more on taking off in freezing events
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more on taking off in freezing events
folks, awhile ago I started a thread regarding taking off in certain freezing events. here is the latest that I think should be of interest to all pilots of all aircraft.
jon
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ALPA Alerts Pilots About Operating in Light Ice or Snow Pellets
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On February 21, the Association issued ALPA Safety Alert 2006-02 to warn pilots that some U.S. airlines have wrongly interpreted a recent FAA notice to permit takeoffs in light ice pellets or light snow pellets, though no data support doing so.
ALPA issued several recommendations with the safety alert:
a.. Until the airline industry develops holdover times for deicing/anti-icing fluid during conditions of ice pellets and snow pellets, flight crews should exercise extreme caution while operating in these conditions.
b.. ALPA does not endorse operations in ice pellets or snow pellets, regardless of whether ground crews have applied anti-icing fluid to the airplane.
c.. Flight crews must exercise extreme caution when operating in freezing precipitation without anti-icing fluid on the airplane.
d.. Flight crews must always comply with their airline's guidance.
e.. Flight crews, in conjunction with their airline, must use their best judgment in determining whether to take off.
f.. A pilot in command who believes that the safety of flight may be compromised must always exercise command authority.
In October 2005, the FAA Flight Standards Service issued FAA Notice N 8000.309, "Dispatching During Precipitation Conditions of Ice Pellets, Snow Pellets, or Other Icing Events for which No Holdover Times Exist." The notice recommended that airlines not authorize their flight crews to take off in ice pellets and other extreme weather conditions because of lack of data available to flight crews to support such operations. Such data would include deicing/anti-icing holdover times, failure criteria for deicing/anti-icing fluids, aircraft performance, and other mitigating factors that would reduce the risks of operating in these conditions.
Some airlines have interpreted the FAA notice to permit operations in ice pellets or snow pellets if (1) no deicing or anti-icing fluid is applied to the airplane and (2) the operator can determine that no contamination is adhering to flight surfaces.
This interpretation of the FAA notice does not account for the possibility of residual ice remaining on an untreated wing after exposure to ice pellets. Even momentary exposure to ice pellets may create a layer of clear ice adhering to the upper surface of the wing, thus degrading aerodynamic performance by an undetermined amount. This contamination may be extremely difficult to detect visually. Also, meteorological conditions may worsen between the time of a visual contamination check of the airplane's unprotected surfaces and the beginning of the takeoff roll.
ALPA's Ground Deicing Project Team has been actively involved with the U.S. and Canadian governments and the airline industry in developing adequate deicing/anti-icing holdover times for ice pellets and snow pellets. Testing is scheduled to continue through 2006 to reach consensus on effective holdover times for these conditions.
ALPA will encourage the FAA and Transport Canada to conduct flight and wind tunnel tests that support holdover times that more accurately reflect real-world conditions. At present, Transport Canada has chosen to continue with the guidance offered by current deicing/anti-icing holdover time tables--i.e., that no holdover times exist for ice pellets, snow pellets, or other icing events.
jon
===
ALPA Alerts Pilots About Operating in Light Ice or Snow Pellets
Back to top
On February 21, the Association issued ALPA Safety Alert 2006-02 to warn pilots that some U.S. airlines have wrongly interpreted a recent FAA notice to permit takeoffs in light ice pellets or light snow pellets, though no data support doing so.
ALPA issued several recommendations with the safety alert:
a.. Until the airline industry develops holdover times for deicing/anti-icing fluid during conditions of ice pellets and snow pellets, flight crews should exercise extreme caution while operating in these conditions.
b.. ALPA does not endorse operations in ice pellets or snow pellets, regardless of whether ground crews have applied anti-icing fluid to the airplane.
c.. Flight crews must exercise extreme caution when operating in freezing precipitation without anti-icing fluid on the airplane.
d.. Flight crews must always comply with their airline's guidance.
e.. Flight crews, in conjunction with their airline, must use their best judgment in determining whether to take off.
f.. A pilot in command who believes that the safety of flight may be compromised must always exercise command authority.
In October 2005, the FAA Flight Standards Service issued FAA Notice N 8000.309, "Dispatching During Precipitation Conditions of Ice Pellets, Snow Pellets, or Other Icing Events for which No Holdover Times Exist." The notice recommended that airlines not authorize their flight crews to take off in ice pellets and other extreme weather conditions because of lack of data available to flight crews to support such operations. Such data would include deicing/anti-icing holdover times, failure criteria for deicing/anti-icing fluids, aircraft performance, and other mitigating factors that would reduce the risks of operating in these conditions.
Some airlines have interpreted the FAA notice to permit operations in ice pellets or snow pellets if (1) no deicing or anti-icing fluid is applied to the airplane and (2) the operator can determine that no contamination is adhering to flight surfaces.
This interpretation of the FAA notice does not account for the possibility of residual ice remaining on an untreated wing after exposure to ice pellets. Even momentary exposure to ice pellets may create a layer of clear ice adhering to the upper surface of the wing, thus degrading aerodynamic performance by an undetermined amount. This contamination may be extremely difficult to detect visually. Also, meteorological conditions may worsen between the time of a visual contamination check of the airplane's unprotected surfaces and the beginning of the takeoff roll.
ALPA's Ground Deicing Project Team has been actively involved with the U.S. and Canadian governments and the airline industry in developing adequate deicing/anti-icing holdover times for ice pellets and snow pellets. Testing is scheduled to continue through 2006 to reach consensus on effective holdover times for these conditions.
ALPA will encourage the FAA and Transport Canada to conduct flight and wind tunnel tests that support holdover times that more accurately reflect real-world conditions. At present, Transport Canada has chosen to continue with the guidance offered by current deicing/anti-icing holdover time tables--i.e., that no holdover times exist for ice pellets, snow pellets, or other icing events.
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Here is the actual notice from the Federal Aviation Administration
N 8000.309NOTICE
U.S. DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
N 8000.309
00.xx
10/5/05
Cancellation
Date: 10/5/06
SUBJ:
DISPATCHING DURING PRECiPiTATION CONDITIONS OF ICE PELLETS, SNOW PELLETS, OR OTHER ICING events FOR WHICH NO HOLD OVER TIMES EXIST
1. PURPOSE. This notice provides guidance to aviation safety inspectors and to all air carrier operators engaged in air transportation on the potential hazards of conducting ground operations and departures during precipitation of ice pellets, snow pellets, or other icing conditions for which hold over times (HOT) do not exist.
2. DISTRIBUTION. This notice is distributed to the division level in the Flight Standards Service in Washington headquarters; to the branch level in the regional Flight Standards divisions; to the Flight Standards District Offices, and to the Regulatory Standards Division at the Mike Monroney Aeronautical Center. This notice is also distributed electronically to the division level in the Flight Standards Service in Washington headquarters and to all regional Flight Standards divisions and district offices. This information is also available on the Federal Aviation Administration’s (FAA) Web site at:
http://www.faa.gov/library/manuals/examiners_inspectors/8000/media/N8000-309.doc.
3. DISCUSSION. Ground operations in ice pellets and other icing conditions where HOTs do not exist are a very serious concern to the Flight Standards Service (AFS). The Service has learned that a number of certificate holders continue to operate (dispatch) in these conditions.
a. Such operations must be considered a direct threat to the safety of flight for the following reasons:
(1) No tests have been conducted for ground icing conditions in ice pellets or other conditions such as heavy snow, snow pellets, moderate and heavy freezing rain, and hail.
(2) There is no reliable data regarding the changes or characteristics of Type IV fluid when exposed to ice pellet conditions.
(3) Fluid failure in ice pellet conditions is nearly impossible to determine from inside the cabin of an aircraft during a pretakeoff check.
(4) No data exists regarding the adherence affinity of ice pellets in Type IV fluid.
(5) No HOTs exist for ice pellets.
b. Dispatching during these conditions is equivalent to operating in unknown performance areas. Pilots have no numerical references, and there is no available supporting data to determine the condition of the deice/anti-ice fluid before takeoff. It has been suggested that a pretakeoff contamination check (PCC) can be done within 5 minutes before departure. This practice would be unreliable at best since no data is available that shows the process of fluid failure subjected to any concentration or intensity of ice pellets/snow pellets.
c. Furthermore, a PCC is conducted only at the expiration of the HOT for operators that have a deicing/anti-icing program approved under Title 14 of the Code of Federal Regulations (14 CFR) part 121, section 121.629(c). There are no HOTs during ice pellets/snow pellets precipitation conditions. Section 121.629(d), which allows only for an outside check of the wings, etc.,
5 minutes before departure, was not intended for use by large air carriers with national and international operations.
d. Departures in ice pellets/snow pellets, even for small air carrier operations, present a hazard to the safety of flight and subjects the flying public to a level of safety below that intended by the regulations.
4. ACTION. Principal inspectors should examine the deicing/anti-icing program or plan for all certificate holders for whom they have oversight responsibility to determine whether that certificate holder has authority to dispatch or operate in conditions of ice pellets, snow pellets, and other icing conditions for which no HOTs exist. Any authorization or approval to operate in these conditions should be removed for that certificate holder’s program or plan until sufficient scientific data is obtained to show that such operations can be conducted safely.
5. TRACKING. Document the conveyance of the information contained in this notice for each air carrier or fractional ownership program affected.
a. Use Program Tracking and Reporting Subsystem (PTRS) code 1030, Convey Non-Reg. Info.
b. Enter “N8000309” in the “National Use” field (without the quotes).
c. Once the above information has been provided to the operator’s representative, as appropriate, close out the PTRS.
6. DISPOSITION. This notice will not be incorporated into Order 8400.10, Air Transportation Operations Inspector’s Handbook. Any questions concerning this notice should be directed to the Air Carrier Operations Branch, AFS-220, at (202) 267-3749.
/s/ Carol E. Giles (for)
James J. Ballough
Director, Flight Standards Service
N 8000.309NOTICE
U.S. DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
N 8000.309
00.xx
10/5/05
Cancellation
Date: 10/5/06
SUBJ:
DISPATCHING DURING PRECiPiTATION CONDITIONS OF ICE PELLETS, SNOW PELLETS, OR OTHER ICING events FOR WHICH NO HOLD OVER TIMES EXIST
1. PURPOSE. This notice provides guidance to aviation safety inspectors and to all air carrier operators engaged in air transportation on the potential hazards of conducting ground operations and departures during precipitation of ice pellets, snow pellets, or other icing conditions for which hold over times (HOT) do not exist.
2. DISTRIBUTION. This notice is distributed to the division level in the Flight Standards Service in Washington headquarters; to the branch level in the regional Flight Standards divisions; to the Flight Standards District Offices, and to the Regulatory Standards Division at the Mike Monroney Aeronautical Center. This notice is also distributed electronically to the division level in the Flight Standards Service in Washington headquarters and to all regional Flight Standards divisions and district offices. This information is also available on the Federal Aviation Administration’s (FAA) Web site at:
http://www.faa.gov/library/manuals/examiners_inspectors/8000/media/N8000-309.doc.
3. DISCUSSION. Ground operations in ice pellets and other icing conditions where HOTs do not exist are a very serious concern to the Flight Standards Service (AFS). The Service has learned that a number of certificate holders continue to operate (dispatch) in these conditions.
a. Such operations must be considered a direct threat to the safety of flight for the following reasons:
(1) No tests have been conducted for ground icing conditions in ice pellets or other conditions such as heavy snow, snow pellets, moderate and heavy freezing rain, and hail.
(2) There is no reliable data regarding the changes or characteristics of Type IV fluid when exposed to ice pellet conditions.
(3) Fluid failure in ice pellet conditions is nearly impossible to determine from inside the cabin of an aircraft during a pretakeoff check.
(4) No data exists regarding the adherence affinity of ice pellets in Type IV fluid.
(5) No HOTs exist for ice pellets.
b. Dispatching during these conditions is equivalent to operating in unknown performance areas. Pilots have no numerical references, and there is no available supporting data to determine the condition of the deice/anti-ice fluid before takeoff. It has been suggested that a pretakeoff contamination check (PCC) can be done within 5 minutes before departure. This practice would be unreliable at best since no data is available that shows the process of fluid failure subjected to any concentration or intensity of ice pellets/snow pellets.
c. Furthermore, a PCC is conducted only at the expiration of the HOT for operators that have a deicing/anti-icing program approved under Title 14 of the Code of Federal Regulations (14 CFR) part 121, section 121.629(c). There are no HOTs during ice pellets/snow pellets precipitation conditions. Section 121.629(d), which allows only for an outside check of the wings, etc.,
5 minutes before departure, was not intended for use by large air carriers with national and international operations.
d. Departures in ice pellets/snow pellets, even for small air carrier operations, present a hazard to the safety of flight and subjects the flying public to a level of safety below that intended by the regulations.
4. ACTION. Principal inspectors should examine the deicing/anti-icing program or plan for all certificate holders for whom they have oversight responsibility to determine whether that certificate holder has authority to dispatch or operate in conditions of ice pellets, snow pellets, and other icing conditions for which no HOTs exist. Any authorization or approval to operate in these conditions should be removed for that certificate holder’s program or plan until sufficient scientific data is obtained to show that such operations can be conducted safely.
5. TRACKING. Document the conveyance of the information contained in this notice for each air carrier or fractional ownership program affected.
a. Use Program Tracking and Reporting Subsystem (PTRS) code 1030, Convey Non-Reg. Info.
b. Enter “N8000309” in the “National Use” field (without the quotes).
c. Once the above information has been provided to the operator’s representative, as appropriate, close out the PTRS.
6. DISPOSITION. This notice will not be incorporated into Order 8400.10, Air Transportation Operations Inspector’s Handbook. Any questions concerning this notice should be directed to the Air Carrier Operations Branch, AFS-220, at (202) 267-3749.
/s/ Carol E. Giles (for)
James J. Ballough
Director, Flight Standards Service
Snow and ice pellets raise a number of concerns
Ambient temperature comes into play when considering flying surfaces. If it's well below freezing, the stuff should bounce off untreated surfaces.
But if there's liquid content, the stuff is nasty.
And of course, pellets at one stage have considerable liquid content before entering below freezing temps -- I wouldn't want to be flying in that zone
- Runway Contamination
- Engine Ingestion and Induction Air Blockage
- Flying Surface Contamination
- Possibility of encountering freezing precipitation when higher
Ambient temperature comes into play when considering flying surfaces. If it's well below freezing, the stuff should bounce off untreated surfaces.
But if there's liquid content, the stuff is nasty.
And of course, pellets at one stage have considerable liquid content before entering below freezing temps -- I wouldn't want to be flying in that zone
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Bottom line... don't go if your carrier does not have HOT charts to support data when operating in conditions outline in the FAA's Notice. What is the position of the CAA or JAA for that matter regarding, lets say, operating when snow/ice pellets are present?
Paxing All Over The World
Non-pilot asking:
From the initial post:
So, if the FAA says "Don't Go" and the airline says, "Go" - what do you do? Or have I missed something?
From the initial post:
d.. Flight crews must always comply with their airline's guidance.
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Originally Posted by PAXboy
Non-pilot asking:
From the initial post:
So, if the FAA says "Don't Go" and the airline says, "Go" - what do you do? Or have I missed something?
From the initial post:
So, if the FAA says "Don't Go" and the airline says, "Go" - what do you do? Or have I missed something?
