icing conditions, and the line pilot becomes essentially an impromptu test pilot on a dark, icy night at the marker. The final fix altitude is not where I want to be when beginning my test pilot career!
These pilots were put in a bad position, and the reason is probably they believe the sort of retoric that you wrote above. These airplanes are NOT protected in icing other than the minimum testing criteria set down by the Fed. All of the rest is covered by pilot training, and that is a hit and miss depending on the knowledge and ability of the collective pilot training group at each airline operator.

It's a weak system, full of holes, so the pilots don't deserve the damning they receive any more than the knowledge they've had withheld from them through their careers.

A good primer is the FAA film posted in a link above. I saw it early in my career and even though it was long after the old cigar chewers of the Twin Beech and DC-3 days told me the in's and out's of icing and boots, it's is and was a good refresher for a very dynamic natural force, the dangers of icing.

FAA Certificated Airplanes Are NOT Certified To Fly In Any Conditions That They Can Possibly Encounter!!!! Captain Bob Is Dead Wrong!!!!!

Chris...

Flyfalcons

Spot on, Chris.

Captainbob

My Feedback: (4)

Dear Stuntflier,
Iā€™m not sure what you think Iā€™m so ā€œdead wrongā€ about, but Iā€™m reminded of a line from Shakespeareā€™s Macbeth something about ā€œhe doth protest too muchā€. As a professional aviator with over 13,000 flight hrs in high performance jet aircraft, chief of Standardization and Evaluation in a large (fortune 100) flight department, and FAA Designee for the DA-20, DA-50, and F-2TH I stand by my statements.

I wonā€™t quibble over certification standards for transport category airplanes. All you have to do is read Partā€™s 23 and 25 of the FARā€™s which are very demanding concerning deicing system requirements as they are about all items pertaining to flight safety.

Crew training is not an issue here as Part 135 clearly mandates periodic refresher training for all 135 crews. And surely you canā€™t be serious when you imply that training is being ā€œwithheld ā€œ. With the emphasis placed on safety by the FAA , NTSB, and other government entities that would mean certain death to any commercial operator in todayā€™s environment.
Unfortunately most aviation safety experts agree that at least 60 and probably more like 90 percent of all air accidents are caused by crew error as was the case in the last big icing related accident involving a commuter aircraft over ORD about 8 years ago where the crew chose to hold in severe icing conditions for over an hour! (Duhhhha, wake up boys). If you have been reading the aviation news lately, you know that the Buffalo crew is already culpable even at this early stage of the investigation, statements to the effect that the crew disregarded standard company and flight manual procedures. It is my guess that the outcome of this one, unfortunate as it is,. Will be similar to the one over ORD- poor crew judgment, poor airmanship..

stuntflyr

Well Captain Bob,
I'm a 20,000 hour pilot and long time 121 air carrier captain. Started a log book when I was 9 yrs. Flown 100's of different types. Hold speed records. So what?

The difference between training and knowledge transference is one that a lot of DE's don't get. I can see you may have a bit of that trait. The POI at the major air carrier I work for is a perfect example of letting a seriously flawed training system remain intact while serious operational incidents, which are technically accidents, continue. Badly written FAA rubber stamped books, poor levels of standardization in training and line operation, etc contribute to myths and wives tales. Much like you wrote about the certification testing compared to possible experience of real icing in nature.
Too bad.

Quote from Captain Bob,
"Unfortunately most aviation safety experts agree that at least 60 and probably more like 90 percent of all air accidents are caused by crew error as was the case in the last big icing related accident involving a commuter aircraft over ORD about 8 years ago where the crew chose to hold in severe icing conditions for over an hour! (Duhhhha, wake up boys)."
Bob, I thought you wrote once certificated that these airplanes can handle any icing conditions ....?

By the way, the ATR guys in the 90's were holding over Indiana and their destination was ORD.

I don't like press trials of pilots, I would like to think that the trade is a brotherhood and you would not like the press conference witch hunt style either. Information as fact from CNN is hardly fair and just to the crew whatever their errors, if they indeed did commit any. I'll wait for the NTSB report and do my usual picking apart of their expert opinions.

Have a nice day,
Chris...

Captainbob

My Feedback: (4)

Stuntman,
Iā€™m well aware of where the ROSELAWN fix is in the 1994 accident of the ATR 72 going into ORD. Been there many times. I was merely trying to condense a theme and not bore people with unnecessary details. So donā€™t try to BS a BSā€™r as they say. You can whine until the cows come home about inadequate crew training, deficient aircraft design, greedy management or draconian government agencies and poor staneval, but you and I both know that the last hurdle in the quest to build a safer air transport system is in the cockpit.

When you invoked the phrase ā€œthe trade is a brotherhoodā€ I knew where you were coming from. Typical union talk, blue collar rhetoric for: ā€œdonā€™t mess with us ā€“ weā€™re untouchableā€. Ronald Regan did the right thing in the late ā€˜70ā€™s when he busted PATCO and fired the controllers. Pity he stopped there. He should have gone after ALPA and other pilotā€™s unions as well. It should be abundantly clear to everyone reading this where collective bargaining has taken this country. The union has no place in aviation because when the union gets involved quality goes down the toilet. Itā€™s hard enough to teach pilotā€™s anything, pompous and arrogant as they are, without having the union involved. Which brings to mind another universal wisdom from Shakespeareā€¦ā€¦.ā€PRIDE GOETH BEFORE THE FALLā€.

The Buffalo accident in my opinion was caused by, carelessness, complacency, poor discipline, poor CRM, poor situational awareness. in short poor airmanship. Just listen to the tapes! And so it goes.

Oh, and by the way. The Turkish disaster at Schipolā€¦ā€¦..same thing.

Flyfalcons

Tell us how you really feel Captain Bob. BTW it's the companies that cut corners in pilot training. The unions are the ones who fight for better training and work rules that increase safety. Until just a month or two ago Colgan was non-union.

Captainbob

My Feedback: (4)

OK, flyfalcons its your turn. Tell us what you think is the major cause of air carrier accidents today? Why do pilots continue to hold or fly in icing conditions? Why do crews fall victim to CFIT such as the 737 at Schipol?????????