Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
bigbird
Topic Author
Posts: 385
Joined: Fri Aug 13, 2004 10:38 pm

737NG Vs A320 Question

Thu Sep 10, 2015 11:50 am

I have read that the 737NG is certified for 75000 cycles and the A320 for only 48000. Is this number correct or if not what is the correct number. Also does this hold true for the A319 and A321?
 
Bongodog1964
Posts: 3554
Joined: Wed Oct 18, 2006 6:29 am

RE: 737NG Vs A320 Question

Thu Sep 10, 2015 12:12 pm

It was 48,000 cycles, but I recall that Airbus were working to raise it, there's a few articles on the net that the work was being carried out, but nothing immediately to hand that the result was announced.
 
roseflyer
Posts: 9602
Joined: Fri Feb 13, 2004 9:34 am

RE: 737NG Vs A320 Question

Thu Sep 10, 2015 1:42 pm

In 2006 the FAA began work in creating limit of validity for each airplane. This is related to the fatigue structural program. When initially certified the A320 and 737 had no hard cycle limit. The FAA established these. They used the baseline design goal certification numbers and have allowed structural maintenance programs to extend life beyond these numbers.

These are the design life goals that were used in the design process. This is what the structures and system components were designed and tested for at certification. For example systems components were certified to last 2-4 times the life of the airplane. Structures was designed with fatigue and damage tolerant design. The FAA used these numbers when starting the limit of validity calculations. Airbus has extended the structural maintenance program for the A320 to allow it to fly longer and has issued service bulletins for where there are areas that the airplane design does have hard limits. Boeing has extended limit of validity on some airplanes as well such as the 747, 757 and 767 since some of the airplanes in the fleet have exceeded the initial design targets. While these maintenance programs allow the airplane to continue flying, the original design goals and objectives indicate that the 737NG was designed to fly more cycles than the A320.

A300 B2 Series 48,000 FC
A300 B4-100 40,000 FC
A300 B4-203 34,000 FC
A300-600 30,000 FC/67,500 FH
A310-200 40,000 FC/60,000 FH
A310-300 35,000 FC/60,000 FH
A318 48,000 FC/60,000 FH
A319 48,000 FC/60,000 FH
A320-100 48,000 FC/48,000 FH
A320-200 48,000 FC/60,000 FH
A321 48,000 FC/60,000 FH
A330-200, -300 40,000 FC/60,000 FH
A340-200, 300 20,000 FC/80,000 FH
A340-500, 600 16,600 FC/100,000 FH
717 60,000 FC/60,000 FH
727 60,000 FC
737 737-100, -200 200C, -300, -400, -500 75,000 FC
737 (NG): 737-600, -700, -700C, 75,000 FC
737-900ER.75,000 FC
747 20,000 FC
757 50,000 FC
767 50,000 FC
777-200, -300 40,000 FC
777-200LR, 777-300ER 40,000 FC


http://www.gpo.gov/fdsys/pkg/FR-2010-11-15/html/2010-28363.htm
 
User avatar
Aesma
Posts: 16003
Joined: Sat Nov 14, 2009 6:14 am

RE: 737NG Vs A320 Question

Thu Sep 10, 2015 4:40 pm

Isn't the 737 helped by experience here ? The Jurassic would probably not last that long, there has in fact been incidents (Aloha...) of airplanes correctly maintained that showed the need for these limits, and Boeing had to change its manufacturing techniques/materials etc. to make the 737 more robust. Even recently 737 Classics had problems (holes in the fuselage).
 
User avatar
zeke
Posts: 17420
Joined: Thu Dec 14, 2006 1:42 pm

RE: 737NG Vs A320 Question

Thu Sep 10, 2015 9:22 pm

Quoting bigbird (Thread starter):

I have read that the 737NG is certified for 75000 cycles and the A320 for only 48000. Is this number correct or if not what is the correct number. Also does this hold true for the A319 and A321?

The current number I believe is 60,000 cycles and 120,000h that came in around 2010, they are working on 90,000 cycles and 180,000h.

The A320 series is flying longer sectors than the fatigue spectrum was originally designed for, it is hitting the hour limit before the cycle limit. I think the first aircraft hit the original hour limit in 2007, and the original cycle limit in 2011.
 
AA737-823
Posts: 5629
Joined: Wed Mar 01, 2000 11:10 am

RE: 737NG Vs A320 Question

Tue Sep 22, 2015 9:31 am

Quoting Aesma (Reply 3):
The Jurassic would probably not last that long, there has in fact been incidents (Aloha...) of airplanes correctly maintained

...That airplane was NOT correctly maintained. Any airframe can crack, and they all do. This is why inspections are carried out.
The Aloha aircraft had a crack VISIBLE to boarding passengers on the day of the incident.
It was certainly not "properly maintained."
 
diverted
Posts: 1311
Joined: Sat May 17, 2014 3:17 pm

RE: 737NG Vs A320 Question

Tue Sep 22, 2015 12:00 pm

Quoting AA737-823 (Reply 5):
The Jurassic would probably not last that long, there has in fact been incidents (Aloha...) of airplanes correctly maintained
...That airplane was NOT correctly maintained. Any airframe can crack, and they all do. This is why inspections are carried out.
The Aloha aircraft had a crack VISIBLE to boarding passengers on the day of the incident.
It was certainly not "properly maintained."

There's been AD's regarding lap joints on the 737. I'd have to ask maintenance people for more detailed info, but it has been addressed.
 
pfletch1228
Posts: 95
Joined: Thu Aug 10, 2006 1:45 am

RE: 737NG Vs A320 Question

Tue Sep 22, 2015 5:01 pm

Quoting zeke (Reply 4):
The current number I believe is 60,000 cycles and 120,000h that came in around 2010, they are working on 90,000 cycles and 180,000h.

Correct. Here are some sources :

http://www.airbus.com/presscentre/pr...package-will-extend-a320039s-life/

http://www.flightglobal.com/news/art...ervice-life-of-a320-family-220962/


I know of a few ex US Airways A320 flying in SA now (for Global Aviation) that are under ESG1 already, and the feedback I have received from mates flying them is that they are still rock solid and problem free.... They have aged extremely well and way above expectations.
 
KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: 737NG Vs A320 Question

Tue Sep 22, 2015 8:01 pm

Quoting diverted (Reply 6):
Quoting Aesma (Reply 3):The Jurassic would probably not last that long, there has in fact been incidents (Aloha...) of airplanes correctly maintained
...That airplane was NOT correctly maintained. Any airframe can crack, and they all do. This is why inspections are carried out.
The Aloha aircraft had a crack VISIBLE to boarding passengers on the day of the incident.
It was certainly not "properly maintained."

That was also a rare, early build 737-200 (not an advanced) that featured the -100 style lap joints. Part of the 737-200/Adv redesign was a new style fuselage lap joint that lasted longer and was less susceptible to corrosion.
 
User avatar
CALTECH
Posts: 3638
Joined: Thu May 17, 2007 4:21 am

RE: 737NG Vs A320 Question

Wed Sep 23, 2015 7:27 pm

Was a design feature of that era's 737s, the rivet heads could get cutoff. Fix was to drill larger holes and put in buttonhead rivets rather than countersunks.

The skin would cut the rivet head right off,

http://lessonslearned.faa.gov/ll_main.cfm?TabID=4&LLID=20&LLTypeID=2

http://lessonslearned.faa.gov/ll_main.cfm?TabID=4&LLID=20&LLTypeID=2
 
User avatar
Starlionblue
Posts: 21268
Joined: Fri Feb 27, 2004 9:54 pm

RE: 737NG Vs A320 Question

Wed Sep 23, 2015 11:15 pm

Quoting AA737-823 (Reply 5):

Quoting Aesma (Reply 3):
The Jurassic would probably not last that long, there has in fact been incidents (Aloha...) of airplanes correctly maintained

...That airplane was NOT correctly maintained. Any airframe can crack, and they all do. This is why inspections are carried out.
The Aloha aircraft had a crack VISIBLE to boarding passengers on the day of the incident.
It was certainly not "properly maintained."

A combination of incorrect maintenance and high-cycle operation in a salt-water environment. Awareness of the effects of the Hawaii operating environment was not as well know as it is now.
 
KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: 737NG Vs A320 Question

Wed Sep 23, 2015 11:52 pm

Quoting Starlionblue (Reply 10):
A combination of incorrect maintenance and high-cycle operation in a salt-water environment. Awareness of the effects of the Hawaii operating environment was not as well know as it is now.

And throw in a touch of design defect   (see the previous two comments about how Boeing changed the lap joint design from the 737-100 and -200 to the -200/Advanced )   The Flash animation on the NTSB website is particularly enlightening...
 
User avatar
crimsonchin
Posts: 592
Joined: Fri Feb 07, 2014 8:16 pm

RE: 737NG Vs A320 Question

Thu Sep 24, 2015 12:38 am

Quoting pfletch1228 (Reply 7):

This is about 7 years ago, so is it safe to say they've achieved 90,000 cycles and 180,000fh? I can't seem to find any further, more recent articles on it.
 
prebennorholm
Posts: 7210
Joined: Tue Mar 21, 2000 6:25 am

RE: 737NG Vs A320 Question

Fri Sep 25, 2015 2:15 am

Quoting diverted (Reply 6):
There's been AD's regarding lap joints on the 737. I'd have to ask maintenance people for more detailed info, but it has been addressed.

Following the SWA 2294 and SWA 812 lap joint failures in 2009 and 2011 (both B733) the FAA issued an emergency AD for all classic 737 with more than 30k cycles.

Ultimately I think that they were both blamed on "one of" manufacturing defects, and passed undetected partially due to too lax mx procedures.

Yeah, the 737 has had a troubled fuselage fatigue record. Which seems only corrected with the NG.

Strange since it inherited so much fuselage technology from 707 and 727, and they didn't seem to have the same problems.
 
strfyr51
Posts: 5588
Joined: Tue Apr 10, 2012 5:04 pm

RE: 737NG Vs A320 Question

Fri Sep 25, 2015 1:31 pm

Airbus Has o be working on more than a 60K hr limit since United has one at 70K Hours but only 26K cycles,
The Airframe Hours I think are a nebulous number because it's Cycles that causes the majority of wear. Sampling inspections can chart and airframe wear and the present limits I think are for Airbus and Boeing ti Sell more airplanes, rather than to set life limits on the airframe.
 
User avatar
CALTECH
Posts: 3638
Joined: Thu May 17, 2007 4:21 am

RE: 737NG Vs A320 Question

Sun Sep 27, 2015 3:36 am

Quoting bigbird (Thread starter):
I have read that the 737NG is certified for 75000 cycles and the A320 for only 48000. Is this number correct or if not what is the correct number. Also does this hold true for the A319 and A321?

Model Minor Model Anticipated LOV Hours Next-Generation 737 -600/-700/-700 Cargo/-800/-900/-900 Extended Range
Cycles Flight Hours
100,000 125,000

ESG I will enable A320 Family aircraft to fly up to 60,000 flight cycles or 120,000 flight hours, and is planned for approval by the end of 2010. ESG II will go even further, up to the maximum economic potential of the airframe.

ESGII Airbus has set a target of 90,000 cycles and 180,000h - three times the original flight hour limit 20 years ago (!!!) So the ESG I progamme will enable airlines to operate their A320 family aircraft for another 10-20 years, and ESG II considerably longer.

It is for all the A-320 family.
 
User avatar
lightsaber
Moderator
Posts: 24424
Joined: Wed Jan 19, 2005 10:55 pm

RE: 737NG Vs A320 Question

Mon Sep 28, 2015 5:49 am

I hope everyone realizes we're debating the life of airframes very far along in their carriers.

To my knowledge, only HA pushed to nearly 100k cycles with the DC-9, but they can have as many as 17 cycles a day during peak tourist season!    Most airlines are more in the 6 to 8 cycles per day range (for heavy utilization airlines) and thus we're talking 20 years of utilization.

B6 pushes hours (highest hourly utilization of the A320 that I know of), averaging almost 15 per day (5,300 hours per year IIRC, going from memory). So the new 120k hour ESG1 means even after 20 years, there is some left.

But most 737NG or A320 are not in heavy utilization duty at 20 years of age.

We talked about this is 2013:
http://www1.airliners.net/aviation-forums/tech_ops/read.main/335189

I'm bummed my links are not longer valid from that older thread as it went into detail of Airbus' goal to reduce maintenance costs of the A320 30% from an earlier baseline (2008 or 2009, IIRC).

Quoting zeke (Reply 4):
The current number I believe is 60,000 cycles and 120,000h that came in around 2010, they are working on 90,000 cycles and 180,000h.

ESG1 (extension to 60,000 cycles and 120,000h) data was completed in 2011. Links below seem to indicate certified in 2012 (I couldn't find the exact date). ESG2... no news.

http://www.ainonline.com/aviation-ne...11-06-19/paris-2011-long-live-a320

I found a Lufthansa link with ESG1 approved, but ESG2 'not a high priority.'
http://www.lufthansa-technik.com/documents/100446/160376/Technik Connection 4-2012.pdf

Last I heard, ESG2 was on hold (the 90,000 cycle/180,000 hour package). I do not know the reasons why. I suspect that NEO work was higher priority. But my sources are not in the MRO community.



The reality is we're debating service costs after 20 years of operation... that doesn't impact new sales much due to little impact on today's present value...

Lightsaber
 
User avatar
CALTECH
Posts: 3638
Joined: Thu May 17, 2007 4:21 am

RE: 737NG Vs A320 Question

Tue Sep 29, 2015 11:59 am

Quoting lightsaber (Reply 16):
Last I heard, ESG2 was on hold (the 90,000 cycle/180,000 hour package). I do not know the reasons why. I suspect that NEO work was higher priority. But my sources are not in the MRO community.

Airbus found issues with the 'fatigue' testing,

https://www.federalregister.gov/articles/2015/08/28/2015-20951/airworthiness-directives-airbus-airplanes

"Airworthiness Directives; Airbus Airplanes
A Rule by the Federal Aviation Administration on 08/28/2015"

"We are adopting a new airworthiness directive (AD) for all Airbus Model A319, A320, and A321 series airplanes. This AD was prompted by reports that during a full scale fatigue test, several broken frames in certain areas of the cargo compartment have been found, especially on the cargo floor support fittings and open tack holes on the left-hand side. This AD requires a rototest inspection of the open tack holes and rivet holes at the cargo floor support fittings of the fuselage, including doing all applicable related investigative actions, and repair if necessary. We are issuing this AD to detect and correct cracking in the open tack holes and rivet holes at the cargo floor support fittings of the fuselage, which could affect the structural integrity of the airplane."

"Delta Air Lines (DAL), United Airlines (UAL), and US Airways requested that certain service information be removed from the NPRM (79 FR 42716, July 23, 2014) as it is not applicable to the U.S. fleet."

"is one of eight structural modification service bulletins required to operate Model A320 airplanes beyond 48,000 flight cycles/96,000 flight hours (referred to as extended service goal (ESG). "
 
Chaostheory
Posts: 1222
Joined: Wed Mar 06, 2013 2:09 am

RE: 737NG Vs A320 Question

Tue Sep 29, 2015 11:48 pm

Hello Lightsaber.

Quoting lightsaber (Reply 16):
B6 pushes hours (highest hourly utilization of the A320 that I know of), averaging almost 15 per day (5,300 hours per year IIRC, going from memory).

That's incorrect.

Unlike widebody aircraft, it is rare for a NB fleet to average above 13 hours utilisation.

The operator with the highest A320 fleet utilisation in 2014 according to Airbus was Air Arabia with an average utilisation of 13 hours. The next highest was Cebu at 12.5 hours.

According to Airbus 2014 utilisation figures for 2014, Jet Blue A320 fleet utilisation averaged 11.3 hours. This tallies with the combined A320 and E190 fleet utilisation figure of 11.8 hours given in JetBlue's 2014 10K filing here :

http://investor.jetblue.com/~/media/.../Annual%20Reports/2014-ar-10-k.pdf

See page 10 under the 'Fleet Structure' heading or alternatively page 24 in the 'Operating statistics' table..
 
User avatar
lightsaber
Moderator
Posts: 24424
Joined: Wed Jan 19, 2005 10:55 pm

RE: 737NG Vs A320 Question

Wed Sep 30, 2015 4:03 am

Quoting CALTECH (Reply 17):
Airbus found issues with the 'fatigue' testing,

Well, that is the whole point of fatigue testing!    Sad to hear, but good to know.

Did this impact ESR1 beyond the 8 inspections/repair areas? My interpretation is that the answer is "no" excluding some of the inspections happen early into the non-ESR operating time frame.

Quoting ChaosTheory (Reply 18):
According to Airbus 2014 utilisation figures for 2014, Jet Blue A320 fleet utilisation averaged 11.3 hours.

Thank you, I remembered wrong. I think I was recalling use of aircraft dedicated for TCON service, but as those were rotated to other operations, what matters is the fleet average.

Thanks for the link.





Lightsaber
 
User avatar
CALTECH
Posts: 3638
Joined: Thu May 17, 2007 4:21 am

RE: 737NG Vs A320 Question

Thu Oct 01, 2015 3:48 am

Quoting lightsaber (Reply 19):
Well, that is the whole point of fatigue testing!    Sad to hear, but good to know.

Think it caught them off guard though. US Airlines do not seem to want the FAA to mandate repairs on aircraft that haven't reached those cycles. Might be a expensive repair on a tired airframe.

Who is online

Users browsing this forum: LH707330, venemaje and 10 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos