Delta MD-11s with 618,000lbs and 630,500lbs takeoff weight.

[DAL2728]

Hello! I have identified all but two former Delta MD-11s as 618k takeoff weight models.

Since I still unable to find a copy of the weight and balance manual or any airlines' MD-11 FOM, I would like some help from our experts.

What is entailed with the 618k takeoff weight? Does this include the forward cargo hold auxiliary fuel tank bringing the total fuel up to about 278k lbs, or is this without the extra fuel tank (~258,000lbs max fuel)?

Also, are the max landing weights for these models 430k or 458k lbs?


Next, I am showing two models eligible for the 630.5k takeoff weight. Am I right to assume these come standard with the auxiliary 3000 gallon fuel tank in the forward cargo hold? Again, what would be the max landing weights for these models?

Thanks guys,
-Shane

[Flightmech]

Originally Posted by DAL2728

Hello! I have identified all but two former Delta MD-11s as 618k takeoff weight models.

Since I still unable to find a copy of the weight and balance manual or any airlines' MD-11 FOM, I would like some help from our experts.

What is entailed with the 618k takeoff weight? Does this include the forward cargo hold auxiliary fuel tank bringing the total fuel up to about 278k lbs, or is this without the extra fuel tank (~258,000lbs max fuel)?

Also, are the max landing weights for these models 430k or 458k lbs?


Next, I am showing two models eligible for the 630.5k takeoff weight. Am I right to assume these come standard with the auxiliary 3000 gallon fuel tank in the forward cargo hold? Again, what would be the max landing weights for these models?

Thanks guys,
-Shane

All of our MD-11's here at FedEx are at 630.5K MTOGW. The only time they drop to 625.5K is if there is a fuel system MEL which renders the tail fuel management system inoperative, and therefore the weight & balance is computed in mode "L". (Low mode 625.5K MTOGW). None of our MD-11's have auxillary tanks in the forward hold like the pax -ER models. (Our max fuel is around 258K). Max landing weight is 481.5K. Hope this helps a little

[DAL2728]

This is very good information!

I am curious what a typical load and landing weight would for your average FEDEX MD-11. What is a typical flap setting and approach speed when landing at such a high landing weight? Since I don't have the FEDEX MD-11 to help me, some *rough* figures for this stuff would help me a lot. I can extrapolate from anything you can tell me!

-Shane

[FoxHunter]

Originally Posted by DAL2728

This is very good information!
I am curious what a typical load and landing weight would for your average FEDEX MD-11. What is a typical flap setting and approach speed when landing at such a high landing weight? Since I don't have the FEDEX MD-11 to help me, some *rough* figures for this stuff would help me a lot. I can extrapolate from anything you can tell me!
-Shane

Typical payload is 130,000-180,000 lbs.
Vref 480,000lbs LDG WT Flaps 35 161Kts, Flaps 50 156Kts
Vref 500,000lbs LDG WT Flaps 35 165Kts, Flaps 50 159Kts
MAX LGW 481,500
UPS operates MAX LGW 491,500
LIMITATIONS
"When operating aircraft at a MTOGW of 630,500 lbs on the ground with a total of 9,000 lbs or more fuel in the Aux and Tail tanks, manage the fuel system to maintain a ratio of approximately 7.5 to 1 between the Aux tank quantity and Tail tank quantity"
I was taught that this is due to a load limitation of the nose landing gear.
Tail fuel management does not have to work but you have to be permitted to load fuel in the tail. A good example is when for some reason the fuel system has to be operated in manual you can still load the proper amount in the Tail fuel tank, take off at 630,500 and then put it back into the AUX after take off.

When I first flew the aircraft(1992) the MGTOW was 610K, changed to 618K, then 625.5K and then 630.5K.

[DAL2728]

These Vref speeds seem awfully low with these flap settings. I had no idea they were so low! By Vref of 161kts at flaps 35, is this the speed you're touching down at, or the VAPP? I would have assumed the approach speeds at such a setting would have been something close to 170kts.

What would a typical approach speed be for a landing weight of, say, 430k? I'm just trying to get some estimates here so I can extrapolate for other weights for my flight model since I don't have real references but word of mouth right now.

Thanks!
-Shane

[FoxHunter]

Originally Posted by DAL2728

These Vref speeds seem awfully low with these flap settings. I had no idea they were so low! By Vref of 161kts at flaps 35, is this the speed you're touching down at, or the VAPP? I would have assumed the approach speeds at such a setting would have been something close to 170kts.
What would a typical approach speed be for a landing weight of, say, 430k? I'm just trying to get some estimates here so I can extrapolate for other weights for my flight model since I don't have real references but word of mouth right now.
Thanks!
-Shane

Normal approach is Vref+5. You think these speeds are LOW!!!! The are probably 20kts+ faster than everyone else.

[DAL2728]

So what would a Vref speed be for 430k?

[FoxHunter]

Originally Posted by DAL2728

So what would a Vref speed be for 430k?

152kts Flaps 35, 148kts Flaps 50

[DAL2728]

That's excellent! That's only two kts off from what I calculated!


Is there a performance chart or book that determines these speeds that I might be able to get a look at?

[FoxHunter]

Originally Posted by DAL2728

That's excellent! That's only two kts off from what I calculated!
Is there a performance chart or book that determines these speeds that I might be able to get a look at?

We normally get the speeds from a performance computer as a crosscheck. The airplane gives you the speed based on the actual weight.

[DAL2728]

This is excellent! [email protected]


I thank everyone here for their support and their time.