Icing . What is acceptable

[bush]

Turned up for work the other day , a/c covered in ice and snow . no de ice avail , snow was brushed from wings , hoar frost (excuse poss dodgy spelling ) everywhere . We didnt go thou engineers said 'its ok' was I being a pussy , wat can u take off with ?

[Squawk 8888]

Your POH should contain info on how much, and where, ice buildup is acceptable. If the information wasn't available to you when you were preparing to departure, then the no-go call was the right one to make.

[Al Weaver]

I agree with Squawk 8888. I was a presenter at a DAC sponsored conference some years ago where the motif was "THERE"S NO SUCH THING AS A LITTLE ICE"

Lots of crashed aircraft pictures to bring home the point.

[Cyclic Hotline]

The answer is NONE.

From the smallest to the largest airplane, they all will succumb to a lack of ice and frost removal prior to flight. You made the right call and you need to let anyone who is suggesting otherwise, that they read these responses before they send somone else off to crash.

Search the NTSB database (search ice or frost) for the hundreds of accidents that have occurred because of inadequate removal, or inadvertent build up of ice or snow prior to flight. Of course none of these record the ones who did it and landed, or never got airborne and got away with it.

We operate in an area of seriously bad weather for 5 months of the year - and ice and snow removal seems to occupy our entire lives! :eek:

There is an excellent first hand account of what happens here on PPRuNe. (http://www.pprune.org/cgibin/ultimatebb.cgi?ubb=get_topic&f=53&t=001051)

The FAA wrote the basic rule of icing right into Part 91.

§ 91.527 Operating in icing conditions.

(a) No pilot may take off an airplane that has --

(1) Frost, snow, or ice adhering to any propeller, windshield, or powerplant installation or to an airspeed, altimeter, rate of climb, or flight attitude instrument system;

(2) Snow or ice adhering to the wings or stabilizing or control surfaces; or

(3) Any frost adhering to the wings or stabilizing or control surfaces, unless that frost has been polished to make it smooth.

(b) Except for an airplane that has ice protection provisions that meet the requirements in section 34 of Special Federal Aviation Regulation No. 23, or those for transport category airplane type certification, no pilot may fly --

(1) Under IFR into known or forecast moderate icing conditions; or

(2) Under VFR into known light or moderate icing conditions unless the aircraft has functioning de-icing or anti-icing equipment protecting each propeller, windshield, wing, stabilizing or control surface, and each airspeed, altimeter, rate of climb, or flight attitude instrument system.

(c) Except for an airplane that has ice protection provisions that meet the requirements in section 34 of Special Federal Aviation Regulation No. 23, or those for transport category airplane type certification, no pilot may fly an airplane into known or forecast severe icing conditions.

(d) If current weather reports and briefing information relied upon by the pilot in command indicate that the forecast icing conditions that would otherwise prohibit the flight will not be encountered during the flight because of changed weather conditions since the forecast, the restrictions in paragraphs (b) and (c) of this section based on forecast conditions do not apply.


There is a ton of light reading on the subject, if you are interested.

AC 135-16 (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/ACNumber/CB561EED09A1A561862569EB006CF4B0?OpenDocument)

AC 120-60 (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/ACNumber/CD907EA7FDE9EE76862569EA0069609E?OpenDocument)

AC 91-51A (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/ACNumber/451296DBDF212C81862569E70077C8F9?OpenDocument)

AC 91-13C (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/ACNumber/0A6BF63C8FB95285862569D900744829?OpenDocument)

A couple of years ago, I attended a Cessna Caravan operators safety meeting dealing with cold weather operations. Following a spate of accidents, Cessna prepared a very good video and CD presentation on the effects of ice on airplanes. At this conference was a pilot who descibed first hand the alarming behaviour of the aircraft after it was attempted to take off with ice present.

Easier to know completely what you are up against, than becoming a statistic and the subject of research and analysis!

One final consideration when the engineers (or anyone else is trying to persuade you to go). Look carefully at 91.527 line (a) - No pilot...."

Guess where the buck stops when it all turns to crap!

[rr892igw]

I'm glad you chose to stay alive to tell the story.Good on you! :D

[SentryIP]

bush,

Good on you. You did the right thing. Did you ask anyone who called you a pussy if they would ly with the airplane in that condition?

<img src="cool.gif" border="0">

[ 19 December 2001: Message edited by: SentryIP ]</p>

[machone]

The only acceptable ice is the stuff in the glass at the bar. Your life your choice!!!

[Don D Cake]

Spent nearly an hour scraping heavy frost off an a/c last Saturday before flying. It was painful towards the end as I'd forgotten my gloves. Didn't mind a bit though, I'd much rather be in a hospital frostbite report than an AAIB report....

You're not a pussy, trying to fly in an iced up aircraft doesn't make you a hard man.

[raitfaiter]

Another example of an infinite series of why groundcrew do not have the last say in whether an aircraft flies or not.......

[Herod]

Right decision, fly with you anytime, Captain. It's been said, but is worth repeating: the acceptable amount of ice is NONE

[777AV8R]

Having flown in the Arctic and after having many hours of cold weather operations, I agree with what has been said. First of all, there is a legal issue that has been stated. Secondly, there is no such thing as a little ice that you can safely go with. Hoarfrost on a wing is not acceptable as the airflow is disturbed as it passes over the wing. The net affect is increased stall speed and no margins for maneuver. There have been many precedents set from guys that have taken off in iced up, frosted up aircraft. Sadly, they are not here to tell us their story. We can only read about their mistakes in safety investigation reports.

You did the right thing. Complements of the season, you are here to talk about it.

[4g_handicap]

Hi guys,

We don't get much ice here in South Africa, except maybe a bit of hoare frost in the middle of winter an the middle of the night.

What I would like your opinions on is this - can one use avgas to clean the wings of frost? It melts any frost and may keep them frost free long enough to get airborne, and it works(I think) on the same principle as de-icing fluids.

Just a thought.

4g
<img src="smile.gif" border="0">

[rick1128]

4G, NO!!!!!!!! For several reasons beside the fact it is a safety hazard in and of itself. The only reason it removed the frost previously is that the fuel temp was above the freezing temp of water. There are better options, leave the aircraft in the sun until the frost melts. Or, if the air temp is warm enough a mop and some hot water. If the temp is not warm enough a mop and hot water followed up by spraying the areas treated with gylcol or moonshine. There is an old bush pilot trick, that is approved by the FAA, of polishing the frost with a length of hemp rope. But unless you know what you are doing, don't try it.

Richard

[yxcapt]

I speak from a near death experiance! Ice and airplanes, helicopters, birds, and insects don't mix!!!!

Please note: FAR 91.527 listed above applies to "Large and Turbine Powered Multiengine Airplanes" not small aircraft. FAR 91.9 (a) prohibits flight without complying with aircraft operating limitations. It's the flight manual that prohibits flight in icing conditions, or takeoff with ice/frost adhearing to the aircraft.

I know the last paragraph was knit picky. You made the right choice!

[yxcapt]

For U.S. comercial operators FAR 135 & 121 have simular regs as 91.527

[fergineer]

An old pilot once told me " flying with ice on your wings makes you a test pilot on the first flight of an untested aircraft" I have never forgotten that and still abide by his rules.
Good call on not going. <img src="smile.gif" border="0">

[Steamhead]

A fair few years ago a Cessna Twin finished up as a smoking heap just of the far end of the runway.
The pilot (a CAA EXAMINER) was found , by the rescue crew,Scraping ice off what was left of the wings with a credit card !!

Regards
Merry Christmas

[A and C]

If you have eny doubt about the ice on an aircraft then there is no doubt GET IT REMOVED BEFOR YOU FLY.

[Mago]

Sorry for being repetitive but, NO ONE SHOULD EVEN THINK to try to take off with ANY ICE on any surface on you aircraft.
I understand that when someone has little flight time and that someone has hears hangar talk about "super-skills" regarding flying aircraft full of ice, there could be a shadow of a doubt about maybe having a "little ice" anywhere (I´ve seen it).
Everybody that have had rapid ice buildup, must know what are the effects on your envelope.

Yes, I had it once and the best way to describe me during it is: <img src="frown.gif" border="0"> <img src="eek.gif" border="0">

[G3]

The problem with ice is, it tends to melt in the post crash fire!

Best regards,

G3

[Monkey Tennis]

The other day in KTT on a very cold clear day, each aircraft, which included a selection of uk charter guys and Finnair a/c, got de iced prior to departure. This being to remove the build up of frost and ice which develops very quickly at -20. Then all of sudden a JMC a/c departs after a longer turn around than most, without deicing, thus saving £400+.

Whilst it was cold and clear, with no snow deposits, was he being practical and us wasteful, or him the cowboy and us professional.

It was my decision to deice and seeing the Finnair who has far more cold weather ops experience follow suit provide reassuance of a good decision.

If rumours are to be believed then of all the operators on the ramp his company is maybe the most finnancially insecure, I hope this did not play any part in his decision making process.

[dullcopilot]

Guys thanks for the great advive , I originally posted this question on a friends PC , as BUSH . Feel relieved , have printed the pages . all great advice and i would like to thank you all very much .

[Siddique]

None Nil yilch....your engineers should know better. We are trained in this and believe me it is NIL.....BA have a wonderful CD ROM on this I am sure there are copies around it is good for boith ground and flt crew use. See if you can get a copy.

[RatherBeFlying]

Showed up one cold day to pick up a C-172, then fly to another airport to pick up some friends to fly to still another airport and found the a/c covered in frost. Spent a couple hours thoroughly scraping the frost off between rivet lines and had an interesting moment discovering climbout required considerably more pitch while having a low level look at the convenient creek bottom thoughtfully placed at the end of the runway. <img src="eek.gif" border="0">

After that I kept a couple extra jugs of automotive windshield deice fluid and a good squeegee/sponge combo in the car because no way am I taking off an a/c unless the wings SPARKLE.

In another vein, I checked with the Wardair chief pilot after witnessing an A310 take off with frost over the wing tanks because of cold-soaked fuel. Turned out that Airbus had done flight testing and had approvals for that operation.

[Steamhead]

Just a minor point, are you aware that Aeroshell Compound 6 (De-Ice) is now £4 per Litre plus vat.
Anyone know of a chemical supplier of
isopropyl alcohol in 25 Ltr drums, this being the main constituent.
regards

[Stagnation Point]

Ddon't know if you think this relevant but I once saw a Dung Duster (Agricultural Fertilser Spreader) that was parked at the time. The Horizontal stabiliser, it was a tail dragger, was caked with at least an inch of mud on 90% of the leading edge. The acft had obviously flown in this condition, from memory it was a Pawnee, perhaps they are a very forgiving acft.

The point is its not just ice that will affect the aerodynamic efficiency of your acft, but any for of solid contamination.

[Idunno]

My companies Ops Manual and other winter ops documents used to explicitly state a "Clean Aircraft policy". In other words, no contamination allowed.

Lately however this has gradually been diluted. The old mantra no longer appears in the books, and most operators manuals (jet types) allow up to 1/8th inch of 'hoar frost' on the fuselage as acceptable. They even suggest that if you can read the logos on the fuselage through the ice then you have around 1/8th inch contamination...and can go.

Personally I don't feel comfortable with this and I insist on a clean aircraft. Among the reasons...if you have contamination on the top of the fuselage you probably have it on top of the wing too!
It only takes a few minutes more to spray the fuselage, but I still get funny looks from engineers and even some F/O's who are quick to remind me what th book allows as acceptable!

The difficulty is that many other skippers accept this level of contamination...including training Captains. Makes it a lonely path to tread at times, but still less lonely than the graveyard.

[Black_Dawn]

Good point Idunno

some days ago in Turin (coming from a long flight at FL330)cold fuel was creating a widespread hoar frost on the upper wings (spreading to the ailerons).I was behind schedule for the next leg. Nevertheless i added another 10 minutes of delay to get the wing deiced. Whether necessary or not didn't matter!

B_D

[bluskis]

STEAMHEAD
WAS A COMPANY, ELLIS & EVARARD, 0208 858 5808 OR 01962 864446 SELLING BULK CHEMICALS.
TWO CAVEATS, 1)MAY NOT BE THAT SIMPLE A CHEMICAL FOR AIRCRAFT
AND 2)MAY NEED A CUSTOMS PERMISSION TO BUY AN ALCAHOL IN BULK.

[HotDog]

A couple of points in our Winter Operation handbook.

A light sandpaper roughness on a leading edge can reduce lift by 18%.

As little as one half inch of ice can reduce aircraft lift by 50%.

I also have been called a pussy in the past but never ever departed with ice or snow on the aircraft.

[crossfeedclosed]

Well done young man. Any ice on an airplane is too much. Another old pilot once told me "the only place for ice in an airplane is inside a large whiskey." Good advice. Heard a story recently about a Captain who refused to put on the wind anti-ice when the windscreen was covered in the stuff. Co-pilot had to force him to do it. Any more info on that? If true what a prat and a dangeroud one too.

[spannersatcx]

Legolas, don't tar us all with the same brush, ask the crew who didn't want their a/c de-iced tonight even though I said it required it and refused to release the a/c until it was de-iced.

[whatbolt]

Bush-I think most of what needs to be said has been on this subject. I would just like to add that if airoplanes where meant to have any crinkly rough surfaces then someone would have built them that way-no good eng would offer a kite for service with any contamination and no good pilot would take it-its also interesting to note that some 80 percent of quality reports I saw from this period last year with an airline I know refered to deicing being carried out incorrectly - know your subject -Kilfrost do some good training vidoes etc.