PPRuNe Forums


Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Reply
 
Thread Tools Search this Thread
Old 7th Dec 2009, 22:36   #221 (permalink)
Trash du Blanc
 
Join Date: Mar 2001
Location: KBHM
Posts: 1,181
Quote:
That saying, all these protection schemes deal with one aspect, pitch attitude, which is a repeating factor in MD-11 accidents/incidents.
I just went through recurrent training on the MD11, the first time since the Narita crash.

In the simulator, the focus was on pitch angle control in the flare - they froze us in the flare and let us play with pitch until we absolutely could nail 7.5 degrees pitch up by outside reference only. The theory is that the plane can take just about any reasonable landing, including a bounce, if you can hold 7.5 and control altitude with power.

Then we came in and landed with spoilers disarmed, held pitch and added a little power, then set it back down, then repeated. My best effort led to three touch & goes in a row on a 10,000 foot runway....

And by the way, tail fuel management does work on the ground, in "H" mode (gives you another 5k takeoff weight capability).
Huck is offline   Reply With Quote
Old 7th Dec 2009, 23:35   #222 (permalink)
 
Join Date: Apr 2004
Location: Planet Earth
Posts: 1,613
An interesting exercise but, it's just that. You can do a lot of things in the simulator but whether you can replicate the scenario (and your performance)
in the real Aircraft day after day, month after month, year after year in all kinds of weather / gross weight /cg /personal fatigue levels is doubtful.


If 7.5 degrees pitch up is optimal for landing, fine, will you always 'nail' that ?the answer is no.


The same applys for a 'reasonable landing' this is not something you can guarantee, I have seen some rather 'unreasonable' arrivals with some of mine certainly included.


Fortunately none of these have been on a very unforgiving type, except for one but it was built like a brick sh**house.
stilton is offline   Reply With Quote
Old 8th Dec 2009, 08:39   #223 (permalink)
 
Join Date: Apr 2002
Location: EGSS
Posts: 874
As Huck says, mode H does work on the ground. Gives a MTOGW of 630.5K instead of 625.5K. The FSC will schedule fuel to the tail when the LSDU (fuel panel) is turned off based on the aux tank quantity. 100lbs to the tail for every 750lb (above 9000) in the aux tank (or divide total aux tank fuel by 8.9). Tail tank remains empty on t/o regardless if W&B is performed in mode L, due to MEL item etc or in mode H if total FOB is around 153-154K lbs or less.

Last edited by Flightmech; 8th Dec 2009 at 12:26.
Flightmech is offline   Reply With Quote
Old 8th Dec 2009, 11:01   #224 (permalink)
MPH
 
Join Date: Dec 1999
Location: Both sides of 40W
Posts: 219
Poina: Not True, As Mentioned On The Ground It Does Work. And How About No Fuel In The Tail? There Are A Few Scenario´s That Could Have Contributed To This Accident. This Is One And As Mentioned W/b Problems Plus Wrong Config, Etc.
MPH is offline   Reply With Quote
Old 8th Dec 2009, 14:34   #225 (permalink)
 
Join Date: Jun 2009
Location: Tunisia
Age: 64
Posts: 143
mph,

Saudia md-11's 285990kg mtow with fsc in auto, fsc in manual mtow reduced to 283134kg. of course there is tail fuel if fuel load exceeds 66 tons.
in fsc taxi mode fuel can be auto transferred but aft transfer is inhibited and stays inhibited until fsc transitions to climb mode.

the ones that said you can get 5000 lb increase in h mode must be ones with extended aux tanks we did not have.

that's how ours worked, not trying to bs anyone.
poina is offline   Reply With Quote
Old 8th Dec 2009, 14:44   #226 (permalink)
 
Join Date: Apr 2002
Location: EGSS
Posts: 874
Poina,

The aircraft with an extra 5,000 lbs MTOGW in mode H did not have extended range aux tanks. You have described the difference (mode H/L) on your Saudia aircraft youself albeit in Kgs rather than lbs. There are a few scenarios per our MEL where you can still have a mode H W&B with the FSC in manual. Fuel has to be manually put in the tail during refuelling per the normal schedule but once airborne there is no tail fuel management. This can confuse some crews as if they see "Tail fuel management is not available" in the (o) notes of the MEL and therefore don't expect to see any fuel in the tail after refuelling. Basically with the FSC in manual they take off with the main tank pumps on and aux/tail pumps off and then turn on the aux/tail tank pumps during the after-takeoff checklist.
Flightmech is offline   Reply With Quote
Old 8th Dec 2009, 14:49   #227 (permalink)
Trash du Blanc
 
Join Date: Mar 2001
Location: KBHM
Posts: 1,181
As I recall, the MD11 did not meet some range requirements when it was first flight tested. Gross weight was increased, but the FAA did not like the added stress on the nosewheel. Ground fuel shifting (the 7.5 ratio) was added into the FSC software to shift the CG back. Is this what you folks remember?

Concurrently they took off the heavy shroud around the number 2 engine and put on some gap seals on the wings. This is why the "ENG 2 A-ICE DUCT" warning can be either level 2 or level 1, depending on whether that shroud is in place on that tail number.

This is when the deflected aileron option was invented, as well.....
Huck is offline   Reply With Quote
Old 8th Dec 2009, 15:20   #228 (permalink)
 
Join Date: Apr 2002
Location: EGSS
Posts: 874
Lots of changes were made to improve range requirements. Improved slat seals, repositioned windshield wipers (horizontal to vertically parked) and extended flap hinge fairings (on later models off the line) to name a few. I know that a/c 620,621 and 623 at FedEx have the extended flap hinge fairings.
Flightmech is offline   Reply With Quote
Old 9th Dec 2009, 00:02   #229 (permalink)
 
Join Date: Jun 2009
Location: Mountain View
Posts: 88
The unofficial word from PVG is that the a.c was overloaded. My contacts, multiple, on the ground there with local contacts, believe the a/c was overloaded significantly.
Recently flew with an individual very familiar with the entire cockpit crew, word is they were all capable pilots.
carry on.....

Last edited by WrldWide; 9th Dec 2009 at 07:17. Reason: removed PS
WrldWide is offline   Reply With Quote
Old 9th Dec 2009, 00:05   #230 (permalink)
 
Join Date: Mar 2007
Location: USofA
Posts: 1,009
It's been awhile now but Delta operated two MD11's with two aux tanks mounted under the floor. Total additional fuel was 26,000#, which of course came right out of the pay load. These two aircraft were dedicated to the LAX/HKG non stop which on occassion would exceed 15+ hours. Very hard to do this aircraft and make a buck with the restricted payload. They actually use to fuel the airplane with scuppers under the wings so as to catch the fuel as it topped off with the overfill breakers pulled. The MGTOW on these aircraft were 628K and I believe there were further gross weight increases as the aircraft matured.
Spooky 2 is offline   Reply With Quote
Old 9th Dec 2009, 00:09   #231 (permalink)
 
Join Date: Jun 2009
Location: Mountain View
Posts: 88
the Delta MD11s with ext range were a DAL mod. the ER that MD produced worked a little better. Not sure what your point is because the Delta Mod tended to put the initial cg forward until the aux was burned off. I have extensive experience with the DAL birds as we used one for a backup on our LAD flights and I flew them often when ours was in hvy check.

PS: the a/c in Pudong had no relation to the DAL fleet so.......what?
WrldWide is offline   Reply With Quote
Old 9th Dec 2009, 00:49   #232 (permalink)
 
Join Date: Jul 2006
Location: East of LGB
Age: 62
Posts: 618
Quote:
the LAX/HKG non stop which on occassion would exceed 15+ hours.
My first Business Trip for the Company (1995 I think). It was 15.5 hours, door close to door open.
11Fan is offline   Reply With Quote
Old 9th Dec 2009, 04:43   #233 (permalink)
 
Join Date: Nov 2004
Location: Gangster Paradise, RSA
Posts: 230
Quote:
Originally Posted by WrldWide View Post
The unofficial word from PVG is that the a.c was overloaded. My contacts, multiple, on the ground there with local contacts, believe the a/c was overloaded significantly.
Recently flew with an individual very familiar with the entire cockpit crew, word is they were all capable pilots.
carry on.....

PS: was the loadies FIRST flight on the MD11 with Aviant.
Who was the loadie?
Maurice Chavez is offline   Reply With Quote
Old 9th Dec 2009, 07:19   #234 (permalink)
 
Join Date: Jun 2009
Location: Mountain View
Posts: 88
I have removed the PS about the loadie from my earlier post because I actually do not know who the loadie was.
WW
WrldWide is offline   Reply With Quote
Old 9th Dec 2009, 11:44   #235 (permalink)
 
Join Date: Mar 2007
Location: USofA
Posts: 1,009
Relax WrldWide. Just talking about some of the different fuel configs in the MD11 and yes, it has nothing to do with this accident.
Spooky 2 is offline   Reply With Quote
Old 9th Dec 2009, 13:19   #236 (permalink)
 
Join Date: Mar 2002
Location: Florida
Posts: 4,685
Rather easy to speculate about significant overloading based on rumor. Can we discuss the overt symptoms relative to the crew.

Things like speed vs time and distance. point of rotation vs point of liftoff. Availability of thrust margin to accomodate. Do the symptoms in this accident (an MD11 on this runway) match up with the possibility of overloading? can one discern the difference between flaps and slat annomalies vs overloading?
lomapaseo is offline   Reply With Quote
Old 9th Dec 2009, 13:25   #237 (permalink)
CR2

Top Dog
 
Join Date: May 2000
Location: Close to FACT
Age: 49
Posts: 2,099
Assuming a/c was at MZFW, what would TOW be PVG-FRU? Does anyone have some rough numbers?
CR2 is offline   Reply With Quote
Old 9th Dec 2009, 15:04   #238 (permalink)
 
Join Date: Aug 2002
Location: London, UK
Posts: 26
PVG TOW

CR2 I would estimate TOW of approx 600,000 lbs based on 6hrs flight time PVG-GRU.
cargobird is offline   Reply With Quote
Old 9th Dec 2009, 15:31   #239 (permalink)
CR2

Top Dog
 
Join Date: May 2000
Location: Close to FACT
Age: 49
Posts: 2,099
Thanks cargobird, so roughly 25K lbs ballpark figure under mtow. Don't see them carrying extra fuel given PVG fuel price. For them to be overloaded & not make it off the runway, how much extra cargo would they have to carry? 50K Lbs or more? Not counting structural limits, what do the performance charts say?
CR2 is offline   Reply With Quote
Old 9th Dec 2009, 15:52   #240 (permalink)
 
Join Date: Aug 2002
Location: London, UK
Posts: 26
With the general nature of cargo exported from China (e.g. computers, electricals, solar panels), I find it hard to believe that the aircraft would have been significantly overloaded based on the aircraft's useable volume.

Time will tell, but in my opinion the reason for this accident is far more likely to be due to the way the aircraft was hurriedly introduced into service with a carrier that was unfamiliar with the type and poor company SOP's allowed the holes of the swiss cheese to line up.
cargobird is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT. The time now is 23:25.


© 1996-2012 The Professional Pilots Rumour Network

SEO by vBSEO 3.6.1