sxmarbury33
Posts: 405
Joined: Fri Oct 20, 2000 5:41 am

Pre And Post Flight Systems Question

Sun Sep 28, 2003 2:05 pm

This is a series of questions directed mostly at pilots flying turboprops to 747's.

Ok from what ive seen as an aircraft pulls up to the gate the parking brake is set the engines are shut down the beacon is turned off fuel and hydralics are turned off the IRU's are "shut down" (where the PFD goes the black color) and the APU and airconditioning stays on. The pilots then say goodbye and leave the aircraft for the next crew. These are just my observations as a passenger and im sure i left out a few things but ive always wondered what else goes on behind the scenes. Also what factors determine what state the flightdeck is left in eg time of stopover etc. Is it rare for a crew to come into the plane to a totally powerless aircraft and then have to power the apu and get all the systems ready?
One other thing ive always been interested in asking a pilot is, what the time line is for getting a flight ready behind the scenes.


 
AAR90
Posts: 3140
Joined: Fri Jan 21, 2000 11:51 am

RE: Pre And Post Flight Systems Question

Mon Sep 29, 2003 7:20 am

...but ive always wondered what else goes on behind the scenes.

There are a lot of checklist items, but basically you secure the aircraft so it can safely sit for a while without problems.

Also what factors determine what state the flightdeck is left in eg time of stopover etc.

Does the plane go back out? If so, how soon?

Is it rare for a crew to come into the plane to a totally powerless aircraft and then have to power the apu and get all the systems ready?

Relatively rare. Normally only the "first flight of the day" for that aircraft and only if it was parked overnight at that specific gate.

One other thing ive always been interested in asking a pilot is, what the time line is for getting a flight ready behind the scenes.

Approx. 45-90 minutes for my first flight that day. Less if I've already been in the air [already know the wx basics, etc.].
*NO CARRIER* -- A Naval Aviator's worst nightmare!
 
CX Flyboy
Posts: 6030
Joined: Sun Dec 26, 1999 6:10 pm

RE: Pre And Post Flight Systems Question

Mon Sep 29, 2003 11:05 am

For the timeline, we arrive at the aircraft an hour before. At home base we will already have looked at the paperwork. At outports we will examine the paperwork first. This takes 5-10minutes depending on the day. We then examine the logbook for a history of defects on the aircraft. This takes 5 minutes or so. So, STD-45-50mins the PNF does a cockpit check and then a walkaround. This takes 10 minutes or so. The PF starts programming the FMC. On a long flight this will take longer, but normally takes around 5-10 mins. Between having drinks and chatting to the engineer, at around STD-25 mins, both pilots have gone through the FMC. Paperwork begins to appear and time is spent checking it all and inputting relevant data into the FMC. At STD -15mins we start our various briefings, eat sandwiches, get drinks refills and at STD-5 we call ATC for our clearance. Doors should be closed around this time and we get going on time or a couple of minutes early.

Of course this varies from day to day. Sometimes we are finished very early, sometimes we work hard to get out on time, Depends how many defects there are, whether the MEL (Minimum Equipment List) needs to be referred to etc..
 
Shenzhen
Posts: 1664
Joined: Wed Jun 25, 2003 12:11 pm

RE: Pre And Post Flight Systems Question

Mon Sep 29, 2003 12:50 pm

Generally speaking, the flight crew do not power an airplane. The maintenance guys should have been out at the airplane before the crew arrives and started APU and made sure there were no obvious show stoppers.
 
sxmarbury33
Posts: 405
Joined: Fri Oct 20, 2000 5:41 am

RE: Pre And Post Flight Systems Question

Tue Sep 30, 2003 8:44 am

cx flyboy very interesting. Can you relate that back to what the passengers are doing during the different phases, like boarding, waiting outside the gate, checking in etc. and when catering baggage comences and ends. Also when an aircraft comes in for a flight out in 1 to 2 hours will the aircondingitong and APU be left on. Is the aircondintioning ever turned off for passenger disembarkment, whenever i leave an aircraft it usually sounds like its still going. Are GPU's used a lot? Do the IRU's need to be turned off before and realigned for every flight? And lastly how different is the preflight procedures for a short range flight compared to a long range flight. I realize i asked a lot of questions so if anyone feels like awnsering just one or two any help would be appreciated
 
CX Flyboy
Posts: 6030
Joined: Sun Dec 26, 1999 6:10 pm

RE: Pre And Post Flight Systems Question

Tue Sep 30, 2003 11:22 am

Sxmarbury33,

Normally we start boarding at STD -35 to 30mins. Normally by this stage both pilots are back in the cockpit and working in there. Before that, in the cabin, the catering and cleaners are on board. After they leave, the cabin crew carry out their security check. The ground engineer potters around all during this, fixing any aircraft or cabin defects there may be, with a priority obviously on anything which means seats are cordoned off, or things which affect the actual aircraft flying.
Having a galley right behind, us we hear the champagne bottle go "pop". This means that it's 5 mins to passenger boarding normally.
Ground aircon and power depends on the airport. Some always have it ready, and ask you to turn off the APU for noise reasons as soon as ground power/air is established. NRT and BKK are like this. Some airports like BOM don't have the luxury.
 
CX Flyboy
Posts: 6030
Joined: Sun Dec 26, 1999 6:10 pm

RE: Pre And Post Flight Systems Question

Tue Sep 30, 2003 11:29 am

On the 777 we have something called the ADIRU, which is a single unit which cpombines all the IRUs etc, but offers redundancy. We only cycle this at the beginning of the day, and before each ETOPS flight. For a normal turnaround we don't touch it. Modern navigation is so accurate that the IRUs don't wander too much as they are constantly updated with GPS positions.

Preflight for a short flight and a long fliht are pretty much the same. The only difference is that we have more wind information to input into the FMC. You see, we enter the expected wind at various flight levels in order for the FMC to more accurately calculate ETAs and fuel flow. For a long flight we enter more of this, and it is the most time consuming part of the FMC preflight. Also, for a short flight we normally enter an arrival STAR, whereas on a long flight we leave it till we are airborne, and then play with it.
 
Shenzhen
Posts: 1664
Joined: Wed Jun 25, 2003 12:11 pm

RE: Pre And Post Flight Systems Question

Tue Sep 30, 2003 1:05 pm

""Modern navigation is so accurate that the IRUs don't wander too much as they are constantly updated with GPS positions""

Just thought I would add a little here, not saying you aren't correct. The ADIRU does not use the GPS to correct any ADIRU errors, only for calibration of the internal sensors (gyros and accelerometors) which helps reduce drift.

The only reason I thought to add this, is because we wouldn't want anyone to think the ADIRU could be led astray by the GPS system, since it is really the only independent nav source on the airplane.

Cheers
 
ba299
Posts: 182
Joined: Wed Jun 04, 2003 9:18 pm

RE: Pre And Post Flight Systems Question

Tue Sep 30, 2003 9:26 pm

Talking about long range flights, here in BA when we board the aircraft are already powered by the maintenance guys, so we jump on the aircraft and we run our cockpit preparation procedure (I prefer to use my QRB during this procedure). After landing the only thing that we do are to turn off fuel and hydraulics the APU and connect the GPU and a few of other items such as check the flaps handle and a lot of paper work.
About insert the wind in the FMC normally we insert the first 4 or 5 the other are insert during the flight (the classic killing time thing to do during the cruise).
 
CX Flyboy
Posts: 6030
Joined: Sun Dec 26, 1999 6:10 pm

RE: Pre And Post Flight Systems Question

Wed Oct 01, 2003 10:29 am

Shenzhen,

I had a feeling someone would pick me up on that!! Big grin

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