Few SLF questions about airline flying
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Few SLF questions about airline flying
Hello. A few unrelated questions stemming from pure curiosity prompted by recent flying experiences:
1. Whenever I fly short haul in Europe, it always seems to be the captain who speaks to us on the outbound leg and informs us that the FO will be flying us to our destination. And in the return leg, the FO speaks and tells us the captain is doing the flying. Why does it always seem to be this way around? Is it so the FOs get experience of flying approaches into a range of foreign airfields, or is there just some nautical tradition of the captain always bringing the ship home or something?
2. Got to departure gate very early recently, in time to see our aircraft arrive from previous flight. Once it had stopped and shut down, someone in the ground crew opened a cap in the ground and connected some cables to an insert on the fuselage underneath the nose. Another passenger made a comment about them "refuelling" it....but it looked like cables to me rather than pipes and I was pretty sure the refuelling was being done by the big fuel truck parked at the side with the connection to the wing area. I just couldn't correct the guy because...although I was pretty sure this connection to the ground wasn't fuel related, I had no idea what it actually was.
3. I know that you fly SIDs outbound and STARs inbound, and that they're made up of a series of waypoints that tend to be based on distances along radials from certain beacons. But what I've often wondered is whether you can programme in these SIDs and STARs to the computer and just fly them, from waypoint to waypoint, without having to get ATC's permission for each turn, or whether you actually have to be authorised to make each course change even if you're on autopilot following a well defined track? In other words, I guess I want to understand, particularly when you're in the immediate vicinity of an airport, to what extent you can make heading and altitude changes based on...just your flight plan or how much has to be directed by ATC?
Thanks in advance for any insight.
1. Whenever I fly short haul in Europe, it always seems to be the captain who speaks to us on the outbound leg and informs us that the FO will be flying us to our destination. And in the return leg, the FO speaks and tells us the captain is doing the flying. Why does it always seem to be this way around? Is it so the FOs get experience of flying approaches into a range of foreign airfields, or is there just some nautical tradition of the captain always bringing the ship home or something?
2. Got to departure gate very early recently, in time to see our aircraft arrive from previous flight. Once it had stopped and shut down, someone in the ground crew opened a cap in the ground and connected some cables to an insert on the fuselage underneath the nose. Another passenger made a comment about them "refuelling" it....but it looked like cables to me rather than pipes and I was pretty sure the refuelling was being done by the big fuel truck parked at the side with the connection to the wing area. I just couldn't correct the guy because...although I was pretty sure this connection to the ground wasn't fuel related, I had no idea what it actually was.
3. I know that you fly SIDs outbound and STARs inbound, and that they're made up of a series of waypoints that tend to be based on distances along radials from certain beacons. But what I've often wondered is whether you can programme in these SIDs and STARs to the computer and just fly them, from waypoint to waypoint, without having to get ATC's permission for each turn, or whether you actually have to be authorised to make each course change even if you're on autopilot following a well defined track? In other words, I guess I want to understand, particularly when you're in the immediate vicinity of an airport, to what extent you can make heading and altitude changes based on...just your flight plan or how much has to be directed by ATC?
Thanks in advance for any insight.
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1) Normally, a captain and co-pilot would take turns. However, there are situations in which it would always be the captain flying the plane. Certain aerodromes, for example, are captains-only aerodromes. On the other hand, some captains let the co-pilot fly the first leg when they haven't flown for a while, like after their holidays. No nautical tradition, though.
2) Sounds very much like the ground power cable. Your are right about the refuelling ports being under the wings. Another hose often seen is the one for the air conditioning which is mostly plugged-in under the fuselage.
3) ATC will clear you for a STAR or SID. If you are cleared for one you are obliged to follow the published route. Very often, however, ATC will give you radar vectors, i.e. they tell you to fly a certain heading. But generally it's always ATC who tell you what to do.
2) Sounds very much like the ground power cable. Your are right about the refuelling ports being under the wings. Another hose often seen is the one for the air conditioning which is mostly plugged-in under the fuselage.
3) ATC will clear you for a STAR or SID. If you are cleared for one you are obliged to follow the published route. Very often, however, ATC will give you radar vectors, i.e. they tell you to fly a certain heading. But generally it's always ATC who tell you what to do.
2. Ground Electrical Power (GEP) 115v 400Hz.
Sometimes known as FEP (F = Fixed). During the turn-round the aircraft needs to be powered electrically. The APU (Auxiliary Power Unit) often does the job especially if air conditioning is required, however some airports have 'green' policies that prohibit APU usage and insist the FEP is used. It also keeps the noise down on the apron.
Edit, HV... got there before me.
Sometimes known as FEP (F = Fixed). During the turn-round the aircraft needs to be powered electrically. The APU (Auxiliary Power Unit) often does the job especially if air conditioning is required, however some airports have 'green' policies that prohibit APU usage and insist the FEP is used. It also keeps the noise down on the apron.
Edit, HV... got there before me.
Last edited by TURIN; 12th Sep 2011 at 22:16. Reason: cross posting
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The STAR usually takes you as far as the holding area near the airfield. Thereafter, everything is radar controlled in terms of heading, altitude and speed.
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Thanks for the responses so far guys, very interesting. I knew about APUs but I had no idea they shut them down during a turn around for environmental/noise reasons.
What criteria make an airfield "captains only"? And is that a designation the operators of the airfield make, or the aviation authority, or the airline?
What criteria make an airfield "captains only"? And is that a designation the operators of the airfield make, or the aviation authority, or the airline?
I knew about APUs but I had no idea they shut them down during a turn around for environmental/noise reasons.
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Main reasons for using ground power is to save on fuel. Let's say a 738 does 6 sectors in a day, with an hour turnaround per sector, having an APU running for 6 hours can add quite a bit to the fuel bill 
Also, if the aircraft was to get a slot delay of lets say one or two hours, keeping the APU running may require a fuel top up before they can depart.
Some airlines where I work don't even turn the APU on once they've landed, just come straight onto stand and get GPU/FEP power plugged in as soon as they've come to a stop.
Also, if the aircraft was to get a slot delay of lets say one or two hours, keeping the APU running may require a fuel top up before they can depart. Some airlines where I work don't even turn the APU on once they've landed, just come straight onto stand and get GPU/FEP power plugged in as soon as they've come to a stop.
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Some airlines where I work don't even turn the APU on once they've landed, just come straight onto stand and get GPU/FEP power plugged in as soon as they've come to a stop.
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I would suggest it costs more to use FEP/GPU than a few kgs of fuel.
What makes me laugh is that inbound they will shut an engine down and leave the apu start for when turning onto the gate, yet the outbound crew put the apu on for over an hour before departure!
What makes me laugh is that inbound they will shut an engine down and leave the apu start for when turning onto the gate, yet the outbound crew put the apu on for over an hour before departure!
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What criteria make an airfield "captains only"? And is that a designation the operators of the airfield make, or the aviation authority, or the airline?
Some airlines, however, follow a different policy. They want their co-pilots to land at and depart from all aerodromes, so the co-pilots can learn and become experienced captains.
An APU on a 737/A320 will burn about 100kg an hour - roughly $90 at current fuel price. A 747 will burn 1000kg an hour. As to where APUs will be used, it may be the airport demands APUs can only be used in the 20 minutes prior to departure for environmental reasons. That's when you discover the airport charges a lot for the use of ground power! But that is the crux. In our operation, we tend to use ground power / air con at our home base because we have negotiated a good deal with the airport. At nearly all our airports we use the APU because it's cheaper.
Captains usuallly do the PA because (so we're told) the passengers want to hear the Captains voice for reassurance. First officers often do the outbound leg because the Captain usually gives them the choice of sector, and most chose not to fly into the home base so they get experience of all the outports. But some they can't fly to. Sometimes the company operations manual will limit the weather conditions First Officers can operate in - for example, 20 knots cross wind is a typical limit. And also some airports are more difficult.
Airports are usually categorised Cat A,B or C. A means few difficulties, B means some difficulties and C means significant dificulties. Cat C airports are invariably Captain only operating. We have two Cat C airports on our network. Kathmandhu in Nepal (a very steep non precision approach over terrain) and Busan in Korea (a very tight and difficult circling approach). Both are Captains only, partly for difficulty, but also becuase special simulator training is required for these airfields and it's cheaper to train just half your pilots to do the handling.
Captains usuallly do the PA because (so we're told) the passengers want to hear the Captains voice for reassurance. First officers often do the outbound leg because the Captain usually gives them the choice of sector, and most chose not to fly into the home base so they get experience of all the outports. But some they can't fly to. Sometimes the company operations manual will limit the weather conditions First Officers can operate in - for example, 20 knots cross wind is a typical limit. And also some airports are more difficult.
Airports are usually categorised Cat A,B or C. A means few difficulties, B means some difficulties and C means significant dificulties. Cat C airports are invariably Captain only operating. We have two Cat C airports on our network. Kathmandhu in Nepal (a very steep non precision approach over terrain) and Busan in Korea (a very tight and difficult circling approach). Both are Captains only, partly for difficulty, but also becuase special simulator training is required for these airfields and it's cheaper to train just half your pilots to do the handling.
spanner....
....the outbound crew put the apu on for over an hour before departure!
Even in the non-tropical UK it's not unusual to see cabin temps in the low to high 30's (celsius) if the aircraft has been sat on the ramp for a couple of hours with with no conditioning, and once the pax start boarding the temp may climb even further..not great (and perhaps even positively dangerous) for crew or the paying passengers.
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Usually the airlines themselves designate certain fields "captains only" in their operations manuals. Aspects like strong and gusty winds, steep approach paths or difficult terrain (mountains) could lead to such a classification. Prominent examples are Funchal, Gibraltar, Innsbruck and the old Hong Kong Kai Tak airport.
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Sorry to nit pick ,most aircraft use 200volts 400cycles 3 phase as power and use 1phase to get the required 115 volts for smaller voltages which then use transformers for 28 volts that was 16 years ago when I retired and there are a lot of planes still using this system and cannot for the life of me think why they would change and that is/was the power supplied by the mobile and static G.P.U.s In the days of electric starting for the Comets we had triple power mobile G.P.U. 200volt ac for the Tridents though they were air started 112 volts DC for the starter motors of the Comets and 28volts DC for all the Viscounts ,Vanguards ,Dakotas ect which were electric started. The actual G.P.U. plugs into the aircraft were made so the wrong plug could not be fitted into the wrong power point.OH JOY!!!
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Both are Captains only, partly for difficulty, but also becuase special simulator training is required for these airfields and it's cheaper to train just half your pilots to do the handling.
The FO diverts to the alternate
To be honest, if the FO went ill or incapacitated it's highly likely a Captain would also divert to an easier airfield for the single pilot approach/landing.
To be honest, if the FO went ill or incapacitated it's highly likely a Captain would also divert to an easier airfield for the single pilot approach/landing.
