cobra27
Posts: 939
Joined: Wed May 23, 2001 6:57 pm

TBO's For Airliners?

Sat Oct 06, 2007 1:31 pm

How much time beetwen maintenance intervals for planes like 744, 777, A330, A320, B738 and how much time does it take to service these planes? Is an overnight stay enough for regular checkup? Into how many categories are they divided?
The 747 that fly around 18 hours a day must collect hours preety quickly
 
Dufo
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Joined: Tue May 18, 1999 2:41 am

RE: TBO's For Airliners?

Sat Oct 06, 2007 2:12 pm

Daily checks, 10-day checks, line checks, 300-hours, 1200-hours, A-B-C-D.. it varies according to each model.

For example L410 has:
- routine maintenance A (before every flight)
- routine maintenance B (after every landing)
- routine maintenance C (after last flight of the day)
Pilots are allowed to perform A and B in this case.

- periodic check 1 (every 10 +/-1 days)
- periodic check 2 (every 300 +/- 30 hours)
- periodic check 3 (every 1200 +/- 30 hours)
- periodic check 4 (every 2400 +/- 30 hours)
- general inspection (after 4800 +/- 150 hours or latest after 10 years)
- seasonal maintenance (preparation for winter)
- unscheduled maintenance (after hard landing, landing on nose wheel, landing with bank angle greater than 10deg, leaving the runway, landing above maximum landing weight, after lighting strike).
And some other quirks Big grin
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cobra27
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Joined: Wed May 23, 2001 6:57 pm

RE: TBO's For Airliners?

Sat Oct 06, 2007 5:40 pm

Is this the slovenian army L410?
 
tdscanuck
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RE: TBO's For Airliners?

Sat Oct 06, 2007 7:10 pm

Quoting Cobra27 (Thread starter):
How much time beetwen maintenance intervals for planes like 744, 777, A330, A320, B738 and how much time does it take to service these planes? Is an overnight stay enough for regular checkup? Into how many categories are they divided?

The only real answer is...it depends. All current production aircraft are damage-tolerant designs, so they have to have various inspections at specified intervals along with the normal servicing maintenance. However, there is no restriction on what order or what grouping you have to do those inspections and maintenance.

Each aircraft comes with a slightly different "stock" maintenance plan from the manufacturer but operators are free to design any maintenance program they wish, provided their regulators will accept it. At one extreme you have maintenance plans where the plane stays out of the hanger as long as possible, just getting line maintenance every night, then has a great big long check. At the other extreme you could hanger the plane every night and never have to bring the plane down for more than a day except for the really heavy structural inspections every few years (this is a simplification, but it's the two theoretical extremes). The former is good for airlines that don't do their own checks, the latter is good for those that have extensive in-house facilities.

Both Airbus and Boeing will help new customers design a maintenance plan that suits their operation and style.

Tom.
 
cobra27
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Joined: Wed May 23, 2001 6:57 pm

RE: TBO's For Airliners?

Sun Oct 07, 2007 8:44 am

Tanks Tdscanuck.
Does anybody have any info about service intervals for airline like KLM that seems to have most heavily utilized airliners in the industry?
 
FlyASAGuy2005
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RE: TBO's For Airliners?

Sun Oct 07, 2007 8:51 am

So how oftern is an HMV done? Lets say, one of Delta's 757's. Would I be correct to say that one of their newer aircraft (T7 738, CRJ's) hasen't done an HMV yet? If so, what time frame are we looking at for that to begin.
What gets measured gets done.
 
tdscanuck
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RE: TBO's For Airliners?

Sun Oct 07, 2007 6:15 pm

Quoting FlyASAGuy2005 (Reply 5):
So how oftern is an HMV done? Lets say, one of Delta's 757's. Would I be correct to say that one of their newer aircraft (T7 738, CRJ's) hasen't done an HMV yet? If so, what time frame are we looking at for that to begin.

I can't comment on the maintenance program for specific airlines. However, the stock 757 maintenance program is as follows:
Every flight: Transit check (aka pre-flight check)
Every 300 cycles: Structural A check
Every 500 cycles: Systems/Zonal A check
Every 3000 cycles/18 months*: Structural C check
Every 6000 cycles/18 months*: Systems/Zonal C check
Every 12000 cycles/72 months*: Structural 4C check (aka HMV, D-Check)

* = whichever occurs first.

Checks overlap so, for example, when you do a structural 4C you'd also do a systems/zonal C check.

A lot of newer 737-800's haven't hit their first heavy check yet. Not sure about the interval for CRJ's so I can't comment.

Tom.
 
Dalmd88
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Joined: Fri Jul 28, 2000 3:19 am

RE: TBO's For Airliners?

Mon Oct 08, 2007 1:32 am

Quoting FlyASAGuy2005 (Reply 5):
So how oftern is an HMV done? Lets say, one of Delta's 757's. Would I be correct to say that one of their newer aircraft (T7 738, CRJ's) hasen't done an HMV yet? If so, what time frame are we looking at for that to begin

I think the 757 fleet is on a 6 year HMV check cycle at DL. There are PSV checks that I think fall every18 -24 months. The 777 and 738 fleets are on PSV system only. Each sucessive PSV gets more involved until the cycle is complete. Those fleets are now beginning to under go the last checks in the cycle.
 
cobra27
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Joined: Wed May 23, 2001 6:57 pm

RE: TBO's For Airliners?

Mon Oct 08, 2007 8:28 am

Quoting Tdscanuck (Reply 6):

I can't comment on the maintenance program for specific airlines. However, the stock 757 maintenance program is as follows:
Every flight: Transit check (aka pre-flight check)
Every 300 cycles: Structural A check
Every 500 cycles: Systems/Zonal A check
Every 3000 cycles/18 months*: Structural C check
Every 6000 cycles/18 months*: Systems/Zonal C check
Every 12000 cycles/72 months*: Structural 4C check (aka HMV, D-Check)

This is more like it.
 
Dufo
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Joined: Tue May 18, 1999 2:41 am

RE: TBO's For Airliners?

Mon Oct 08, 2007 8:32 am

Quoting Cobra27 (Reply 2):
Is this the slovenian army L410?

My data is from L410 training manual, so it is probably applicable also to L4-01! Big grin
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cobra27
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Joined: Wed May 23, 2001 6:57 pm

RE: TBO's For Airliners?

Mon Oct 08, 2007 11:00 am

what does HMV stand for?
 
dispatchguy
Posts: 605
Joined: Sun Jan 29, 2006 6:08 am

RE: TBO's For Airliners?

Mon Oct 08, 2007 1:22 pm

Quoting Cobra27 (Reply 10):
what does HMV stand for?

Heavy Maintenance Visit
Nobody screws you better than an airline job!
 
FlyASAGuy2005
Posts: 3964
Joined: Sun Sep 23, 2007 4:55 am

RE: TBO's For Airliners?

Mon Oct 08, 2007 4:47 pm

Cool! thanks guys. I don't want to get into an actual airline comment as a new subect might have to be brought up in Genreal Forum but I brought up the whole new aircraft check thing because I remember a big argument on here about how much B6's costs is going to start going up when their 320's will have to eventually do HMV.
What gets measured gets done.
 
EIDAA
Posts: 444
Joined: Thu Oct 26, 2006 12:12 am

RE: TBO's For Airliners?

Fri Oct 12, 2007 5:20 pm

Quoting FlyASAGuy2005 (Reply 12):
Cool! thanks guys. I don't want to get into an actual airline comment as a new subect might have to be brought up in Genreal Forum but I brought up the whole new aircraft check thing because I remember a big argument on here about how much B6's costs is going to start going up when their 320's will have to eventually do HMV.

On the A320, the manufacturer's MPD suggests the following:-

C Check - 6,000FH / 4,500FC / 20 Mths
4C / 6Y Check - 72 Mths
8C / 12Y Check - 144 Mths

Each airline can have variations on the above, but that is a rough guide. B6 will already have carried out the first of its HMVs on the early aircraft.
Most Flown:- G-BUVA (20 Flights), EI-DEB (12 Flights), EI-JFK (11 Flights)
 
AirframeAS
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RE: TBO's For Airliners?

Fri Oct 19, 2007 12:27 pm

When I was working at AS, our heavy maintenance checks for the 732's & 734's were for C's: every 14 months. For D's & SI's every 4-5 years. This was policy in 2000, IIRC.
A Safe Flight Begins With Quality Maintenance On The Ground.

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