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Expert advice needed about towing procedures

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Author Post
Member
Registered: Jan 2014
Posts: 299
Location: France (LFQQ)
Hello,

I am writing an enhanced towing and sound environment for my simulator usage, and I have a question.

In the before start sequence, the HYD demand pump 4 must be set to AUX position and after the 1,2 and 3 must be set to AUTO position. I saw also that some caution have to be taken before to pressurize the hydraulics, in order to avoid some flight controls or steering controls to move and injury some ground persons.

My question is : do the captain contact the towing crew to request clearance before to set the HYD demand pumps to AUX/AUTO ?

Thanks
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Jean-philippe
« Last edit by JP744 on Fri, 10 Jul 2015 11:15:46 +0000. »
Member
Registered: May 2009
Posts: 374
Location: LLBG
Yes.
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Avi Adin
LLBG
Member
Registered: Jan 2014
Posts: 299
Location: France (LFQQ)
Avi wrote
Yes.


Short answer, but this is all I needed. Thanks a lot Avi.
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Jean-philippe
Member
Registered: May 2009
Posts: 374
Location: LLBG
Simple question requires simple answer, not complications :)
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Avi Adin
LLBG
Member
Registered: May 2010
Posts: 843
These days, there can be a considerable amount of communication between the flight deck and the ground (and vice versa).

Flight deck to ground:
Notification of last minute engineering problems in the cabin or on the flight deck
Clearance for hydraulics
Clearance to start APU (to put on bleed air and packs). See Aerowinx Forum message thread on simultaneous use of ext conditioned air and packs.
Last minute fuel uplift revisions (Don't let the fueller disconnect/drive away!)
Notification that the aircraft is now using APU Electrics (sometimes the indicator lamps don't work on the Ext Power panel downstairs, so the engineers don't know if it's ok to disconnect external power).
Thoughtful updates on pushback delays (pax problems, weather problems, flightplan changes, etc). Sometimes the crew want to remain on the ground a little longer because they might get to the arrival airport before early morning curfews are lifted. Ground staff start to get a bit fidgety if the departure time has passed and the flight crew hasn't called them.
Requests for updates on estimation of completion of cargo loading (e.g. how many pallets/bags to go)
Clearance to release Park Brake early (to fool the ACARS into thinking the aircraft has pushed back... so the ontime departure reports look better :P )
Notification of which direction the aircraft needs to be pushed (sometimes the directions are standard, but a tailwind might be too strong for a normal engine start).
Park brake released call (so engineers can push the aircraft). Not all 744's are fitted with park brake indicators on the nosewheel.
Notification of a tower-requested extended pushback (To allow other aircraft to move to various positions).
Completion of engine start.
Notification of problems during/after start.

Ground To Flight Deck
Report of completion of fuelling ... i.e. are you happy with what's on board?
Hints to the flight deck that the engineers/groundstaff want to remove Ext Air/Ext Power/Conditioned Air... otherwise a delay might ensue. The process can take 5~10 minutes depending on manpower availability.
Some airlines require a call to the flight deck to say that all is ok on the ground for pushback (before the flight crew call the tower for pushback clearance). Sometimes the tug is late getting to the aircraft. Sometimes there are vehicles/equipment/aerobridges still in position that the pilots are not aware of.
"Lifting aircraft" call if the tug is the type which lifts the nosewheel (the crew might interpret aircraft movement as the aircraft rolling away uncommanded.
"Commencing pushback" call, so the flight crew know the aircraft is about to move. e.g. sometimes the push is delayed depending on aircraft taxying behind the pushback aircraft.
Delayed clearance to start engines call during pushback. The jet blast might affect aircraft/people/buildings behind the pushing aircraft.
"See you on the Left/Right side" of the aircraft (Normally the engineers/pushback crew will return go to the side where the departure gate was, but circumstances may dictate otherwise.
Common courtesy call e.g. "Disconnecting (interphone), have a good flight".
"Roger"/"Wilco/Will Do" calls to acknowledge every call from the flight deck.

There are some very precise communications when an Ext Air-assisted engine start is required at the gate.

Of course, anything can and will go wrong which require comms between the flight deck and ground: Tow bar breakages, engine fuel leaks, tailpipe fires (during engine start) and brake fires which don't yet show up on EICAS (on arrival).... :mrgreen:
Member
Registered: Jan 2014
Posts: 299
Location: France (LFQQ)
Thank you so much John. Your very precise description will help me for building multiple scenarios (normal way and maybe some unlikely delays or last minute issues reported by ground staff to get various scenario). It is very nice ;)

I guess the communications during arrival at the gate are about the reverse ? Excluding engine start and pushback of course.

- Technical issues report during the flight (aircraft status)
- EXT PWR connexion clearance ?
- Parking brake status / chocks in place ? Don't know the exact procedure :(
- Other items ?

Cheers

Edit : The casting is open to find the towing guy who will record many sounds for the program :D :D
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Jean-philippe
« Last edit by JP744 on Fri, 10 Jul 2015 11:33:19 +0000. »
Member
Registered: May 2010
Posts: 843
Like the departure, the arrival depends on the airline procedures and if the staff are up to date with their hourly updated memos :P There is usually a written procedure somewhere for each airline, but there were many changes over the years and, inevitably there was a lot of improvisation.

As a former ground engineer, I just used to say in one breath.

Ground to Flight Deck (or Flight Deck - Ground), good morning/afternoon/evening, wheels chocked. Sometimes my wheels chocked message was lost as the pilot quickly and politely answered my good morning/afternoon/evening. If the flight crew didn't hear the wheels chocked, then they would ask us later.

The flight deck would respond with various items such as time-on-chocks, fuel remaining and maintenance events. We didn't have photographic memories or notepads, 3 hands and shorthand writing abilities, but we got a general idea of what was going on :P If the arrival engineer was an expert in the maintenance problems being reported, he/she would ask for more details. Often you could get a lot more helpful information from the pilots, verbally, than was written in the logbooks. If you met the crew on the aerobridge, the whole crew would chime in (and you'd get an even better picture). However, as staff numbers shrank at our airline, we'd still be busy downstairs 15~20 minutes after arrival, so tended to miss them. In some cases, the flight crew would ask for our immediate presence upstairs (especially if a passenger had lost something important in the mysterious cavities of the Business/First Class seats). In this case, we rushed straight up... hoping that a supermodel had lost something :P Hopefully a supermodel option will be included in PS11???

Some airlines release the park brake most of the time during turnarounds (so we had to make sure the chocks were really in tight). Sometimes the pilots would tell us that they wanted to release the park brake because of hot brakes and we would double check that that the wheels were securely chocked (and, of course, there were no flames coming from the undercarriage) :P

I roger-ed whatever the pilots said and then said Please standby for external power and air if the crew hadn't already asked if we were going to put it on. Before the airlines got really conscientious about APU fuel saving, we just used to say Roger, standing by (in case they wanted to talk to us about something else later). Because they were generally in a hurry to leave the aircraft and, in many cases, external power and air was only available if the aerobridges were parked firmly against the aircraft (which took time), we would sometimes hear the ground crew call horn sounding before we had finished hooking everything up. It took time to position mobile stands to help plug Ext Power in and in some cases Ext Air (the connection Ext Air is a little lower to the ground, but still often needed tall guys). In some cases the pilots didn't call us and just left the cockpit, so we had to go and switch over from APU to Ext ourselves. There were a quite a few physical injuries occuring during external power installation/removal, so we would tend to take our time doing this. I had several weeks off work because of related injuries, so I usually did things slowly ....or left this work to younger/stronger folks ;)

The Ext Power AVAIL lights in the cockpit were usually operative, so the pilots put the Ext power on as soon as we provided it (No permission necessary). As long as the pilots switched off the packs, we didn't have to remind them to do so before plugging in ground airconditioning. With the packs off, the pilots can actually hear the external conditioned air coming through the vents, so they would know we'd put it on (and wouldn't need to contact us).

If the APU was U/S on arrival, the procedures would be different. We would get an external mobile electrical power cart ready for the arrival and hook it up prior to all engine shutdown. If no mobile power carts were available, there were ways of bypassing the interlocks on the aerobridge-sourced power supplies. When using this type, when the aerobridge came in, it was important that its wheels didn't run over the installed power leads. This method definitely wasn't recommended.... It's just too difficult to maintain communications with the aerobridge driver. The bridge has cutout pushbuttons if you wanted to stop the bridge moving, but, if your timing was off, you would probably get run over, too, trying to push the button.

PSX has the option to provide only one source of external power. The 744 will run on one power lead (in real life), but it's not recommended. The lead gets quite "warm", especially if everything is turned on (recirc fans, fuel pumps, elec hydraulic pumps, etc). There may be electrical loadshedding under such circumstances.

Looking forward to hearing the old/bold pilots' perspective :mrgreen:

Rgds
JHW
Member
Registered: Jan 2014
Posts: 299
Location: France (LFQQ)
Your experience share is very instructive and useful. It's a pleasure to read you. Again, thank you John.

Regards
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Jean-philippe
Member
Registered: Aug 2014
Posts: 375
Location: Camberley, UK
Definitely old, and no longer bold!
I think you got the complete set there John!
As he says, in real life, comms can be quite protracted. John's excellent description gives an insight into day-to-day operations.
One thing that might help is that many airlines have an EXACT phraseology for pushback which ensures there is no ambiguity for such things as PARK BRAKE set or release.
( this ensures that we don't
run over valuable peeps like John)

Cheers

Peter

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