Plane too heavy to land?
Posted by jlitch@reddit | aviation | View on Reddit | 43 comments
I was recently on a flight and the captain said the plane was too heavy to land. The solution was to move bags from the cargo area into the cabin. How does this help the weight?
shiftyjku@reddit
I wondered if it was a distribution (fore to aft) thing
PlaneDiscussion3268@reddit
Yes, all planes have a Center of Gravity “envelope.” The CG can vary depending on total weight. Moving cargo or passengers can correct an “out of balance” CG. Planes may take off with more weight than they may land with. Some planes can jettison fuel in an emergency in order to quickly land. Much of the chatter above is moving baggage with one “assumed” weight to a place where it might have a different assumed weight. It should make the aircraft heavier for all the added bullshit.
shiftyjku@reddit
Thats what i thought, so a front to back move vs bringing stuff up from belowdecks.
DDX1837@reddit
First of all, what type of plane?
Second, moving bags from the cargo area to the cabin won't make the plane weigh less.
More than likely, the place was beyond the CG limits. Probably too far aft CG. So if the baggage area was in the back of the plane, moving bags from the back to the front would correct this.
LookoutBel0w@reddit
It does help the plane weigh less. Belly bags weigh X and cabin bags weigh Y which is less on paper, so we move them up top to make the magic numbers in the magic box happy so we can fly.
DDX1837@reddit
Please explain how moving something from one place on an aircraft to another place will result in the aircraft weighing less.
LookoutBel0w@reddit
Cabin bags weigh 20lbs. Stowage bags weigh 50lbs.
DDX1837@reddit
Let me try again; How does moving a 50lb bag from one place in at aircraft to another place in the same aircraft while in flight change the total weight of the aircraft?
LookoutBel0w@reddit
Like I and many others have said, it changes the magic numbers in the magic box. We don’t care about the bags, we care about the numbers in the box to print takeoff data so we do whatever It wants to be happy. The FAA says the bags weight changes therefore it dows
DDX1837@reddit
That is not what you stated. You wrote that moving the bag makes the plane weigh less.
LookoutBel0w@reddit
Yes, moving the bags makes the plane weight less. Youre not very bright are you… you’re not picking up what I’m putting down here
DDX1837@reddit
I keep asking a very simple question but either you can't understand it or are not capable of answering it. That you resort to insults is rather telling.
So one more time, how does moving a bag weighing 50lbs on an aircraft inflight reduce the weight of the aircraft?
LookoutBel0w@reddit
Like I said 4 comments ago: “Like I and many others have said, it changes the magic numbers in the magic box. We don’t care about the bags, we care about the numbers in the box to print takeoff data so we do whatever It wants to be happy. The FAA says the bags weight changes therefore it does”
The FAA says cabin bags on average weight 20 and stowage bags weigh 50, so if you move it, they become lighter magically.
The FAA
DDX1837@reddit
Your statement that moving the bags makes the aircraft lighter is incorrect. That you refer to a "magic numbers" in a "magic box" doesn't mean it can alter physics and change the gross weight of an aircraft.
So here's a very simple question: Take your fully loaded aircraft and put it on scales. Record the weight from those scales. Now go in the aircraft and move the bags anywhere inside the aircraft you want. Now read the scales again. Do you really think that the weight recorded on those scales is going to be lower?
LookoutBel0w@reddit
Jesus Christ dude. Think outside of the box. Us airline pilots barely give a crap about several hundred pounds, but the FAA does. By moving the begs from the belly to the cabin you can lower the weight of the aircraft on paper and in the eyes of the FAA so you can fly.
I’ve explained it so many times. You’re not LITERALLY changing the weight of the plane. You’re changing the “weight” of the plane in the box
DDX1837@reddit
Please point out where I said anything about changing the weight in a box.
You can't. Just like you can't understand a simple question.
Maybe you should try improving your reading comprehension.
LookoutBel0w@reddit
This entire conversation started with changing the aircraft weight by moving luggage. You asked why we do it, and I explained. Go re read it all.
Obviously there’s no physical change in weight, that’s stupid and we all thought you knew we were talking about the FMS but instead you chose to be pedantic
DDX1837@reddit
Like I said, work on improving your reading comprehension (that means UNDERSTANDING what your read). Maybe you should "re read it all". BTW, I never asked why you do anything.
FINALLY. You acknowledge that the weight of the aircraft doesn't change. Was it really that difficult?
I can't help but wonder if you're capable of reading an approach plate. Then again, you probably have no idea what one of those is since you think an FMS is a "magic box" with "magic numbers".
LookoutBel0w@reddit
Holy shit you’re insufferable. Nobody was implying the literal weight changes. Youre just being pedantic. The weight of the aircraft changes when you move the bag. This is why you’re a PPL and I’m an ATP
DDX1837@reddit
Not only are you incapable of understanding what someone else wrote, you can't even understand what YOU wrote.
Actually, you did. TWICE.
Your words. In response to me asking how moving a bag could make an aircraft weigh less. Nowhere did I mention the FMS.
There's no way you're an ATP son. It's impossible that someone who can't even understand a SIMPLE QUESTION could make it past the first flight in an actual airplane. So go back to your flight simulator in your mom's basement and stop pretending to be something that you're not.
LookoutBel0w@reddit
It’s called context clues. scroll up and read comments about moving bags and how I explained several times it’s all to make the paperwork work.
Clearly this is so confusing to you because you’re just a PPL. Once you fly real planes this will make much more sense to you. The plane weighs less when you move the bags, every pilot knows this
DDX1837@reddit
Keep trying to justify your inability to understand a simple question. I realize it's difficult for you.
LookoutBel0w@reddit
I responded to the very first comment where this all started. Start up there boomer.
DDX1837@reddit
Swing and a miss... again.
LookoutBel0w@reddit
I literally said to fix the magic numbers in the box. What part of that sentence made you think anyone thought literal weight changes?
DDX1837@reddit
I never asked about your "magic numbers" or your "box".
LookoutBel0w@reddit
And that’s where you’ve led yourself astray. The answer to OPs question, the answer to YOUR question IS the magic numbers in the magic box we call it. The whole reason these bags were moved, the kid made this post, and you asked what type of plane it was is because of an airplanes magic box being unhappy with where the bags were.
Does it all make sense now?
49Flyer@reddit
Because of the FAA's non-science that says a bag in the cargo area weighs what it weighs (actually a standard weight per bag; they don't weigh them individually), but a carry-on bag in the cabin is part of the weight of the passenger.
At one of my previous companies we had a policy prohibiting this (as it completely defies the laws of physics), but the FAA tacitly allows it. Now, is a 150,000 lb airplane going to notice if it's 50 lbs overweight? Of course not, but in aviation the paperwork is what gets you in trouble.
Somhlth@reddit
At a certain point, it absolutely notices.
49Flyer@reddit
What point is that, exactly, given that our fuel gauges only read to the nearest 100 lbs and all passenger and bag weights are based on averages rather than weighing each individual passenger and bag?
THCinOCB@reddit
There is always the potential to stall that split second earlier.
twarr1@reddit
On a flight out of Kansai my checked bag was slightly overweight. The agent suggested I take some items out of the bag and put in my pockets.
thisistheenderme@reddit
That’s different. Overweight bags are more about 2-man lift rules for baggage handlers than anything else. And there needs to be an upper limit to prevent someone for trying to transport 1000s of pounds of gear more cheaply than paying for it properly.
Full_Situation4743@reddit
Flight was obviously overweight on MLW, rare but happens Probably due to tankering or a lot of extra fuel (alternate airport, weather). What they did is more like paperwork trick.
Checked-in bag in hold is coutned as a bag as has a weight, obviously. Either it is weighed or some kind of standard weight. But when you count it as cabin bag/hand luggage then one thing you carry into cabin by yourself, it is part of weight of passanger. And it is not counted again.
Hairy-Ad-4018@reddit
But at the end of the day that’s just semantics. The plane is either too heavy or it’s not.
Moving bags from the hold to the main cabin sounds sketchy
veganspacerobot@reddit
Write a song that explains why
LawManActual@reddit
You have to understand all these weight and balance calculations are an estimation.
I don’t know exactly how heavy the aircraft is at any moment.
I might know how many people are in the aircraft, but I don’t know how much they weigh (individually or collectively).
I don’t know how many of them brought carry on luggage or how much those bags weigh.
I don’t know how much the infants and children weigh.
I don’t even know exactly how much fuel is aboard at any moment.
So we estimate.
The fuel readings are close, but not exact
There are standard passenger weights that that include carry on bags.
There are standard bag weights.
How we input all of this into our calculations is how we get our takeoff data. Cargo hold bags are counted and have a weight assigned, overhead bin bags do not. So by taking say 10 bags from under the aircraft and putting them in the overheads, per the calculation that’s 500 pounds that go from cargo weight into passenger weight, but that passenger weight was already accounted for. So it “goes away” in the calculation or it was counted twice. It’s all an estimation.
It seems sketchy to you because you aren’t familiar with how it works. But judging by the dozens of thousands of flights that operate a day, the system works
Hairy-Ad-4018@reddit
I think my sketchy comment may have been misunderstood.
Allowing for all of the above you have a mlw. If for some reason you need to return after take off and you are above mlw then moving the bags from the hold to the cabin is what I consider sketchy. This movement in no way changes the weight of the plane. You are still above your calculated mlw
LawManActual@reddit
Want to know a real sketchy fact, commercial airliners across the globe likely fly well overweight across the globe every day. Because the weighs we use are just rough estimations.
This isn’t an exact science.
Full_Situation4743@reddit
Yeah but then you still really don't know if you are too heavy or not because you don't weigh passengers individually as well as sometimes their bags.
It all depends on how big change and trick we are talking about. It is like draining 40 kgs of water from 777 to be within MTOW limit. We all know that none is draining that water. And we all know that you are not going to crash almost 300 tons 200ER due to 40 kg.
jlitch@reddit (OP)
Bingo! That was it, thank you.
WhiskeyCasper@reddit
It will never be too heavy to land. Gravity is a b!tc#.
Sounds like you had a center of gravity issue that did not give valid performance output making it unsafe for landing.
Shifting the balance of weight allows for better approach and landing safety margins
CranstonBickle@reddit
I have never heard of this happening before and I fly a lot. That is a serious underestimation by the people responsible. I am guessing that weight distribution is what they are talking about. Else they were throwing heavy stuff out of the cockpit window.