qwame
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Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:20 pm

How is Sonair able to fly an MD11 non stop 3x a week between IAH and LAD when clearly that distance is pushing the limits of the airline?
 
JRadier
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:26 pm

Sonair isn't operating it. It is operated by World. And if you don't mind me asking, what exactly do you mean 'that distance is pushing the limits of the airline'?
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wilco737
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:27 pm

http://www.sonairsarl.com/houstonExpress_en.shtml

Their website says it is a direct flight and not nonstop, so it could be that it stops somewhere for refuelling.

The distance between IAH and LAD is 6636 nm. Which is pretty much for the MD11.

our longest flight with the MD11 is: LEJ to HKG with 4789NM and the longest we had in the schedule was FRA-MNL with 5568NM. but then we had weight restrictions already.

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Viscount724
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:28 pm



Quoting Qwame (Thread starter):
How is Sonair able to fly an MD11 non stop 3x a week between IAH and LAD when clearly that distance is pushing the limits of the airline?

Since it operates in a premium configuration with something like 113 seats, that probably helps since it will be well below it's maximum payload.
 
wilco737
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:28 pm



Quoting Viscount724 (Reply 2):
Since it operates in a premium configuration with something like 113 seats, that probably helps since it will be well below it's maximum payload.

Oh only 113 seats. Well, then that is possible.

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flyf15
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:31 pm

Delta Air Lines, at one point, operated LAX-HKG with the MD-11. Although I've heard they did have weight restrictions especially during periods of strong headwinds, nevertheless, they were operating it with a full cabin. It is only 300nm shorter than IAD-LAD.
 
md11sdf
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:37 pm

Perhaps they have only 30 to 60 PAX on board each way. After all, it IS operating exclusively for the wealthy oil industry. The aircraft (N278WA) is an ER model and it's a shame that world does not paint it in the full SONAIR livery. It is pretty nice looking.

Terry
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A342
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:38 pm



Quoting WILCO737 (Reply 3):
our longest flight with the MD11 is: LEJ to HKG with 4789NM and the longest we had in the schedule was FRA-MNL with 5568NM. but then we had weight restrictions already.

Didn't you once say that with a full payload the MD-11F can only fly 2800nm? The weight restrictions on LEJ-HKG and FRA-MNL must be substantial.
Exceptions confirm the rule.
 
LAXintl
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:41 pm



Quoting Flyf15 (Reply 5):
Delta Air Lines, at one point, operated LAX-HKG with the MD-11. Although I've heard they did have weight restrictions especially during periods of strong headwinds, nevertheless, they were operating it with a full cabin.

They only so did with extra AUX fuel tanks in the bellies... As I recally 2-4 MD-11s were specially equipped at the time.

And even then enroute stops in ANC were I'd say a weekly occurrence especially the winter months.

Lastly flight did not last long -- probably a mix weak DL market presence and poor economics of the flight.
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wilco737
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:45 pm



Quoting A342 (Reply 7):
Didn't you once say that with a full payload the MD-11F can only fly 2800nm? The weight restrictions on LEJ-HKG and FRA-MNL must be substantial.

Yes, full payload would be 95 tons of cargo, that is the same weight as 950 passengers  crowded 

So, flying LEJ-HKG is max payload roughly 60-65 tons. which is enough, because it is a DHL flight, so only you shippings and with SonAir and only 113 seats, it shouldn't be a problem.

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wilco737
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:51 pm



Quoting A342 (Reply 7):
Didn't you once say that with a full payload the MD-11F can only fly 2800nm?

Did I say 2800NM? That's not a lot for a long haul aircraft... Let me try to remember what I posted there.
Oh I think I remember: HKG-ALA I think it was. We couldn't take more cargo with us, because we were landing weight limited. Our take off weight was roughly 10 tons below the maximum, which would be about 1.5 hours more flight time beyong ALA and that means about 800NM more range, so, maybe 3600NM.

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qwame
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:56 pm



Quoting JRadier (Reply 1):

I was under the impression that even though the MD 11 has a limit of 6691nm, it is impossible to do that distance with a full load. However, Viscount724 cleared it up by explaining that the flight only has some 113 passengers.
 
CosmicCruiser
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 8:57 pm

Our MD-11s have a MaxZFW of 431.5; Max fuel load 258.3 and MTOGW 630.5

With max fuel your zfw would be approx 374.0 counting taxi fuel. These are basic as t/o climb or obstacle may affect the numbers. I have seen 630.5 at t/o a number of times with heavy cargo loads or max fuel loads. We do CDG-SFS ,MEM-NRT and KIX-MEM
 
A342
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 9:02 pm



Quoting WILCO737 (Reply 9):
So, flying LEJ-HKG is max payload roughly 60-65 tons. which is enough, because it is a DHL flight



Quoting WILCO737 (Reply 10):
Oh I think I remember: HKG-ALA I think it was. We couldn't take more cargo with us, because we were landing weight limited. Our take off weight was roughly 10 tons below the maximum, which would be about 1.5 hours more flight time beyong ALA and that means about 800NM more range, so, maybe 3600NM.

Thanks for your explanations.  thumbsup 
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qwame
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 9:04 pm

So what kind of weight restriction will a A342 or 343 have to have to make a non-stop IAH - LAD flight without a fuel stop? (Basically how many passengers and how much cargo)
 
fxra
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 11:29 pm

The Houston Express is very much weight limited. IAH-LAD rarely is able to operate with more the 40,000 lbs, occasionally higher in winter. The return leg is much worse, 25,000 lbs is a good day. Going down we would send as much cargo as possible. ironically, not a lot of freight moving on the return legs. We rarely stopped on either eg as SonAir preferred to go non stop and leave cargo behind. Most the time, stops were results of MEL restrictions (the dreaded 2.7% no tail fuel management penalties).

The normal aircraft, 278, has aux tanks in the forward hold and can usually get about 270,000lbs of fuel max. The return leg from LAD usually requires a full load. The aircraft, as mentioned above, only holds like 120 pax. 3 classes, with "coach" being the normal business class seats. First class is the sleeper seats and almost like small cabins. And a cappuccino machine.

World used one of the Delta Queens (801,803, or 804) on the route when 278 was in check. Even though those planes hold more fuel, they were usually more restricted on payload due to lower thrust engines, no deflected ailerons, and being much heavier.

Some trips from LAD-IAH could be a challenge to carry a 15000lb payload.
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fxra
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RE: Pushing The MD 11 To Its Limit

Sat Sep 06, 2008 11:39 pm



Quoting Qwame (Reply 14):
So what kind of weight restriction will a A342 or 343 have to have to make a non-stop IAH - LAD flight without a fuel stop? (Basically how many passengers and how much cargo)

Before I left WOA, we did an analysis for replacement types for the Houston Express. As I recall, we ran B744 and A340's (ex Air Canada examples). The 340s did very well. About 50,000lbs or so without much problem on the LAD-IAH legs. Of course these were generic numbers without runway data.
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A342
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 1:39 am



Quoting WILCO737 (Reply 10):
Oh I think I remember: HKG-ALA I think it was. We couldn't take more cargo with us, because we were landing weight limited.

On a second thought, I have another question: Why were you landing weight limited? Any aircraft should be able to land with its max. structural payload and sufficient fuel reserves to reach an alternate airport. (I do realize that alternate airports are rather thinly spread around ALA, but still)
Exceptions confirm the rule.
 
qwame
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 1:48 am



Quoting FXRA (Reply 16):

FXRA, so why hasn't WOA changed the aircraft to a B744 or a A343? Wouldn't it be more economical for them?
 
9VSIO
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 2:09 am



Quoting A342 (Reply 17):
Any aircraft should be able to land with its max. structural payload and sufficient fuel reserves to reach an alternate airport.

The aircraft can, but can the runway take it? Might have been a length issue?
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fxra
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 2:23 am

With Sonair only doing 1 year at a time contracts, it's not worth it to add a new type for just one customer who may vanish in a year. With the 744F's there now, they may be more inclined add a pax version for that route.
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qwame
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 2:56 am



Quoting Fxra (Reply 20):

Fxra, doubt SonAir is going anywhere anytime soon. Question though, they fly a 744F 3 times a week into LAD also?
 
CosmicCruiser
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 3:18 am



Quoting A342 (Reply 17):
I have another question: Why were you landing weight limited? Any aircraft should be able to land with its max. structural payload and sufficient fuel reserves to reach an alternate airport

As far as our MDs go if you landed at Max ZFW AND MLGW you would have 50,000 lbs on board. That's a fair amount of gas. I've done HKG-ALA a number of times and it's only about 6+30 hrs. Of course going into ALA requires keeping up with the wx since ALA can fog in being at the base of the mtns.
 
iairallie
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 4:48 am



Quoting WILCO737 (Reply 3):
Their website says it is a direct flight and not nonstop, so it could be that it stops somewhere for refuelling.

It is usually non-stop.

I belive Sonair and World are in discussions about using a 747. Time will tell if it comes to fruition.
Enough about flying lets talk about me!
 
wilco737
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 4:59 am



Quoting A342 (Reply 17):
On a second thought, I have another question: Why were you landing weight limited? Any aircraft should be able to land with its max. structural payload and sufficient fuel reserves to reach an alternate airport. (I do realize that alternate airports are rather thinly spread around ALA, but still)

If you add up all that weight (Airplane, cargo, fuel) and then burn some fuel on your way to ALA, then you need to be below MAX LANDING WEIGHT. And because the flight is rather short and TSE (1.5 hours away) was our alternate you are landing weight restricted. We landed in ALA on that day with 222.0 tons, which is 0.9 below our maximum. And we had enough reserves for contingencies, holding, alternate. So no fuel problem at all here.

Quoting 9VSIO (Reply 19):
Might have been a length issue?

The runway in ALA is 4400m long. So LONG enough  Wink

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A342
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 9:28 pm



Quoting WILCO737 (Reply 24):
If you add up all that weight (Airplane, cargo, fuel) and then burn some fuel on your way to ALA, then you need to be below MAX LANDING WEIGHT. And because the flight is rather short and TSE (1.5 hours away) was our alternate you are landing weight restricted. We landed in ALA on that day with 222.0 tons, which is 0.9 below our maximum. And we had enough reserves for contingencies, holding, alternate. So no fuel problem at all here.

Alright, I had assumed that you had a closer alternate. TSE is indeed quite a distance from ALA.

Sorry if I ask another question, but which other airports in that area do you use as alternates? FRU, KHG, FEG, TAS, DMB, OSS, KGF, URC, BXH?
I'm really interested in that region.
Exceptions confirm the rule.
 
CosmicCruiser
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 10:35 pm



Quoting WILCO737 (Reply 24):
We landed in ALA on that day with 222.0 tons, which is 0.9 below our maximum

I know you told me before but what do you use for max ldg? Ours is 481.5/1000lbs
 
A342
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RE: Pushing The MD 11 To Its Limit

Sun Sep 07, 2008 10:45 pm



Quoting CosmicCruiser (Reply 26):
Quoting WILCO737 (Reply 24):
We landed in ALA on that day with 222.0 tons, which is 0.9 below our maximum

I know you told me before but what do you use for max ldg? Ours is 481.5/1000lbs

Obviously they use 222.944kg/491.500lb, as described on page 3:

http://www.boeing.com/commercial/airports/acaps/md11sec2.pdf
Exceptions confirm the rule.
 
wilco737
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RE: Pushing The MD 11 To Its Limit

Mon Sep 08, 2008 5:49 am



Quoting A342 (Reply 27):
Obviously they use 222.944kg/491.500lb, as described on page 3:

Exactly.

Quoting A342 (Reply 25):
Sorry if I ask another question, but which other airports in that area do you use as alternates? FRU, KHG, FEG, TAS, DMB, OSS, KGF, URC, BXH?

Our 4 alternates for ALA: FRU, TAS, TSE, KGF and if the weather is bad there, then sometimes I saw ISB as well. But not very often

but this is getting off topic now. Let's stay on the main topic.

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RE: Pushing The MD 11 To Its Limit

Mon Sep 08, 2008 3:09 pm



Quoting FXRA (Reply 15):
World used one of the Delta Queens (801,803, or 804) on the route when 278 was in check. Even though those planes hold more fuel, they were usually more restricted on payload due to lower thrust engines, no deflected ailerons, and being much heavier.

This year while 278 is is check, aircraft 277 will be converted as a temp replacement. My company is doing the interior reconfiguration engineering for this which should take place in October. Apparently, the ER tanks on 277 will also be reactivated.

Quoting IAirAllie (Reply 23):
I belive Sonair and World are in discussions about using a 747. Time will tell if it comes to fruition.

They are discussing it as a replacement for aircraft 278 and 2009 may be the last year for the MD-11 on that route. SONAIR has just acquired 3 ex-OASIS 744s, but I am not sure if these would be operated by World.
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michi
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RE: Pushing The MD 11 To Its Limit

Tue Sep 09, 2008 2:23 pm

The A340 is able to do take offs in LAD up to MTOW in typical WX Conditions.

MTOW 271Tons / 597000pounds C4 Engines, OAT +35°C

Max Fuel Load would be 111T / 244700pounds --> Range with 113pax shouldn't be a factor, additional cargo would be possible as well.

MTOW 271Tons - max Fuel 111Tons --> LAW 160Tons
typical DOW 135Tons --> at least 25Tons of payload, possibly more, because you don't need 111Tons of fuel for the 6636nm LAD-IAH.


Regards,
Michi

[Edited 2008-09-09 07:26:01]
 
A342
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RE: Pushing The MD 11 To Its Limit

Tue Sep 09, 2008 6:42 pm



Quoting Michi (Reply 30):

A 275 or 276.5 tonne MTOW would yield even better results.
Exceptions confirm the rule.
 
michi
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RE: Pushing The MD 11 To Its Limit

Thu Sep 11, 2008 1:21 pm

Quote:

A 275 or 276.5 tonne MTOW would yield even better results.

Of course  

However I only have the take off performance for the A340 version with 271tons MTOW and C4 engines. And there are many different A340 versions on the market.

I posted those data because somebody was wondering if the A340 take off performance and RWY length in LAD would be sufficient for the mission profile to IAH.


Regards,
Michi

[Edited 2008-09-11 06:25:14]

[Edited 2008-09-11 06:26:15]

[Edited 2008-09-11 06:27:23]
 
A342
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RE: Pushing The MD 11 To Its Limit

Thu Sep 11, 2008 4:56 pm



Quoting Michi (Reply 32):
However I only have the take off performance for the A340 version with 271tons MTOW and C4 engines.

See page 72:

http://www.content.airbusworld.com/S...C/DATA_CONSULT/AC_A340-200-300.pdf

Assuming sea level, ISA+15°C conditions and a 3700m runway, you can see that the A343 with C4 engines could theoretically take off at 283 tonnes or so.  Smile
Exceptions confirm the rule.
 
michi
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RE: Pushing The MD 11 To Its Limit

Thu Sep 11, 2008 7:07 pm

Hey, great link  bigthumbsup 

I was using "real world" data with obstacles and all the other things you consider during T.O. calculation. Sometimes obstacles will have significant effect on performance issues.

Maybe Wilco737 can add the "real world" data for the MD11. This would bring this thread back on course  Wink

Regards,
Michi
 
wilco737
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RE: Pushing The MD 11 To Its Limit

Thu Sep 11, 2008 7:15 pm

Quoting Michi (Reply 34):
Maybe Wilco737 can add the "real world" data for the MD11. This would bring this thread back on course Wink

We don't have LAD in our laptops (which we do our calculation with), so I cannot provide any information about that special airport.

But the MD11 is pretty powerful. I took 272tons out of 2800m runway.  weightlifter 

WILCO737 (MD11F)


[Edited 2008-09-11 12:24:22]
 
A342
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RE: Pushing The MD 11 To Its Limit

Thu Sep 11, 2008 11:33 pm



Quoting Michi (Reply 34):
Hey, great link

If anyone is interested, more of this stuff can be found here:

Airbus:

http://www.content.airbusworld.com/S...cal_Data/html/800x600_AC_main.html

Boeing/MD/Douglas:

http://www.boeing.com/commercial/airports/plan_manuals.html
Exceptions confirm the rule.
 
fxra
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RE: Pushing The MD 11 To Its Limit

Fri Sep 12, 2008 5:19 am

I don't recall there being any obstacle issues four our MD-11's. Rarely though did they ever reach max structural weights coming out of LAD. Usually ran out of places to put fuel before that would happen.

Given what i remember about LAD, there's not a lot of tall structures or mountains to worry about, just runway length and heat. I can't imagine there would be any thing as such limiting and A340
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