[ashphil]

A very unique thread! Thank you ifly for starting such an informative and interesting thread. Somehow I missed this thread earlier and caught up by reading all the eleven pages in one go!

[Jeroen]

Just thought I would share another text I put up years ago on the PS forum I mentioned earlier. Through the PS forum we got to know a lot of aviation professionals. So at some point in time, my friend Ton and myself decided than rather to hang out on an internet forum or chat rooms, we would actually organise a live event, where at all the Dutch folks could meet face to face. We got a KLM pilot and a KLM maintenance engineer to give a talk and presentation.

There is an interesting bit about system difference between Boeing and Airbus, so I'd be interested to hear from the real pilots what they think and whether this has been changed since. Bear in mind this meeting and meeting notes are more than 10 years old, so all a bit dated. I certainly have learned a lot since then (and got my PPL!)

So here goes:

QUOTE:
So, at long last: Last Saturday we had the very first Dutch PS gathering in Nootdorp, the Netherlands. There was a good turnout with about 16 PS-Captains. We had arranged for what we had hoped would be an interesting and diverse program. First a real KLM pilot, then Fred on maintenance and Jeroen Hoppenbrouwers on online-flying. Unfortunately, Jeroen had to cancel due to unforeseen private circumstances. But we had prepared an “alternate” of course: Our video of Ton and me: “Full motion Simulator experience”

Without any doubt, Paul the KLM pilot, was the star of the day. All the attendees had forwarded questions up front so he could prepare himself. He spent well over three hours talking to us about operations, procedures etc. etc. It was very, very interesting. I’ve taken some notes of some of the items Paul mentioned. So here goes in total random order, my impressions/notes:

For those of you who wonder if pilots still like to fly the classic 747: On the line it is not known as classic, but as Jurassic. (For the Dutch out here: Ook een aardige bijnaam voor de classic: “zand & grind bak”)

Paul spoke about “failure management” and how that is very much operator dependent, as it is also highly linked to different cultures. Irrespective of operator and or culture some captains, when pestered by smart questions from the FO go into BISS-mode. (Because I say so!!).

Boeing maintains a different philosophy compared to Airbus when it comes to how the valve positions (e.g. fuel valve) are represented on the EICAS (synoptic) screen. On a Boeing it will show the switch position and not the actual valve position. If it differs you get an EICAS message.

I knew for a fact that on a real 744 (or full motion SIM) the valves do show a different colour whilst in transition and pointed this out. But according to Paul this is just Boeing trickery. There is no feed back from the actual valve to the synoptic display. (I guess this is good news to Hardy as this is much easier to simulate).

Paul explained in great detail the paperwork before the flight. And also the flight planning and in particular fuel planning. Must of us will be familiar with the ETOPS concept. (Extended Range Operation with Two-engine Airplanes). As we fly 4-engine planes, we tend not to bother about ETOPS, but Paul pointed out that the basic principle applies as well. I.e. if you lose an engine, you really need to consider for the remaining part of the flight what your options are. It’s not so much what you can do with three engines, as what will happen if another one fails!! ETOPS defines, amongst others, how far you’re allowed to be from the nearest suitable airport. Again, the restriction being two engines. I was surprised to hear that in the early days of 744’s they were limited by their fire suppressing capabilities. You have to be able to suppress a fire for a certain amount of time. This amount of time also determines the maximum time allowed to reach a suitable airport. Apparently, this was a real limitation on the 744 at first and lots of extra fire bottles were fitted to increase the suppression time and therefor the flying time away from a suitable airport.

It’s something you should really bear in mind. Once you have brought an abnormal situation under control, you need to determine what the next most “critical” system is. Being able to determine that accurately, also determines what options are open for you. The MEL (Minimum Equipment List) is based on this principle. Paul talked us through an example where hydraulic pump number 4 is inoperative. You really have to know the different systems in order to figure out what the next critical item(s) will be and what options you have.

We got a lot of information on fuel management and planning. KLM has an impressive set of tools, which allows them to determine the optimum amount of fuel to carry. The flight plan shows the step climbs, and it's really the flight plan that will determine the actual moment for the step climb, rather than the FMC. We spend a lot of time on wind prediction, as this is the key to fuel planning. Make sure you understand how the FMC interpolates the wind from an entry level up and or down!

At our specific request, as it ranks easily as the most frequented subject on our forum, Paul talked extensively about the use of VNAV over/against other vertical modes. As I understand it, VNAV is the preferred mode always. However whilst descending, under FL10, KLM procedure calls for FL CH. The basic reasoning behind this is that FL-CH is more predictable in what it will do then VNAV. (Check out those forum messages where VNAV suddenly puts you into a steep climb, whereas you thought you were descending so nicely.)

V/S is used rarely. But it does come in handy on for instance a VOR approach. Where you want to descend at a given rate f/min.

So now we can cut these discussions short on the forum . Going up: go for VNAV, coming down VNAV again until you hit FL10, then FL CH will do you nicely.

Now here’s another little tip for all you SIM Captains out there from a real pro: Never, ever, capture the ILS LOC in LNAV mode!! Always intercept on HDG!! With HDG you can ensure that you really cross that Localizer, whereas on LNAV you might not get a lock. Also, always capture the Localizer before arming/engaging APP. This will allow sufficient terrain clearance.

So, no excuses for smacking into that hill again! Wait until you get a lock on the localizer, or at least you are within one dot on the PFD.

We also discussed the altimeter settings, STD versus QNH. In essence, as soon as ATC tells you to climb to a Flight Level rather than an altitude in feet, you switch to STD. Coming down it’s exactly the other way around. As soon as ATC starts calling for xxxfeet altitude go for QNH.

Really, the “highest object” in the area determines the STD setting. You want to make sure you’ve got sufficient vertical separation to any objects on the ground . For instance in the Netherlands, you would be able to clear LOPIK with no problems at 3000 feet. As soon as you’re above an altitude where you can’t smack into anything on the ground, you start worrying about smacking into other planes. So here flight levels ensure sufficient vertical separation, thus go for STD.

Something to bear in mind for those of us who frequent the polar or other icy regions. Be aware that your altimeter is compensated for barometric pressure only. Especially in very cold regions you need to correct for temperature as well!! Low temperature will put you lower than you think!! Putting a dent into tarmac is one thing, crushing ice is a different matter all together!

Ok, so we had covered the paperwork, lots of other stuff, the ever-elusive VNAV, so now time for the ultimate questions:
Why the hell do we derate??
What is derating anyway??
When to use derate??
What sort of assumed temperatures should you be able to enter into the FMC (Questions like this assume you know what the hell derate is in the first place!)

Anyway, only one person in the audience managed to answer question number 1: Why derate at all? Only Fred knew: it cuts down on maintenance!! (You tend to know this sort of stuff when making a living in aircraft maintenance!

Just for the record: It will not cut down maintenance on your PC, only on the engines on the real aircraft.

Boeing’s certification allows for a maximum deration, or rather minimum thrust of 75%. KLM never uses the standard derated settings of the FMC. They will, by means of tables, enter an assumed temperature. The assumed temperature basically fools the engine control system. It thinks it operating at a higher ambient temperature than it really is. And therefor it reduces its thrust, thus reducing maintenance. (Thus the sour face of Fred as well).

It’s really the runway length that at a given Take off weight determines to what extend you can derate. Make sure you can clear any obstacles as well once you have achieve lift off. And being able to stop in time, in case you need to abort might come in handy too.
Me, personally, I go with Mel Ott (see page 333 of the PS manual) and “it is my personal choice to always use TO and CLB, and not to derate”. I like to have as much clearance as quickly as possible, but than again, I don’t have to worry about maintenance.

Entering relative low temperatures as “assumed” temperature in your FMC won’t work, because you’re still in the flat rate area. (I.e. mechanical limitations, rather than thermal). If you want to know what this means, go and study Ief Cooreman excellent Jet Engines document from the support page.

Paul also talked us through a standard crew briefing. The main challenge here is to make sure that you’re covering the essentials and not putting your crew to sleep.

Lastly, for all you jump seat riders: Looks like this will not be possible for the time being.

All in all, a very interesting talk by a very enthusiastic professional. Many thanks to Paul.

Fred gave us an overview of what aircraft maintenance is all about. His story elaborated on a D-check. It boils down that every so often you rip a 744 apart. And I mean rip it apart! Not much is left unturned. It’s stripped of paint, passenger chairs, interior, instruments, landing gear, engines, flaps etc. etc.

What impresses me most is the enormous amount of work put into such an overhaul. I had the pleasure of visiting the KLM hangars some time ago, whilst they were doing a D-check. The mind boggles as to how they can rip such a complex piece of machinery apart, repair, maintain and put it back together in under 5-6 weeks. I always find it quite stunning to see and I simply fail to understand how it is possible to get a return ticket Amsterdam – New York for less than Dgl 1.000,--.

In addition to the D-check, Fred had also brought a video on 744 – painting. Again, a very impressive and comprehensive story about putting paint on a 744.

We finished the day by looking at our video of the Full SIM experience. Lots of laughs.

UNQUOTE

[Ricci]

Originally Posted by revtech

spool times for jets is long. so if you calculate the time from advancing thrust levers will be a while though it will be quicker than 45 secs but definitely not under 10

the take off roll should take 15-20 sec, that would mean 15-20 sec for spool up ? That seems excessive. Fighter engines of late are 3-4 sec from idle to full AB. Commercial jets have bigger diameters and more inertia, but rev less. 10 sec maybe , twice that seems excessive. Unless that is a deliberate slow spool up , being a commercial operation with an eye on much longer maintenance/replacement cycles than military jets.

[Jeroen]

Originally Posted by Ricci

the take off roll should take 15-20 sec, that would mean 15-20 sec for spool up ? That seems excessive. Fighter engines of late are 3-4 sec from idle to full AB. Commercial jets have bigger diameters and more inertia, but rev less. 10 sec maybe , twice that seems excessive. Unless that is a deliberate slow spool up , being a commercial operation with an eye on much longer maintenance/replacement cycles than military jets.

Spool up times on the older jet engines could easily be in the 10-15 seconds. Most modern jet engine, even the big bypass fans will usually do it within 10 seconds, some well within 8 seconds.

Take off roll can be well beyond 15-20 seconds. All depends on the plane, the ambient conditions, take off weight etc. Take a look at this video. Spool up, judging by the sound is 4-5 seconds. But from the moment he starts rolling untill rotation is nearly 50 seconds!

http://www.youtube.com/watch?v=y7gtfAm4NjA

Jeroen

[Ricci]

Originally Posted by AirbusA340

All said and done, we have to understand that it's helpful only in specific situations wherein manual braking would be helpful and you don't run the risks of a locked wheel,etc., When it pours outside, we are seriously advised to use the auto brakes for the obvious reason to have the best balance between braking enough and stopping enough without having a locked wheel.

ABS was invented for/by aviation engineers, wasn't it ? So your post indicates ABS isn't always effective in preventing wheel lock up ?

Originally Posted by norhog

Here goes
1).Do aircrafts fly at crusing altitude with nose slightly up (trim by aft as in marine industry)?Why?
2).How do fighter planes fly upside down, the wings generating lift would bring the plane down to earth in this upside down position?
Thanks

1. Perhaps they do, but I'm not 100% certain without relevant figures/numbers but I have read of non-zero alpha during level flight. The slight nose up attitude is for maintaining enough lift , since the air density is lower at cruising altitude and airspeed alone at zero alpha might be insufficient, at high loads. Once enough fuel is burnt , the weight may reduce enough to resume flight at zero alpha. Mostly though, nose up flight is only during low speed.

Some aircraft actually have wings designed offset with a positive alpha while direction of flight is level, usually small civil planes and some military ones.

2. Yes, I wondered the same, but never asked. The inverted flight regime would likely have the pilot push the stick slightly forward to make the aircraft pitch the nose up (from the horizon) , cancelling out the earthward lift. I suppose flight computers automatically set the elevator/ailerons to minimize pilot input. Anyway, inverted flight is rarely longer than a few seconds.

@Jeroen : thanks for the clarification and vid. It's been a while I flew (sadly) , hopefully I'll fly again and will try to measure the To run duration, though it would be hard to tell exactly the point of getting airborne.

[Jeroen]

Originally Posted by Ricci

@Jeroen : thanks for the clarification and vid. It's been a while I flew (sadly) , hopefully I'll fly again and will try to measure the To run duration, though it would be hard to tell exactly the point of getting airborne.

Hi Ricci what did you use to fly? When you see vertical airspeed you're airborne!

Jeroen

[Ricci]

Jeroen : Fly as passenger. I'm not counting flight sims, and no one will give me one to fly without a license (and other paperwork!) .

Sometimes the take off can be gradual , between rotation and lift off, that you don't easily make out until a few seconds later.

[revtech]

Approximately from a semi rolling start (about 5 -10 kmph)

150 Kmph in 15 sec
190 Kmph in 20 sec
275 Kmph in 33 sec

these values will vary with weight, type of aircraft, temperature, altitude etc.


Rev

[sindabad.sailor]

I have faced high temperatures in cabin prior take off, lot of times. Once it was too much to bear at Goa - Dabolim. It was Sahara Airlines flight then. I kept on asking the attendants for the reason. After seeing my persistence, I was informed that for running the air con while on tarmac, the aircraft uses fuel as coolant. Since there was an appreciable delay in take off, the fuel was getting heated up and hence pilot had to switch the air con off.
I till date don't believe this. I guess this thread can throw some light.

Anyways thanks for the thread. Air Crash Investigation show on Nat Geo has made me interested a lot in the whole flying affair. Have purchased MS Flight Simulator LOCALLY few months ago and getting familiar with the things. It is one of my favorite pass times.

[norhog]

The aeronautical number cruncher's please chip in..
The domestic flights between the metro cities in India are having same timing and cost of seat. e.g there are Indigo, Air India and Jet flight from kolkata to Mumbai at 0600 hrs on week day mornings.
The ticket cost is exactly the same.
All of then fly airbus A320s or Boeing737.
So aircraft carrying approx 160 passangers each.
So total number of passangers 160 x 3 is 480.
Why not get a bigger aircraft like a 747 and one part can be looked after by one airline say Air India seat nos 1 to 30, Indigo by 31 to 50..you get the picture.Then divide the fuel and maintenance cost 3 ways.
Wont that turn out cheaper.
If it is a crazy idea please excuse.

[Guite]

Originally Posted by norhog

If it is a crazy idea please excuse.

Crazy idea obviously but entertaining nevertheless.

So lets say Air India owns the aircraft and sublets to Jet middle part of aircraft and Indigo rear portion. Oh no, but Jet wants front portion and first class seats too!

A first time traveler, you are told to board this aircraft sporting Air India livery and think you are being directed to wrong plane because you are Indigo passenger. So you spend 20 minutes arguing with the staff. Finally you get in at the front door through an aerobridge and you are greeted by Air India staff. So you trample down Air India and Jet property until you arrive at Indigo 'door'.

I could go on and on.

[norhog]

Originally Posted by Guite

Crazy idea obviously but entertaining nevertheless.

So lets say Air India owns the aircraft and sublets to Jet middle part of aircraft and Indigo rear portion. Oh no, but Jet wants front portion and first class seats too!

A first time traveler, you are told to board this aircraft sporting Air India livery and think you are being directed to wrong plane because you are Indigo passenger. So you spend 20 minutes arguing with the staff. Finally you get in at the front door through an aerobridge and you are greeted by Air India staff. So you trample down Air India and Jet property until you arrive at Indigo 'door'.

I could go on and on.

I know its crazy but what about the costs.
This idea is for persons flying on budget from A to B and who does not want or dont want to pay for extra legroom or all the frills for just 2 to 3 hrs.
Please allow me to explain
Airline A,B,C chips in equally and buys or leases the big aircraft.
This idea is strictly for the low cost no frill airlines flying in INDIA.
The Plane can be all white on outside, no livery. We generally board through a aero bridge so cannot see it. And what difference does it make to a passenger if the plane is blue, red or white.
As long as the aluminium pressure vessel can transport him/her from A to B in the comfort that allows him/her to survive at 35000 feet at 900 kmph it should be enough. Also I read an article that to reduce costs virgin airlines came up with the idea, among others, to strip off the paint to save weight that will save fuel in the long run.
For a passenger or guests as the airline likes to call us these days (coined by now defunct Kingfisher airlines) he/she will approach the counter of the airline from who the ticket is bought and gets a boarding card.
Then he/she proceeds to security check and then onwards to the gate to board.
At the gate you could have the following
1) 3 different counters manned by the respective airline staff who will check the boarding card.
2) 1 counter where representatives of the respective airlines are present to do the same so no confusion.

Boarding.
If it is a aerobridge boarding, which is now common on all metro airports, the last row passengers board first eg airline A boards first then B and so on.
If we are boarding from the tarmac well respective airline buses can ferry passengers to proper places. A Boeing 747 has 4 to 5 doors each of which can have staircase placed and manned by respective airline staff.
Once inside in a low cost carrier they any way do not serve anything like in the good old days. The staff is present to comply with DGCA regulation stating their presence during flights.
So each section gets "served" by the respective staff and you can buy what they want.
Quite frankly that is also not needed as the maximum duration of domestic flight in India is not more that 3 hours, so eating can very well be done on the ground before or after the flight.
The whole purpose of this exercise is for the low cost operators to save more money which will translate into cheaper tickets.
Thus the railways can be spared of some passenger traffic and used extensively for goods transport.

[Jeroen]

Originally Posted by norhog

The aeronautical number cruncher's please chip in..
The domestic flights between the metro cities in India are having same timing and cost of seat. e.g there are Indigo, Air India and Jet flight from kolkata to Mumbai at 0600 hrs on week day mornings.
The ticket cost is exactly the same.
All of then fly airbus A320s or Boeing737.
So aircraft carrying approx 160 passangers each.
So total number of passangers 160 x 3 is 480.
Why not get a bigger aircraft like a 747 and one part can be looked after by one airline say Air India seat nos 1 to 30, Indigo by 31 to 50..you get the picture.Then divide the fuel and maintenance cost 3 ways.
Wont that turn out cheaper.
If it is a crazy idea please excuse.

It's a very good idea/question. Not an easy answer I'm afraid. You can roughly say that because it's not done, it's likely to be not economically feasible.

There are many factors, and I'm far an expert on this one. But by and large using wide body aircraft on short haul routes doesn't happen very often. I know there were several route in Europe and I used to fly a 747 domestically in Japan many years ago. Also American Airlines used to have a few routes in the US using wide bodies.

Still, wide bodies (i.e. 747, 777, 380 etc.) are difficult to operate economically on short routes. They use a lot of fuel during taxi, waiting and take off.

There are other factors to consider as well. Just because the seats are cheap doesn't necessarily mean they will all sell. Look at the Delhi-Mumbai vv. route.
From 0500am you have a plane taking off every 45-60 minutes. Replace that with a wide body and you might have one plane taking off every 3-4 hours. I fly the Delhi_Mumbai run at least once a week. For me the frequency is more important than a slightly cheaper ticket.

Jeroen

[Sedate]

Originally Posted by norhog

The aeronautical number cruncher's please chip in..
The domestic flights between the metro cities in India are having same timing and cost of seat. e.g there are Indigo, Air India and Jet flight from kolkata to Mumbai at 0600 hrs on week day mornings.
The ticket cost is exactly the same.
All of then fly airbus A320s or Boeing737.
So aircraft carrying approx 160 passangers each.
So total number of passangers 160 x 3 is 480.
Why not get a bigger aircraft like a 747 and one part can be looked after by one airline say Air India seat nos 1 to 30, Indigo by 31 to 50..you get the picture.Then divide the fuel and maintenance cost 3 ways.
Wont that turn out cheaper.
If it is a crazy idea please excuse.

Some people who fly have bigger egos than the airplane!

My friend never fly Jet Airways - just because the courier company didn't deliver him the jet privilege card stating his residence is beyond delivery area! My friend wrote an email to Jet loyalty customer care, but never received a reply. He simply stopped flying Jet and JetKonnect!

When companies try cost cutting by taking cheap service(even in loyalty/privilege card delivery!!!) they are losing valuable(profitable and paying) customers!

[norhog]

I am sorry I have hijacked the thread to be one about boring but the most important point, the economics of airline industry instead of technical, pleasure and excitement parts of flying.
But all my flights, as well as for most of the persons here in this forum, are in a seat just enough to fit my knees in and looking out through an elliptical glass window and all this while paying two times the amount as charged by the next practical long distance mode of transport the railways.
I mentioned railways over driving long distance as you cannot drive 2000 km and arrive to the city in the morning and expect to get work done or work 8 to 9 hrs, this is only feasible if you fly to that particular place.
The point I am trying to make is all the airlines have very close by timings schedules. You generally find three of four different airline leaving the city and arriving at the other just minutes apart. (Almost always for flights between metro cities).
So if the different airlines clubs together may be it will lead to fares reduction and economy of scale.
If the tickets are cheap and volume good (I know there are 2 "ifs" which is difficult to attain but just consider this hypothetical case) we can maintain high frequency of flights.
Cheers