Questions tagged [weight-and-balance]

Weight-and-balance is determining that an aircraft is loaded within the limits of it's weight carrying capability and that the center of gravity is within the operational envelopes of the aircraft.

Filter by
Sorted by
Tagged with
0 votes
1 answer
123 views

Can passengers boarding back first tip back an airplane? [duplicate]

I came across this image and don't have any details nor do I know the exact reason, but it made me ask myself if passengers boarding to the back first can tip back an airplane?
Gabe's user avatar
  • 2,769
0 votes
0 answers
26 views

TEB-NAS Midsize Jet max weight

We have hours with Sentient Jet and typically fly their Midsize jets -- Hawker 800, Citation XLS, Lear 60 etc. Usually only the XLS will work for us due to large luggage. Can someone help with me with ...
Michael Fishman's user avatar
1 vote
1 answer
85 views

Determining Required Fuel from Payload/Range Diagram

I would like to determine the amount of fuel required for a flight at a given range/payload combination - ideally from the payload/range-diagram [1] of the corresponding aircraft alone. I know that ...
Wasserwaage's user avatar
  • 1,640
24 votes
7 answers
7k views

Why do pilots have to calculate their center of gravity? Couldn't this simply be measured?

I was watching Air Disasters, and one of the root causes of that episode's particular crash was due to the pilots underestimating their payload weight and being improperly trimmed for take-off. This ...
Ryan_L's user avatar
  • 529
2 votes
0 answers
106 views

What is MZFW and what will happen if an airplane exceeded this weight?

What is MZFW and what will happen if an airplane exceeded this weight? Is that the wing root experiences the highest bending moment under the loading condition corresponding to Maximum Zero Fuel ...
Stan's user avatar
  • 66
6 votes
1 answer
244 views

Is there a reason why the vertical lines of some airplane envelope graphs are not parallel?

I am working on a project to develop an easy solution for mass and balance generation for my aviation club. (First example below) I checked the Graph of a PA-44-180 from the POH and wondered why piper ...
Ted Staggs's user avatar
0 votes
1 answer
210 views

Does the useful load contain taxi fuel?

While doing the “Mass and Balance” subject for the EASA ATPL, I came around two useful load definitions which contradict itself. The first definition says: The Useful Load is the total mass of the ...
n00b's user avatar
  • 155
2 votes
1 answer
269 views

How do I interpret these Center of Gravity limits?

In the normal category of my c172, I have a COG range of forward 35.0 aft of datum at 1950lbs or less, with straight line variation to 40.0 inches aft of datum at 2450lbs The aft range is 47.3 of ...
youngpilot's user avatar
0 votes
0 answers
25 views

Why does changes in load factor affect the stalling speed? [duplicate]

Why does changes in load factor affect the stalling speed? Is it because with an increase of load, the airplane has to fly at a faster airspeed to maintain performance because of the weight it has to ...
youngpilot's user avatar
2 votes
1 answer
157 views

Are there additional structural measures in airliners with asymemtrical seating arrangements?

I was recently flying onboard an A220 and was surprised by the asymmetrical five abreast seating arrangement. Are there any structural measures (e.g. counter weights, ...) to balance out the aircraft ...
pat3d3r's user avatar
  • 219
1 vote
1 answer
239 views

optimal airplane propeller placement along the vertical axis?

is there a guideline for optimizing flight based on where the engine/propeller is placed along the vertical axis? some planes have the propellers well below the wings, some on the wings, some above ...
stuart's user avatar
  • 125
-1 votes
2 answers
273 views

Controlling a plane only by shifting weight

Suppose that a plane lost the ability to use all the control surfaces on the wings (e.g., flaps and ailerons). Can the weight inside the plane be shifted to help maneuver the aircraft? For example, ...
Justintimeforfun's user avatar
1 vote
1 answer
2k views

What is the real formula for Pressure altitude? [duplicate]

OK. The formula we commonly know is (29.92-Altimeter)x1000+Elevation. However, the E6B calculator I have does not fit this formula at all. For example, if the airport elevation is 175 ft and the ...
rockybear's user avatar
  • 131
2 votes
1 answer
413 views

limits of the cg envelope graph for a helicopter

I am looking for information or any explanation, I want to know how this envelope is graphed, the limits (underlined in the image) from where they are obtained and what do they tell me? I want to know ...
Alex Ramirez's user avatar
2 votes
3 answers
390 views

What should be the size of a lifting body aircraft that can carry 5 passengers (385kg/850lbs)?

So I just want to know the size of an aircraft with a lifting body that would fly at low altitudes (around 40 meters/100 feet), and at low speeds (maximum 200 km/h 124 mph). But I don't know if these ...
Fulano's user avatar
  • 119
0 votes
0 answers
59 views

General rule for CG shift margins and possible databases for existing aircraft

I am currently working on a weight and balance problem focused mostly on loading operations, and I want to add a new feature that compares the calculated CG travel and those of existing aircraft. Do ...
stlbw's user avatar
  • 1
7 votes
1 answer
973 views

What is concentrated payload?

Reading about the Embraer c390 millennium. Two different payloads are listed. Maximum concentrated payload and distributed payload. What is the difference?
Boeing787's user avatar
  • 6,454
11 votes
2 answers
9k views

How are fighter jets allowed to be flown by one pilot even with maximum take off weights exceeding 12,500 lb?

I know that planes that are under 12,500 lb MTOW can be flown by a single pilot. But what about fighter jets like the F-18 and F-35 that way exceed that. For instance, the F-35 has a max takeoff ...
Boeing787's user avatar
  • 6,454
5 votes
4 answers
632 views

Weight & Balance with multiple stops

When you have multiple stops for a single flight, without refuelling, how do you do deal with the weight and balance ? For every single leg, or just from departure to arrival ?
Sqwak's user avatar
  • 53
2 votes
0 answers
143 views

How is %MAC affected by flap/slat position on swept wing, transport category aircraft?

If you watch the slats and flaps deploy on a swept wing, transport category aircraft, and you mentally draw a chord line, you'll notice that it's changing through the slats/flaps deployment schedule. ...
ryan1618's user avatar
  • 14.9k
18 votes
6 answers
4k views

Is the Centre of Gravity moved by an aircraft travelling at “High Speeds”?

The following quote is from G. Bristol’s book, Ace the Technical Piloting Interview: [The] movement of the centre of gravity is due to a change in weight. The distribution of the aircraft’s weight ...
tedioustortoise's user avatar
16 votes
3 answers
8k views

Why is this plane struggling to gain altitude?

Here in this video, you can see an airplane trying hard to gain altitude (happens at 1 min 17 secs, original video): Plane Gets Struck By Lightning I am skeptical. Does it actually happen, or is the ...
Auberron's user avatar
  • 1,567
11 votes
1 answer
694 views

How do water bomber pilots deal with the changing forces and mass when scooping water?

How does a pilot flying the scooping maneuver in a CL415 firefighting plane deal with the changing forces from taking on such a large mass of water (nearly 50% of the plane's own mass) as quickly as ...
AJMansfield's user avatar
0 votes
1 answer
288 views

What is the location of the CG on the T-38?

Is the Northrop T-38 Talon's CG forward or aft of the center of lift (like the F-16)?
George Geo's user avatar
  • 2,111
0 votes
0 answers
74 views

Passenger cabin asymmetric seating and balance [duplicate]

In the early 1990s I made many short haul flights in Short 360 aircraft. These had passenger seats set up as two rows on the right, one row on the left as per the picture. Assuming a full load of ...
Alan B's user avatar
  • 253
1 vote
1 answer
746 views

How to calculate and check if a/c can carry additional reserve fuel without affecting payload and if so how much?

Find payload and state if a/c can carry additional reserve fuel without affecting payload and if so how much? Max take off weight= 45000 lbs. Max landing weight= 40000 lbs. Flight fuel= 4000 lbs. ...
Nish's user avatar
  • 597
3 votes
1 answer
913 views

Why is the CG assumed to be between the CP and the tail?

While discussing stability (Longitudinal, Lateral, Directional), invariably, all texts assume CG to be between CP and tail. Ex: Look at the specific image in wikipedia https://en.wikipedia.org/wiki/...
user007's user avatar
  • 155
1 vote
1 answer
250 views

Do aircraft usually fly with CG at 50 percent of chord or do I need to reduce the tail volume?

I'm working on a design having a 3.2-metre wing with a constant chord section in the middle and taper on the sides. With a tail volume of about 0.68, the neutral point is at 60% chord from the leading ...
Mridul's user avatar
  • 1,222
3 votes
1 answer
214 views

How does a small charter operator determine where the centre of gravity is for a given flight?

I was reading an account of the 2001 crash of a charter aircraft carrying the singer Aaliyah and her companions. Within it there's a summary of the investigation by the NTSB which includes the text '...
glaucon's user avatar
  • 1,655
1 vote
0 answers
83 views

What are the regulatory requirements requiring Weight and Balance be onboard aircraft for flight? [duplicate]

The common mnemonic ARROW teaches private pilots a Weight and Balance must be onboard the aircraft for flight (usually included in the POH/AFM). What is the regulatory requirement for this? In my ...
Alex Cooper's user avatar
15 votes
6 answers
6k views

What kind of problems can a flight have if passenger weight is miscalculated?

There was a widely reported news story about a TUI Boeing 737 flight, where a bug in reservations system caused 38 passenger on the flight to be allocated a 38kg standard weight as opposed to the ...
Mavrik's user avatar
  • 259
1 vote
1 answer
189 views

What are the empty weight and maximum takeoff weight of the Moller Skycar?

I know what are empty weight and MTOW, which are data I need for my school project. But the website for Moller Skycar only shows the gross weight and net payload: https://www.moller.com/...
user39178's user avatar
  • 313
3 votes
1 answer
1k views

Why is the CG envelope wider when the aircraft is heavy?

I mean, the same aircraft, but empty or on MTOW. According to MAC, those limits are the same, but the indexes are different. So if I understand that correctly, the CG can be more forward when the ...
ZugZug's user avatar
  • 31
1 vote
2 answers
207 views

In a hydrogen fueled plane, could part of the fuel load be allowed to become lighter than air to offset or trim for the load?

This is inspired by How can adverse maneuverability due to a fuel tank behind the rear pressure bulkhead be mitigated in Airbus ZeroE hydrogen plane? . I was thinking, with the cryogenically stored ...
James D's user avatar
  • 228
2 votes
2 answers
600 views

How can adverse maneuverability due to a fuel tank behind the rear pressure bulkhead be mitigated in Airbus ZeroE hydrogen plane?

Airbus recently announced three concept aircraft for commercial use, powered by liquid hydrogen, with an ambition to have the plane in operation by 2035. https://www.airbus.com/innovation/zero-...
Erik's user avatar
  • 433
1 vote
1 answer
392 views

What does the ACARS Weight and Balance Request page look like?

In the ATSU AOC Preflight menu of an Airbus (maybe Boeing too), there is an option for a weight and balance request. The selection name varies by airline but it may say "W/B Req" "Send ...
Wil's user avatar
  • 31
1 vote
1 answer
2k views

What is Full Fuel load and how does it differ from Fuel Capacity?

I've noticed that the fuel capacity is much higher than the full fuel load. For example in a Cessna citation 560XL The Fuel Capacity is 6740 lbs The Payload W/Full Fuel load is 960 lbs Why is there ...
Shashank Amin's user avatar
7 votes
5 answers
2k views

How do handling characteristics depend on flying with a full vs. an empty tank?

Modern aircraft are capable of carrying a lot of fuel to achieve extra-long range; we're at a point where nearly every pair of destinations can be reached non-stop. Carrying so much fuel imposes ...
JohnEye's user avatar
  • 179
2 votes
4 answers
7k views

How is the Max Zero Fuel Weight used in calculating weight and balance?

In some weight and balance apps there is an option to "Use Max Zero Fuel Weight". Having never seen this in any of the aircraft I have experience flying, I am curious how this value is typically used ...
Aeyrium's user avatar
  • 439
1 vote
0 answers
135 views

Are there regulations about carrying cargo on passenger seats?

We see that passenger aircraft have recently made cargo flights so that the supply chain does not decrease due to the Covid-19 crisis. It is seen that the cargo boxes are loaded on the passenger ...
GolfCharlie's user avatar
2 votes
3 answers
202 views

Adjustment for non-balanced passenger loads?

It is well established (How Centre of Gravity (CG) is adjusted? and elsewhere) that adjustments can and need to be made to insure that airplane loading maintains a suitable center-of-gravity for the ...
Milwrdfan's user avatar
  • 1,789
2 votes
5 answers
210 views

Should the weight of the lifting surfaces be deducted from the weight used to calculate the C of G of the aircraft?

If the aerofoils are creating lift they are doing the work to lift the helicopter. When the helicopter is hovering, the blades are carrying the weight of the entire ship. The forces on the aerofoils ...
AME's user avatar
  • 21
2 votes
3 answers
560 views

How to adjust the center of gravity of an aircraft if not level when being weighed?

how do you adjust the center of gravity when weighing an aircraft in not-leveled position using platform scales under the nose and the main gears, and dropping a plumb bob to mark the gears locations.
Mike's user avatar
  • 51
12 votes
2 answers
7k views

Why is there a maximum landing weight limit?

I was told that if the aircraft's weight exceeds the maximum landing weight, it could cause a structural damage during landing, but why? My understanding is that with a heavier aircraft, I need fly ...
VvV's user avatar
  • 1,579
1 vote
0 answers
68 views

Do negligible weights affect the control of a commercial aircraft? [duplicate]

I was watching a video and it said that switching seats on a commercial airplane would be fatal. "Switching of seats from the rear of the airplane to the front seats would result in probable accident"....
RawahaKB's user avatar
0 votes
4 answers
529 views

Can i create a home built aircraft with this engine?

http://www.chiefaircraft.com/da-100.html Would this engine work for a homebuilt ultralight aircraft? I am still in the research phase, so i don't know what the weight of the aircraft will be, but I ...
EEE's user avatar
  • 7
8 votes
1 answer
1k views

Why would a plane perform 360° turns to balance fuel on the ground?

Why would a plane need to do a couple of 360’ turns on the taxi way/run-up area. The crew were given clearance to taxi and hold. They told the tower they needed to turn the plane 360’ and were cleared....
user42456's user avatar
  • 161
1 vote
1 answer
883 views

When does a Maximum Taxi Weight Restriction happen on a 737-800?

This is the first time I experienced restriction in taxi weight on B737-800. Have you experienced that before? All I know that restrictions will be from MZFW/MTOW/MLW. When does it happen?
Load Controller Anonymous's user avatar
1 vote
1 answer
573 views

Do airline dispatchers pre-block seats for weight and balance on large wide body aircraft?

I was reading a Oman Air flight review and one of the bits intrigued me: I had earlier used ExpertFlyer to monitor both how busy the flight would be and the seat map. I selected a window seat ...
curious_cat's user avatar
  • 8,446
1 vote
2 answers
355 views

Is moving payload masses during flight to restore mass centering, or to avoid having to trim, a useful approach?

Note: Title was previously "Movable big missiles/bombs/tanks under fighter jets: conceivable?" Example: lateral weight distribution in fighters Fighter-bombers jets are small and lightweight in ...
curiousguy's user avatar