# Questions tagged [performance-calculation]

Questions about calculating the various measures of performance of an aircraft.

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### Can this plane make it to an airport after dual engine failure?

If you are flying to the most remote airport(according to simple flying most remote airport is Mataveri International Airport), while flying on a typical airliner with normal weather, in the event of ...
1 vote
358 views

### What is the mathematical relationship between mass and speed for constant thrust in level fight?

Imagine that we have a wing with constant thrust in level flight. Then imagine that we add mass to that wing. In order to maintain level flight, I would expect that the angle of attack would need to ...
238 views

### For a fixed density altitude, how does climb performance depend on pressure altitude?

Below is the climb performance from the 1978 Cessna 152 POH, which I've plotted as climb rate versus density altitude. It shows that higher pressure altitude gives decreased performance even when the ...
1k views

### How can I calculate the C.G height for an Aircraft?

before I continue I would like to thank you guys beforehand for the help. I am new to this forum and in aviation in general. I am helping my professor to obtain the C.G coordinates in x, y , z for a ...
1 vote
100 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 ...
185 views

### Why is higher V1 preferred over lower V1 in takeoff performance calculations?

I am using a takeoff performance application that seems to prioritize a higher V1 speed whenever there is extra runway available. It does this as long as the Acceleration-Stop Distance (ASD) remains ...
1k views

### Confused about screen height definition

I’m a bit confused about screen height definition and I’m seeking help to understand it. I understand that this height for landings is at least 50 ft above the landing threshold for all airplane ...
34 views

### What are the parameters typically used by airlines to assess the fuel economy and efficiency for their flights?

Are there parameters that are typically being used by airlines to assess the fuel economy and efficiency done in their flights? And how exactly those parameters are being used to do the assessments ...
115 views

### How do you calculate the theoretical vertical speed of an aircraft? [duplicate]

I'm doing this for a High School research paper, so it would be preferable if little calculus is used for any calculations (up to Calculus I is probably okay). This should be based off of the flight ...
803 views

### What are the standard numbers for fuel consumption (kg), kg/NM, and kg/h, of Boeing 737-300?

I'm currently working on a school project regarding the analysis of Boeing 737-300 fuel consumption. I'm working on some parameters that my supervisor gave me, which are : Total fuel consumption (kg),...
1 vote
2k views

### Propeller Characteristics at Different Altitudes

Assuming I have a propeller with a given diameter (D), pitch, blade twist, and number of blades, I can theoretically analyze discrete airfoil sections in XFOIL and come up with lift and drag polars ...
77 views

### Material Shape Parameter (n)

In order to calculate the plasticity reduction factor given in Michael C.Y. Niu's book a constant (n) is being multiplied which is called the material shape parameter, does anyone know the meaning of ...
99 views

### Are UDF/Propfan Engines Thrust Producing or Power Producing? [duplicate]

For the purposes of aircraft performance (best endurance/range speeds, Vx, Vy, etc.) would a propfan be considered a power producing engine or a thrust producing engine? I would imagine it would be ...
163 views

### Why do I keep getting different results to an aircraft's turn radius when I plug variables into different calculators and solve on my own?

I'm trying to solve for an aircraft's turn radius at mach 3.17 (2432 mph) and a bank angle of 19.8; however, after using various online calculators and personally solving the equation, I keep getting ...
95 views

### Is there an equation to solve for bank angle using load factor and wing loading as variables? If so, what is it?

The problem is that I'm looking for both wing loading and load factor as variables to solve for bank angle and cannot find any equation that represents this. After searching various websites and not ...
18k views

### How do I calculate FPNM for standard take-off minimums?

I have trouble understanding and calculating FPNM for standard take-off minimums. As I understand, the formula is: (Ground speed)/60 * FPNM = FPM Let's say the ODP says: 565' per NM to 2800, or ...
1 vote
303 views

### Question about V1 Vr V2 computations

On ASA’s ATP test book they mention the following: “V1 is computed using the actual airplane gross weight, flap setting, pressure altitude and temperature.” I understand that v1 gets adjusted for ...
1 vote
301 views

### Dispatch Landing vs. Inflight Landing Performance Calculation

What is the difference between Dispatch Landing and Inflight Landing Performance Calculations? Are you obliged to use both? Specifically concerned with EASA rules.
3k views

### How would I calculate CG in this practice problem?

As I'm studying PPL theories, I've encountered with this kind of a question below and it would be great to understand the principle behind the calculation of the 'CG' Calculated take-off mass = 2300 ...
3k views

### Help me understand the A220-100 takeoff chart

Here is the takeoff performance chart of the Airbus A220 (CS100). According to Wikipedia, the MTOW runway length needed is 1500 metres. However, this chart seems to suggest that a runway length of ...
1 vote
281 views

### How would Vy be adjusted for changes in gross weight?

For piston propeller aircraft, Vy calibrated airspeed[CAS] is equal to CAS for best Lift/drag at the plane's absolute ceiling, and at lower altitudes Vy increases above best L/D as excess power is ...
3k views

### How does a fighter pilot calculate approach/landing speeds?

Let's say an F/A-18C returns to land after expending some payload. Fuel burned and weapons released made the plane lighter. I guess the aircraft computer can tell the pilot the actual weight of the ...
823 views

### takeoff and landing distance GRAPH for a Cessna 150

I cannot find a takeoff and landing distance GRAPH for a Cessna 150. The C172 is easy to come by but why no C150?
102 views

### Is there a simple formula for estimating supercharger throttling losses?

I’ve noticed that in both Aerodynamics for Naval Aviators, and most old WWII engine power charts, power vs altitude seems to be composed almost entirely of linear relationships: at a given ...
1 vote
585 views

### what is ''extended runway centerline''?

When we calculate performance with fly smart，we see：‘‘Take off based on climbing on extended runway centerline‘‘. What is the meaning of‘‘extended runway centerline‘‘？How long is Extended？
1 vote
148 views

### Why does the airplane manual state S1 is equal to or greater than the higher of ground minimum control speed or critical engine failure speed

I don't understand why S1 is equal to or greater than the higher of Ground Minimum Control Speed or Critical Engine Failure Speed (Vcef). I do understand that S1 has to be the lowest of Refusal Speed, ...
103 views

### How to measure fuel level from uneven tank?

If you measure the fuel level with a dipstick on the C172 I fly, you can get two different readings. This is because directly under the filler cap opening there is a cuboid-shaped sensor. Obviously, ...
182 views

### How to calculate boundary layer thickness?

So I have a flat plate with a surface of 7sqm and an aspect ratio of 12 with air blowing straight at it (like a wing) at a speed of 50km/h. I would like to manually calculate the thickness of the ...
524 views

### Is a ducted fan considered a jet or propeller for the performance parameters?

Right now I am working on a UAV design which will use ducted fan. But the performance calculations are a bit troublesome. For some calculations jet and propeller results are almost same but for the ...
400 views

### What is the meaning of "airport pressure altitude" on a flight performance graph?

In a flight performance graph what is the meaning of airport pressure altitude? Is it the top of climb? Because if I set my altimeter to 29.92 it will give me the pressure altitude for an airport at ...
361 views

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### Are there significant differences between EASA and FAA when teaching jet aircraft performance?

Both regulatory bodies did a great effort in regulation harmonization, but I'm looking for any significant differences (if any) in how is taught the subject from the pilot point of view, i.e. ...
288 views

### Do pilots of piston/prop aircraft have discretion to determine how much runway is required for an intersection departure?

For piston/prop aircraft requesting intersection departure, is it pilot discretion for the minimum amount of runway length required? Is there a takeoff calculator in conjunction with calculations?