DC10 slats
Thread Starter
Joined: Jun 2007
Posts: 191
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From: UK
DC10 slats
I often lurk in the background of this wonderful forum and sadly contribute little, I am however in a bit of hot water and in need of a bit of help. The only publications I have got to show for my time on the DC10 as a type rated DC10 Engineer are 2 LAMM schematics, one for a GK customer -30 series and the other a TK customer for the -10. I have been asked to do a private presentation of my experience on type whilst working at a major airport south of London in the 70's/80's. I have been steamrollered into having it done by Monday. I ask if anyone out there can let me have some AMM 27-83-XX stuff for slat rigging or any other presentable diagrams for the system description and operation. This is purely for the purpose of a demonstration in a private viewing place and not for circulation or distribution. It goes without saying, any assistance would be very much appreciated in helping me through this somewhat Herculean project ! Cheers - Terry
Joined: Mar 2002
Posts: 649
Likes: 10
From: EU
Hi,
did you check SmartCockpit - Airline training guides, Aviation, Operations, Safety ?
not sure it has what your looking for (no time to check myself)
Good luck
did you check SmartCockpit - Airline training guides, Aviation, Operations, Safety ?
not sure it has what your looking for (no time to check myself)
Good luck
Joined: Mar 2001
Posts: 82
Likes: 0
From: KENT, UK
http://ntrs.nasa.gov/archive/nasa/ca...9960052267.pdf
The DC10 has 3 mechanical slat actuation assemblys.
Each of these assemblys moves a set of slats via cables (big, heavy cables).
You have:
1) An inboard slat actuation assy located at the aircraft centerline which move the L/H & R/H slats inboard of #1 & #3 engine
2)Left outboard slat actuation assy which moves all slats outboard of #1 engine.
3)Right outboard slat actuation assy which moves all slats outboard of #3 engine
Each of these mechanical slat actuation assys use 2 hydraulic actuators to move the cable drum on these actuation assys which moves the cables which in turn extend and retract the slats (Douglas and their cables).
Normally the slats are extended and remain extended due to hydraulic pressure trapped in the hyd. lines between the actuators on the actuation assy and its respective control valve (one control valve per actuation assy for a total of 3).
With AA in ORD, the catastrophic engine separation severed the lines going to the L/H outboard slat actuation assy causing the airload to retract the L/H outboard slats.
To protect against this possibility from reoccurring, the right and left actuation assys have "balanced relief valve" assys installed. Now, should a loss of hydraulic pressure occur with the slats extended, the balanced relief valve will close locking the respective slats extended by trapping fluid in the actuator regardless of hydraulic line damage. These balanced relief valves are on both outboard slat actuation assys but not the inboard assy(located within the fuselage).
The MD11 has a mechanical locking mechanism as well as the aforementioned balanced relief valves for use in case of mechanical failure of the slat actuation mechanism.
On either aircraft, the slats should remain extended in the event of hydraulic failure.
The DC10 has 3 mechanical slat actuation assemblys.
Each of these assemblys moves a set of slats via cables (big, heavy cables).
You have:
1) An inboard slat actuation assy located at the aircraft centerline which move the L/H & R/H slats inboard of #1 & #3 engine
2)Left outboard slat actuation assy which moves all slats outboard of #1 engine.
3)Right outboard slat actuation assy which moves all slats outboard of #3 engine
Each of these mechanical slat actuation assys use 2 hydraulic actuators to move the cable drum on these actuation assys which moves the cables which in turn extend and retract the slats (Douglas and their cables).
Normally the slats are extended and remain extended due to hydraulic pressure trapped in the hyd. lines between the actuators on the actuation assy and its respective control valve (one control valve per actuation assy for a total of 3).
With AA in ORD, the catastrophic engine separation severed the lines going to the L/H outboard slat actuation assy causing the airload to retract the L/H outboard slats.
To protect against this possibility from reoccurring, the right and left actuation assys have "balanced relief valve" assys installed. Now, should a loss of hydraulic pressure occur with the slats extended, the balanced relief valve will close locking the respective slats extended by trapping fluid in the actuator regardless of hydraulic line damage. These balanced relief valves are on both outboard slat actuation assys but not the inboard assy(located within the fuselage).
The MD11 has a mechanical locking mechanism as well as the aforementioned balanced relief valves for use in case of mechanical failure of the slat actuation mechanism.
On either aircraft, the slats should remain extended in the event of hydraulic failure.
Joined: Nov 2009
Posts: 500
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From: flying by night
this is from an NTSB report (1979 AA Chicago crash), which may contain some information:
Report of DC-10-10 AA Accident near O'Hare
Report of DC-10-10 AA Accident near O'Hare
Thread Starter
Joined: Jun 2007
Posts: 191
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From: UK
I can use a lot of that thanks. What would be of real interest is the cable turnbuckle details, especially the bigguns at slat 2 and 3, and the position sensors on slat 2 and 4 ? Thanks everyone. . .
Joined: Sep 2010
Posts: 1,339
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From: earth
For whom had described this system as a "nightmare", I am extremely rusty. It is a system that is pretty damn reliable. As far as rigging goes it can be a nightmare the first time you perform the task, it is demanding yet after performing the task several times it becomes quite routine and all the mystery is gone. Much like having sex with the same woman...
