Why are there so little cockpit announcements?
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Hampshire Hog Thanks From All Of Us!!
Once again HH super posts;
I now don't feel so bad about engine noise and am going to put those thoughts into motion (ha ha) when I next fly in October. The volcanic ash incident has been discussed on here not too long ago (try archives) because there was someone who actually got to speak to that pilot about that incident (he made some sort of joke) and met with probably half a dozen expletives in jest, but fantastic achievement to that pilot for re-starting engines mid-flight and landing the plane; phew!! As for multi-tasking, thanks for re-typing all these points for us (shouldn't you be reading briefs???
); I never have the time at work to go into pprune, so I hog the computer in the study at night!! 
I really, really appreciate all your sterling posts HH, and I hope that all others reading too feel the same and that you have helped them to overcome one or two or their gremlin fears of flying! I hope that you do do pressurisation and air systems; this is so much light relief from legal jargon!
Gorgeous
I now don't feel so bad about engine noise and am going to put those thoughts into motion (ha ha) when I next fly in October. The volcanic ash incident has been discussed on here not too long ago (try archives) because there was someone who actually got to speak to that pilot about that incident (he made some sort of joke) and met with probably half a dozen expletives in jest, but fantastic achievement to that pilot for re-starting engines mid-flight and landing the plane; phew!! As for multi-tasking, thanks for re-typing all these points for us (shouldn't you be reading briefs??? ); I never have the time at work to go into pprune, so I hog the computer in the study at night!! I really, really appreciate all your sterling posts HH, and I hope that all others reading too feel the same and that you have helped them to overcome one or two or their gremlin fears of flying! I hope that you do do pressurisation and air systems; this is so much light relief from legal jargon! Gorgeous
Gender Faculty Specialist
Just a small correction if I may HH.
If an engine fails before V1 (stop/go speed if you like) we will stop, no questions. This is due to the reduced acceleration performance of the aeroplane and if we tried to continue the takeoff we would, probably, run out of runway.
However, if an engine fails between V1 and Vr (rotate speed; at which we start to pitch up to our climb attitude) then we would continue to accelerate to Vr and climb at the one engine inoperatvie (OEI) speed. This is because we will now be going too fast to stop in the remaining runway length. Although V1 and Vr are, generally, within a few knots of each other (if not the same speed, depends on runway length) you can have certain situations where there can be upto 25 knots difference in the two speeds.
Keep up the good work
If an engine fails before a speed known as V1, the speed at which the aircraft is calculated to be committed to take-off, the pilot will take off at the pre-calculated speed and climb at the single engine climb speed
However, if an engine fails between V1 and Vr (rotate speed; at which we start to pitch up to our climb attitude) then we would continue to accelerate to Vr and climb at the one engine inoperatvie (OEI) speed. This is because we will now be going too fast to stop in the remaining runway length. Although V1 and Vr are, generally, within a few knots of each other (if not the same speed, depends on runway length) you can have certain situations where there can be upto 25 knots difference in the two speeds.
Keep up the good work
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Hi
I Love announcements from the flight deck. I would love a commentry from brakes off to brakes on.
Let me explain: I was on a British Midland flight from Jersey to Birmingham in the early 1990's that shut an engine down (DC9) in mid flight. No announcements made, Why were all the Fire services meeting us on arrival? A few years later ( October 2000) I was on a flight that left LGW bound for JER that never made it due to horrendous conditions that were in the area at the time. Flight crew told us that we were diverting to SOU but we crash Landed at Bournmouth. 6 Months later I was returning to JER from America via LGW when an engine failed on a 146 out of LGW. Comms on this occasion from the Capt was excellent.
Let me fast forward to 8 Sept 06. My Family & I were comming back to LGW from Paphos (PHO) with GB airways. The Captain was fantastic, Introducing himself whilst standing in the aisle, making regular in flight announcements whilst on route and welcoming us to LGW on arrival. This Captain allowed my kids on to the flight deck prior to departure and I have the photos to prove it.
After all of my incidents whilst flying, (over 200 flights with BA in the last 3 years) a Captain like the one from PFO to LGW would help me relax. Please all you Captains talk to your passangers as much as you can.
Thanks
Michael
I Love announcements from the flight deck. I would love a commentry from brakes off to brakes on.
Let me explain: I was on a British Midland flight from Jersey to Birmingham in the early 1990's that shut an engine down (DC9) in mid flight. No announcements made, Why were all the Fire services meeting us on arrival? A few years later ( October 2000) I was on a flight that left LGW bound for JER that never made it due to horrendous conditions that were in the area at the time. Flight crew told us that we were diverting to SOU but we crash Landed at Bournmouth. 6 Months later I was returning to JER from America via LGW when an engine failed on a 146 out of LGW. Comms on this occasion from the Capt was excellent.
Let me fast forward to 8 Sept 06. My Family & I were comming back to LGW from Paphos (PHO) with GB airways. The Captain was fantastic, Introducing himself whilst standing in the aisle, making regular in flight announcements whilst on route and welcoming us to LGW on arrival. This Captain allowed my kids on to the flight deck prior to departure and I have the photos to prove it.
After all of my incidents whilst flying, (over 200 flights with BA in the last 3 years) a Captain like the one from PFO to LGW would help me relax. Please all you Captains talk to your passangers as much as you can.
Thanks
Michael
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Chesty,
Thanks very much for that. I don't know what I was thinking - my fingers must have been running ahead of my brain! What Chesty said was exactly what I meant - and clearly not what I wrote! Lucky I'm not in an A320 yet!
I'm grateful for the correction - please feel free to add more.
More soon.
HH
Thanks very much for that. I don't know what I was thinking - my fingers must have been running ahead of my brain! What Chesty said was exactly what I meant - and clearly not what I wrote! Lucky I'm not in an A320 yet!
I'm grateful for the correction - please feel free to add more.
More soon.
HH
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I'm afraid I'm away for work until Wednesday, so I'll have to apologise for the delay and do air systems and pressurisation in more detail then. A couple of points to keep you going though:
1) In most airliners, air is taken from the engine surrounds and fed into the cabin. Because this is hot, it is usually cooled first by air conditioning packs. There are several of these and one alone can do the job. Temperature is set on the flight deck, so if you are really too hot/cold, tell the cabin crew - if they are any good (and the point is reasonable) they'll tell the flight crew who can alter the temperature. Some airlines (cheapskates) try to cook people in the cabin by keeping the heat higher than it should be - less work for the air conditioning packs uses less fuel = more brownie points.
2) Air density at 38,000 feet is considerably less than at sea level. So much less that there is insufficient oxygen to sustain consciousness in the average human being. In an airliner at 38,000 ft therefore, you need more air density than the ambient density (which is more than enough to fly the plane - just not enough to breathe). It is achieved by pumping air into the cabin at a greater rate than it is let out the back. The outflow (and thus, pressure) is controlled by valves. On most airliners, there are separate types of valve and separate control systems, so all should not be lost at once. This rule may be changing on the new A380, which has several valves from the same manufacturer. The point is, the systems are duplicated.
3) When the cabin is pressurised, you cannot open any doors or emergency exits - even if the nutter in row 9 tries, you'll be perfectly safe. The pressure holds them in place and they will only release once the plane has been de-pressurised.
4) In the extremely unlikely event of a sudden depressurisation, the flight crew will usually put on oxygen masks (passenger masks may also drop - depending on how high you are - put them on straight away - and do yours before helping anyone else, you may have only a short time of useful consciousness). The pilots then turn the aircraft off track, select a safe altitude on the auto-pilot and maximum rate of descent. Because there may be some sudden condensing of water in the cabin (misting), the steep rate of descent coupled with some vibration from the speed brakes (helping to increase the rate of descent and keeping the aircraft below the maximum handling speed) the whole maneouvre will almost certainly scare the life out of passengers - whether or not they are usually fearful flyers. What you need to know is that these incidents are very very rare and that the flight crew will be managing everything for maximum safety using the automatic systems to reduce the risk of human error. Your ears may hurt like hell and your heart may be doing overtime, but this type of incident is very unlikely to kill you. I have asked several pilots about this and I have yet to meet one (personally) who has ever experienced a cabin de-pressurisation for real. They do happen, just not very often, and a good number of those that do are not very dramatic, because they comprise of the cabin failing to pressurise properly when climbing (in which case the climb is just stopped early and, if the destination can be reached at a lower safe altitude, the flight will continue).
5) But what about the Helios accident in Greece? Well, I just don't know about that. It was almost unique as an incident and a whole thread on here has been subject to substantial contribution from people far more qualified than I. However scarey it sounds, I would try to put in the the context of many thousands of flights taking place safely throughout the world every day.
6) Even IF you were slow to put your mask on, you may become unconscious. So long as the pilots descend the plane in a timely fashion, you will simply come around again when there is sufficient air density.
7) So, a VERY RARE event, one of the few that can be genuinely alarming for all concerned, but you are unlikely to suffer anything worse than some lasting deafness (in the event of a perforated eardrum).
Any pilots whose companies have different SOPs for this, I'd be interested to hear about them.
HH
1) In most airliners, air is taken from the engine surrounds and fed into the cabin. Because this is hot, it is usually cooled first by air conditioning packs. There are several of these and one alone can do the job. Temperature is set on the flight deck, so if you are really too hot/cold, tell the cabin crew - if they are any good (and the point is reasonable) they'll tell the flight crew who can alter the temperature. Some airlines (cheapskates) try to cook people in the cabin by keeping the heat higher than it should be - less work for the air conditioning packs uses less fuel = more brownie points.
2) Air density at 38,000 feet is considerably less than at sea level. So much less that there is insufficient oxygen to sustain consciousness in the average human being. In an airliner at 38,000 ft therefore, you need more air density than the ambient density (which is more than enough to fly the plane - just not enough to breathe). It is achieved by pumping air into the cabin at a greater rate than it is let out the back. The outflow (and thus, pressure) is controlled by valves. On most airliners, there are separate types of valve and separate control systems, so all should not be lost at once. This rule may be changing on the new A380, which has several valves from the same manufacturer. The point is, the systems are duplicated.
3) When the cabin is pressurised, you cannot open any doors or emergency exits - even if the nutter in row 9 tries, you'll be perfectly safe. The pressure holds them in place and they will only release once the plane has been de-pressurised.
4) In the extremely unlikely event of a sudden depressurisation, the flight crew will usually put on oxygen masks (passenger masks may also drop - depending on how high you are - put them on straight away - and do yours before helping anyone else, you may have only a short time of useful consciousness). The pilots then turn the aircraft off track, select a safe altitude on the auto-pilot and maximum rate of descent. Because there may be some sudden condensing of water in the cabin (misting), the steep rate of descent coupled with some vibration from the speed brakes (helping to increase the rate of descent and keeping the aircraft below the maximum handling speed) the whole maneouvre will almost certainly scare the life out of passengers - whether or not they are usually fearful flyers. What you need to know is that these incidents are very very rare and that the flight crew will be managing everything for maximum safety using the automatic systems to reduce the risk of human error. Your ears may hurt like hell and your heart may be doing overtime, but this type of incident is very unlikely to kill you. I have asked several pilots about this and I have yet to meet one (personally) who has ever experienced a cabin de-pressurisation for real. They do happen, just not very often, and a good number of those that do are not very dramatic, because they comprise of the cabin failing to pressurise properly when climbing (in which case the climb is just stopped early and, if the destination can be reached at a lower safe altitude, the flight will continue).
5) But what about the Helios accident in Greece? Well, I just don't know about that. It was almost unique as an incident and a whole thread on here has been subject to substantial contribution from people far more qualified than I. However scarey it sounds, I would try to put in the the context of many thousands of flights taking place safely throughout the world every day.
6) Even IF you were slow to put your mask on, you may become unconscious. So long as the pilots descend the plane in a timely fashion, you will simply come around again when there is sufficient air density.
7) So, a VERY RARE event, one of the few that can be genuinely alarming for all concerned, but you are unlikely to suffer anything worse than some lasting deafness (in the event of a perforated eardrum).
Any pilots whose companies have different SOPs for this, I'd be interested to hear about them.
HH
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Interesting Post Hh
Thanks HH, interesting; think though that I would prefer not to be on a plane when that happens with the air pressure; pretty damn scary!! Posting at 3am, couldn't sleep? Gorgeous
Gender Faculty Specialist
But what about the Helios accident in Greece? Well, I just don't know about that
A bit of preamble.
With the pressurisation system on our aircraft we have 3 settings: Manual; Auto; Dump. I'm assuming the 737 has a similar system (any 737 chaps want to correct me?). We usually use the system in Auto and it just gets on and does it's thing. Occasionally we have to use Manual if the Auto system is playing silly buggers. This is perfectly safe and a recognised procedure, it just means that we have to pay more attention to the pressurisation and adjust it accordingly. Dump is used for such things as smoke clearance and basically it opens the outflow valves fully to vent the internal air.
Apparently the Helios pressuriation system was left at Dump, I think by the engineers, and it was missed by both pilots during their before start checklist. This then meant that the aircraft would not pressurise. The pressuriation warning was ignored by both pilots, they thought it was related to something else, and ultimately resulted in their incapacitation due to hypoxia.
As an aside. After the last flight of the day we used to select the pressurisation to Dump (I can't recall why) but we now leave it in Auto. Good call I say!
HH and Gorgeous if you're interested. On my type, Dash 8 Q400, there are NO drop down oxygen masks for the passengers. The flight deck has oxygen masks which supply upto 2 hours of emergency O2 if it's needed.
Basically this is because the maximum operating altitude is 25000 feet and the aeroplane had to be able to reach 14000 feet within 4 minutes for certification purposes. Therefore it was deemed unnecessary for passenger oxygen as you would be back in breathable air very quickly. We even have time to request an emergency decent rather than just dive ('scuse the pun!) straight into one.
Check out this link which should allay some of your fears Gorgeous
Interestingly I've heard that the pressurisation can cope with the loss of one window, or a hole the size of one, and still maintain the cabin altitude. I've never tried to prove that though!
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3am, yes well, away for work - too much beer, can't sleep. Thank goodness I'm going home tomorrow - rubbish hotel too
Chesty, thanks very much for that. I've flown on the q400 quite a lot as PAX, I live close to SOU and I guess you probably fly for one of the main operators that flies out of there! (or Scandinavian?)
I never realised that type didn't have masks in the cabin - I guess I never noticed the absence of that part of the cabin crew briefing. Nice plane to fly on though and I really appreciate your professional input here.
I agree with Gorgeous, a depressurisation is one of the most dramatic things that can happen to you on an airliner. I really don't want to scare anyone so, while describing what happens, I would emphasise again how rare that is. It still scares me a little, but I'm content to accept that the chances are very low and that, if I am unlucky enough ever to encounter it, at least I'll know what the procedure is. When I find myself sat in the back worrying about it, I just remember a flight engineer I met who told me, just before his retirement, 'Well I've never experienced one' and neither had any of his colleagues on the flight deck.
Chesty, thanks for the input on the Helios incident. I think I remember reading something about the aircraft failing to pressurise. I still don't understand why two pilots missed or ignored the alarms, but since one of my particular interests is human factors, I guess I'll have to put it down to just that. A bizaar instance of groupthink and possibly miscommunication on the flight deck.
Now you say about the lost window scenario, I remember my dad (who used to work as a scientist in the aviation structures deparment at RAE Farnborough) telling me about the testing of the Comet airliners (on which he flew as a test engineer - with them looking for thunderstorms and spinning the things to see if they would fall to pieces - scary). He also told me about the experiments they did to see what would happen to Concord in the event of a sudden depressurisation. It was designed to hold together, even though all sorts of things might go flying out of the window. Interestingly, there have been a couple of incidents of depressurisation caused by whole sections of aircraft skin being lost (not to mention the occasional window). Few have resulted in hull loss.
As I said, I will add a bit more to this subject when I get home and have sufficient reference material available to me. Thank goodness my PA28 doesn't have such complications!
Gorgeous, if you want to see some of this in practice - I'll be happy to offer you a short flight in a small plane once I've covered all the subjects I intend to cover. Alternatively, you could see if one of the ATPLs on here would be prepared to fly with you on a short trip as PAX. The learning from this can really help. There are also, as you will have seen, commercial companies that offer that kind of thing. I think if you can arrange something informally, you will do just as well for a lot less money.
HH
Chesty, thanks very much for that. I've flown on the q400 quite a lot as PAX, I live close to SOU and I guess you probably fly for one of the main operators that flies out of there! (or Scandinavian?)
I never realised that type didn't have masks in the cabin - I guess I never noticed the absence of that part of the cabin crew briefing. Nice plane to fly on though and I really appreciate your professional input here.
I agree with Gorgeous, a depressurisation is one of the most dramatic things that can happen to you on an airliner. I really don't want to scare anyone so, while describing what happens, I would emphasise again how rare that is. It still scares me a little, but I'm content to accept that the chances are very low and that, if I am unlucky enough ever to encounter it, at least I'll know what the procedure is. When I find myself sat in the back worrying about it, I just remember a flight engineer I met who told me, just before his retirement, 'Well I've never experienced one' and neither had any of his colleagues on the flight deck.
Chesty, thanks for the input on the Helios incident. I think I remember reading something about the aircraft failing to pressurise. I still don't understand why two pilots missed or ignored the alarms, but since one of my particular interests is human factors, I guess I'll have to put it down to just that. A bizaar instance of groupthink and possibly miscommunication on the flight deck.
Now you say about the lost window scenario, I remember my dad (who used to work as a scientist in the aviation structures deparment at RAE Farnborough) telling me about the testing of the Comet airliners (on which he flew as a test engineer - with them looking for thunderstorms and spinning the things to see if they would fall to pieces - scary). He also told me about the experiments they did to see what would happen to Concord in the event of a sudden depressurisation. It was designed to hold together, even though all sorts of things might go flying out of the window. Interestingly, there have been a couple of incidents of depressurisation caused by whole sections of aircraft skin being lost (not to mention the occasional window). Few have resulted in hull loss.
As I said, I will add a bit more to this subject when I get home and have sufficient reference material available to me. Thank goodness my PA28 doesn't have such complications!
Gorgeous, if you want to see some of this in practice - I'll be happy to offer you a short flight in a small plane once I've covered all the subjects I intend to cover. Alternatively, you could see if one of the ATPLs on here would be prepared to fly with you on a short trip as PAX. The learning from this can really help. There are also, as you will have seen, commercial companies that offer that kind of thing. I think if you can arrange something informally, you will do just as well for a lot less money.
HH
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[quote=knobbygb;2797064]Despite all the reasons above, there do seem to be less announcements made these days than, say 10 years ago.
I personally (as just pax) put this down to the fact that pilots these days are less happy in their work - more worried about the latest "security" procedures, threats, management penny-pinching and backstabbing and are generally less inclined to make that extra bit of effort. To be honest I can't blame them. I know that probably isn't true of everyone, but the industry has changed so much... Also, people generally fly much more often now so often don't want the full explanation of exactly what's happening and that everything's going to be OK. I know there are nervous fliers still, but surely less than in the past, in general.
Hey knobby et al
Lets not forget that pilots (& speaking as one), have had their work load in the last 10 yrs drastically increased. By that, I mean having to deal with excess traffic in & around airports.
I still know many pilots, inc yours truly who really enjoy keeping the punters informed & amused, but it can be difficult at times when you know ATC are going to be barrelling in your ear for the next 20 mins - you just can't ignore them. So in response to "knobbygb's" comments above they cannot be any further from the truth.
The majority of my flying takes place in S/SE Asia, & I will always take the time to point out any places of interest along route. Only last week my pax were treated to a rare, but wonderful view of Mt Everest at 25nms during morning twilight. Even though it happened only 15 mins after depature, we still made time to tell the pax.
Next time your pilot takes the time to have a chat with you, remember it might be the only window of opportunity that he/she gets, not because they are lazy sods.
Thanks for letting me rant
HPC
I personally (as just pax) put this down to the fact that pilots these days are less happy in their work - more worried about the latest "security" procedures, threats, management penny-pinching and backstabbing and are generally less inclined to make that extra bit of effort. To be honest I can't blame them. I know that probably isn't true of everyone, but the industry has changed so much... Also, people generally fly much more often now so often don't want the full explanation of exactly what's happening and that everything's going to be OK. I know there are nervous fliers still, but surely less than in the past, in general.
Hey knobby et al
Lets not forget that pilots (& speaking as one), have had their work load in the last 10 yrs drastically increased. By that, I mean having to deal with excess traffic in & around airports.
I still know many pilots, inc yours truly who really enjoy keeping the punters informed & amused, but it can be difficult at times when you know ATC are going to be barrelling in your ear for the next 20 mins - you just can't ignore them. So in response to "knobbygb's" comments above they cannot be any further from the truth.
The majority of my flying takes place in S/SE Asia, & I will always take the time to point out any places of interest along route. Only last week my pax were treated to a rare, but wonderful view of Mt Everest at 25nms during morning twilight. Even though it happened only 15 mins after depature, we still made time to tell the pax.
Next time your pilot takes the time to have a chat with you, remember it might be the only window of opportunity that he/she gets, not because they are lazy sods.
Thanks for letting me rant
HPC
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Thanks Once Again Hh!!! Great Posts
HH, thanks for the response, and I am glad that Chesty has joined in and is adding interesting points. Will wait then for you to cover more things when you are back from your work jaunt. Are you away for a case? Anyhow, THANKS for the offer of the short flight; really really incredible of you, but not sure I'd be ideal company, would scream the whole way through it for you.
Can just about cope with big planes, so am not sure about small aircraft. If, however, you are ever flying near or at MAN please let me know. Would like to come and watch you; that may give me some confidence!!
Thanks Hampshire Hog,
Gorgeous
but not sure I'd be ideal company, would scream the whole way through it for you. Can just about cope with big planes, so am not sure about small aircraft. If, however, you are ever flying near or at MAN please let me know. Would like to come and watch you; that may give me some confidence!! Thanks Hampshire Hog,
Gorgeous
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Gorgeous,
You'll be more than welcome to meet and watch me fly. What would probably be helpful would be for you to come and sit in the plane (so a small airfield is better, rather than MAN, where I imagine security is a pain), so I can take you around some of the bits and pieces and show you the instruments, which are far simpler versions of what is on a modern airliner. More on them later. Anyway, we'll leave that for when I've finished this series of lessons - there is no pressure. The aim is to make you feel better about flying in the big aeroplanes you need to use, not scare you in my small one!
When I checked what I have at home on air systems and pressurisation, I found I didn't have much more to add (without making it all horribly complicated).
In some airliners, compressed air is also used to operate slats (see previous article about wings) and as back-up to other drive systems. I seem to recall that some RAF types use compressed air for undercarriage extension/retraction. Cooled air from the air conditioning is also used for cooling electrical plant.
I did not mention anything about actual altitude of cabin pressure and humidity either. To build an aircraft strong enough to pressurise the inside as if it were at sea level would result in too much weight being carried on the airframe. So, most airliners are pressurised to an air density equivalent to around 5,000 - 7,000 feet (depending on the aircraft type). Most people are comfortable at these altitudes - it's not much different to going about 3/4 of the way up a typical mountain in the Bernese Oberland (Switzerland). The systems depressurise back to airfield altitude during descent (when your ears block/pop - more on this in a later post). Interestingly, there are a couple of airports which are actually higher than the usual pressure altitude and so the plane is de-pressurise to that altitude instead. We don't have any such airports in Europe.
Humidity can be a problem. Most people are familiar with feeling rather 'dry' after spending too long in an air conditioned environment. At cruise altitude, the same applies and there is less moisture in the air coming into the air conditioner as well. Some (but not all) planes have humidifying systems to mitigate the problem. However, best advice is to avoid dehydrating drinks (which most fearful flyers use to calm them down
) and to drink lots of water. The down side is that, if you get the balance wrong, you have to get up to go to the toilet a lot, which some fearful flyers worry will cause the plane to tip. Don't worry, it won't. Even if your weight did cause a shift in the balance, the trim would automatically be adjusted and the wing levelers will keep it all straight and level. As an aside, taking a short stroll and realising nothing happens might help with some of your fears. It will also help stop you getting DVT.
I can't remember if I covered hydraulic systems earlier, I'll have a read and check. If not, I'll do that next, followed by a post about what the pilots look at on the flight deck (which obviously depends on the aircraft type to some extent).
More soon.
HH
You'll be more than welcome to meet and watch me fly. What would probably be helpful would be for you to come and sit in the plane (so a small airfield is better, rather than MAN, where I imagine security is a pain), so I can take you around some of the bits and pieces and show you the instruments, which are far simpler versions of what is on a modern airliner. More on them later. Anyway, we'll leave that for when I've finished this series of lessons - there is no pressure. The aim is to make you feel better about flying in the big aeroplanes you need to use, not scare you in my small one!
When I checked what I have at home on air systems and pressurisation, I found I didn't have much more to add (without making it all horribly complicated).
In some airliners, compressed air is also used to operate slats (see previous article about wings) and as back-up to other drive systems. I seem to recall that some RAF types use compressed air for undercarriage extension/retraction. Cooled air from the air conditioning is also used for cooling electrical plant.
I did not mention anything about actual altitude of cabin pressure and humidity either. To build an aircraft strong enough to pressurise the inside as if it were at sea level would result in too much weight being carried on the airframe. So, most airliners are pressurised to an air density equivalent to around 5,000 - 7,000 feet (depending on the aircraft type). Most people are comfortable at these altitudes - it's not much different to going about 3/4 of the way up a typical mountain in the Bernese Oberland (Switzerland). The systems depressurise back to airfield altitude during descent (when your ears block/pop - more on this in a later post). Interestingly, there are a couple of airports which are actually higher than the usual pressure altitude and so the plane is de-pressurise to that altitude instead. We don't have any such airports in Europe.
Humidity can be a problem. Most people are familiar with feeling rather 'dry' after spending too long in an air conditioned environment. At cruise altitude, the same applies and there is less moisture in the air coming into the air conditioner as well. Some (but not all) planes have humidifying systems to mitigate the problem. However, best advice is to avoid dehydrating drinks (which most fearful flyers use to calm them down
) and to drink lots of water. The down side is that, if you get the balance wrong, you have to get up to go to the toilet a lot, which some fearful flyers worry will cause the plane to tip. Don't worry, it won't. Even if your weight did cause a shift in the balance, the trim would automatically be adjusted and the wing levelers will keep it all straight and level. As an aside, taking a short stroll and realising nothing happens might help with some of your fears. It will also help stop you getting DVT. I can't remember if I covered hydraulic systems earlier, I'll have a read and check. If not, I'll do that next, followed by a post about what the pilots look at on the flight deck (which obviously depends on the aircraft type to some extent).
More soon.
HH
Join Date: Aug 2006
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Slight O/T
If you want some more 'chat' and are on United, just tune in to channel 9 and you can hear who is out and about in the skies with you.
However, if you are on a Q200 with Alaska, you can hear most of what happens on the flight deck!
However, if you are on a Q200 with Alaska, you can hear most of what happens on the flight deck!
Join Date: Jul 2006
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Hampshire Hog, hope others reading your posts appreciate them as much as me!! Great effort again and research and thanks. Know what you mean about drinking water, but no, for me its whatever is on offer, preferably champers or something!!. When I do go to the loo, espcially on last flights loo was right near the cockpit door and do feel once you are in a) will the door open and you can get out again or b) will the plane dip when you flush?? Something for all you pilots/crews to LOL at!! 
Sure others feel that way too.
Looking forward to the next posts; especially flight deck bit.
Gorgeous
Great effort again and research and thanks. Know what you mean about drinking water, but no, for me its whatever is on offer, preferably champers or something!!. When I do go to the loo, espcially on last flights loo was right near the cockpit door and do feel once you are in a) will the door open and you can get out again or b) will the plane dip when you flush?? Something for all you pilots/crews to LOL at!! Sure others feel that way too.Looking forward to the next posts; especially flight deck bit.
Gorgeous
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...just to be pedantic.
but then again, there is free beer and wine on all Horizon flights.
Join Date: Aug 2006
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Hey, I did 4 flights as a SLF, Spokane- Seatle -Vancouver (Alaskan, Yes, Horizon) - Dulles - LHR (Virgin) and am still reeeling a bit!
Heard on Channel 9;
'Not hearing you much, Cleveland'
Plaintive return 'I have no one to talk to' Aaah....
h.
Heard on Channel 9;
'Not hearing you much, Cleveland'
Plaintive return 'I have no one to talk to' Aaah....
h.