Blackbird
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L-1011 Flaps

Mon Dec 10, 2001 5:10 am

What settings of flaps are used on the L-1011.

Also, what settings do the slats deploy at and at what flap-settings.

 
411A
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RE: L-1011 Flaps

Mon Dec 10, 2001 8:38 am

Flap settings are,
4
10
18
22
27 (not used)
33
42 (blocked on most aircraft).

4, 10, 18, 22 are approved for takeoff, depending on the individual airline procedures.

The slats deploy fully when the flap HANDLE moves beyond the 3 degree position.

DLC activates when the flap HANDLE is moved beyond the 30 degree position.

Hope this helps.
 
CPH-R
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RE: L-1011 Flaps

Wed Dec 12, 2001 6:03 am

How come that 42 is blocked? Too much drag, or?
 
RyDawg82
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RE: L-1011 Flaps

Wed Dec 12, 2001 6:35 am

"DLC activates when the flap HANDLE is moved beyond the 30 degree position. "


What is DLC? RyRy
You can take the pup out of Alaska, but you can't take the Alaska out of the pup.
 
b767-400er
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RE: L-1011 Flaps

Wed Dec 12, 2001 10:17 am

Rydawg82:

DLC: Direct Lift Control. Unique system to the L-1011(afaik, for airliners anyways). Uses Spoilers (instead of relying on the elevator) during approach to make percise adjustments on the glide-slope. Also smoothen out the ride.

Tony,
B767-400er
 
LZ-TLT
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RE: L-1011 Flaps

Thu Dec 13, 2001 2:52 am

The L-1011 is kinda uncommon when it comes to the tailplane:

-the WHOLE surface moves upon pushing the control column

-the "elevators" are used as TRIMTABS

(ie, the surfaces are used in the REVERSE way than on common airliners).

DLC is another feature Lockheed incorporated on the TriStar. AFAIK, it's a kind of "stick puller" which yanks the elevators up according to the speed on takeoff. Lockheed used this even as an advertising gag, claiming(and proving in various flight tests) that the 1011 will takeoff even with the totally wrong(virtually ANY) elevator trim setting.
 
411A
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RE: L-1011 Flaps

Thu Dec 13, 2001 12:19 pm

LZ-TLT

How's that....once again?

Have flown the TriStar for twenty years...don't seem to remember it quite THAT way. Especially the DLC business.
 
Notar520AC
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RE: L-1011 Flaps

Thu Dec 20, 2001 1:32 pm

Hey- I gotta question- does the #2 engine have a clamshell reverse thruster?
BMW - The Ultimate Driving Machine
 
charliecossie
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RE: L-1011 Flaps

Fri Dec 21, 2001 5:35 am

Thrust reverser!
No.
 
DC-10inLB
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RE: L-1011 Flaps

Fri Dec 28, 2001 12:42 pm

Ya it was cool watching the Tristars roll out from T5 and do their preflight control surface tests....the whole horizonal stabilizer moved. They called it "The Flying Tail" As for DLC. This allowed for a much smoother, more precise descent. The spoilers reduced lift without changing the aircraft's pitch. Also on the -500 series there were what's called ACS - Active Control System, inwhich the ailerons were simultaniously deflected upwards slightly in flight. This would actually bring the load imposed on the wings closer to the wing root, in a sense increasing the rigidity of the wing. Lockheed you must admit was pretty innovative.
 
411A
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RE: L-1011 Flaps

Sat Dec 29, 2001 3:10 pm

Close, but no cigar. ACS increased wing bending relief, not rigidity
 
rendezvous
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RE: L-1011 Flaps

Sat Dec 29, 2001 9:03 pm

So does anyone know why 27* isn't used and why 42* is blocked?
 
411A
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RE: L-1011 Flaps

Sun Dec 30, 2001 2:22 pm

27 is not used because NO operator requested ops at that flap setting....and 42 is blocked because the flap load relief system was not all that reliable.
 
A342
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RE: L-1011 Flaps

Sat Oct 04, 2008 5:44 pm

While having a look at the L1011 TCDS, I saw the flap settings. So I'll bring back this topic and ask: Why does the Tristar have so many flap settings? Most other large aircraft have about four positions.

Quoting 411A (Reply 1):
Flap settings are,

By chance, did you forget flap 14?
Exceptions confirm the rule.
 
474218
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RE: L-1011 Flaps

Sat Oct 04, 2008 8:18 pm



Quoting A342 (Reply 13):
By chance, did you forget flap 14?

L-1011-500's used the 14 degree flap setting. But not the 42 degree position, because the load relieving system was never installed on the -500's.


I am not sure 411A has flown the -500.

Quoting A342 (Reply 13):
While having a look at the L1011 TCDS, I saw the flap settings. So I'll bring back this topic and ask: Why does the Tristar have so many flap settings? Most other large aircraft have about four positions.

My question is why the others don't have more.

Unlike todays airliners L-1011 were designed to flown. The additional flap settings allow the flight crew optimize aircraft for all flight regimes.
 
411A
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RE: L-1011 Flaps

Sun Oct 05, 2008 12:31 am



Quoting 474218 (Reply 14):
am not sure 411A has flown the -500.

Only about 3,000 hours...out of 15,000 in total, in the L1011.
Will add another 300 very shortly.
 
Transpac787
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RE: L-1011 Flaps

Sun Oct 05, 2008 5:12 am



Quoting B767-400er (Reply 4):
DLC: Direct Lift Control. Unique system to the L-1011(afaik, for airliners anyways).

F-14's have DLC. Good system for keeping the critical angle of attack while landing aboard the ship and needing to make adjustments on the glideslope.
 
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Jetlagged
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RE: L-1011 Flaps

Sun Oct 05, 2008 3:15 pm

Quoting A342 (Reply 13):
While having a look at the L1011 TCDS, I saw the flap settings. So I'll bring back this topic and ask: Why does the Tristar have so many flap settings? Most other large aircraft have about four positions.

Most large aircraft have about four positions? Five or six is much more the norm.

747: 0, 1, 5, 10, 20, 25, 30.

757/767/777: 0, 1, 5, 15, 20, 25, 30.

DC-10: UP, EXT, 1, variable, 15, 22, 35, 50

MD-11: UP, EXT, 1, variable, 28, 35, 50

The DC-10 and MD-11 have a large number of possible positions due to the variable detent dial-a-flap system.

It's only FBW Airbuses that have a reduced number of flap settings. even these have 5 plus UP:

UP, 1, 1+F, 2, 3, FULL.

[Edited 2008-10-05 08:16:43]
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
A342
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RE: L-1011 Flaps

Sun Oct 05, 2008 3:53 pm



Quoting Jetlagged (Reply 17):
Most large aircraft have about four positions? Five or six is much more the norm.

Well, the number I gave did not consider the up/0 position. And I said ABOUT four.  Smile
Exceptions confirm the rule.
 
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Jetlagged
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RE: L-1011 Flaps

Sun Oct 05, 2008 10:18 pm



Quoting A342 (Reply 18):
Well, the number I gave did not consider the up/0 position. And I said ABOUT four.

I wasn't counting the UP position either.  Smile
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
johnclipper
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RE: L-1011 Flaps

Wed Oct 08, 2008 1:47 pm

What about 737, 717 and EMB-170 flap settings?
"Flown every aircraft since the Wright Flyer" (guys, if you take this literally, then you need to get a life...)
 
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dash500
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RE: L-1011 Flaps

Sat Oct 18, 2008 5:22 pm

In the L-1011-500 we have the following detent positions:

0, 4, 10, 14, 18, 22 & 33º.

However, I never saw 14 and 18 being used. Normally the sequence for approach/landing was 0->4->10->22->33. When going from 22 to 33º, DLC would become active.

For take off they used 4º and 10º settings. For shorter runways 22º.



[Edited 2008-10-18 10:23:39]
Flying all Across the World
 
411A
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RE: L-1011 Flaps

Sun Oct 19, 2008 2:22 am



Quoting Dash500 (Reply 21):
However, I never saw 14 and 18 being used.

If you came aboard my -500 airplane, you would notice flaps 14 used nearly all the time, for takeoff...shorter runways, flaps 22.
 
474218
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RE: L-1011 Flaps

Sun Oct 19, 2008 2:46 am

Just below the trim panel with the degree marks shown in Reply 21 is the "flap handle track". The track has detents machined it to them that correspond with the degree marks on the trim panels. These is at least half dozen different configurations of "flap handle tracks".

Another thing, if you stop the handle half way between 22 and 33 degrees (or any other setting)the flaps will stop there.

[Edited 2008-10-18 19:48:15]

[Edited 2008-10-18 19:49:17]
 
411A
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RE: L-1011 Flaps

Sun Oct 19, 2008 11:19 am

In addition, not all L1011's have the same flap setting that trigger the takeoff configuration warning.

For example, SVA used flaps 18 for takeoff at all times....any other flap setting for takeoff resulted in the takeoff warning sounding, even though the airplane was originally certified for other flap configurations.

TWA, on the other hand, always used flaps 10 for takeoff...any other flap setting with a TWA airplane also resulted in a takeoff warning for an inappropriate flap setting.
 
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Jetlagged
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RE: L-1011 Flaps

Mon Oct 20, 2008 3:17 am



Quoting 474218 (Reply 23):
Another thing, if you stop the handle half way between 22 and 33 degrees (or any other setting)the flaps will stop there.

That's true of most aircraft with analogue style flap controls. Aircraft with digital flap controllers can only select defined detent positions. Of course, not having the flap lever in a detent means it's very likely to be moved inadvertently, depending on flap lever friction only.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
point8six
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RE: L-1011 Flaps

Mon Oct 20, 2008 7:50 am

It's more than 22 years since I last flew a L1011, but my recollection is that DLC enabled constant pitch-angle approaches and ACS 'allowed' the aircraft to ride light turbulence by 'floating' approx. 100 ft above or below selected altitude. As for the -500, one tip given to me was to make sure the mainwheel brakes were applied before pulling full reverse on No.2 engine (otherwise it was difficult to get the nose-wheel on to the runway). Seem to remember Flaps 14 as a take-off setting, but can't remember if this was normal or specific runways. Great aircraft, though the original -1s were a tad underpowered - French ATC used to refer to us as "a slow-climbing TreeStar)!
 
411A
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RE: L-1011 Flaps

Mon Oct 20, 2008 4:18 pm



Quoting Point8six (Reply 26):
ACS 'allowed' the aircraft to ride light turbulence by 'floating' approx. 100 ft above or below selected altitude.

Close, but no cigar.
That altitude deviation was a function of the FMS thrust management mode, which minimised excessive throttle movements.
With RVSM, this has been reduced, IE: modified FMS software.

Quoting Point8six (Reply 26):
As for the -500, one tip given to me was to make sure the mainwheel brakes were applied before pulling full reverse on No.2 engine (otherwise it was difficult to get the nose-wheel on to the runway

True under some circumstances...full forward column is always necessary.

Quoting Point8six (Reply 26):
Seem to remember Flaps 14 as a take-off setting, but can't remember if this was normal or specific runways.

Normal, except for very short runways, then flaps 22 are used.
 
474218
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RE: L-1011 Flaps

Mon Oct 20, 2008 6:01 pm



Quoting Point8six (Reply 26):
ACS 'allowed' the aircraft to ride light turbulence by 'floating' approx. 100 ft above or below selected altitude.

The L-1011-500's Active Control System (ACS) function was to unload the wings when maneuvering or gust loads were encountered. Because the -500 wing span was increased, wing bending was also increased. This bending could have been overcome by stiffing the wing structure, but that would increase weight. By adding the ACS very little additional stiffing was required and weight was kept at a minimum. Activation of the ACS causes little or no altitude change, no where near 100 feet.

A byproduct of the ACS was a smoother ride for the passengers.
 
411A
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RE: L-1011 Flaps

Tue Oct 21, 2008 2:18 am



Quoting 474218 (Reply 28):
A byproduct of the ACS was a smoother ride for the passengers.

Indeed so, and it makes quite a difference in turbulence.

However, to dispatch with ACS inoperative is a HUGE weight penalty.
Having said this, it never seems to quit.

TriStar, a superb airplane.
For a dated design, nothing finer.
Must be seen and flown to be believed.
I kid you not.
 
474218
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RE: L-1011 Flaps

Tue Oct 21, 2008 3:04 am



Quoting 411A (Reply 29):
TriStar, a superb airplane.
For a dated design, nothing finer.
Must be seen and flown to be believed.
I kid you not.

You don't have to convince me I have been involved with the L-1011 for over 38 years.

Quoting 411A (Reply 29):
However, to dispatch with ACS inoperative is a HUGE weight penalty.
Having said this, it never seems to quit.

The ACS has proven to be very reliable. However, when it does fail it takes longer to find a stand than it does to reposition the ailerons for flight.

I wonder how the weight penalty compares to say a 747-400 with a winglet missing?
 
411A
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RE: L-1011 Flaps

Tue Oct 21, 2008 3:30 am



Quoting 474218 (Reply 30):
I wonder how the weight penalty compares to say a 747-400 with a winglet missing?

Don't know abot the B744, but as I recall the weight penalty is on the order of 70,000 pounds for the -500 airplane with ACS inoperative.
A significant amount.
Also a weight (and speed) penalty for MDLC inop, although that never seems to fail, either.
 
474218
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RE: L-1011 Flaps

Tue Oct 21, 2008 3:47 am



Quoting 411A (Reply 31):
Don't know abot the B744, but as I recall the weight penalty is on the order of 70,000 pounds for the -500 airplane with ACS inoperative.
A significant amount.

With ACS inop both outboard ailerons are deflected up 10 degrees, so there is a lot of drag induced.
 
2H4
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RE: L-1011 Flaps

Tue Oct 21, 2008 5:17 pm



Quoting 474218 (Reply 32):
With ACS inop both outboard ailerons are deflected up 10 degrees, so there is a lot of drag induced.

Interesting that they would fail in the UP position.

Quoting 411A (Reply 29):
Having said this, it never seems to quit.



Quoting 411A (Reply 31):
although that never seems to fail, either.

Not afraid of tempting fate, are we?  Wink

2H4
Intentionally Left Blank
 
474218
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RE: L-1011 Flaps

Tue Oct 21, 2008 8:51 pm



Quoting 2H4 (Reply 33):
Interesting that they would fail in the UP position.

They don't fail in the up position.

If the ACS is inop, dispatch is still possible but both outboard ailerons have to be rigged 10 degrees up. This is done by lengthening the outboard aileron input control rods (one on each wing). The rods have one inside the other and by removing and reinstalling two bolts the rods length can be extended.

This is required to unload the outboard wing tips.

If the ACS fails in flight, you can continue but at a reduced speed.

Additionally, even with the ailerons up 10 degrees they still function in roll control, ie: they move further up on the down wing and move down on the up wing.
 
2H4
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RE: L-1011 Flaps

Tue Oct 21, 2008 9:54 pm



Quoting 474218 (Reply 34):

Interesting. Thanks for clearing that up.

2H4
Intentionally Left Blank
 
twal1011727
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RE: L-1011 Flaps

Tue Oct 21, 2008 11:29 pm



Quoting 411A (Reply 29):
TriStar, a superb airplane.
For a dated design, nothing finer.
Must be seen and flown to be believed.
I kid you not.

My dad flew them for TWA between 1980 - 1987....he absolutely loved it.

KD

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