Questions tagged [performance-calculation]
Questions about calculating the various measures of performance of an aircraft.
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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.
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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 ...
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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 ...
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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?
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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 ...
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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？
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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, ...
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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, ...
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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 ...
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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 ...
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Calculating center of gravity when calculated CoG, T/O mass, fuel burn and fuel burn station are known
I'm practicing for my EASA PPL(A) exam and one of the questions I came across sound like this:
Calculated take-off mass = 1082 kg, calculated CG = 0.254 m, fuel burn
= 55 l on station 0.40 m.
A. 24.6
...
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How is Fuel needed to be consumed calculated when MTOM and Actual Mass is known
I'm practicing for my EASA PPL(A) exams and one of the questions I came across looks like this:
How much taxi fuel must be consumed before take-off to reduce the
aircraft mass to the maximum take-off ...
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How to calculate the climb performance of an A320
Recently I have been taking off in Innsbruck (LOWI) with my A320 (in Microsoft Flight Simulator, because I cannot afford the real one) and quickly found myself greeted by a GPWS Warning: "Terrain ...
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Why do helicopter performance charts for hover out of ground effect (HOGE) have a "knee"?
Have a look at the following performance charts from Section 5 of Robinson R-22 Pilots Operating Handbook for hover out of ground effect (HOGE). If the temperature and gross weight are known, the ...
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Why does V2 decrease for intersection takeoff
I have noticed that the VR and V2 decreases for same FLEX when departing from an intersection runway even when sufficient stop margin is available. What is the reason for this? And also does EFB ...
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How useful were the wings and tail of Jean-Pierre Blanchard's balloon?
In 1784, Jean-Pierre Blanchard fitted a hand-powered propeller to a balloon, the first recorded means of propulsion carried aloft. In 1785, he crossed the English Channel in a balloon equipped with ...
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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. ...
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Calculating airspeed by flying in a U shape: Horseshoe Heading Technique
I saw some equation in a log recently and I believe it went something as follows:
$v_1$ : flying North, $\ \ v_2$ : flying West, $\ \ v_3$ : flying South.
$$
\text{TAS} = \frac 1 2 \sqrt{v_1^2+v_2^2+...
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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?
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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 ...
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Takeoff distances published in OEM manuals
Background
For academic research purposes, I have developed a first-principle takeoff performance model that returns a takeoff distance required (TODR) based on the aircraft type (incl. its associated ...
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How to read performance chart? [duplicate]
From the Flight Planning and Performance quiz for PPL, there is a question asking to calculate the distance needed for landing over 50ft barrier.
According to the example shown by the manufacturer (...
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Why is maximum zero fuel mass used in take off mass calculation?
In calculation we consider maximum takeoff weight , maximum landing weight and maximum zero fuel weight
we selected the lowest of below mentioned
Maximum Zero fuel weight + Take off fuel
Regulated ...
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Is there a way to calculate the braking distance for a light aircraft?
PPL student, I train in a C152. Reviewing its POH I cannot find a method to estimate brake performance roll (as I would do with T/O roll).
Is there any method or rule to calculate brake roll in ...
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Why does Vr increase with lower air density and decrease with higher air density?
Can someone explain why Vr increase with lower air density and decrease with higher air density? I read such a phrase in my ATPL(A) performance textbook, but without further explanation. As far as I ...
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Why does V1 increase with headwind and decrease with tailwind?
Can someone explain why V1 increases with headwind and decreases with tailwind? I read such a phrase in my ATPL(A) performance textbook, but without further explanation.
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Can the energy dissipated in a power-off descent be calculated and expressed in horsepower?
If the weight in pounds of an aircraft is known along with its sink rate in feet per minute at best power-off glide conditions, can the horsepower being dissipated by drag as the plane descends via ...
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Why do we calculate 25% more of TODR?
In general aviation aircraft, we are being told to calculate TODR (takeoff distance required) using AFM and TODR x 1.25. Why do we need the value with 25% added?
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I don't quite understand the derivative in this vertical wind gust formula
First my english writing skill is still bad so pardon me if i accidentally made any mistake TT-TT.
So recently I have learnt about how the vertical gust affect the load factor and the calculation ...
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Why do we still interpolate in performance tables?
I'm getting my Private Pilot License. In the coursework, we learn about flight planning, which requires looking at performance charts for your particular aircraft. These charts in my case are tables ...
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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 ...
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Should a runway overrun be expected if takeoff is begun with one-engine-out?
Multi-engine aircraft have enough power to successfully takeoff if one engine fails after V1. But what if, on a runway equal to the specified takeoff distance, someone decided to roll with one engine ...
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Why is my calculated seat-miles per gallon of small aircraft higher than of big aircraft?
I've calculated the seat-miles per gallon for three planes. This factors in the speed; it basically means how much does it cost to transport 1 person 1 mile.
Plane
Seats
Cruise (MPH)
gph
seat-mpg
...
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What power have I obtained?
I am currently working on a question in aeronautical engineering. The question has asked me to provide the available power. I have calculated the drag, and am given the constant velocity. With that, I ...
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Are there more refined rules-of-thumb for Top of Descent calculation, than the simple FL x 3?
Forgetting the excellent capabilities of VNAV for a moment and reverting to simpler days, is there a rule of thumb to further refine the FL x 3 rule for Top of Descent calculation, when there are ...
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Mathematical function in performance diagrams
I have taken upon myself to digitise some scanned old performance diagrams, e.g. roll distance as function of mass and OAT, TAS as function of power setting, etc. The obvious goal is to allow the ...
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Slotted wing loading and structural analysis
I'm trying to determine moments and forces on a wing with a fixed leading edge slot (trying to verify the Ragwing RW19 wing before starting the project). It's quite straightforward for a non-slotted ...
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How to calculate TAS and fuel for Diamond DA20-C1?
The PoH for the Diamond DA20-C1 is here: http://support.diamond-air.at/fileadmin/uploads/Canada/Tech_Pubs_DA20-C1/AFM/DA202-C1-Rev-28.pdf.
The plane has an MT prop, and the supplement for it is here: ...
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What are the best methods for calculating lift during different stages of flight?
Supposing I have the all dimensions of an RC airplane: wingspan, NACA airfoil, aspect ratio, fuselage length, etc., what would be the best methods of calculating the expected lift the aircraft should ...
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Replacing or supplementing turbofan with electric fan [duplicate]
Could you replace 2 B747 engines with electric turbofans? Could the 2 standard turbofans produce enough power to allow electric cruise with jets used for take off?
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What are the equations to compute takeoff and landing distance?
I am flying a Piper 28-336 Dakota. Based on this paper I was able to reproduce the take-off distances from the POH and incorporate the calculations directly in Excel. It can be seen that the effects ...
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Is the quickest way to reverse direction by turning horizontally or vertically?
Assume my aircraft is flying with Mach 2 and I want to quickly change my direction of travel 180°.
So for a horizontal turn flight I found the formula: angular velocity = g* sqrt(n²-1) / v
For a ...
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How to calculate Night Flight time for a given flight? [duplicate]
I am currently working on a project (web app) at university to be able to calculate the amount of time spent during night flying. Currently, I have, Departure Lat and Long and Departure Time in UTC ...
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What units should use for velocity prediction equations?
I'm not an expert aviation but I'm designing my own RC Plane and I wanted to estimate the maximum velocity using equations (15-20) from this paper. Honestly, I am not quite sure on the units to use ...
