Take off with snow on wing
I have heard of "the rope trick" (either removing, or sometimes just "polishing smooth") being performed in Alaskan bush flying before.
No fair commenting on "interesting Chinese water" trick without telling what it is.
No fair commenting on "interesting Chinese water" trick without telling what it is.
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This take-off would be illegal in Canada today, but only according to fairly recent regulations. Just a few years ago, it might have been legal.
Here is what the Regs say, in this part of the world anyway
The key word is "adhering".
That definition is the same as it was 10 years ago and is still unchanged because when an aircraft is de-iced and anti-iced and it continues to snow, by the time it begins its take-off roll, the wings may very well be covered in snow, but snow that does not adhere to the critical surfaces of the aircraft thanks to the anti-icing fluid. Before the new principles were adopted, (sept 1990 I think in Canada, following the accident report on the March 1989 Dryden accident) that same principle could be applied for dry snow: it did not "adhere".
After 1990, they had to keep the above definition but the philosophy changed, although I can't find the exact wording change in the regs they used to apply the new principles. .
When very dry snow falls on a very cold and clean aircraft (like when it's -25 Celsius on the ground) none of it sticks to the aircraft. One can blow on it and it flies off, leaving no trace on the surface of the aircraft. Back in those days, our spoilers were painted black. When we wanted to ascertain that our aircraft was "clean", one pilot would walk back in the cabin and look at the wings while the pilot remaining in the cockpit would raise the spoilers. If the spoilers were clean and free of snow while in the vertical position, we could take off, if not we would have to de-ice. They were painted black so that any snow or ice would stick out.
Russia is now where Canada was in August 1990 and everyone acts as though it was never done in these parts of the world.........
Here is a picture of such an aircraft with a black spoiler.......
Here is what the Regs say, in this part of the world anyway
No person shall conduct or attempt to conduct a take-off in an aircraft that has frost, ice or snow adhering to any of its critical surfaces.
That definition is the same as it was 10 years ago and is still unchanged because when an aircraft is de-iced and anti-iced and it continues to snow, by the time it begins its take-off roll, the wings may very well be covered in snow, but snow that does not adhere to the critical surfaces of the aircraft thanks to the anti-icing fluid. Before the new principles were adopted, (sept 1990 I think in Canada, following the accident report on the March 1989 Dryden accident) that same principle could be applied for dry snow: it did not "adhere".
After 1990, they had to keep the above definition but the philosophy changed, although I can't find the exact wording change in the regs they used to apply the new principles. .
When very dry snow falls on a very cold and clean aircraft (like when it's -25 Celsius on the ground) none of it sticks to the aircraft. One can blow on it and it flies off, leaving no trace on the surface of the aircraft. Back in those days, our spoilers were painted black. When we wanted to ascertain that our aircraft was "clean", one pilot would walk back in the cabin and look at the wings while the pilot remaining in the cockpit would raise the spoilers. If the spoilers were clean and free of snow while in the vertical position, we could take off, if not we would have to de-ice. They were painted black so that any snow or ice would stick out.
Russia is now where Canada was in August 1990 and everyone acts as though it was never done in these parts of the world.........
Here is a picture of such an aircraft with a black spoiler.......
Last edited by Minorite invisible; 20th Apr 2012 at 13:58.
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Water check: Special book.
Checkboard;
My apology, just did not want to appear to know all. The procedure used as described by Captain Smith was to catch a few drops of fuel in the cupped palm of one hand and then gently blow on the fuel to cause some evaporation. If evaporation did not occurr then the liquid was water.
" China Pilot" is a very special book. It's a book written in pilots' language that only a fellow pilot can fully understand. An example is when converting onto the C119 Felix said of the stall sequence " I shoved the nose down and the power up and tucked the sounds and feeling into my memory " It's the flying life of a soldier of fortune who upon retirement back to the USA said " the world is flat after life in asia " Michael Collins of Apollo 11 said "China Pilot " is a wonderfull book. Buy it and give yourself a treat, at the moment Amazon Books have 5 copies in stock.
My apology, just did not want to appear to know all. The procedure used as described by Captain Smith was to catch a few drops of fuel in the cupped palm of one hand and then gently blow on the fuel to cause some evaporation. If evaporation did not occurr then the liquid was water.
" China Pilot" is a very special book. It's a book written in pilots' language that only a fellow pilot can fully understand. An example is when converting onto the C119 Felix said of the stall sequence " I shoved the nose down and the power up and tucked the sounds and feeling into my memory " It's the flying life of a soldier of fortune who upon retirement back to the USA said " the world is flat after life in asia " Michael Collins of Apollo 11 said "China Pilot " is a wonderfull book. Buy it and give yourself a treat, at the moment Amazon Books have 5 copies in stock.
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That definition is the same as it was 10 years ago and is still unchanged because when an aircraft is de-iced and anti-iced and it continues to snow, by the time it begins its take-off roll, the wings may very well be covered in snow, but snow that does not adhere to the critical surfaces of the aircraft thanks to the anti-icing fluid.
The glycol present in the anti-icing fluid will effectively melt the snow falling on it and the fluid will become progressively more and more diluted as time passes. Eventually the glycol will be diluted to a level where it becomes totally ineffective and the snow will start to form or accumulate on the treated surfaces. At this time the so called 'Holdover Time' will have run out and the aircraft will require a further de-icing/anti-icing treatment.
While under certain conditions any anti-icing fluid residues remaining in contact with the structure may prevent the accumulating snow from bonding or freezing to the surface of the aircraft, there is no guarantee of this and certainly no guarantee that this partially melted snow will effectively flow off on any anti-icing fluid residues that may be still present.
To quote from Section 3.15 in Edition 26 of the AEA Recommendations for De-icing/Anti-icing Aeroplanes on the Ground, "..Holdover time will have effectively run out when when frozen deposits start to form/accumulate on treated aeroplane surfaces.." At this time a further de-icing/anti-icing treatment would of course be required.
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This is a totally incorrect and misleading statement which, in my opinion, should be removed before the less well informed start to believe it's true..!!
Thank you, Ice-bore! It's really surprising how little fellow pilots (?) understand when it comes to this subject. Or maybe scary is the correct word?
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Originally Posted by Ice-Bore
The glycol present in the anti-icing fluid will effectively melt the snow falling on it and the fluid will become progressively more and more diluted as time passes. Eventually the glycol will be diluted to a level where it becomes totally ineffective and the snow will start to form or accumulate on the treated surfaces. At this time the so called 'Holdover Time' will have run out and the aircraft will require a further de-icing/anti-icing treatment.
In fact there is, and that is why the Regs, here anyway, still allow take-off as long as none of that stuff adheres to the surfaces.......
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Originally Posted by Clandestino
First issue with QH90 was very primitive (but legal at the time) FDR, which did not record attitude or power. In AirRabbit's alternative view on the accident, holes left by primitive recording equipment are filled by conjecture
Fact: According to the Accident Report, the Trump De-Icing Vehicle did not incorporate the “mix-monitor” which allows the operator to ascertain that the desired mixture is indeed being delivered at the nozzle.
The Trump De-Icing Vehicle used to deice/anti-ice the accident airplane had recent “repairs” completed that resulted in the nozzle dispensing fluid at 18 percent glycol mixture from the deicing wand at a minimal flow rate, but when the operator increased the flow rate, all of the additional volume flow came from the heated water tank, and none from the glycol tank – effectively lowering the solution percentage by an unknown but substantial proportion, potentially reaching a solution of “zero glycol” being dispensed.
Question: Why is it that this information was not included in the Accident Report?
Answer: Up to you.
Question: Could the deicing/anti-icing solution provided by this “repaired” deicing vehicle, in combination with the ambient temperature of 24F, applied to a “cold-soaked” airplane, have had any effect on whether or not ice could accumulate on the aircraft? Could this solution, in combination with any potential snow fall, have had any effect on whether or not ice could accumulate on the aircraft?
Answer: Up to you.
Originally Posted by lomapaseo
It's easy for some to suggest that wing contamination might have played a part (after all the evidence melts immediately after a crash).
However the validated contributions are covered in the NTSB report hence the recommendations regarding engine power set "check'.
The Forum thread we are burried within is an equally important opportunity thread to discuss wing ice as a prime consideration on its own without mixing it up in a controversial message about Air Florida in the Potomac
However the validated contributions are covered in the NTSB report hence the recommendations regarding engine power set "check'.
The Forum thread we are burried within is an equally important opportunity thread to discuss wing ice as a prime consideration on its own without mixing it up in a controversial message about Air Florida in the Potomac
Question: Why would only one of those aircraft (the one in the middle) have had a problem?
Answer: Up to you.
The first of the 3 causes of the accident, cited by the Accident Report:
“...the flightcrew’s failure to use engine anti -ice during ground operation and takeoff...”
Fact: The CVR transcript shows that during the “after start” checklist (which was conducted as a challenge/response exercise) at the F/O’s challenge (reading the checklist) item “Anti-ice” (referring to the engine anti-icing switches) the response, provided by the Captain, is indicated as “OFF,” and is shown within parentheses. The legend for the CVR shows that any transcript content contained within parentheses indicates “questionable text.”
Question: In that there are only two positions for those switches, either “ON” or “OFF,” when the response, as recorded on the cockpit voice recording tape, is not clear, why was “OFF” chosen to be placed within those parentheses instead of the only other alternative, “ON”? This is the only indication that engine anti-ice was not used. If the actual recording is not clear, and there are only 2 choices – why was “OFF” determined to be the response that should be included within those parentheses, instead of “ON”?
Answer: Up to you.
(Information: Just in case anyone may be interested ... when the wreckage of the airplane was retrieved, the position of the switches on the overhead panel and the position of each of the 3 associated valves in each of the engines were inconclusive – which is not uncommon for the amount of impact destruction experienced.)
The second of the 3 causes of the accident, cited by the Accident Report:
“...their decision to take off with snow/ice on the airfoil surfaces of the aircraft...”
Fact: for that day, the recorded information regarding snow fall was as follows...
Moderate snow began at 1240 and ended at 1320.
Heavy snow began at 1320 and ended at 1525.
Moderate snow began at 1525 and ended at 1540.
Light snow began at 1540 and ended at 1553.
Moderate snow began at 1553 and ended at 1616.
Again, the airplane preceding and the airplane following the accident B-737 were subjected to the same processes and weather prior to takeoff.
Question: If it was the snow fall that accumulated on the B-737 between the gate and their takeoff that caused the accident – what prevented the other two airplanes from suffering the same fate?
Answer: Up to you.
The third of the 3 causes of the accident, cited by the Accident Report:
“...the captain’s failure to reject the takeoff during the early stage when his attention was called to anomalous engine instrument readings.”
Fact: The first time the F/O expressed anything that sounded like he was questioning something was at 1600:02 when he said, “That don’t seem right does it?” This was followed at 1600:05 by “Ah, that’s not right” and then an inaudible comment, followed by the Captain saying “Yes it is, there’s eighty” at 1600:09. Then at 1600:10 the F/O said “Naw, I don’t think that’s right, followed at 1600:19 with “Ah, maybe it is.” Two seconds later, at 1600:21, the Captain says “Hundred and twenty.” Then the F/O says “I don’t know.”
Observation: The committee that listened to the actual CVR recording apparently concluded that the F/O was expressing a concern over an “engine anomaly,” and of course, that is certainly a possibility. For almost 20 seconds it would appear that both the Captain and the F/O were attempting to recognize something in the cockpit that was causing the F/O to make the comments he made – apparently without being able to identify what that was.
Question: What would have been anomalous to the F/O and not to the Captain? Would this be the only thing that would have caused the F/O to make the comments he made?
Answer: Up to you.
Fact: A landing airplane was on final when the accident B-737 was cleared into position and cleared for takeoff. Approximately 20 seconds elapsed from the time the tower advised that there was a landing airplane on final at 2 and ½ miles behind the departing B-737 (at 1559:28) to the time the CVR recorded the sound of the engines spooling up toward the desired takeoff setting (at 1559:48). Another 14 seconds had passed when the F/O first indicated that there was something that he thought didn’t “seem right” (at 1600:02). Another 7 seconds had passed when the Captain noted that the B-737 had reached 80 knots (at 1600:09).
Question: How far behind the B-737 was the landing aircraft at these points?
Answer: Up to you.
Fact: At 1600:11 the landing aircraft called, “Fourteen fifty-one, cleared to land over the lights” (which extended 2400 from the runway’s threshold). We do not know the specific point over those approach lights the landing B-727 actually was at the time of that radio call.
Question: At this point, how far behind the B-737 was the landing aircraft?
Answer: Up to you.
Question: Would you have aborted the takeoff?
Answer: Up to you.
Fact: The accident report states “there were other incidents similar to this one reported, in which the crew was able to overcome the contamination, but they needed the proper thrust level of 2.04 EPR.” On the same day as the Air Florida accident, another B-737 attempted a takeoff out of Oslo, Norway, where the taxi and takeoff were conducted during a snowstorm. During the takeoff, as the crew began to rotate, the airplane pitched-up and due to the asymmetry of the deformity of the wings, began a roll. Neither the pitch nor the roll was controllable by the crew. Even though the throttles were “slammed” to the firewall immediately and the fact that the pilot used full opposite aileron and full opposite rudder, the pitch and roll of the aircraft was not controllable. Apparently, due to the radical bank angle reached (approaching 90 degrees), the nose dropped back down toward the horizon, and with the throttles fully forward, the airplane began to accelerate. As the acceleration continued, apparently lift was produced over the outboard portions of the wing, including the ailerons, and the crew was able to roll back to level flight. The crew recovered the airplane; but that recovery was below 100 feet above the ground.
Question: Why were the only incidents of B-737 pitch-up and/or roll-off described in the Accident Report those that were recoverable?
Answer: Up to you.
Originally Posted by lomapaseo
Have a question about adhering ... then ask the regulator
Care to interpret it yourself then accept the violation
If it is still on your aircraft when you push back then it is adhering.
There is still room in an SOP once you depart with a clean wing. But you need to start someplace with a known degree of safety
Care to interpret it yourself then accept the violation
If it is still on your aircraft when you push back then it is adhering.
There is still room in an SOP once you depart with a clean wing. But you need to start someplace with a known degree of safety
As long as the rule uses that term, I think we all have to recognize that there is likely to be a substantial number of people who will find that definition to be a way to continue operations when that continuation may not be the most conservative decision.
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"I am mindful of the fact that most of those aviators are heavily influenced by all sorts of external factors – their boss, their job, their salary, etc."
reading through the thread, I worry that I might be in the minority. When I fly, I have two primary considerations: my safety, and that of the passengers behind me.
If those considerations don't suit my boss, then I will soon be bossless. However, in my minimal experience, my bosses have been on the same channel. Even if only because a mighty screw up is going to cost them big time.
As before. Contamination on any surface = no fly. End of.
If any boss doesn't like that, then that's tough. Stuck up the pointy end, it's my responsibility and I take that seriously, not least because my a**e is equally on the line.
reading through the thread, I worry that I might be in the minority. When I fly, I have two primary considerations: my safety, and that of the passengers behind me.
If those considerations don't suit my boss, then I will soon be bossless. However, in my minimal experience, my bosses have been on the same channel. Even if only because a mighty screw up is going to cost them big time.
As before. Contamination on any surface = no fly. End of.
If any boss doesn't like that, then that's tough. Stuck up the pointy end, it's my responsibility and I take that seriously, not least because my a**e is equally on the line.
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Originally Posted by Rabski
reading through the thread, I worry that I might be in the minority. When I fly, I have two primary considerations: my safety, and that of the passengers behind me...
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Canada icing conditions
Not wanting to hijack the thread (mods please move it if you like)
Monday 16th flew from an Alberta location to one in Texas - Flew commercial as the company units were busy. Pushed back at 10 mins late 07:10. The aircraft had been at gate for over 8 hours over night and the temps were all below freezing, but no precip in the preceeding 12 hours.
Promptly taxied past all the WestJet aircraft being de-iced and lined up and rolled - needless to say studied stbd wing very closely to see any signs of ice, but it did appear clean.
If the locals de-ice all their overnighting aircraft, why not the legacy US carrier?
Monday 16th flew from an Alberta location to one in Texas - Flew commercial as the company units were busy. Pushed back at 10 mins late 07:10. The aircraft had been at gate for over 8 hours over night and the temps were all below freezing, but no precip in the preceeding 12 hours.
Promptly taxied past all the WestJet aircraft being de-iced and lined up and rolled - needless to say studied stbd wing very closely to see any signs of ice, but it did appear clean.
If the locals de-ice all their overnighting aircraft, why not the legacy US carrier?
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Are you claiming that when an aircraft takes off during snow showers and within the allowed hold-over time, thanks to the magical effect of glycol, the snow instantly turns into water and the wings just look wet, as though it was just raining? There is no presence of slush, partially melted snow, snow crystals, nothing that has consistence?
Due to the thickening agent present in Type II and IV de-icing/anti-icing fluids these fluids are able to remain on and protect aircraft surfaces for a period of time (see holdover time tables for applicable times).
As the snow flakes impinge on the fluid film they melt, due to the low FP of the glycol in the fluid, progressively diluting the fluid and yes the surface does look wet at this stage. Depending on the intensity of the snowfall it may take a few seconds for the individual snow flakes to melt but once slush or snow is seen to be building up on the fluid film the holdover time will have expired and a further treatment will be required.
The viscosity of the fluid is relatively high when applied to the surfaces of an aircraft on the ground, however, as the aircraft accelerates during take-off the shearing effect of the airflow over the wings breaks down the structure of the fluid, reducing the viscosity and allowing it to flow off to provide a clean wing. Clearly if the fluid film has snow on top of it, it will be prevented from working as designed.
In fact there is, and that is why the Regs, here anyway, still allow take-off as long as none of that stuff adheres to the surfaces.......
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Ice-bore is correct.
Extract from a Ground Icing Ops Manual :
Extract from a Ground Icing Ops Manual :
Aircraft surfaces treated with de/anti-icing fluid should appear glossy, smooth and wet, if not, the fluid is no longer effective.
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Originally Posted by ICE_BORE
It would be appreciated if you could let us know where, in your regulations, it allows you to take-off with snow/slush present on top of an applied film of anti-icing fluid...
TP 10643 - When in Doubt... - Transport Canada
in paragraph 77
Frost, ice or snow on top of deicing or anti-icing fluids must be considered as adhering to the aircraft and take-off must not be attempted.
Aircraft surfaces treated with de/anti-icing fluid should appear glossy, smooth and wet, if not, the fluid is no longer effective.
Some indications of loss of fluid effectiveness are:
- Progressive surface freezing (loss of wetness);
- Random accumulation, i.e. snow flakes remain on the fluid surface without melting;
- Snow accumulation;
- Dulling of surface reflectiveness (loss of gloss);
- Foggy fluid appearance (gradual deterioration of the fluid to slush); or
- Ice pellets precipitation is susceptible to degrade the de/anti-icing fluid very rapidly. It is believed that ice pellets are capable of penetrating the fluid and have enough momentum to contact the aircraft’s surface beneath the fluid. A local dilution of the fluid by the ice pellet would result in the vey rapid failure of the fluid.
If the de/anti-icing fluid exhibits one of more of the preceding indications, the aircraft must be considered contaminated.
Some indications of loss of fluid effectiveness are:
- Progressive surface freezing (loss of wetness);
- Random accumulation, i.e. snow flakes remain on the fluid surface without melting;
- Snow accumulation;
- Dulling of surface reflectiveness (loss of gloss);
- Foggy fluid appearance (gradual deterioration of the fluid to slush); or
- Ice pellets precipitation is susceptible to degrade the de/anti-icing fluid very rapidly. It is believed that ice pellets are capable of penetrating the fluid and have enough momentum to contact the aircraft’s surface beneath the fluid. A local dilution of the fluid by the ice pellet would result in the vey rapid failure of the fluid.
If the de/anti-icing fluid exhibits one of more of the preceding indications, the aircraft must be considered contaminated.
Part VI - General Operating and Flight Rules - Transport Canada
(2) No person shall conduct or attempt to conduct a take-off in an aircraft that has frost, ice or snow adhering to any of its critical surfaces.
(4) Where conditions are such that frost, ice or snow may reasonably be expected to adhere to the aircraft, no person shall conduct or attempt to conduct a take-off in an aircraft unless
(a) for aircraft that are not operated under Subpart 5 of Part VII (meaning commercial non-airline),
(i) the aircraft has been inspected immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces, or
(ii) the operator has established an aircraft inspection program in accordance with the Operating and Flight Rules Standards, and the dispatch and take-off of the aircraft are in accordance with that program; and
(b) for aircraft that are operated under Subpart 5 of Part VII (airliners), the operator has established an aircraft inspection program in accordance with the Operating and Flight Rules Standards, and the dispatch and take-off of the aircraft are in accordance with that program.
(5) The inspection referred to in subparagraph (4)(a)(i) shall be performed by
(a) the pilot-in-command;
(b) a flight crew member of the aircraft who is designated by the pilot-in-command; or
(c) a person, other than a person referred to in paragraph (a) or (b), who
(i) is designated by the operator of the aircraft, and
(ii) has successfully completed an aircraft surface contamination training program pursuant to Subpart 4 or Part VII.
(6) Where, before commencing take-off, a crew member of an aircraft observes that there is frost, ice or snow adhering to the wings of the aircraft, the crew member shall immediately report that observation to the pilot-in-command, and the pilot-in-command or a flight crew member designated by the pilot-in-command shall inspect the wings of the aircraft before take-off.
(4) Where conditions are such that frost, ice or snow may reasonably be expected to adhere to the aircraft, no person shall conduct or attempt to conduct a take-off in an aircraft unless
(a) for aircraft that are not operated under Subpart 5 of Part VII (meaning commercial non-airline),
(i) the aircraft has been inspected immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces, or
(ii) the operator has established an aircraft inspection program in accordance with the Operating and Flight Rules Standards, and the dispatch and take-off of the aircraft are in accordance with that program; and
(b) for aircraft that are operated under Subpart 5 of Part VII (airliners), the operator has established an aircraft inspection program in accordance with the Operating and Flight Rules Standards, and the dispatch and take-off of the aircraft are in accordance with that program.
(5) The inspection referred to in subparagraph (4)(a)(i) shall be performed by
(a) the pilot-in-command;
(b) a flight crew member of the aircraft who is designated by the pilot-in-command; or
(c) a person, other than a person referred to in paragraph (a) or (b), who
(i) is designated by the operator of the aircraft, and
(ii) has successfully completed an aircraft surface contamination training program pursuant to Subpart 4 or Part VII.
(6) Where, before commencing take-off, a crew member of an aircraft observes that there is frost, ice or snow adhering to the wings of the aircraft, the crew member shall immediately report that observation to the pilot-in-command, and the pilot-in-command or a flight crew member designated by the pilot-in-command shall inspect the wings of the aircraft before take-off.
Last edited by Minorite invisible; 21st Apr 2012 at 03:52.
Notice that the word "adhere" is always there, when the law could have been written with the exact same wording but with the word "present" instead of "adhere". Why ?
"present"
Like blowing snow across a cold flat surface that does not accumulate on such surface
"adhere"
Where it does accumulate
If you start your taxi (after dispatch) and the snow has already accumulated on the wing even in patches, it has "adhered" and you should be in violation of a hard rule if you dispatched that way.
A clean wing/engine etc, at dispatch, that subsequently accumulates snow or ice falls under a different operational SOP (one that minimizes the effect)
A wing/engine that accumulates ice in the air falls under a design regulation as well as an operational SOP
to adhere...
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If you start your taxi (after dispatch) and the snow has already accumulated on the wing even in patches, it has "adhered" and you should be in violation of a hard rule if you dispatched that way.
There are a lot of the Canadian rules that are quite direct and to the point and would probably be preferred by most aviators – given the chance … but even then, the language our friends in Canada use can present the same sort of understanding or interpretation questions. For example the Canadian rule quoted as saying “…conditions are such that frost, ice or snow may reasonably be expected to adhere to the aircraft…” Then the question becomes, what is “reasonable?” Does “expected” mean that it is suspicioned to have adhered already, or will, within a short time in the future, begin to adhere? If it is expected in the future, what time frame would be acceptable – or – how short is short? Or, do we throw it all in the air and let the lawyers figure it out?
Using the word “accumulate” doesn’t necessarily solve these issues either. If any rule was changed to say takeoff must not be attempted when ice or snow has accumulated on the wing … then virtually any snow fall would prevent virtually any taxi time between “deicing” and “takeoff”. Anyone who has taxied from a gate to a runway for takeoff when snow was falling, can easily attest to the fact that “some” snow accumulated on the wings prior to taking off. If the parameters of such an accumulation cannot be clearly articulated and then adequately communicated, then, the conversation between the two Air Florida pilots becomes a lot more prophetic …
Captain: Right there is where the icing truck…they oughta have two of them, you pull right…
F/O: …right out
Captain: Like cattle … like cows right.
Captain: Right in between these things and then…
F.O: …get your position back
Captain: Now you're cleared for takeoff
F/O: Yeah and you taxi through … kinda like a car wash or something
Captain: Yeah
I know there are some airports who use precisely this method … and I would presume that there have been very few, if any, takeoff incidents attributed to ice or snow presence, accumulation, or adherence at those airports. The problem with this method is one of expense … both initial and maintenance … and then there is always going to be the environmentalists that would need to be satisfied with respect where the runoff would be captured and disposed of properly.
Ahhh … the simple life of an aviator …
I note a few references to the crash of Air Ontario Flight 1363, a Fokker F28 which crashed into a forest less than a kilometer from the end of the runway at Dryden Ontario in 1989. The accident resulted in 24 fatalities, including both of the flight deck crew and the senior flight attendant. There were 45 survivors, including a second flight attendant.
Subsequent to the accident and the official accident report the government formed a Commission of Inquiry chaired by the Honourable Vincent Mashansky to examine not just the immediate cause of the accident (which was unquestionably the decision of the pilot to depart the runway with snow-contaminated wings) but also all of the causal factors which may have influenced the captain’s unfortunate decision to attempt the takeoff, given that he had a reputation for being cautious and responsible (although this may have contributed to his decision, inasmuch as he no doubt also felt a responsibility to get his passengers to their destination, particularly as it was the start of a school break and many passengers were to connect to flights which would take them to vacation destinations).
Justice Mashansky’s 1,300 page report is very comprehensive. It could serve as a textbook example of how all of the holes can line up, insofar as the Commission found that virtually everyone having anything to do with Flight 1363 and this aircraft made errors or omissions which individually might be deemed insignificant but collectively led to a smoking hole in the ground. (To be clear, the interpretation that the errors might be deemed insignificant is mine alone… Mashansky was less forgiving). These factors included the ground worker who fueled the craft but failed to bring the snow on the wing to the captain’s attention, and the senior flight attendant who dismissed the concerns expressed by a nervous passenger, as well as the junior attendant who deferred to the judgement and authority of her senior colleague.
Perhaps most relevant to this discussion the Commission examined the responses of two surviving passengers… an off-duty Air Ontario Dash 8 captain and an off-duty Air Canada DC9 captain. One of these testified that he knew that the aircraft would not fly (emphasis mine) but presumed that the captain knew this too. In any case, he testified that he presumed that the captain planned to monitor the snow on the wings during the takeoff roll and would abort the takeoff once he saw that the snow was adhering to the wing. According to the testimony of others this method of determining wing contamination during the takeoff roll was not entirely uncommon at Air Ontario (which had evolved from Austin Airways, flying DC3 and Otters around northern Canada) and if I recall correctly Justice Mashansky (a pilot himself) found this practice to be unsatisfactory to say the least. We can be certain that the regulations drafted subsequent to this accident were not intended to allow pilots to make their determination of whether snow and ice were “adhering” when they were halfway down the runway approaching V1.
It’s nice to see that many on this board say that they would have… had they been passengers… prevented the takeoff attempt. However, in this context it ought to be noted that the other off-duty captain was also aware of the condition of the wing, but felt that professional courtesy and respect required that he remain silent. The two passenger-pilots had something like 18,000 hours experience between them while the two at the pointy end had something like 130 hours of combined experience (on type).
I recognize that this report is now twenty years old and we now have a greater appreciation of human dynamics (if only because of subsequent incidents and accidents). Taken as a whole the report was (and remains) a damning indictment of the airline`s owners and managers (largely one and the same) and Air Canada (Air Ontario`s code-share partner and part-owner at the time). Ultimately, of course, the report infers that industry deregulation in the absence of adequate regulatory authority created an environment which contributed to the accident. Mashansky made 191 recommendations, and while I believe that some were acted upon I’ve a hunch that most were not. Indeed, something like 18 months after the release of the report another F28 (USAir 405) crashed at LaGuardia under similar circumstances.
I presume, of course, that I am preaching to the choir here. In fact, I hope that I am.
And I apologize to those who I've offended, given that... well, my username says much. Indeed, I was going to keep my thoughts to myself until I realized that I am one of those people who would keep my thoughts to myself even if there was a foot of snow on a wing.
Apologies for being so long-winded, and mods feel free to edit.
The full text of the report can be found here:
Commissions of Inquiry
Also, there is an episode of “Air Crash Investigation” devoted to the accident and Mashanky’s report here:
Subsequent to the accident and the official accident report the government formed a Commission of Inquiry chaired by the Honourable Vincent Mashansky to examine not just the immediate cause of the accident (which was unquestionably the decision of the pilot to depart the runway with snow-contaminated wings) but also all of the causal factors which may have influenced the captain’s unfortunate decision to attempt the takeoff, given that he had a reputation for being cautious and responsible (although this may have contributed to his decision, inasmuch as he no doubt also felt a responsibility to get his passengers to their destination, particularly as it was the start of a school break and many passengers were to connect to flights which would take them to vacation destinations).
Justice Mashansky’s 1,300 page report is very comprehensive. It could serve as a textbook example of how all of the holes can line up, insofar as the Commission found that virtually everyone having anything to do with Flight 1363 and this aircraft made errors or omissions which individually might be deemed insignificant but collectively led to a smoking hole in the ground. (To be clear, the interpretation that the errors might be deemed insignificant is mine alone… Mashansky was less forgiving). These factors included the ground worker who fueled the craft but failed to bring the snow on the wing to the captain’s attention, and the senior flight attendant who dismissed the concerns expressed by a nervous passenger, as well as the junior attendant who deferred to the judgement and authority of her senior colleague.
Perhaps most relevant to this discussion the Commission examined the responses of two surviving passengers… an off-duty Air Ontario Dash 8 captain and an off-duty Air Canada DC9 captain. One of these testified that he knew that the aircraft would not fly (emphasis mine) but presumed that the captain knew this too. In any case, he testified that he presumed that the captain planned to monitor the snow on the wings during the takeoff roll and would abort the takeoff once he saw that the snow was adhering to the wing. According to the testimony of others this method of determining wing contamination during the takeoff roll was not entirely uncommon at Air Ontario (which had evolved from Austin Airways, flying DC3 and Otters around northern Canada) and if I recall correctly Justice Mashansky (a pilot himself) found this practice to be unsatisfactory to say the least. We can be certain that the regulations drafted subsequent to this accident were not intended to allow pilots to make their determination of whether snow and ice were “adhering” when they were halfway down the runway approaching V1.
It’s nice to see that many on this board say that they would have… had they been passengers… prevented the takeoff attempt. However, in this context it ought to be noted that the other off-duty captain was also aware of the condition of the wing, but felt that professional courtesy and respect required that he remain silent. The two passenger-pilots had something like 18,000 hours experience between them while the two at the pointy end had something like 130 hours of combined experience (on type).
I recognize that this report is now twenty years old and we now have a greater appreciation of human dynamics (if only because of subsequent incidents and accidents). Taken as a whole the report was (and remains) a damning indictment of the airline`s owners and managers (largely one and the same) and Air Canada (Air Ontario`s code-share partner and part-owner at the time). Ultimately, of course, the report infers that industry deregulation in the absence of adequate regulatory authority created an environment which contributed to the accident. Mashansky made 191 recommendations, and while I believe that some were acted upon I’ve a hunch that most were not. Indeed, something like 18 months after the release of the report another F28 (USAir 405) crashed at LaGuardia under similar circumstances.
I presume, of course, that I am preaching to the choir here. In fact, I hope that I am.
And I apologize to those who I've offended, given that... well, my username says much. Indeed, I was going to keep my thoughts to myself until I realized that I am one of those people who would keep my thoughts to myself even if there was a foot of snow on a wing.
Apologies for being so long-winded, and mods feel free to edit.
The full text of the report can be found here:
Commissions of Inquiry
Also, there is an episode of “Air Crash Investigation” devoted to the accident and Mashanky’s report here:
DOVE
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I wrote:
Let me add that after that accident some woolen threads were installed at the roots of the wings of the MD80, free to shake into the wind, in order to facilitate the identification of subtle icing Vetrone by the crew, often unnoticed.
I am grateful for correcting me.
As a matter of fact I remember that we were expected to perform a visual inspection of the tuft on the upper surface of the wings from the cabin, in case of doubt we had to open the wing emergency exit, go out and touch the surface to ensure that there was no ice.
As we all know there’s a phenomenon called cold-soaked fuel, which happens if the aircraft is parked with wing tanks not completely filled with fuel, which then evaporates. This gas expansion reduces the temperature, and so even if the outside air temperature does not fall below zero, the moisture in the air condenses and then freezes in contact with the sheet of the wing. During the walk around a 3 mm layer of frost was acceptable below the wing corresponding with the tanks.
It seems that those ice formations, resulting from the cold soaked fuel, broke during take off, causing both engine flame out which determined the crash of the MD-81 SAS in Gottrora on December 27, 1991.
So why, before their production was discontinued, a plan has been made to install de-icing panels at the root of the wings of MD 90/Boeing MD 717?
AirRabbit:
It's really moving the ardor with which you defend the actions of the crew of Air Florida Flight 90 which crashed into the Potomac January 13, 1982.
Many wise philosophers in ancient Greece argued that we should defend a friend by all means also we know he's guilty.
Nevertheless you will agree with me that the following illegalities were committed:
- They did not insert Engine Anti-ice after start, and did perform the periodic engine run up.
- They tried invain to push back (the tug connected) through the use of reverse (thus raising clouds of snow and slush).
- They knew they had snow on the wings, so that they approached the preceding DC9, in the vain hope that their jet engines would swept it away.
- They started the take off run 50 minutes after the de-icing.
- They accepted a very little separation with the landing traffic despite the poor visibility and the snow storm. (If they had to abort the takeoff? If the others were to go around?)
- They underestimated the irregularity of the engines parameters for takeoff
- They had found that the acceleration was so poor that they had reached 120 knots after 45 seconds.
- They began to rotate as per “the soft field” (I began to hear such an expression only since I'm instructing in general aviation) and then starting the rotation well before Vr.
I'm sorry but I have to tell you that History has been written.
So much time and money has been spent to establish the causes of the disaster, so justice was done and the incident would had never happened again (sic!).
So unless you have any new evidence to reopen the trial, agree with NTSB.
Let’s shout together:
“How can you know if any kind of snow is ‘ADHERING’ to the surfaces of your airplane, and no ice is beneath it, if you don’t remove it?”
“No clean aircraft? No Fly!”
Here you are Lomapaseo.
Is this the way you like it?
Let me add that after that accident some woolen threads were installed at the roots of the wings of the MD80, free to shake into the wind, in order to facilitate the identification of subtle icing Vetrone by the crew, often unnoticed.
Mostly correct but they were not put there to depend on the wind for visualization. They required movement by a pole device held by a man on a ladder. If you couldn't move them they were probably covered by a film of ice.
As a matter of fact I remember that we were expected to perform a visual inspection of the tuft on the upper surface of the wings from the cabin, in case of doubt we had to open the wing emergency exit, go out and touch the surface to ensure that there was no ice.
The biggest problem with the dispatch with wing ice was the first flight of the day after an overnight in drizzle/snow. The snow would be blown off on the ground but they missed the check underneath for ice
It seems that those ice formations, resulting from the cold soaked fuel, broke during take off, causing both engine flame out which determined the crash of the MD-81 SAS in Gottrora on December 27, 1991.
Contrary to popular belief there were only a few incidents of ice due to cold soaked fuel in above freezing conditions.
AirRabbit:
It's really moving the ardor with which you defend the actions of the crew of Air Florida Flight 90 which crashed into the Potomac January 13, 1982.
Many wise philosophers in ancient Greece argued that we should defend a friend by all means also we know he's guilty.
Nevertheless you will agree with me that the following illegalities were committed:
- They did not insert Engine Anti-ice after start, and did perform the periodic engine run up.
- They tried invain to push back (the tug connected) through the use of reverse (thus raising clouds of snow and slush).
- They knew they had snow on the wings, so that they approached the preceding DC9, in the vain hope that their jet engines would swept it away.
- They started the take off run 50 minutes after the de-icing.
- They accepted a very little separation with the landing traffic despite the poor visibility and the snow storm. (If they had to abort the takeoff? If the others were to go around?)
- They underestimated the irregularity of the engines parameters for takeoff
- They had found that the acceleration was so poor that they had reached 120 knots after 45 seconds.
- They began to rotate as per “the soft field” (I began to hear such an expression only since I'm instructing in general aviation) and then starting the rotation well before Vr.
I'm sorry but I have to tell you that History has been written.
So much time and money has been spent to establish the causes of the disaster, so justice was done and the incident would had never happened again (sic!).
So unless you have any new evidence to reopen the trial, agree with NTSB.
Let’s shout together:
“How can you know if any kind of snow is ‘ADHERING’ to the surfaces of your airplane, and no ice is beneath it, if you don’t remove it?”
“No clean aircraft? No Fly!”
Here you are Lomapaseo.
Is this the way you like it?
Last edited by DOVES; 22nd Apr 2012 at 19:51.