[Utopian]

One of my regular flights on the Delhi-Mumbai route. Love the space, though the AV systems on the AI101/102 are showing signs of now.
Can you tell me where does the Dreamliner stand in this whole product positioning route for Boeing.

[mail2vm]

Wow. A big thank you for providing us great insights of an airplane. For a layman like me, these are great to know. I'm still trying to decipher the functionalities of every switch i see in the pictures. I know that i cannot become an expert by doing so, but certainly tells me the high complexity involved in manoeuvring these sky machines - Hats off to all the pilots for keeping us safe in their palms..

[F150]

Nice review of the Boeing 777. Having traveled in both the Boeing 777 and Airbus A380, I must say that the A380 is ahead in passenger comfort, seat width and headroom in the economy class.
Reference: Emirates Boeing 777 and Emirates A380

[searchingheaven]

Originally Posted by govindremesh

1. I read in one of the technical documents of the B787 that much of its hydraulic systems have been replaced with electronic ones and the engine now employs bleedless configuration.

2. I've noticed that the landing at Bangalore is very hard. This was common across the Emirates B777-300ER and the Oman Air B737-800. Is there something wrong with the approach or runway at Bangalore, or was I unlucky to get a hard landing in all the three instances ?

3. I've felt that the A320 lands more smoothly than a B737. Is it just my perception or does the fly by wire of the A320 have to do something with this?

1. I think you are confusing hydraulic systems with pneumatic systems. Hydraulic ones use fluid while pneumatic uses air. What quickdraw asked was why we aren't using electric systems instead of hydraulic ones to control aircraft control surfaces. Reasons to use hydraulic are already mentioned in my previous post.

All commercial aircrafts use hydraulics for flight control surfaces, including the 787. The key difference between the traditional and 787 hydraulic system is the power source for the center hydraulic system. In the traditional architecture, the center system is powered by two large air-turbine-driven hydraulic pumps to meet peak hydraulic demands for landing gear actuation, high lift actuation and primary flight control during takeoff and landing. In the 787 no-bleed architecture, the center hydraulic system is powered by two large electric-motor-driven hydraulic pumps. They are electric driven but still hydraulic.

2. I remember that Bengaluru had issues with the glideslope angle till 2011 or so. Aircrafts often had a bumpy landing on RWY 27. The descent angle should be 3 degrees according to ICAO. But it was set at 3.4 degrees which was termed as a technical mistake. This change in degree made the descent of the flight steeper and the landing harder. But it was changed to 3 degrees in 2012. I landed in Bangalore with the 777-300ER a month ago or so, and the landing was very smooth for me. You must've been unlucky I guess.

3. I am not rated on the A320, so I cannot answer this. But coolboy007 is undergoing his A320 type rating and his answer is correct.

Originally Posted by coolboy007

777 is also a fly by wire aircraft with flight envelope protections, Boeing's first if am not wrong.

Yes, you're correct. But there is a difference between the FBW on Airbus & Boeing. The 777 flight control system is designed to restrict control authority beyond certain range by increasing the back pressure once the desired limit is reached. This is done via electronically controlled backdrive actuators. The flight envelope protection system provides crew awareness of envelope margins and limitations by means of warnings. However, the protection functions of the system do not reduce or limit pilot control authority. A very senior A380 captain explained it to me in this way.

Airbus's computers are like your father while the Boeing's computers are like your brother. If your father knows that you're doing something wrong, he is going to tell you that it's wrong and he is going to stop you from doing it no matter what. And your brother? He is going to tell you that it's wrong. But he is not going to stop you from doing it.

Originally Posted by shivshanker

I did 9W543 yesterday and have the following observations, does my logic have any logic to it at all.?

1. The No load weight of an 737-800 Aircarft is 41, 145 Kgs
2. The Max Take off weight for an 737-800 Aircraft is 70,535 Kgs
3. Fuel required to support 168 Pax and 12 Crew for 2.5 hrs would be atleast = 6,859 Kgs
4. Weight of PAX + 28 Kgs Checked in Luggage + 15Kgs Hand Luggage is atleast 22,152 Kgs
5. The total of all of the above is at 70,156 Kgs or 99.45% of the Max Take Off Weight.

In my example shown above there is only 379 Kgs room for error!

1. The Max. takeoff weight of the B738 is 78.425 kgs and not 70.535.

2. The payload values are calculated as follows for my operator as follows. I have over simplified the calculation, but they will give you a general idea.


3. The fuel is loaded as follows. As you can see, you are nowhere near the maximum limit for takeoff.



Even so, we regularly fly 777-300ER at 97%-98% of the maximum takeoff weight. These limits are imposed after considering a safety margin anyway. So even if we were at 100% of the MTOW, there would be no issues.

Originally Posted by Jeroen

What is true that the layout of a Boeing is very different from an Airbus. A large part of that has to do with a different design philosophy. And some very fundamentals such as a Boeing traditional yoke over the Airbus side stick. Even the way a Boeing fly by wire system works is very different from an Airbus fly by wire.

Jeroen

I seem to have missed this question the first time.

The Airbus vs Boeing debate

To start off, let me get one point out of the way. Both Airbus & Boeing produce VERY SAFE aircrafts. Isolated incidents like the AF447/OZ214 do not, in any manner, tarnish the safety record of the aircraft or the company. Please keep in mind that it is one of the only 2 hull loss accidents with the A330 since it was introduced in 1994. And that's a very good record.

The primary difference between Airbus & Boeing is the FBW philosophy. Both the 777 and the A330 are FBW aircraft and have Flight Envelope Protection. In simple terms, the flight envelope implies the structural and aerodynamic operating limits of the aircraft. For example, if the pilot uses the yoke/stick to pitch the aircraft nose up, the control computers creating the flight envelope protection will prevent the pilot pitching the aircraft beyond the stalling angle of attack. As a result, even if the pilot tried to apply more and more rearward control, the flight envelope protection would cause the aircraft to ignore this command.

Up till this point, it's the same. After this however, things change.

In the B777, if I want to do a 180 degree roll, the computers will calculate and realize that this maneuver is outside of the flight envelope. They will inform the pilot through appropriate warnings(yoke, aural, and on EICAS) and try to resist movement beyond certain range by increasing the back pressure once the limit is reached. This will be done via electronically controlled backdrive actuators. But it WILL NOT prevent me from rolling the aircraft. It will try to make it harder, but won't prevent it. The pilot is ALWAYS in command on the B777.

The Airbus philosophy is different. They prefer to give more control to the computer, believing that it would eliminate pilot error. On the Airbus, hard limits are used. If somebody tried to roll a FBW Airbus, it would stop around 67 degrees. The computer would then ignore any further inputs in that direction. The benefits to hard limits are that a pilot doesn't need to worry about any limits. In an emergency climb, for example, they can pull the stick all the way back without having to worry about what the plane is trying to tell them and trying to select inputs that are as close as possible to the limits. However, some have expressed concern that the plane has become too sophisticated.

A perfect example of this is China Air 006. In this incident, the crew was forced to overstress (and structurally damage) the aircraft in order to recover from a roll and near-vertical dive. They finally recovered from the roll and dive at around 10000 feet, but the pilot had to pull the aircraft with an estimated 5.5 G, or more than twice its design limits. If the aircraft had a flight envelope protection system, this recovery could not have been performed. However, Airbus responded that an A320 in the situation of Flight 006 "never would have fallen out of the air in the first place: the envelope protection would have automatically kept it in level flight in spite of the drag of a stalled engine".

Originally Posted by Jeroen

Are you saying that in an Airbus during a manual landing the computers does nose down during flare? That sounds odd. On most planes the flare means you put the nose up a few degrees higher then the attitude you were flying during the final approach. The flare reduces your vertical speed and gets you into ground effect. You want to shorten that, but nose down?
Jeroen

While landing a conventional aircraft you pull the yoke back close thrust and as the nose drops also as the speed is dropping you need to keep pulling on the yoke to control the descent till touch down. In Airbus FBW stick out of neutral is some load factor demand. So when you flare by moving the stick back you ask for certain load factor and the aircraft starts pitching to give you that and will continue to pitch as long as the stick is out of neutral. So you will have to keep releasing the stick to neutral after each backward flare movement. This will not work well all the time so they have devised the flare mode where the auto trim stops and from 30 feet the aircraft starts pitching down. The pilot can now maintain steady backward pressure like conventional aircraft and continue to land. In direct law pilot directly moves the elevators and computers do not modify control out put so aircraft behaviour is like a conventional aircraft from the time it goes in direct law. In pitch Alternate law is same like normal law and due to multiple failures flare mode is not available so aircraft is put in direct law for landing. Direct law is flare mode of alternate law.

Originally Posted by ISO

Excellent review.

I have few questions.

1. Why cabin lights are switched off during takeoff maneuver?
2. Why seats should be in upright position during takeoff and landing?
3. Takeoff should be against wind direction. But what to do if there is cross wind to the direction of takeoff.
4. During pre-landing maneuver, how speed is reduced (breaking) in the air?
5. What are main responsibility of Pilot and co-pilot?

1. You're most likely to have some sort of accident during takeoff and landing. This is also why your tray tables have to be up and you can't have laptops during these times: ease of evacuation. If your seat is back, and something happens and the plane needs to be evacuated quickly, you just made it harder for the person behind you to get out. Also, your reclined seat won't allow the person behind you to assume brace position and he is going to die. Your window has to be up also, so that in the event of an emergency, emergency personnel can see into the plane/you can see a fire, should there be one.
   
   
2. The interior lights or cabin lights are adjusted to match the exterior environment, so that in case of an emergency, especially if the interior lights fail, your eyes are already accustomed to the light setting and you do not require additional valuable seconds for adjustment to a possibly darker or brighter environment. The dimmed light also makes it easier to identify the "EXIT" signs which illuminate and make the guidance lighting on the floor easier to follow. The bright emergency lighting is more prominent to identify when the cabin light is dimmed, saving valuable seconds as the aircraft is evacuated.
   
   
3. The technique used during the initial takeoff roll in a crosswind is generally the same as used in a normal takeoff, except that the aileron control must be held INTO the crosswind. This raises the aileron on the upwind wing to impose a downward force on the wing to counteract the lifting force of the crosswind, and prevents that wing from rising.
   
   
4. Reducing throttle and extending flaps. Flaps are used to lower the minimum speed at which the aircraft can be safely flown, by increasing drag.
   
   
5. Well, that's going to be a really long answer. I am resting in the crew rest area of my 777 right now and my shift begins in an hour. I will answer that and other questions at night.

[Jeroen]

Originally Posted by ISO

3. Takeoff should be against wind direction. But what to do if there is cross wind to the direction of takeoff.

just to add to Searchhaven earlier answers. Planes can actually take of with the direction of the wind behind you.

As far as I know the plane’s certification will tell you whether you can and what the maximum wind speed can be.

Take offs are against the wind as it is not ground speed but air speed that determines the amount of lift. So with a strong headwind your take off roll is actually going to be shorter. With the wind behind you, it would be the exact opposite. You will need extra wind.

Wind speed direction is an important input to the take off and landing calculation.

Also, certain airports and or runways might impose restriction on landings with the wind behind you.

Jeroen

[RVD]

Originally Posted by searchingheaven

The Boeing 777 is a long range, twin aisle, twin-engine jet manufactured by Boeing.

What a brilliant review Searchingheven!! I was on a layover and wondering how to kill time after the usual shopping, outing etc and finally retired to watching from my room, aircrafts landing on Runway 34 in Doha. I saw your review and killing time was no longer an issue .

Originally Posted by searchingheaven

I rember that Bengaluru had issues with the glideslope angle till 2011 or so. Aircrafts often had a bumpy landing on RWY 27. The descent angle should be 3 degrees according to ICAO. But it was set at 3.4 degrees which was termed as a technical mistake. This change in degree made the descent of the flight steeper and the landing harder. But it was changed to 3 degrees in 2012.


1. The Max. takeoff weight of the B738 is 78.425 kgs and not

Actually Bangalore RWY 27 still has the maximum number of hard landings to its credit. Don't ask me why though. Maybe it's got to do with the runway slope. I have plonked her down a few times myself

Regarding the max take off weight, you both are right. The same CFM 56 engine is rated at 70500Kgs and 79000 Kgs ( including a few more options). It just depends on the operator and the kind of operations intended. It just requires a modification to the EEC ( oversimplification)as everything else is the same. As you know it takes money to certify anything and a operator that does not feel the need for it does not have to pay to get a higher Max take off weight certification. Just to give you an example, jet airways has 22k,24k, 26k, 27k engine options for their fleet depending on the desired operation. All these are essentially the same engines with minor modifications.

RVD

[Jeroen]

Originally Posted by RVD

Actually Bangalore RWY 27 still has the maximum number of hard landings to its credit. Don't ask me why though. Maybe it's got to do with the runway slope. I have plonked her down a few times myself

I was wondering about that. I assume you would have to start the flare a little earlier or more aggressively.

Flying my little planes, when doing VFR, I’m very likely to come in quite steep. Keep it up at pattern height for as long as you can, forward slip down to 500ft, stabilise and continue only the last bit on the glide slope, papi or just visual. With one engine you want to stay high and fast as long as you possibly can. Gliding in on the glide slope with no engine is not an option unless you find yourself very close to the threshold.

This summer we are ‘house sitting’ for friends of ours in their home in London. I have just booked the flight. We are flying from Rotterdam to London City. Never flown into London City. It is, I believe the steepest glide slope in the world. Originally 7o, but now reduced to 5.5o. I think it was only Dash 7 that could handle the 7 degree glide slope.

Looking forward to that landing, is going to be first for me.

This is what it looks like from the cockpit

https://www.youtube.com/watch?v=uBwKX3WIUZ4

And some A318s doing London City airport too

https://www.youtube.com/watch?v=XDWKheHMDYs

Enjoy,

Jeroen

[RVD]

Originally Posted by Jeroen

I was wondering about that. I assume you would have to start the flare a little earlier or more aggressively

Actually the landing in itself quite straightforward. If there is a tailwind component then the higher ground speed and hence the higher closure rate and an up sloping runway could be a contributing factor to the reduction in the reaction time and hence "firmer" than usual landing.

[harpreetkanwar]

Originally Posted by Jeroen

Sure you can get leather in the cockpit, but you have to downgrade from the airbus and Boeings to my kind of planes:

http://cirrusaircraft.com/whats-new-in-2016/

Note the Bluetooth connectivity!? Bring you iPod or iPhone.

Jeroen

Now we're talking.

Pun apart, awesome thread.

___________________
crosses out the ferrari's and the lambo's from his wish list and adds a bold G650.

[swiftdiesel]

First off, thanks very much for the treasure trove of information you've provided. Some of them look like classified to me, but I'm glad you chose to share them! Being an avid Airbus fan myself, I've always tried to pick on Boeing every time I fly. Having flown the B-787 and the A380, I knew which one I liked. But with the 777-300ER, which I've flown extensively, there is nothing I could pick on, to complain. It's a no-nonsense aircraft that goes about doing its business. That said, I've found the 777's economy class cabin cramped (narrower) in comparison to the A330. Am I right with my assumption? I've always found the A330's cabin space wider and more roomier, making it less claustrophobic.

Couple of questions:
1. I see onboard Wi-fi on many airlines now. How have they overcome the challenges of electronic interference? And how does the Wi-fi connect with the ISP at 35000 ft?

2. This is a query related to the airport: Approximately, 5 days of the week I see the flight path of landing planes over my house and I get to see some biggies like the B747 cargo. But once or twice a week, the flight path for landing is completely changed and no flights fly over my house. Why is this? Has it got something to do with wind direction/speed on a particular runway?

3. When planes fly over my house, that's the time they usually get the landing gear down. In addition, I hear a "whooooo" sound from the engines that seem to sound separate from the engine sound. It sounds like the turbo whistle in cars. I've tried to identify it in various forums but I'm not able to explain it any better. It's an additional "whooooo" sound along with the engine sound. Does that make sense?

4. I find turbulence to be a lot lesser on an A320 than say, an A380, seating being near the wing. Does the intensity of turbulence vary by size of the aircraft? I do understand that being seated near the wing or the front of the aircraft results in mild turbulence feel.

5. As a pilot, how do you keep yourself engaged during ultra-long haul flights? Also, do you have your meals in the cockpit or a specific area for that? I can understand if that's something you wouldn't wanna discuss on a public forum.

6. I've seen a lot of aborted landings due to blustery conditions. How is the aircraft able to produce so much lift at near stall speed (landing) and take off again?

Too many questions I know but it's good to hear from someone who's passionate about aviation. Thanks in advance!

[apachelongbow]

Originally Posted by karan561

Hey Fantastic content there, Thank you for sharing all this information with us



I had a question regarding landing gear i.e. What tyres / brands are used ? Is it the regular Michelin, Good Year etc ? Or some other companies manufacture it ?

Have you faced a puncture /loss of air anytime ? If Yes then can the tyre be re-used after a puncture or is scrapped for a new one ?

Also are these tubeless, with tube or run flat type ?

Whats the size ?

Also do the pilots have an option to upsize ?

I will try and answer from an Airbus perspective since I fly one, however most systems are common to Airbus Boeing or other manufacturers.

Tyres are tubeless, filled with pure nitrogen and designed to operate at high speeds. The Airbus 320 tyre is rated at 195 kts..approximately 360kmph. The main landing gear wheels are larger in size than the nose wheel. The brakes are only on main landing gear and nose wheel is free castoring type.
Brakes are carbon brakes made by a subsidiary of Bugatti and operate at high temperatures. A typical 64 tonne landing weight aircraft stopping down the runway increases break temperature to about 300 degrees. Types are replaced per x number of landings. Each landing takes out a portion of rubber from the tyres which you can see as black strips on the runway. Tyres can be reconditioned once before being thrown away.

[govindremesh]

Originally Posted by searchingheaven

1. I think you are confusing hydraulic systems with pneumatic systems. Hydraulic ones use fluid while pneumatic uses air. What quickdraw asked was why we aren't using electric systems instead of hydraulic ones to control aircraft control surfaces. Reasons to use hydraulic are already mentioned in my previous post.


2. I remember that Bengaluru had issues with the glideslope angle till 2011 or so. Aircrafts often had a bumpy landing on RWY 27. The descent angle should be 3 degrees according to ICAO. But it was set at 3.4 degrees which was termed as a technical mistake. This change in degree made the descent of the flight steeper and the landing harder. But it was changed to 3 degrees in 2012. I landed in Bangalore with the 777-300ER a month ago or so, and the landing was very smooth for me. You must've been unlucky I guess.

3. I am not rated on the A320, so I cannot answer this. But coolboy007 is undergoing his A320 type rating and his answer is correct.



The Airbus vs Boeing debate
...

Up till this point, it's the same. After this however, things change.

In the B777, if I want to do a 180 degree roll, the computers will calculate and realize that this maneuver is outside of the flight envelope. They will inform the pilot through appropriate warnings(yoke, aural, and on EICAS) and try to resist movement beyond certain range by increasing the back pressure once the limit is reached. This will be done via electronically controlled backdrive actuators. But it WILL NOT prevent me from rolling the aircraft. It will try to make it harder, but won't prevent it. The pilot is ALWAYS in command on the B777.

The Airbus philosophy is different. They prefer to give more control to the computer, believing that it would eliminate pilot error. On the Airbus, hard limits are used. If somebody tried to roll a FBW Airbus, it would stop around 67 degrees. The computer would then ignore any further inputs in that direction. The benefits to hard limits are that a pilot doesn't need to worry about any limits. In an emergency climb, for example, they can pull the stick all the way back without having to worry about what the plane is trying to tell them and trying to select inputs that are as close as possible to the limits. However, some have expressed concern that the plane has become too sophisticated.

Thank you for your response! I now understand the difference between the two. My knowledge comes from the show "Air crash investigations" on NatGeo (Sorry for spooking you out if I did ) plus my curious searches on Wikipedia.

Originally Posted by coolboy007

I do not think that there is any thing with fly by wire that would give a smooth landing with the 320.

There are so many factors when landing an aircraft, crosswinds, glide slope angle, runway length available for landing etc so depends, one can be a pilot with thousands of hours but it does not guarantee that you will always get a smooth touchdown. In wet conditions, airbus itself recommends to avoid aiming for a very smooth landing and the pilots should have a firm touchdown.

As for interiors juddering, i had asked my instructor about it and he told me that once the aircraft is off the ground, the main landing gear wheels keep rotating at a high speed and if they are unbalanced, they may transmit vibrations to the aircraft, it is for a very small time.

About the landing, I was wondering if the flight envelop protection would do something to prevent the hard landing in Airbus aircraft. As stated by searchingheaven, if the computers on the Airbus don't allow the pilot to perform actions that may jeopardize the flight envelop, then I thought it might also prevent a hard landing by sensing high sink rate while descending towards the airport.

Mischievous question to coolboy: How do you feel when the aircraft yells out "Retard..Retard" moments before you touchdown? (not using an emoticon since I've already used two!)

Originally Posted by RVD

Actually Bangalore RWY 27 still has the maximum number of hard landings to its credit. Don't ask me why though. Maybe it's got to do with the runway slope. I have plonked her down a few times myself

Originally Posted by RVD

Actually the landing in itself quite straightforward. If there is a tailwind component then the higher ground speed and hence the higher closure rate and an up sloping runway could be a contributing factor to the reduction in the reaction time and hence "firmer" than usual landing.

Can I give a benefit of doubt and assume that its the runway and the approach that is bad, not my luck or the pilots flying the plane?

[searchingheaven]

Originally Posted by swiftdiesel

First off, thanks very much for the treasure trove of information you've provided. Some of them look like classified to me, but I'm glad you chose to share them! Being an avid Airbus fan myself, I've always tried to pick on Boeing every time I fly. Having flown the B-787 and the A380, I knew which one I liked. But with the 777-300ER, which I've flown extensively, there is nothing I could pick on, to complain. It's a no-nonsense aircraft that goes about doing its business. That said, I've found the 777's economy class cabin cramped (narrower) in comparison to the A330. Am I right with my assumption? I've always found the A330's cabin space wider and more roomier, making it less claustrophobic.

Couple of questions:
1. And how does the Wi-fi connect with the ISP at 35000 ft?

2. -----snip-----Why is this? Has it got something to do with wind direction/speed on a particular runway?

3. ----snip---- It's an additional "whooooo" sound along with the engine sound. Does that make sense?

4. I find turbulence to be a lot lesser on an A320 than say, an A380, seating being near the wing. Does the intensity of turbulence vary by size of the aircraft?

5. As a pilot, how do you keep yourself engaged during ultra-long haul flights? Also, do you have your meals in the cockpit or a specific area for that? I can understand if that's something you wouldn't wanna discuss on a public forum.

6. I've seen a lot of aborted landings due to blustery conditions. How is the aircraft able to produce so much lift at near stall speed (landing) and take off again?

1. As of now, in-flight wifi is pretty much in a very early phase. US provider GoGo has built a network of 3G ground stations all across the US, and planes communicate with these as they fly overhead. Some aircrafts connect to satellites to provide connectivity eg. Ka band and Ku band. It's a simple system for now. But a lot of work is going on and we are confident that the technology will improve in the coming months.
   
   
2. Very difficult to answer question without details. At the bare minimum, I need the name of the airport. Weather does cause changes in landing/departure runways but that change cannot be periodic over time.
   
   
3. I may be wrong, but in all probability, what you're hearing is simple aerodynamic noise i.e the noise from air molecules striking the airplane body.
   
   
4. In general, smaller, lighter aircraft like the A320 may be more vulnerable to turbulence than the A380. Lighter weight makes it easier for changes in air movement to accelerate the aircraft in various directions over short periods (the wings flex less and the aircraft moves more). From what I've heard from most A380 passengers, it is a very smooth aircraft and handles turbulence very well, better than the other Airbus aircrafts.
   
   
5. This is the only thing that I don't like about the 777. We have to keep our food on our laps and eat. How much would it have cost Boeing to put a foldable tray table? Just for information, the pilot and the copilot eat different meals, just in case one of the meals cause food poisoning and incapacitates one of us. The Captain is almost always offered the meal choices first. But they courteous enough to allow us(F/O) to choose. And I am shameless enough to order the first class meal.
   
   
   Passing time
   
   For most long-haul flights > 8 hrs, 2 crews are required since the flight time is beyond one crew's daily maximum allowance. After we have completed our 8 hrs, we usually go to the crew rest area to sleep. In flight, cockpit duties fill some of the time. For the 1st hour and last hour of the flight, we are occupied with calculations and flight related work. Rest of the time is spent in conversing with each other or resting. Conversation mostly depends on the other guy in the cockpit (in my case, my captain). Some are talkative and some are not. As far as resting, we usually decide amongst themselves who will have a short shut eye in their seat.
   
   These days however, it's a different story. There is this captain who I am flying with almost regularly for the last two months. He also happens to be the father of my girlfriend. Hence I have to be my best when I am with him. No swearing, no cussing, complimenting each & everyone, no complaining about the long hours and jet lag etc. Only God knows how much I have done to impress that guy.. In fact, these days whenever I am asked to perform a landing, I am extra cautious and alert than normal. One harder than usual landing and my future will disappear like the orders of A380.
   
   
6. TOGA(or takeoff go around) switches are located on the throttle quadrant. Pressing these switches advances the engines to maximum available thrust, the approach mode disengages and the flight director commands a climb on the current heading. The other pilot selects flaps 20. Gear is pulled up. Flaps retracted completely by 1000 ft. All of this ensures that the aircraft easily pulls up for the go around.
   
   Sample image of the TO/GA button(Not from a 777).
   
   

Originally Posted by govindremesh

Thank you for your response! I now understand the difference between the two. My knowledge comes from the show "Air crash investigations" on NatGeo (Sorry for spooking you out if I did ) plus my curious searches on Wikipedia.

There is nothing wrong with asking questions. The only wrong question is the one which isn't asked. Glad I was able to clear your doubts. As my father always says: "Know everything about something, and something about everything."

[Gansan]

Originally Posted by searchingheaven

Basic technical details
-------------------------------------------------------------------
Weight & Payload summary

Why should the maximum landing weight be lower than the maximum take off weight? Why can't it land with the same weight it went up with?

The difference between the two seems to be ~ 100 tons! What happens if a plane takes off with the maximum take off weight, but has to land due to some emergency within a very short time? Jettisoning cargo like a ship is not an option! So I suppose only fuel can be thrown out. Are there any rules and regulations for doing that? Like you can't dump when you are over certain areas?

[RVD]

Originally Posted by Gansan

Why should the maximum landing weight be lower than the maximum take off weight? Why can't it land with the same weight it went up with?

The difference between the two seems to be ~ 100 tons! What happens if a plane takes off with the maximum take off weight, but has to land due to some emergency within a very short time? Jettisoning cargo like a ship is not an option! So I suppose only fuel can be thrown out. Are there any rules and regulations for doing that? Like you can't dump when you are over certain areas?

The reason is simple. The loads on the landing gear and wings are far greater at landing than they are at take off. In case of a hard landing the gears undergo a great amount of stress and the wings undergo great amounts of flex.Hence the need to restrict the landing weight. It is not to say that an overweight landing is not allowed. Most manufacturers recommend overweight landing rather than delaying a landing in order to burn fuel in case of a significant system failure/degradation. Further, most operators also allow for overweight landing if considered necessary by the Crew. Case in point is a seriously ill passenger wherein, the safety of the passenger takes precedence over an overweight landing. The aircrafts are certified to land with a sink rate of 360ft/m with max take off weight and 600ft/m with max landing weight. There is a maintenance inspection schedule to be followed in case of a overweight/ hard landing and then the aircraft is released back for flight.

Regarding fuel dumping, each state may specify unique procedures specific to its airport. Generally, there is an area earmarked for dumping a minimum altitude is defined and proximity to other traffic and people and property are the other considerations for fuel dumping. Note that in case of an emergency the final authority rests with the Pilot in Command and he can use his emergency authority to deviate from any laid down procedure.

RVD