Classic & 400 help.

[CCA]

Can someone with the time please tell me do you require Hydraulics(1 & 4) to operate the LE flaps in PNEUMATIC mode ie. do the FCU's require a TE signal to move the LE.

I remember the classic required something possibly for flap 5 but don't remember the sequence.

Cheers.

[spannersatcx]

CCA, your topic says classic and 400 help. They are a bit different, firstly (as I remember it) 747-400
If there was no hydraulic power on the a/c, but there is pneumatics and electrics, if you were to move the flap lever to say flaps 10 nothing would happen initially with the trailing edges, due no hyd, 1st leading edge group should deploy, after 60 secs it works out that the trailing edges haven't moved and they automatically go to electric mode and star moving with an associated EICAS of FLAPS PRIMARY, I think, when T/E's are at 5 2nd L/E group should go. If you had no pneumatics the l/e's would do the same after 60secs but I think they all come out in one go, With an EICAS message.
Classic, now I'm having to trawl deep, I think! You can move the flap lever with no hyds and nothing will happen to the trailing edges, 1st group of L/E's won't extend until T/E flap signal is FLAPS NOT UP. You would then have to arm the T/E's alt sys then select the inbd and outbd groups to down. And stop them in the desired position. Leading edges would then go in the normal sequence.
I'll have a look when next in work and edit this if needed. Hope it helps anyway.

[redtail]

I always went for the gusto and ran everything, since I had the APU running for pneumatics and used the APU generators since our ground power is marginal for running #2 and #3 demand pumps on the -400. The intention was to avoid nuisance messages, which used to give us fits when we first started operating the aircraft and the manauls were still maturing. I should point out that this was overnight line maintenance, so usually there were only a few folks around to worry about. Usually I prefer to save Alternate Flaps for the crew to use, as it always seemed like a maginal system with its duty time/heat limitations.

[Cornish Jack]

The most accessible and relevant info on this appears to be a couple of warnings from the Maintenance Training manual -
1. WITH ELECTRICAL POWER AVAILABLE, EVEN THOUGH HYDRAULIC AND PNEUMATIC POWER ARE OFF, ALL TE AND LE FLAPS WILL AUTOMATICALLY EXTEND OR RETRACT WHEN THE FLAP LEVER IS MOVED. PRIOR TO MOVING FLAP LEVER, CHECK THAT PERSONNEL AND EQUIPMENT ARE CLEAR OF TRAILING AND LEADING EDGE FLAP SURFACES.

2. LEADING EDGE AND TRAILING EDGE FLAPS WILL MOVE TO THE POSITION SELECTED BY CONTROL LEVER WHEN ALTERNATE ELECTRIC CONTROL IS DISARMED. CHECK THAT ALL PERSONNEL AND EQUIPMENT ARE CLEAR OF OPERATING PATH.

Leading Edge Flap sequencing Primary Control :
Extension - Group A LE flaps extend when the flap lever is moved to 1. Group B LE flaps extend when the flap lever is moved to 5.

Retraction - Group B LE flaps retract when the flap lever is at 1 and the inboard TE flaps are less than 41/2 (four and a half)units. Group A LE flaps retract when the flap lever is UP and the outboard TE flaps are up.
So, CCA, the answer to your questions are:-
Hydraulics? - not necessary.
TE signal - yes, for RETRACTION.

PS - This applies to the 747 - 400. The Classic is sufficiently different to require a further look-see. Will try to do that, if time permits.

[This message has been edited by Cornish Jack (edited 09 October 2000).]

[H721]

spanneratcx,
u should have direct internet access to online manuals.

------------------
Not much of an engineer

[redtail]

So much for winging it. Good answer Cornish Jack.

Maintenance manuals on the Internet? I'd like a look, since our internal Intranet manuals leave a lot to be desired. I believe our tech pubs division's aim is to pare each chapter down to one page each.

[spannersatcx]

Isn't that what I said, never mind.
H721/redtail it is on an intranet and can't be accessed outside of Hong Kong.

[H721]

spannersatcx,
isn't it true u can hv remote access to galacx(spelling!)? i know there are dial-up # outside hkg. guess this can link to in-house online manuals.

------------------
Not much of an engineer

[spannersatcx]

Trouble is H721 I have to pay to use RAS, whereas my Internet ISP is free of all telephone charges, so I won't use RAS at Home I'm not that much a co man!
Thanks anyway.

[CCA]

A mate with QF said he tried it the other day pneumatics and electrics and the system went into Primary Electric for LE and TE (400) said something about the FCU only knows Normal,Primary Elec and Sec Elec so once the TE is Primary Elec then so is the LE ?

[This message has been edited by CCA (edited 10 October 2000).]

[gas path]

Unless QF is different the L/E flaps will run with pneumatics if it is available.
The classic also, with alternate T/E selected; if pnematics are available the L/E flaps will run when the T/E flaps are not up.
The sequence is; Group A flaps 6 thro' 21 when the T/E is approx 1/4 degree, the remaining flaps Group B will extend as soon as the flap lever is moved from 1 to 5 units.
Hope that helps.......

[QAVION]

"A mate with QF said he tried it the other day pneumatics and electrics and the system went into Primary Electric for LE and TE (400) said something about the FCU only knows Normal,Primary Elec and Sec Elec so once the TE is Primary Elec then so is the LE ?"

The strange thing is, I tried it today on a Qantas 400 (in response to this message), and the leading edges did deploy pneumatically (VH-OJU).

The situation was this:
Bleed air coming from the APU _with Bleed Isolation Valves open_.
All hydraulic pumps off.
All circuit breakers set.

Flaps 1 selected:
LE flaps (inboard) deployed in less than 10 seconds (definitely not electric). An observer on the ground also confirmed the flaps were making pneumatic sounds).

Then... Flaps 5 selected:
Leading edge flaps(remaining ones) deployed pneumatically in basically the same time period. The Upper EICAS showed an expanded flap display (reflecting that the TE flaps had gone into Primary Electric mode).

Perhaps your mate had forgotten something (CB's, Isolation Valves)?

Note that the Classic logic varies from this.

Rgds.
Q.

[CCA]

Cheers Qavion,

I'll give him a blast when i next talk to him. Do work at the Sydney Jet base.