Tell me this isn't true please

[klfrodo]

Next time the pilot makes an announcement that you're being delayed at the gate while a few extra bags are loaded below, consider what might be being hoisted into the cargo holds instead. Adding sandbags to correct weight and balance in an airplane by providing ballast and redistributing weight has long been a common practice in the airline industry. But ever since the new checked bag fees were introduced on many airlines, with fewer passengers checking bags as a result, there's been an upturn in the need to add ballast before takeoff, particularly on smaller commuter flights that are more sensitive to weight issues.

 

"The weight balance of the aircraft is set up to where they're usually expecting a certain amount of bags to balance out the plane," explains the captain for a major U.S. airline. "So if we have 50 passengers on board, we expect 50 bags and that offsets the weight of the passengers and balances out the aircraft to give it the right center of gravity for take off.

 

"But what happens now, with charging so much for bags, is that people carry on so there's a weight balance problem. Because of that we end up carrying sometimes 500 or 600 pounds of sand bags to even us out."

 

 

Cut and pasted from the following site:

http://news.travel.aol.com/2010/08/20/five-things-airlines-dont-want-you-to-know/?icid=main%7Chtmlws-main-n%7Cdl4%7Csec1_lnk3%7C166277

[travelntreats]

Regardless if "sand bags" need to be used or actual weighted passenger luggage to be within the correct weight and balance envelope for proper balances.... what is your point ? As long as the plane gets off the ground safely... gets me to my destination safely, I could care less ! Could it mean more possible delays... yes, but that is something we just have to deal with, but then again with all the passengers farting around with carry-on luggage and storage, that too has caused delays in departure lately too !

[Clay Clayton]

I can't speak for the OP, but what bothers me is that two of the reason's the airlines say they charge for checked luggage is to offset their high costs and speed up their turnaround time - and now they are adding weight to the flights raising their fuel costs and delaying departures because of their new fees.:confused:

[klfrodo]

I can't speak for the OP, but what bothers me is that two of the reason's the airlines say they charge for checked luggage is to offset their high costs and speed up their turnaround time - and now they are adding weight to the flights raising their fuel costs and delaying departures because of their new fees.:confused:

 

Exactly

 

More weight = more fuel = higher operational costs

 

Charge for baggage = more revenue = passengers packing less = less weight = lower ticket prices

 

added sand bags = more weight = higher operational cost = Plus WE get to keep the additional revenues = (laugh all the way to the bank) those Dumba@$$ passengers. They really thought we the airlines were going to save them money.

[Cuizer2]

Next time the pilot makes an announcement that you're being delayed at the gate while a few extra bags are loaded below, consider what might be being hoisted into the cargo holds instead. Adding sandbags to correct weight and balance in an airplane by providing ballast and redistributing weight has long been a common practice in the airline industry. But ever since the new checked bag fees were introduced on many airlines, with fewer passengers checking bags as a result, there's been an upturn in the need to add ballast before takeoff, particularly on smaller commuter flights that are more sensitive to weight issues.

 

"The weight balance of the aircraft is set up to where they're usually expecting a certain amount of bags to balance out the plane," explains the captain for a major U.S. airline. "So if we have 50 passengers on board, we expect 50 bags and that offsets the weight of the passengers and balances out the aircraft to give it the right center of gravity for take off.

 

"But what happens now, with charging so much for bags, is that people carry on so there's a weight balance problem. Because of that we end up carrying sometimes 500 or 600 pounds of sand bags to even us out."

 

 

Cut and pasted from the following site:

http://news.travel.aol.com/2010/08/20/five-things-airlines-dont-want-you-to-know/?icid=main%7Chtmlws-main-n%7Cdl4%7Csec1_lnk3%7C166277

 

Why don't the airlines just add helium to the inside of the plane?

[FlyerTalker]

We have a couple of pilots that regularly post here, so I'll try to stay non-technical and leave that for them.

 

What you have is the issue of the distribution of weight within the airframe. Every aircraft has limits on both the amount of weight as well as where the weight is located. You can read more on this topic in HERE.

 

It's also the reason why you are sometimes instructed not to change seats and why baggage is sometimes left behind for another flight.

 

Ho hum.....Must be a slow news day over at AOL Travel.

[Cuizer2]

This is why where the weight is located is important ...

 

 

Also, it is a good idea for people (and luggage) to avoid running engines ...

 

[klfrodo]

We have a couple of pilots that regularly post here, so I'll try to stay non-technical and leave that for them.

 

What you have is the issue of the distribution of weight within the airframe. Every aircraft has limits on both the amount of weight as well as where the weight is located. You can read more on this topic in HERE.

 

It's also the reason why you are sometimes instructed not to change seats and why baggage is sometimes left behind for another flight.

 

Ho hum.....Must be a slow news day over at AOL Travel.

 

Weight distribution and weight balance I get. I understand all that.

 

Maybe adding 600 to 1000 pounds of ballast is not new. Maybe adding all that ballast has been done since the beginning of aviation.

 

The story makes it appear that since people have stopped bringing so much luggage due to the additional charges, that the airlines are just NOW (something new and never seen before) having to add ballast on board to meet the weight balance distribution.

 

Now, would AOL Travel only tell a portion of the story???? Surely not ;)

[scottbee]

Next time the pilot makes an announcement that you're being delayed at the gate while a few extra bags are loaded below, consider what might be being hoisted into the cargo holds instead. Adding sandbags to correct weight and balance in an airplane by providing ballast and redistributing weight has long been a common practice in the airline industry. But ever since the new checked bag fees were introduced on many airlines, with fewer passengers checking bags as a result, there's been an upturn in the need to add ballast before takeoff, particularly on smaller commuter flights that are more sensitive to weight issues.

 

"The weight balance of the aircraft is set up to where they're usually expecting a certain amount of bags to balance out the plane," explains the captain for a major U.S. airline. "So if we have 50 passengers on board, we expect 50 bags and that offsets the weight of the passengers and balances out the aircraft to give it the right center of gravity for take off.

 

"But what happens now, with charging so much for bags, is that people carry on so there's a weight balance problem. Because of that we end up carrying sometimes 500 or 600 pounds of sand bags to even us out."

 

 

Cut and pasted from the following site:

http://news.travel.aol.com/2010/08/20/five-things-airlines-dont-want-you-to-know/?icid=main%7Chtmlws-main-n%7Cdl4%7Csec1_lnk3%7C166277

 

Often you'll find airlines moving people around, it's quite common on a DH8D (Dash-8-400 aka Q400) that with a light load you'll need to move people to get the correct centre of balance of the aircraft . Google "WEIGHT AND BALANCE" and you'll find quite a few articles discussing why/where it needs to be done.

 

However, you'd have to have a lot of people up front and none in the back to force them to load sand to even it all out...

[Marie51]

I was on a flight where they asked for volunteers to move to seats in the back of the plane because the front of the plane was too heavy. Now it makes sense.

[spongerob]

But ever since the new checked bag fees were introduced on many airlines, with fewer passengers checking bags as a result, there's been an upturn in the need to add ballast before takeoff, particularly on smaller commuter flights that are more sensitive to weight issues.

Smaller commuter flights have very limited overhead space and most bags end up being gate-checked and placed with the checked bags. Does the author of the story ever actually fly? Or was this person just making it up as they went along? The line between journalism and creative writing seems rather indistinct here.

 

Weight and balance is something you learn during flight instruction. I'll happily wait a few minutes if things need to be redistributed to maintain a proper CG for the aircraft. Arriving a few minutes late is preferable to becoming an object that makes a big smoking hole in the ground. The mnemonic we used for our pre-flight checks (back in the day when I had a license) started with "B" for...ballast!

[new salt]

The issue is not the weight (mass) but the balance, and it is critical. In my flying career, now receeding into the mists of time:( I was in serious trouble over badly distributed cargo on two occasions, neither of which would I care to repeat! However, I think that there is a bit of an goal for the low cost carriers here in that people are carrying on amazing amounts of stuff in their clothing and handbaggage (a shooting jacket or vest is your friend here!). Therefore if they are going to have to use ballast routinely then they will have a new class of problems in quick turnrounds as it is loaded or unloaded as required. Ballast also has a habit of either being stolen or, perhaps, going on a frolic of its own when it is most needed. However, the essential thing to remember is the aircraft must be in balance, particularly for departure and arrival.

[DougYWG]

At a time when airlines are trying to reduce weight to save fuel, I can't believe for a minute that they are boarding 600lb sand bags.

 

If the flight is full, the weight of passengers and their carry-ons is distributed evenly through the cabin. That's what the aircraft is designed for, for goodness sake.

 

The weight-and-balance guys will tell the ramp guys where to stow the baggage and cargo. Maybe the pilot can shuffle fuel around. The center of gravity of the loaded aircraft must be within defined limits.

 

If the sand bags are need on the outbound but not the return, are they all piling up at some out station? I don't believe it.

[UKBayern]

As a former check-in supervisor I know most airlines perform SD (seating distribution) on very empty flights. The computer assigns seats in a certain way so that the passengers are evenly distributed over the aircraft. I know because I had to calculate the SD and put it into the computer. Therefor it is fairly important to sit in your assigned seat, or at least in the same row or section of the plane, especially on take off and landing.

 

No airline in its right mind would 600 pounds of sandbags, that is just throwing money away. Most airlines also carry freight on very small commuter flights, so I think the bags may have been loaded with oranges, coffeebeans or something similar.

@Cuizer2: MD11s have the tendency to do that, as they are tail heavy because of the engine on the tail. The airline I worked for had MD11s too and when boarding on seat numbers, we were never allowed to board the back rows first. At AMS, a MD11 went on its tail as well once.

[new salt]

At a time when airlines are trying to reduce weight to save fuel, I can't believe for a minute that they are boarding 600lb sand bags.

 

If the flight is full, the weight of passengers and their carry-ons is distributed evenly through the cabin. That's what the aircraft is designed for, for goodness sake.

 

The weight-and-balance guys will tell the ramp guys where to stow the baggage and cargo. Maybe the pilot can shuffle fuel around. The center of gravity of the loaded aircraft must be within defined limits.

 

If the sand bags are need on the outbound but not the return, are they all piling up at some out station? I don't believe it.

 

Believe it or not it is true and is a problem with some loads. As for the pilot moving fuel around, since fuel is stored in the wings that is not possible, or rather pointless (in most cases). I believe Concorde had the ability to manage trim in flight by moving fuel but the wing plan was, I think you will agree, unique. We could do it on the Nimrod maritime patrol aircraft because the fusulage stations which would have held baggage contained fore and aft fuel tanks. Weight and Balance is essential for aircraft safety- full stop.

[kenish]

Most aircraft have their fuel tanks near the center of gravity. Otherwise there would be big shifts in balance as fuel was burned off and you don't want things going "out of balance" mid-flight! It's all moot because fueled on the ramp there's nowhere to shift fuel to!

 

By the way, W&B calculations must be performed for each and every take-off. Who does the math and how it's done depends on the situation...but A380 or Cessna 150, it must be done and the pilot is responsible and makes the final "signoff".

 

The ballast situation in the article is something I can see happening although the airline would try to avoid it for obvious reasons. If a flight had a cargo shipment with unusual density (anvils or pillows :D) there has to be a way to balance it out with other cargo, baggage, or passengers. Structural limits on the cargo hold flooring and needing to load in a certain sequence on multi-stop flights could lead to a situation where ballast provides a solution that is less costly than unloading/reloading cargo at intermediate stops or bumping passengers or cargo.

[Globaliser]

As for the pilot moving fuel around, since fuel is stored in the wings that is not possible, or rather pointless (in most cases). I believe Concorde had the ability to manage trim in flight by moving fuel but the wing plan was, I think you will agree, unique.

Most aircraft have their fuel tanks near the center of gravity. Otherwise there would be big shifts in balance as fuel was burned off and you don't want things going "out of balance" mid-flight! It's all moot because fueled on the ramp there's nowhere to shift fuel to!

Concorde was not unique in this. The B747-400 certainly has stabiliser fuel tanks for the dual functions of additional fuel storage and inflight trimming by moving fuel around, and ISTR that at least some A340 models do too.

[kenish]

Interesting on the A340. I was fortunate to spend a few hours per flight on the flight decks of 10-12 747-400's. This was before 9/11 when most non-US airlines allowed cockpit visits. The pilots were usually bored and happy to give a Cessna pilot a "tour" of the flight deck.

 

Anyway my understanding is the fuel in the stabilizer is only used for taxi. Since fuel in the wings is burned from the center tanks outward (fuel near the wingtips is the last to be used), that shifts the balance rearward due to the sweep of the wings. They must use up the fuel in the stabilizer first to avoid ending up in a very aft-CG situation.

[spongerob]

Interesting, but are you sure you've got that right? The fuel furthest outboard exerts the greatest moment so any unbalance would be magnified. It would seem a bit more logical to use the fuel furthest from the fuselage first and work inwards.

 

Fortunately I never had to deal with those considerations when I flew. I didn't worry about the location of the fuel. I didn't even have an engine.

 

I learned how to land properly very quickly by the way. When you only get one attempt there's a bit of added pressure to do it right! :)

[Cuizer2]

Interesting, but are you sure you've got that right? The fuel furthest outboard exerts the greatest moment so any unbalance would be magnified. It would seem a bit more logical to use the fuel furthest from the fuselage first and work inwards.

 

Fortunately I never had to deal with those considerations when I flew. I didn't worry about the location of the fuel. I didn't even have an engine.

 

I learned how to land properly very quickly by the way. When you only get one attempt there's a bit of added pressure to do it right! :)

 

Does that mean you've been flying the space shuttle?

[gailr42]

DougWG, I used to work for a commuter airline in customer service (no techie stuff from me). The sand bags do pile up in certain stations. Sometimes we had problems with not having enough ballast and had to ask other stations to send back our ballast. Sometimes it would pile up at LAX and we had to get their rampers to "round-up" the bags and send them back. What happens is that some of our flights would go out nealy empty and with ballast. Then the aircraft would go on to its next destination with a full load of PAX and bags and leave the ballast behind at LAX - or wherever.

 

The ballast bags are red marked in white with the code (LAX for example) where they belong. If you enjoy watching what's going on on the ramp, look around as you approach the gate, and you will see the occasional small pile of red bags waiting to be used or sent back where they belong.

 

I get what folks are talking about - charging for bags and then loading up the plane with sand seems like the airline is being greedy and mean, but it is for your safety. One issue is that you can't always predict the need for ballast or how much the weight allotment might be for bags.

[Globaliser]

Anyway my understanding is the fuel in the stabilizer is only used for taxi. Since fuel in the wings is burned from the center tanks outward (fuel near the wingtips is the last to be used), that shifts the balance rearward due to the sweep of the wings. They must use up the fuel in the stabilizer first to avoid ending up in a very aft-CG situation.

I think it's a bit more complicated than that, because aircraft transfer fuel between tanks all the time, and different aircraft are (unsurprisingly) built and operated differently.

 

The nagging in the back of my mind about the A340 led me to a very good description of the A340-600's fuel system that's contained in the factual section of the incident report about G-VATL on 8 February 2005.

 

Amongst other things:-

1.6.9.6.4 Trim tank transfer

 

To control the aircraft’s centre of gravity (CG), fuel is transferred automatically to and from the trim fuel tank inside the horizontal stabiliser. The master FCMC calculates the CG and compares it to a target value; if there is a need to transfer fuel to maintain the CG position, the master FCMC commands fuel transfer either aft or forward.

 

The master FCMC can command forward and aft trim fuel transfer for CG purposes only under certain conditions. One condition is that the aircraft’s flight level must be above FL255 ( about 25,500 feet). Consequently, there is usually an aft fuel transfer as the aircraft passes FL255 during its climb to initial cruising altitude, with several adjustments throughout the remainder of the flight.

 

If the fuel contents of any one of the four inner fuel tanks drops below 4,000 kg, the master FCMC commands the system to transfer fuel forward from the trim tank to the inner fuel tanks, via the auxiliary refuel valve and the four inner tank transfer valves.

 

Forward transfer of trim tank fuel should also take place when the aircraft is 45 minutes from its destination or when the aircraft descends below FL245.

So it's not universally the case that trim tank fuel is only used during taxi. On the 346, the trim tank fuel isn't used at all until quite a long way up the climb. After all, if you still have fuel in the centre tank, which surrounds the aircraft's CG, you're not going to affect the trim very much while you're still burning that.

[Globaliser]

The fuel furthest outboard exerts the greatest moment so any unbalance would be magnified. It would seem a bit more logical to use the fuel furthest from the fuselage first and work inwards.

There are many good reasons for using the centre tank fuel first. I can immediately think of two.

 

First, part of the function of the wing tank fuel is to relieve the wing bending moment at higher weights. The aircraft becomes much lighter later in the flight, so you don't need so much relief later on. If you use the centre tank fuel first, you lighten the aircraft before you reduce the wing bending moment relief when you start using the outboard fuel.

 

Second, fuel from the outermost tanks can feed to the engines by gravity. If you've used all your wingtip fuel early on and then you have a major electrical failure later, you might lose engine power from fuel starvation. But if you still have wingtip fuel, you might be able to keep the engines running by gravity feed for a bit longer.

[DougYWG]

gailr42, thanks for that. Learn something every day!

 

Thanks also to our good friend Globaliser for the fuel shuffling discussion. BTW, my sincere apologies about the Air Transat to LHR thing, I was dead wrong on that. Learn something else everyday!

[spongerob]

Does that mean you've been flying the space shuttle?

A tad smaller but the same principles apply. But I doubt the shuttle can ride thermals.