novice
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Non Precision Approach 1engine Inop (b737)

Mon Aug 13, 2012 10:19 pm

From what i know from my notes once you have the runway in sight you;
Intercept the landing profile, disconnect the autopilot and then "recycle the FD's"

Now i presume that FD's means flight directors but i don't know what it means by recycling them once the autopilot is disconnected, does any one have any insight on this?
 
novice
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RE: Non Precision Approach 1engine Inop (b737)

Mon Aug 13, 2012 10:30 pm

I take it means resetting the flight directors?
 
tdscanuck
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RE: Non Precision Approach 1engine Inop (b737)

Tue Aug 14, 2012 1:59 am

Quoting novice (Thread starter):
Now i presume that FD's means flight directors but i don't know what it means by recycling them once the autopilot is disconnected, does any one have any insight on this?

It's usually called "cycle" rather than "recycle" but it means "turn them off and back on."

The flight director is a separate thing from the autopilot and has it's own switches.

Tom.
 
BoeingGuy
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RE: Non Precision Approach 1engine Inop (b737)

Tue Aug 14, 2012 3:37 pm

I'm not clear why you would ever cycle the Flight Director Switches in flight. The only time I know to do that is on the ground if you landed and want to re-set the autoflight modes to the TO/GA mode without having de-powered the airplane.

In flight you'd simply select whichever Flight Director and/or Autopilot roll and pitch modes that you wish on the Mode Control Panel (e.g. APP, HDG SEL, V/S, LNAV, VNAV, etc).

[Edited 2012-08-14 08:38:12]
 
tdscanuck
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RE: Non Precision Approach 1engine Inop (b737)

Tue Aug 14, 2012 4:44 pm

Quoting BoeingGuy (Reply 3):

I'm not clear why you would ever cycle the Flight Director Switches in flight.

I don't know why you'd do it after autopilot disconnect. There are some circumstances where you might cycle the flight directors to clear out a failed mode.

Tom.
 
novice
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RE: Non Precision Approach 1engine Inop (b737)

Wed Aug 15, 2012 9:08 pm

In my mcc notes with a non-precision approach with 1 engine, once you have the runway in sight you;
intercept the landing profile, disconnect autopilot and then recycle the FD's then at MDA set missed approach altitude in MCP followed by the missed approach and the various checks associated with going missed.

Quoting BoeingGuy (Reply 3):
In flight you'd simply select whichever Flight Director and/or Autopilot roll and pitch modes that you wish on the Mode Control Panel (e.g. APP, HDG SEL, V/S, LNAV, VNAV, etc).

I have never used flight directors's before what way does it work, how is it possible to have flight director and autopilot on at the same time? i thought flight directors show you where to fly, also i noticed that you used 'autoflight' and 'autopilot' is there a difference between these?
Cheers
 
tdscanuck
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RE: Non Precision Approach 1engine Inop (b737)

Wed Aug 15, 2012 10:47 pm

Quoting novice (Reply 5):
I have never used flight directors's before what way does it work

It puts a target for the pilot that you should follow if you want to fly the chosen flight profile (on the PFD for the relevant airplanes, a crosshair on the artificial horizon on older designs). The flight director gets its commands from the MCP (or FMC if you're in a VNAV or LNAV mode) and shows the pilot where to fly to achieve those commands.

Quoting novice (Reply 5):
how is it possible to have flight director and autopilot on at the same time?

The flight director is a display. The autopilot controls the airplane. If just the flight director is on (and autopilot is off) the pilot flies at the flight director. If just the autopilot is on (and the flight director is off) the autopilot follows the MCP/FMC and there is no display of the airplane's target on the PFD. If the autopilot and flight director are both on then the autopilot does the same thing and you'll see the target on the PFD; if the autopilot is working properly then the target will remain centered all the time (i.e. it will look like the autopilot is "following" the flight director).

Quoting novice (Reply 5):
i thought flight directors show you where to fly

They do. The autopilot does the same thing the pilot does...go where you're supposed to fly. Except the autopilot doesn't have eyes, so can't see the PFD, so doesn't need the flight director display to actually be on.

Quoting novice (Reply 5):
also i noticed that you used 'autoflight' and 'autopilot' is there a difference between these?

Autoflight is a function or capability. It includes the autopilot and other automated fuctions, such as autothrottle or autoflight. The autopilot is, specifically, the box/widget/machine that actually flies the airplane when the pilot isn't. The autopilot is part of the autoflight system.

Tom.
 
KELPkid
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RE: Non Precision Approach 1engine Inop (b737)

Fri Aug 17, 2012 12:33 am

Just a note that in a twin, with an engine out, it is generally adviseable to try and find a precision approach to get down...a nonprecision approach single engine is a last resort. There have been many, many VMC accidents in twins operating on one engine levelling out after descending to the next step down altitude    Of course, with a flight crew, it helps that one pilot can monitor airspeed constantly during the approach...
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
novice
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RE: Non Precision Approach 1engine Inop (b737)

Tue Aug 28, 2012 8:47 am

Thanks for the help guys, Tom that has cleared a few issues up thanks  

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