GearDownPlease
Topic Author
Posts: 39
Joined: Mon May 28, 2007 4:46 am

No Outboard Ailerons On A310s And A300B4-600s?

Wed Jun 13, 2007 3:56 am

Hello,

Boeing large airliners traditionally feature an "inboard flaps, inboard aileron, outboard flaps AND outboard aileron" wing geometry, a feature shared in the Airbus range with the A300B4-200, B4-100, B2-200, B2-100 and probably B2-1.

While checking A310 photos on our favourite civil aviation photo database, I wondered why A310s and A300B4-600s do not feature outboard ailerons ? Is is due to the FBW (finer management, if A310s and A300B4-600s are ever equipped) ?

Thanking you all in advance.

Best regards, GearDownPlease

[Edited 2007-06-12 20:57:34]
CItro�«n SM ? Sa Majest�© !
 
PGNCS
Posts: 2249
Joined: Sun Apr 15, 2007 5:07 am

RE: No Outboard Ailerons On A310s And A300B4-600s?

Wed Jun 13, 2007 6:03 am

Quoting GearDownPlease (Thread starter):
Is is due to the FBW (finer management, if A310s and A300B4-600s are ever equipped) ?

This has just been discussed in another thread.

The A-310 and A-300-600 are not FBW aircraft.
 
GearDownPlease
Topic Author
Posts: 39
Joined: Mon May 28, 2007 4:46 am

RE: No Outboard Ailerons On A310s And A300B4-600s?

Sat Jun 16, 2007 9:17 pm

Quoting PGNCS (Reply 1):
Quoting GearDownPlease (Thread starter):
Is is due to the FBW (finer management, if A310s and A300B4-600s are ever equipped) ?

This has just been discussed in another thread.

The A-310 and A-300-600 are not FBW aircraft.

Thanks PGNCS but I was interested in knowing why A310s and A300B4-600s did not feature outboard ailerons (while other A300s featured them), more than if the are or not FBW-ed.
CItro�«n SM ? Sa Majest�© !
 
113312
Posts: 583
Joined: Sat Apr 16, 2005 9:09 am

RE: No Outboard Ailerons On A310s And A300B4-600s?

Sat Jun 16, 2007 10:56 pm

AILERON CONTROL
Roll inputs are transmitted to the ailerons by dual cable
runs providing fail safe operation. Control column
inputs are transmitted to a differential unit. The differential
unit output is modified by:
• Artificial feel unit.
• Aileron droop actuator.
• Trim actuator (located on center console).
If one control jams, the interconnecting spring rod can
compress permitting operation of the control run to the
other wing. Pilot effort with a jammed control run is between
34 LB and 90 LB. Spoiler roll control is available
but degraded.
Artificial feel is a spring mechanism. It operates independently
of airspeed and provides:
• Artificial feel loads proportional to control
wheel deflection.
• A neutral centering mechanism.
To improve low speed aerodynamic characteristics,
Slat extension signals an aileron droop approximately
10°.
ROLL SPOILER CONTROL
The roll spoilers are electrically controlled by two identical
computers (EFCU-Electrical Flight Control Units)
which process signals from the control wheels position
transducers.
Four groups of spoilers are controlled and monitored
by both computers. Each spoiler group consists of one
or two pairs of symmetrical spoilers:
• A300: spoilers 3 & 2, spoilers 4 & 1, spoilers 5
& 7, spoilers 6).
• A310: spoilers 3 & 2, spoilers 4 & 1, spoilers 6
& 7, spoilers 5).
ROLL SPOILER (PANELS 3 - 7) LOGIC
Roll spoiler deployment starts at approximately 10° of
control wheel deflection.
 
GearDownPlease
Topic Author
Posts: 39
Joined: Mon May 28, 2007 4:46 am

RE: No Outboard Ailerons On A310s And A300B4-600s?

Sun Jun 17, 2007 2:51 am

Well, thanks but I am still wondering why... lol !
CItro�«n SM ? Sa Majest�© !
 
User avatar
Starlionblue
Posts: 17097
Joined: Fri Feb 27, 2004 9:54 pm

RE: No Outboard Ailerons On A310s And A300B4-600s?

Sun Jun 17, 2007 12:59 pm

Quoting GearDownPlease (Reply 4):
Well, thanks but I am still wondering why... lol !

Airbus felt there was no need for them. IIRC the ailerons are in fact FBW so quite fine control can be achieved.

Outer ailerons are not used at high speed on most aircraft that have both since the wing tends to bend so much it turns the plane the other way.

So we are left with low speed. Apparently the weight and cost savings from deleting the outer ailerons are great enough to justify the solution. Roll control is provided by spoilers and the inner ailerons.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
UAL747
Posts: 6725
Joined: Mon Dec 13, 1999 5:42 am

RE: No Outboard Ailerons On A310s And A300B4-600s?

Mon Jun 18, 2007 12:21 am

I was the one who posted the earlier thread on this subject. I too, thought that neither aircraft had outboard ailerons, BUTTTTTTTTTT!!!!!!!!!...........

Lookie Here!


View Large View Medium
Click here for bigger photo!

Photo © Kas van Zonneveld



This picture just came available yesterday. So indeed, some of them do have outboard ailerons!

Edit: Nevermind, I thought you meant ALL A310's and A300's

UAL

[Edited 2007-06-17 17:22:52]
"Bangkok Tower, United 890 Heavy. Bangkok Tower, United 890 Heavy.....Okay, fine, we'll just turn 190 and Visual Our Way
 
User avatar
Jetlagged
Posts: 2562
Joined: Sun Jan 23, 2005 3:00 pm

RE: No Outboard Ailerons On A310s And A300B4-600s?

Mon Jun 18, 2007 8:35 am

Quoting Starlionblue (Reply 5):
IIRC the ailerons are in fact FBW so quite fine control can be achieved.

The ailerons of the A310 and A300-600 are conventional. FBW might have been necessary if Airbus had deleted the inboard ailerons, leaving only the outboards, which might need to be variable gearing to reduce high speed control sensitivity. With only the inboards ("all speed ailerons" in Airbus terminology), there is no need for such finesse. In other words, a FBW system could reduce aileron sensitivity at high speed, but can't increase aileron control power at low speed.

As I recall, the rationale for deleting the outboard ailerons (called "low speed ailerons" by Airbus) was that there was sufficient roll control power at low speeds (i.e. with flaps extended) without them.

Quoting 113312 (Reply 3):
ROLL SPOILER CONTROL
The roll spoilers are electrically controlled by two identical
computers (EFCU-Electrical Flight Control Units)
which process signals from the control wheels position
transducers.

This may be the roll FBW you were thinking of?
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
User avatar
Starlionblue
Posts: 17097
Joined: Fri Feb 27, 2004 9:54 pm

RE: No Outboard Ailerons On A310s And A300B4-600s?

Mon Jun 18, 2007 10:59 am

Good info on the FBW absence thx.

Quoting Jetlagged (Reply 7):

As I recall, the rationale for deleting the outboard ailerons (called "low speed ailerons" by Airbus) was that there was sufficient roll control power at low speeds (i.e. with flaps extended) without them.

That rationale works for me. Big grin
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
GearDownPlease
Topic Author
Posts: 39
Joined: Mon May 28, 2007 4:46 am

RE: No Outboard Ailerons On A310s And A300B4-600s?

Thu Jun 21, 2007 7:22 pm

Thank you guys for your replies, most appreciated !

Best regards, GearDownPlease
CItro�«n SM ? Sa Majest�© !

Who is online

Users browsing this forum: No registered users and 23 guests