737 Max flap cycling after deicing
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,423
Likes: 0
Received 0 Likes
on
0 Posts
In my opinion if Your company approved and published a certain procedure, most likely with a no objection from Boeing or actually following directly a Boeing procedure, than it must be followed unless a deviation is required in the interest of safety, but again in my opinion this should be limited to an unlikely and unique scenario and not become a parallel SOP. We all know the threats associated to "don't worry we'll do it this way, we'll be ok" type of procedures. Anyway I am not pointing any finger and I am pretty sure You had loads of good reason to deviate from Your SOPs, but as pilots we should push for changes all together if something does not look right rather than finding alternative paths.
Just my 2 cents.
Just my 2 cents.
Join Date: Aug 2000
Posts: 1,501
Likes: 0
Received 0 Likes
on
0 Posts
I have flown the NG since it came, and I have deiced more times than I care to remember.
Show me where Boeing says this is a procedure after deice. I have never seen this written anywhere and it has never been in our SOP. And I say Boeing procedure, not a procedure that is put in the FCOM at the operators request.
It goes a long way to explain why some operators use forever to get out of the deice area while there is a long line of aircraft waiting to get deiced.
The SP for cold weather operations USED to include this procedure (not associated with deice) along with turning the nosewheels full right/left.
It’s not there anymore.
Never had a flap/slat problem on the NG either.
Show me where Boeing says this is a procedure after deice. I have never seen this written anywhere and it has never been in our SOP. And I say Boeing procedure, not a procedure that is put in the FCOM at the operators request.
It goes a long way to explain why some operators use forever to get out of the deice area while there is a long line of aircraft waiting to get deiced.
The SP for cold weather operations USED to include this procedure (not associated with deice) along with turning the nosewheels full right/left.
It’s not there anymore.
Never had a flap/slat problem on the NG either.
Join Date: Apr 2010
Location: IRS NAV ONLY
Posts: 1,230
Likes: 0
Received 0 Likes
on
0 Posts
Show me where Boeing says this is a procedure after deice. I have never seen this written anywhere and it has never been in our SOP. And I say Boeing procedure, not a procedure that is put in the FCOM at the operators request.
It goes a long way to explain why some operators use forever to get out of the deice area while there is a long line of aircraft waiting to get deiced.
Don't see the issue with taking time to do all the checks before starting taxi, better safe than sorry. Other than a minute or two delay, what's the harm for the aircraft behind? They have to be de-iced anyway, so it's not like it's eating into their holdover time.
Join Date: Aug 2000
Posts: 1,501
Likes: 0
Received 0 Likes
on
0 Posts
The only thing that matters is what is written in the operator's FCOM/OM, as that one is approved by the authority. The Boeing procedures alone aren't.
Don't see the issue with taking time to do all the checks before starting taxi, better safe than sorry. Other than a minute or two delay, what's the harm for the aircraft behind? They have to be de-iced anyway, so it's not like it's eating into their holdover time.
Don't see the issue with taking time to do all the checks before starting taxi, better safe than sorry. Other than a minute or two delay, what's the harm for the aircraft behind? They have to be de-iced anyway, so it's not like it's eating into their holdover time.
Better safe than sorry? 20 years of deicing without this procedure and no problems should mean something.
This procedure (in connection with deiceing) has never been in our FCOM.
Deice in snowy weather, then select FL40 and expose all untreated areas to the snow? Retract. Doesn’t sound like a good idea to me.
You are not Ryanair, by any chance? Their aircraft are like obstacles in the deice flow.
Join Date: Aug 2000
Posts: 1,501
Likes: 0
Received 0 Likes
on
0 Posts
Boeing or company?
With or without deice?
The flap procedure was in our FCOM and was related to cold weather. If I’m not mistaken, we are talking temperatures below -30 C.
I have only done that once. Now my FCOM only calls for take off flaps.
With or without deice?
The flap procedure was in our FCOM and was related to cold weather. If I’m not mistaken, we are talking temperatures below -30 C.
I have only done that once. Now my FCOM only calls for take off flaps.
Gender Faculty Specialist
Boeing. Not related to de-icing just cold weather ops. Take your pick on the temperature...
It's the before taxi procedure so if you've taxied to a remote de-icing area you have already done the flap check. No need to repeat it.
It's the before taxi procedure so if you've taxied to a remote de-icing area you have already done the flap check. No need to repeat it.
Join Date: Aug 2000
Posts: 1,501
Likes: 0
Received 0 Likes
on
0 Posts
Strange. I believe you can opt for various Boeing SOP’s, (feel free to correct me if I’m wrong) but I think this should be standardized.
Join Date: Apr 2010
Location: IRS NAV ONLY
Posts: 1,230
Likes: 0
Received 0 Likes
on
0 Posts
Personally, I don't agree with all the flaps cycling and all. But it's the only approved procedure by my employer, is not unsafe (although time consuming), is what is expected from us and they pay my paycheck at the end of the month, so...
Operator can choose their own SOPs, if they manage to get it approved by their authority. And if they are using a Boeing-tailored FCOM, there will be a statement there that Boeing takes no responsibility for the modifications.
Join Date: Aug 2000
Posts: 1,501
Likes: 0
Received 0 Likes
on
0 Posts
Equally, other operators might have no problems for the past 20 years with procedures different to yours. Why change it if it works?
Personally, I don't agree with all the flaps cycling and all. But it's the only approved procedure by my employer, is not unsafe (although time consuming), is what is expected from us and they pay my paycheck at the end of the month, so...
Operator can choose their own SOPs, if they manage to get it approved by their authority. And if they are using a Boeing-tailored FCOM, there will be a statement there that Boeing takes no responsibility for the modifications.
Personally, I don't agree with all the flaps cycling and all. But it's the only approved procedure by my employer, is not unsafe (although time consuming), is what is expected from us and they pay my paycheck at the end of the month, so...
Operator can choose their own SOPs, if they manage to get it approved by their authority. And if they are using a Boeing-tailored FCOM, there will be a statement there that Boeing takes no responsibility for the modifications.
Can you ask your fleet captain where this procedure comes from?
If Boeing says you have to do this, I wonder why it’s not in our FCOM.
Join Date: Feb 2006
Location: Texas
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
At my US operator we do not cycle the flaps after deice, nor do we wait to select flaps until just before takeoff. Our procedure is to deice with flaps/slats set for takeoff, unless the aircraft arrived with contamination in which case the flaps would only be brought up to 15 after landing to reduce the risk of damage on retraction. We do cycle the elevators 3 times to ensure no fluid is trapped from the spraying, but I haven't seen anything in any of our manuals about cycling the flaps. This is for the 700/800/Max8.
Join Date: Jan 2000
Location: FL410
Posts: 860
Likes: 0
Received 0 Likes
on
0 Posts
I believe these procedure were developed by company, not Boeing, with NTO (No Technical Objection) from Boeing.
Several companies do it, several others do not, so it's unlikely to be a Boeing requirement.
Having operated in companies on both sides of the fence:
- yes, it is time consuming, in fact in certain conditions so much so that holdover time can get compromised if copying with procedure;
- no, it should not be omitted if possible as there is a method to the madness;
Either way, good airmanship should be used when deciding to follow procedure:
- yes, it would make sense to depart and not return to gate to get deiced again as holdover time is now compromised having meticulously followed procedure (ps does your company allow you to continue checklist or do you have to wait for cycling of flaps, as this can significantly increase the time required to complete the checklist in its entirety);
- no, it would not make sense to forego on this procedure if eg freezing rain has fallen on a sub-zero airframe;
- no, it would not make sense to complete this procedure if only light frost was observed prior to flight, no (visible) moisture was present during time on ground nor precipitation, and temperatures are increasing above freezing...
A better ruleset would be very welcome, as the current procedures established by some airlines are way too restrictive, though from safety types on here very likely applauded for thoroughness of company.
Several companies do it, several others do not, so it's unlikely to be a Boeing requirement.
Having operated in companies on both sides of the fence:
- yes, it is time consuming, in fact in certain conditions so much so that holdover time can get compromised if copying with procedure;
- no, it should not be omitted if possible as there is a method to the madness;
Either way, good airmanship should be used when deciding to follow procedure:
- yes, it would make sense to depart and not return to gate to get deiced again as holdover time is now compromised having meticulously followed procedure (ps does your company allow you to continue checklist or do you have to wait for cycling of flaps, as this can significantly increase the time required to complete the checklist in its entirety);
- no, it would not make sense to forego on this procedure if eg freezing rain has fallen on a sub-zero airframe;
- no, it would not make sense to complete this procedure if only light frost was observed prior to flight, no (visible) moisture was present during time on ground nor precipitation, and temperatures are increasing above freezing...
A better ruleset would be very welcome, as the current procedures established by some airlines are way too restrictive, though from safety types on here very likely applauded for thoroughness of company.
Join Date: Mar 2019
Location: Finland
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
LN-DYM in Kittilä 737 almost stalled when suddenly trimmed up for 12 sec.
Similarities to Flydubai in Rostov ?
In Kittilä the cause is reported the de-icing fluid ingress, but does it explain the trimming ? I have no background on flying ( only as passenger) but it seems strange that pilots did fly back home after such incident and reported only afterwards ? How was the ice then found to be the cause, days later ?
I can not post the link to aibn but google it with :
"Report on the serious aircraft incident during approach to Kittilä airport in Finland (EFKT) on 26. December 2012 with a Boeing 737-800, LN-DYM, operated by Norwegian Air Shuttle ASA"
AIBN's investigation has uncovered that de-icing fluid had ingressed the tail section and frozen on three or four of the input cranks for the aircraft's two elevator Power Control Units (PCUs) and thus prevented them from functioning as intended."
Similarities to Flydubai in Rostov ?
In Kittilä the cause is reported the de-icing fluid ingress, but does it explain the trimming ? I have no background on flying ( only as passenger) but it seems strange that pilots did fly back home after such incident and reported only afterwards ? How was the ice then found to be the cause, days later ?
I can not post the link to aibn but google it with :
"Report on the serious aircraft incident during approach to Kittilä airport in Finland (EFKT) on 26. December 2012 with a Boeing 737-800, LN-DYM, operated by Norwegian Air Shuttle ASA"
Description
During approach to Kittilä (EFKT) in Finland on 26 December 2012, LN-DYM, a Boeing 737-800 NG on Norwegian Air Shuttle's (NAS') air service NAX5630 from Helsinki airport (EFHK), came close to stalling. The outcome of a stall would most likely have been catastrophic, primarily because the elevator system at that time did not function normally. The elevator system worked only at a ratio of 1:250.AIBN's investigation has uncovered that de-icing fluid had ingressed the tail section and frozen on three or four of the input cranks for the aircraft's two elevator Power Control Units (PCUs) and thus prevented them from functioning as intended."
Join Date: Jan 2000
Location: FL410
Posts: 860
Likes: 0
Received 0 Likes
on
0 Posts
LN-DYM in Kittilä 737 almost stalled when suddenly trimmed up for 12 sec.
Similarities to Flydubai in Rostov ?
In Kittilä the cause is reported the de-icing fluid ingress, but does it explain the trimming ? I have no background on flying ( only as passenger) but it seems strange that pilots did fly back home after such incident and reported only afterwards ? How was the ice then found to be the cause, days later ?
I can not post the link to aibn but google it with :
"Report on the serious aircraft incident during approach to Kittilä airport in Finland (EFKT) on 26. December 2012 with a Boeing 737-800, LN-DYM, operated by Norwegian Air Shuttle ASA"Description
During approach to Kittilä (EFKT) in Finland on 26 December 2012, LN-DYM, a Boeing 737-800 NG on Norwegian Air Shuttle's (NAS') air service NAX5630 from Helsinki airport (EFHK), came close to stalling. The outcome of a stall would most likely have been catastrophic, primarily because the elevator system at that time did not function normally. The elevator system worked only at a ratio of 1:250.
AIBN's investigation has uncovered that de-icing fluid had ingressed the tail section and frozen on three or four of the input cranks for the aircraft's two elevator Power Control Units (PCUs) and thus prevented them from functioning as intended."
Similarities to Flydubai in Rostov ?
In Kittilä the cause is reported the de-icing fluid ingress, but does it explain the trimming ? I have no background on flying ( only as passenger) but it seems strange that pilots did fly back home after such incident and reported only afterwards ? How was the ice then found to be the cause, days later ?
I can not post the link to aibn but google it with :
"Report on the serious aircraft incident during approach to Kittilä airport in Finland (EFKT) on 26. December 2012 with a Boeing 737-800, LN-DYM, operated by Norwegian Air Shuttle ASA"Description
During approach to Kittilä (EFKT) in Finland on 26 December 2012, LN-DYM, a Boeing 737-800 NG on Norwegian Air Shuttle's (NAS') air service NAX5630 from Helsinki airport (EFHK), came close to stalling. The outcome of a stall would most likely have been catastrophic, primarily because the elevator system at that time did not function normally. The elevator system worked only at a ratio of 1:250.
AIBN's investigation has uncovered that de-icing fluid had ingressed the tail section and frozen on three or four of the input cranks for the aircraft's two elevator Power Control Units (PCUs) and thus prevented them from functioning as intended."
It is not related at all to the Rostov incident, which happened because of pilot spacial orientation.
Report AIBN here
Report IAC (preliminary) here
Last edited by Skyjob; 14th Mar 2019 at 21:19.
Join Date: Feb 2011
Location: Over the Rainbow
Posts: 55
Likes: 0
Received 0 Likes
on
0 Posts
I've flown in snow, sleet, freezing fog and any other type of contamination in the frozen north daily, but we have never used this flap cycling procedure.
Looking at our companies fcom, I can't find any section in sp requiring a cycle to 40.
Looking at our companies fcom, I can't find any section in sp requiring a cycle to 40.
Join Date: Mar 2009
Location: Kyiv
Age: 55
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
“Move the flaps from Flaps up to Flaps 40 back to Flaps up (i.e., full travel) to ensure freedom of movement” SP.16.6
So. They want we do full travel to Flaps 40 when :
“Icing conditions exist when OAT (on the ground) or TAT (in flight) is 10°C or below and any of the following exist:
• visible moisture (clouds, fog with visibility of one statute mile (1600m) or less, rain, snow, sleet, ice crystals, and so on) is present, or
• ice, snow, slush or standing water is present on the ramps, taxiways, or runways.” SP.16.2
IMHO. It is hard to understand why we have to cycle to 40 if OAT is 9°C, visibility of one statute mile (1600m) or less, especially if no rain, snow, sleet, ice crystals is present.
So. They want we do full travel to Flaps 40 when :
“Icing conditions exist when OAT (on the ground) or TAT (in flight) is 10°C or below and any of the following exist:
• visible moisture (clouds, fog with visibility of one statute mile (1600m) or less, rain, snow, sleet, ice crystals, and so on) is present, or
• ice, snow, slush or standing water is present on the ramps, taxiways, or runways.” SP.16.2
IMHO. It is hard to understand why we have to cycle to 40 if OAT is 9°C, visibility of one statute mile (1600m) or less, especially if no rain, snow, sleet, ice crystals is present.
Join Date: Jul 2008
Location: Moscow
Age: 50
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Boeing response: In cold temperature conditions, trapped water may freeze and/or lubricants may thicken. The requirements to cycle the flaps is intended to detect any blockage or contamination of the flap system which might be the result of internal frozen contamination. This check should be accomplished whenever the airplane has been exposed to snow, freezing rain or other conditions which could restrict flight control movement, and when the temperature is cold enough that the fluid cannot melt completely/
Join Date: Jul 1999
Location: UK
Posts: 166
Likes: 0
Received 0 Likes
on
0 Posts
“Move the flaps from Flaps up to Flaps 40 back to Flaps up (i.e., full travel) to ensure freedom of movement” SP.16.6
So. They want we do full travel to Flaps 40 when :
“Icing conditions exist when OAT (on the ground) or TAT (in flight) is 10°C or below and any of the following exist:
• visible moisture (clouds, fog with visibility of one statute mile (1600m) or less, rain, snow, sleet, ice crystals, and so on) is present, OR
• ice, snow, slush or standing water is present on the ramps, taxiways, or runways.” SP.16.2
IMHO. It is hard to understand why we have to cycle to 40 if OAT is 9°C, visibility of one statute mile (1600m) or less, especially if no rain, snow, sleet, ice crystals is present.
So. They want we do full travel to Flaps 40 when :
“Icing conditions exist when OAT (on the ground) or TAT (in flight) is 10°C or below and any of the following exist:
• visible moisture (clouds, fog with visibility of one statute mile (1600m) or less, rain, snow, sleet, ice crystals, and so on) is present, OR
• ice, snow, slush or standing water is present on the ramps, taxiways, or runways.” SP.16.2
IMHO. It is hard to understand why we have to cycle to 40 if OAT is 9°C, visibility of one statute mile (1600m) or less, especially if no rain, snow, sleet, ice crystals is present.
