Questions tagged [performance-calculation]
Questions about calculating the various measures of performance of an aircraft.
162 questions
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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 ...
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Does Green Dot Speed Calculation include banking Angle?
I'm wondering, whether the Green Dot- speed calculation in the Airbus PFD does account for the actual bank angle of the aircraft.
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What is the correct term for the type of performance chart where curved lines are followed?
What is the correct term for the type of performance chart where, from a starting location, curved lines are followed to various reference points to eventually find a solution?
For a specific example, ...
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Have I made a calculation mistake in this ATPL question that uses the CAP 698 Chart?
I have been calculating this question but I just don't seem to get the correct answer.
For this question use Performance Manual CAP 698 SEP1 Figure 2.3.
Using the climb performance chart, for the ...
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What is takeoff power? [duplicate]
I Am asking about the takeoff power here not how the aircraft takes off.
What do I need if I want to calculate the power required by an aircraft to take off?
What parameters should I consider?
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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 ...
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What methods are used for calculating maximum takeoff windspeed of a helicopter?
I would like to calculate the maximum windspeed in which a helicopter may safely take off and safely land, assuming a theoretical wind environment with constant wind direction and no gusts.
I ...
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Why do propellers have less theoretical range (i.e. range ignoring impatient passengers wanting to go fast) than jets, despite greater efficiency?
I was playing around with the breguet range equation recently, and came across a suprising result, that propellers have less range than jets, despite having greater efficiency.
The range equation for ...
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Shall We Consider Reversers in performance Calculations?
Thrust reversers are featured to help slow down the plane after touchdown.
Moving the thrust levers aft activates the translating cowl to open, closing the blocker doors. This action stops the fan ...
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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 ...
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How do I use the takeoff and landing distance charts in the C172 POH?
Can anyone explain how to calculate takeoff and landing distances using the chart for C172s, and please give me an example?
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How do you calculate Profile Drag?
second year aeronautical engineering student here. I'm doing some aerodynamics coursework but have run into a problem.
I've read through the answers to the question "what is profile drag?" but ...
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Why does the takeoff N1 limit start to decrease below 30°C OAT?
It's easy to understand why the takeoff N1 limit decreases with an increase in the OAT in the chart above; the engines get less dense air at higher temperatures, and less dense air means less engine ...
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What formula to use for calculating pressure altitude?
I'm having some trouble making my calculations of pressure altitude match those in apps and text books.
I'm using the formula from Wikipedia:
(29.92 - altimeter setting) * 1000 + airport elevation ...
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Why aren't large, low-speed propellers widely used?
I am trying to calculate different propellers for the simple case like helicopter moving slow up like 1 m/s or staying/hanging in one place.
From generic physics point of view it is more efficient to ...
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What is a good and simple software for calculating propeller thrust and required power?
My main requirements:
Calculate propeller thrust with big range of the altitudes (0 - 200 km) or to have air pressure input parameter, which I can type. For example pressure for 152 km is $4.98\...
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What is a Second Segment Weight Limit?
I am very interested in the principles of take-off performance optimization.
During my research I found an interesting picture, showing the software used by a European carrier.
However, the output ...
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What is the average climb gradient of an aircraft during the takeoff and early phase of a departure procedure?
On chart plates it is written the minimum climb gradient with which an aircraft should climb for obstacle clearance or after ATC request (for traffic flow management etc.).
However, since this is the ...
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Are compressor maps for multistage compressors drawn for one blade row or the whole compressor?
Apologies if this is a stupid question.
I am a little confused about compressor maps.
Are compressor maps such as this one, drawn for one blade row only or the whole compressor?
(source: Wikimedia)
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Does one-engine cruise consume less fuel than two-engine cruise?
Scenario 1. A two-engine airliner experiences rapid depressurization and makes an emergency descent to 10,000 ft, and diverts to the nearest airport.
Scenario 2. The same two-engine airliner ...
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Do takeoff (or other) performance calculations for jet aircraft take into account the type of fuel being used?
Jet aircraft can use any of a number of different fuels:1
Jet A-1 is a straight kerosene, not that much different from what you used to buy for committing arson fuelling portable space heaters.
JP-8 ...
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How do I estimate piston aircraft fuel efficiency?
Is there any way to figure out or calculate fuel consumption of piston engines for aircraft? I'm looking at different engines in a book, and while jet engines have useful values like thrust, bypass ...
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Do aircraft performance figures include corrections for areas with especially strong or weak gravity?
The strength of gravity at the Earth's surface is not constant, but varies from place to place by as much as a few percent:
(Image by NASA.)
As a result, an identically-loaded aircraft weighs less ...
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How would you use the mental clock code to solve this dead reckoning problem?
Can someone explain the question below in details?
You plan to fly a cross country flight at 2 000 feet at a true airspeed of 120 knots. Your track is 270° (True) and the wind is from 225° (True) at ...
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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 ...
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How is altitude correlated with true airspeed?
I am trying to understand the BADA 3.0 dataset (specifically I am looking at Performance Summary Tables):
E.g.
What is not obvious to me is why those tables mention only single TAS for specific FL.
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How to calculate service ceiling and absolute ceiling in PA-44 Seminole?
I am hard to understand to calculate service ceiling and absolute ceiling in PA-44 Seminole. Is there anyone know how to calculate it in the condition(T/O weight: 3599.24 L/D weight: 3354.44 PA:2329 ...
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What margin of error should one reasonably allow regarding aircraft performance?
This question generated a lot of discussion around amateur pilots often making the mistake of calculating aircraft performance based on perfect conditions and not allowing for a 'safety factor' (i.e. ...
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How can I correct an expected climb rate for density altitude?
If a flight manual (for a naturally aspirated piston engine plane) gives a figure for a best climb rate at standard temperature and pressure, is there a way to adjust that figure for a different ...
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Is the route which takes the least time always the one with least fuel-burn?
Geographically longer paths may require less fuel than the shortest (great circle) path. But what about time ?
Is the most fuel efficient route always the one that has the aircraft in the air for ...
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Can longer paths consume less fuel than the (shorter) great circle path?
Is the most fuel-efficient route between points A and B always along a great circle ?
Although somewhat counter-intuitive, this comment on an aviation blog seems to suggest that longer paths (in ...
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How are the takeoff V speeds calculated? [duplicate]
What is the actual formula for calculating the takeoff V speeds of an aircraft with any configuration? Specifically, I mean V1, Vr and V2
I know there are many factors, but what are they specifically ...
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What are the takeoff and landing distances of motor gliders?
I'm doing some estimations of weight and thrust loading for a college project, and in the formula below the landing distance is not a variable, but should be estimated using similar aircraft and usual ...
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How does maximum speed vary with altitude?
Question: How does a commercial jetliner's highest possible groundspeed vary with altitude (assuming wind=0) ?
My understanding is that drag decreases with altitude, therefore maxspeed increases with ...
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How can I calculate takeoff distance in a generic way?
I want to build a generic performance app.
For many of the aircraft the only available method is using the takeoff charts manually (I'm not referring to the more simple-to-calc short field charts but ...
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How can I calculate a pitch/power table?
I want to make a pitch and power table for C172s based on calculation, just like I attached above.
I picked up this table on internet, but I'm not sure where it comes from.
Do you have any ideas how ...
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How to calculate the induced drag coefficient?
In an exercice of Flight mechanic, I have to compute the drag coefficient at zero lift: $C_{D0}$.We saw in class two ways to find it :
$$
C_{D0} = \frac{\pi AR e}{4E_{max}^2}
$$
With $AR$ the aspect ...
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Where can I find climb and cruise performance charts for a specific aircraft?
I'm looking for climb and cruise charts for a cirrus sr20 G3, but I can't find them in the POH? where are these charts typically located?
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How to compare turboprop engines and with which values?
I have found this website that lists a lot of turboprop engines. I would like to compare them with as few values as possible. As an example, there are tons of different values that describe a jet ...
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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 ...
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