If all the passengers ran to the back of a 'plane...
Discussion
Eric Mc said:
Nose wheel types can suffer tail-sit syndrome. Some aircraft used to come with a tail prop to prevent this, such as the Canberra or the C-54/DC-4 -
If you go and watch the island-hoppers and tiny commercial prop planes at say Norwich airport, or maybe Southend, you'll still see them being used. gazzarose said:
Kind of on the same topic, they weigh your bags.when you check in to be able to calculate fuel and balance but never weigh the people. It must make a fair difference if a pile of well fed people are one side and a load of racing snakes the other.
The law of averages. Although there was a crash in America due to the assumed weight per person being too low. They upped it after that.surveyor said:
gazzarose said:
Kind of on the same topic, they weigh your bags.when you check in to be able to calculate fuel and balance but never weigh the people. It must make a fair difference if a pile of well fed people are one side and a load of racing snakes the other.
The law of averages. Although there was a crash in America due to the assumed weight per person being too low. They upped it after that.https://en.wikipedia.org/wiki/Air_Midwest_Flight_5...
I have also been on a flight where the flight crew rearranged the 6 of us onboard an Embraer 145 variant for balance purposes. The captain explained that we were OK on the ground by at we got to take off speed he would not be able to prevent a tail strike. We moved which quickly after that explanation.
J4CKO said:
Isnt this more of a problem on the ground, in the air the lift of the wing and the tail stabilise the plane, it will make a difference but I dont think it would cause the plane to point skywards and stall, the back of the plane isnt the absolute rear, everyone would be between the wing and the tail, and 150 tonnes of people take up a lot of space, passengers can be dense, but they arent that dense so it wouldnt be like a 150 tonne weight hanging off the tip of the tail, some of that load is meant to be there anyway, i.e. the rear ten rows into which they would all have to clamber.
There is 20 tonnes or so of fuel in the middle of the plane, two massive engines, cargo, luggage etc, also, this wouldn't happen instantly like the Bagram cargo shifting, it would take time and be during level flight based on the question so wouldn't the flight computer just compensate or the pilot notice it and push forward on the stick to counteract ?
Scary thought, the Airbus model 911 !
An aircraft must be loaded so that the C of G remains within the fore and aft limits given for the particular type, both on the ground, and more importantly in the air. If the C of G goes outside the fore and aft limits for whatever reason, the aircraft may then go outside the limits that the control surfaces are able to correct. the further away from the c of g a weight gets, be it people, or cargo. the less weight is required to de stabilize an aircraft, and put it in a non recoverable condition. It does not have to be many people, nor do they have to be at the very rear of the aircraft. the key parameters are distance away from the C of G, and the weight of whatever is moving ahead of, or aft of the C of G limits.There is 20 tonnes or so of fuel in the middle of the plane, two massive engines, cargo, luggage etc, also, this wouldn't happen instantly like the Bagram cargo shifting, it would take time and be during level flight based on the question so wouldn't the flight computer just compensate or the pilot notice it and push forward on the stick to counteract ?
Scary thought, the Airbus model 911 !
Pan Pan Pan said:
J4CKO said:
Isnt this more of a problem on the ground, in the air the lift of the wing and the tail stabilise the plane, it will make a difference but I dont think it would cause the plane to point skywards and stall, the back of the plane isnt the absolute rear, everyone would be between the wing and the tail, and 150 tonnes of people take up a lot of space, passengers can be dense, but they arent that dense so it wouldnt be like a 150 tonne weight hanging off the tip of the tail, some of that load is meant to be there anyway, i.e. the rear ten rows into which they would all have to clamber.
There is 20 tonnes or so of fuel in the middle of the plane, two massive engines, cargo, luggage etc, also, this wouldn't happen instantly like the Bagram cargo shifting, it would take time and be during level flight based on the question so wouldn't the flight computer just compensate or the pilot notice it and push forward on the stick to counteract ?
Scary thought, the Airbus model 911 !
An aircraft must be loaded so that the C of G remains within the fore and aft limits given for the particular type, both on the ground, and more importantly in the air. If the C of G goes outside the fore and aft limits for whatever reason, the aircraft may then go outside the limits that the control surfaces are able to correct. the further away from the c of g a weight gets, be it people, or cargo. the less weight is required to de stabilize an aircraft, and put it in a non recoverable condition. It does not have to be many people, nor do they have to be at the very rear of the aircraft. the key parameters are distance away from the C of G, and the weight of whatever is moving ahead of, or aft of the C of G limits.There is 20 tonnes or so of fuel in the middle of the plane, two massive engines, cargo, luggage etc, also, this wouldn't happen instantly like the Bagram cargo shifting, it would take time and be during level flight based on the question so wouldn't the flight computer just compensate or the pilot notice it and push forward on the stick to counteract ?
Scary thought, the Airbus model 911 !
The problem is that if too much weight gets too far in front of, or too far behind the fore and aft C of G limits for a particular aircraft, even full deflection of the control surfaces (in this case the elevators) at any speed, is not going to be enough to bring the aircraft back to controlled flight. If too much weight gets far enough behind the aft C of G limit, the pilot could input full forward stick/yoke, but the aircraft would still be pitching nose up. This in turn would cause any loose articles / people in the cabin, to also slide / move to the rear of the aircraft, making the situation even more unrecoverable.
The weight and balance charts for some aircraft look just like a coffin, which is what would be required if too much weight is allowed to move too far from the fore and aft C of G range.
The weight and balance charts for some aircraft look just like a coffin, which is what would be required if too much weight is allowed to move too far from the fore and aft C of G range.
010101 said:
Can big jets shift their fuel between tanks for balance?
Yes moving fuel around is standard. Not all can dump fuel A320 being an example. One of the issues with the A380 crash was the problems with balancing the aircraft for landing as the fuel transfer pumps were not working correctly. CofG was moving backwards and couldn't be controlled.
Pan Pan Pan said:
The problem is that if too much weight gets too far in front of, or too far behind the fore and aft C of G limits for a particular aircraft, even full deflection of the control surfaces (in this case the elevators) at any speed, is not going to be enough to bring the aircraft back to controlled flight. If too much weight gets far enough behind the aft C of G limit, the pilot could input full forward stick/yoke, but the aircraft would still be pitching nose up. This in turn would cause any loose articles / people in the cabin, to also slide / move to the rear of the aircraft, making the situation even more unrecoverable.
The weight and balance charts for some aircraft look just like a coffin, which is what would be required if too much weight is allowed to move too far from the fore and aft C of G range.
I am off to Boston in the morning, will see if I can organise a test The weight and balance charts for some aircraft look just like a coffin, which is what would be required if too much weight is allowed to move too far from the fore and aft C of G range.
J4CKO said:
Pan Pan Pan said:
The problem is that if too much weight gets too far in front of, or too far behind the fore and aft C of G limits for a particular aircraft, even full deflection of the control surfaces (in this case the elevators) at any speed, is not going to be enough to bring the aircraft back to controlled flight. If too much weight gets far enough behind the aft C of G limit, the pilot could input full forward stick/yoke, but the aircraft would still be pitching nose up. This in turn would cause any loose articles / people in the cabin, to also slide / move to the rear of the aircraft, making the situation even more unrecoverable.
The weight and balance charts for some aircraft look just like a coffin, which is what would be required if too much weight is allowed to move too far from the fore and aft C of G range.
I am off to Boston in the morning, will see if I can organise a test The weight and balance charts for some aircraft look just like a coffin, which is what would be required if too much weight is allowed to move too far from the fore and aft C of G range.
gazzarose said:
Always annoys be a bit when 11stone me gets the same baggage allowance as person of the larger persuasion.
It should annoy large people more as small people wear small clothes, therefore they can pack more in. Have you ever compared mens jeans to ladies skinny jeans? It's about 3-1 for size and weight.Back on topic, no-one answered a previous poster about the army dropping tanks while on the move. How does that work if we're convinced a long toilet queue + the snack trolley will cause the plane to tip over?
I posted a short video that explains things and that when the aircraft is airborne it's not just center of gravity but center of pressure that effects the longitudinal stability of the aircraft.
In the example of dripping tanks these aircraft have a few things in common, flaps down moving the CoP aft, high mounted wings with engines forward of the leading edge so weight is below CoP i.e. Pivot point and elevators the size of barn doors to maintain adequate authority at low speeds and changes in weight distribution.
In the example of dripping tanks these aircraft have a few things in common, flaps down moving the CoP aft, high mounted wings with engines forward of the leading edge so weight is below CoP i.e. Pivot point and elevators the size of barn doors to maintain adequate authority at low speeds and changes in weight distribution.
Id imagine something similar to this:
http://www.youtube.com/watch?v=lksDISvCmNI&sns...
Apparently it was an unsecured container that moved on take off, you can see the pilot correcting but then it shifts again and there's only one outcome, horrific!
http://www.youtube.com/watch?v=lksDISvCmNI&sns...
Apparently it was an unsecured container that moved on take off, you can see the pilot correcting but then it shifts again and there's only one outcome, horrific!
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