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Topic: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Gonzalo
Posted 2013-04-15 03:37:56 and read 17539 times.

"FAA issued an AD to prevent premature failure of the attach pins which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the airplane"

http://news.yahoo.com/faa-orders-ins...ail-planes-071555623--finance.html


Will this inspection have some impact on the operations ? Or is just a quick visual check ?

[Edited 2013-04-15 03:38:39]

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Gonzalo
Posted 2013-04-15 03:45:30 and read 17485 times.

FAA Link :

http://rgl.faa.gov/Regulatory_and_Gu...895D686257B4300490FF8?OpenDocument

Rgds.
G.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: MD11Engineer
Posted 2013-04-15 04:04:25 and read 17336 times.

Please read the AD. They are not talkiing about the stabilizer to fuselage attechment, but about the elevator trim tab linkage mechanism. The repeat inspection of the existing mechanism takes about one hour. The modification takes about 7 hours (afterwards you won´t have to do the repeat inspection anymore).
Normally you don´t need the elevator tabs, but if hydraulic power fails they act as servo tabs to reduce the steering forces for the pilots now flying in manual reversion.

Jan

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: skinnerde
Posted 2013-04-15 04:44:42 and read 16969 times.

thx for the clarification MD11Engineer

i don´t want to imagine what the media will make out of this :/

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Gonzalo
Posted 2013-04-15 04:57:54 and read 16840 times.

Quoting skinnerde (Reply 3):
i don´t want to imagine what the media will make out of this :/

Well, just see the first sentence in the article of Yahoo :

"The Federal Aviation Administration (FAA) has ordered an inspection of more than 1,000 U.S.-registered Boeing 737 jets to examine the tail planes for a potentially faulty part, which it said could cause pilots to lose control of the aircraft if it failed".

Reading this, it is hard to avoid the rememberance of the flight US 427 in Aliquippa.

Quoting MD11Engineer (Reply 2):
The repeat inspection of the existing mechanism takes about one hour. The modification takes about 7 hours (afterwards you won´t have to do the repeat inspection anymore).

Thanks for the info MD11. So, the 7 hours time for the modification could cause a very limited and slight disruption in the smaller fleets, but nothing to be very worried.

Rgds.
G.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: VC10er
Posted 2013-04-15 05:18:20 and read 16694 times.

What about international fleets? Is that up to foreign aviation authorities?

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: atcsundevil
Posted 2013-04-15 05:25:03 and read 16611 times.

Quoting VC10er (Reply 5):
What about international fleets? Is that up to foreign aviation authorities?

Yes, but Europe typically follows suit on most of our ADs and vice versa. If the regulatory authorities abroad don't issue a directive to the carriers, it usually serves as a strong recommendation for the airline to act on their own initiative. If I'm not mistaken, ADs are usually coupled with a service bulletin from the manufacturer to all customers outlining the issue and the fix.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: MD11Engineer
Posted 2013-04-15 05:39:03 and read 16467 times.

Quoting atcsundevil (Reply 6):
Yes, but Europe typically follows suit on most of our ADs and vice versa. If the regulatory authorities abroad don't issue a directive to the carriers, it usually serves as a strong recommendation for the airline to act on their own initiative. If I'm not mistaken, ADs are usually coupled with a service bulletin from the manufacturer to all customers outlining the issue and the fix.

Exactly. The service bulletin from the manufacturer details what actions will have to be carried out and how.

Jan

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Gonzalo
Posted 2013-04-15 07:44:06 and read 15049 times.

Quoting atcsundevil (Reply 6):
Yes, but Europe typically follows suit on most of our ADs

Same here in Chile. We are considered a country with the same level of aviation safety tan U.S. ( I'm not sure if the strict following of the FAA directives is required for this qualification , but I guess should be that way).

In any case the big majority ( if not all ) of the few 737 flying here are classics ( 732-733 ) and are not affected by this AD.

Rgds.
G.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Roseflyer
Posted 2013-04-15 09:39:50 and read 12817 times.

Looks like a somewhat typical airworthiness directive and mandatory inspection and/or design modification. These come out on every airplane, especially as problems are discovered as they age.

Quoting Gonzalo (Thread starter):


Will this inspection have some impact on the operations ? Or is just a quick visual check ?

If you read the AD, there are detailed inspections of the mechanism and terminating action (so airline does not need to continue inspections) by incorporating a modification. I doubt there would be any impact to the operation, but a significant cost impact as outlined in the AD. An inspection to allow time to comply with a design modification allows airline engineering departments plenty of flexibility to get this work done on scheduled maintenance visits.

You can read the comments from American and Delta in the AD about compliance and how they will demonstrate compliance.

Quoting VC10er (Reply 5):
What about international fleets? Is that up to foreign aviation authorities?

With the exception of EASA, almost every regulatory authority in the world follows exactly what the FAA recommends. The FAA and EASA (and to a lesser degree Transport Canada) are the regulatory agencies fully reviewing all design changes on airplanes. Most local regulatory authorities don’t have the expertise or manpower to make their own recommendations, so they follow the FAA. Failure to follow what the FAA and/or EASA recommendations is going to get a local regulatory authority blacklisted by EASA or Category 2 by the FAA which bans their airlines from operating to the EU or US, so they all follow in relative short order unless there are specific reasons not to.

Quoting MD11Engineer (Reply 2):
Normally you don´t need the elevator tabs, but if hydraulic power fails they act as servo tabs to reduce the steering forces for the pilots now flying in manual reversion.

I think you are referring to the balance mode operation for manual reversion. The anti-balance mode is important for takeoff, and is used on every flight, so the tab mechanism is normally used. The anti-balance mode increases elevator authority, which is needed if you lose an engine on takeoff.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: superjeff
Posted 2013-04-15 09:49:21 and read 12610 times.

Quoting Gonzalo (Reply 4):
Reading this, it is hard to avoid the rememberance of the flight US 427 in Aliquippa.

And United at COS; and the near-crash of the Eastwind flight which led to them figuring out what happened. . . .

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Roseflyer
Posted 2013-04-15 10:17:29 and read 12054 times.

Quoting superjeff (Reply 10):
Quoting Gonzalo (Reply 4):
Reading this, it is hard to avoid the rememberance of the flight US 427 in Aliquippa.

And United at COS; and the near-crash of the Eastwind flight which led to them figuring out what happened. . . .

That may be true, but this airworthiness directive is for the elevator tab, and not the rudder, so these are significantly different components.

The Airworthiness Directive and Service Bulletin processes are well established and used to fix problems. Significant events (defined in the FARs) define what must be reported and the manufacturer addresses these concerns and determines if they are safety related problems or not. Problems that could cause safety problems result in Airworthiness Directives and Service Bulletins that provide fixes. It is good to see these type of things happening because that means safety is being addressed. On an airplane like the 737, there are dozens of airworthiness directives per year and most are not the result of crashes.

Take a look at the FAA website for all the technical details you could want. http://rgl.faa.gov/Regulatory_and_Gu...Library/rgAD.nsf/Frameset?OpenPage

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: KarelXWB
Posted 2013-04-15 10:30:48 and read 11795 times.

Quoting Roseflyer (Reply 11):
On an airplane like the 737, there are dozens of airworthiness directives per year and most are not the result of crashes.

  

And not only 737 sized aircraft. For example:

- February 2013: A380 Belly Fairing AD
- March 2013: A330 Horizontal Stabilizer Strut Cracks
- March 2013: FAA Issues Airworthiness Directive for Airbus A320 Family Planes, Oil Residue

etc...

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Gonzalo
Posted 2013-04-15 10:31:59 and read 11794 times.

Quoting Roseflyer (Reply 11):
That may be true, but this airworthiness directive is for the elevator tab, and not the rudder, so these are significantly different components.

Oh yes, totally different components, the thing that makes me think in US 427 is the phrase "could cause pilots to lose control of the aircraft if it failed".

Thanks for your inputs Roseflyer !!

Rgds.
G.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Roseflyer
Posted 2013-04-15 10:43:38 and read 11588 times.

Quoting Gonzalo (Reply 13):
Oh yes, totally different components, the thing that makes me think in US 427 is the phrase "could cause pilots to lose control of the aircraft if it failed".

That includes almost everything related to the aileron, elevator, and rudder, so that term shows up quite often when you are dealing with flight controls.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: yeelep
Posted 2013-04-15 11:46:30 and read 10611 times.

This a complete non event. This is a supersession of an existing AD. The inspection portion of the new AD is nothing new, we've been doing it for years.

Quoting Gonzalo (Reply 4):
So, the 7 hours time for the modification could cause a very limited and slight disruption in the smaller fleets, but nothing to be very worried.

The 7 hours is what is quoted as the time to accomplish the reinspect. Its between 32 and 52 man hours for the mod, so one day out of service or most likely done during heavy check.

Quoting Roseflyer (Reply 9):
The anti-balance mode is important for takeoff, and is used on every flight, so the tab mechanism is normally used.

Also landing, its activated any time the flaps are not up.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: atcsundevil
Posted 2013-04-15 12:02:25 and read 10340 times.

Quoting Gonzalo (Reply 4):
Reading this, it is hard to avoid the rememberance of the flight US 427 in Aliquippa.
Quoting superjeff (Reply 10):
And United at COS; and the near-crash of the Eastwind flight which led to them figuring out what happened. . . .

I thought the UA was on approach to Stapelton? Either way...that rudder issue did down several aircraft (at least three in the US) before the Eastwind pilot successfully saved the aircraft on approach to Richmond. This AD is for different components as the issue with the classics causing those accidents was corrected before the 737NG was produced. Also, this issue has not led to an accident or incident, as far as I'm aware.

In this case, it could have led to something far worse, but ADs and service bulletins exist to mitigate that. There's a good reason aviation in the US and in most of the developed world has had impeccable safety records in the past decade.

Quoting Gonzalo (Reply 8):
Same here in Chile. We are considered a country with the same level of aviation safety tan U.S. ( I'm not sure if the strict following of the FAA directives is required for this qualification , but I guess should be that way).

Following FAA ADs doesn't have much to do with the quality of the oversight body of a country. The FAA and NTSB are the premier agencies in the world at what they do, and as a result, most of the world tends to follow suit in one form or another based on their decisions or actions. The FAA categorizes each country based on their oversight abilities and safety standards, and Chile is among many countries in the developed world that has more than adequate oversight to make their own determination if a mandatory fix is necessary. The FAA won't consider them less adequate for not replicating all of their edicts -- provided the fix isn't a seriously major issue -- but for most countries, common sense would obviously prevail in those determinations.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: MountainFlyer
Posted 2013-04-15 12:43:43 and read 9820 times.

Quoting yeelep (Reply 15):
This a complete non event. This is a supersession of an existing AD. The inspection portion of the new AD is nothing new, we've been doing it for years.

Too bad the media doesn't get that.

The Guardian ran an article with a full-picture of the Lion Air crash, and while it doesn't explicitly say the inspections are related, they mention the Lion Air crash in the article implying there is a connection. I suppose they missed the fact that the Lion Air flight was an almost brand-new aircraft nowhere near the cycles mentioned in the article.

http://www.guardian.co.uk/business/2...5/boeing-737-faa-orders-inspection

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: flashmeister
Posted 2013-04-15 13:35:03 and read 9101 times.

Quoting atcsundevil (Reply 16):
I thought the UA was on approach to Stapelton?

Nope, on approach to COS.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: crj900lr
Posted 2013-04-15 17:31:55 and read 6596 times.

Quoting atcsundevil (Reply 16):
Either way...that rudder issue did down several aircraft (at least three in the US)

3? I can only remember 2, the UA (COS) and US (PIT) ones.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: Derik737
Posted 2013-04-15 20:09:45 and read 5289 times.

Quoting yeelep (Reply 15):
This a complete non event. This is a supersession of an existing AD. The inspection portion of the new AD is nothing new, we've been doing it for years.

Actually it's a supersession of an AD that superseded another AD. *yawn* Old news now - somewhat news in 2010.

Topic: RE: FAA Orders Inspection Of More Than 1000 737's Tail
Username: HAWK21M
Posted 2013-04-17 01:45:33 and read 2415 times.

Quoting MD11Engineer (Reply 2):
but about the elevator trim tab linkage mechanism

This is an ongoing SB right.....


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