Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [aircraft-performance]

Aircraft performance covers areas such as the amount of runway required to takeoff or land and how fast an airplane can climb or descend.

1
vote
1answer
29 views

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 ...
5
votes
1answer
177 views

What is “Carson cruise” and can I determine it myself?

Mike Y. just posted an answer containing the following: With today’s fuel costs, the Carson cruise angle of attack, which represents the most efficient way to fly fast with the least increase in ...
5
votes
1answer
65 views

What ISA temperature to use in the density altitude calculation?

In the density altitude formula: DA = PA + [120 x (OAT - ISA Temp.)], should one use the ISA temperature at the field elevation or the ISA temperature at the pressure altitude?
1
vote
0answers
54 views

What could cause a lower manifold pressure at full power after an annual?

I recently completed the annual on my E33 Bonanza. I notice on takeoff at full power that the MAP is about 1" less pressure than it was in the past at my home airport. It is also about 1.5" less ...
0
votes
3answers
135 views

How can I best prepare for my first lesson on stalls? [closed]

I am a flight student preparing to practice stalls and stall recovery in a Tecnam P-2002. I have already done spin recovery. On top of that, what preparation techniques have others found useful?
0
votes
0answers
51 views

What is 737-8 cg range

How does the Boeing 737MAX-8 CG range in percent mac compare with other Boeing airplanes? Forward cg is more stable but more difficult to control. Does the FAA require a certain cg range? Adding the "...
4
votes
1answer
264 views

How are elliptical winglets better than blended winglets?

I've read in few papers that elliptical winglets give better performance than blended in terms of their L/D ratio. I am not able to find why elliptical winglets are better. the two differ by their ...
0
votes
1answer
178 views

Which helicopter can auto rotate the farthest? [closed]

Could the rotors be modified to perform better at auto rotating and maybe less at powered performance?
1
vote
2answers
125 views

How to calculate the glide distance?

Can somebody please explain how I go about this problem? A Cessna 172S is flying at 9842.52 ft from the ground and the engines stop producing power. If the aircraft is in a glide configuration and ...
0
votes
0answers
35 views

Bird strikes and engine protection [duplicate]

I am just wondering why the creators of aircraft cannot come up with some sort of high utility screens to mitigate bird.srikes. Thank you!
0
votes
0answers
96 views

Why is the F-16's service ceiling 50,000ft? [duplicate]

What defines the service ceiling for aircraft, in particular the F-16? I suppose, as with almost everything, this depends on the aircraft, the engine type, etc. While I'm fine with a comprehensive ...
0
votes
1answer
132 views

Is overall pressure ratio same as compressor pressure ratio for a gas turbine engine?

For a typical gas turbine engine, turbofan in particular, is the compressor pressure ratio same as the overall pressure ratio? For modelling purposes can we use the same value of overall pressure ...
0
votes
1answer
343 views

Why is Boeing being blamed for the recent 737 Max crashes? [closed]

Boeing has received more than 5,000 orders for the aircraft, it has delivered 350 so far and only 2 of them have crashed. That's not a very high crash rate. The FAA, until just a day ago, was very ...
0
votes
0answers
43 views

Can high G aircraft handle extreme turbulent weather?

Can aircraft that can handle high G forces, such as military or aerobatic aircraft, enter extreme weather like thunderstorms or lenticular clouds without structural damage?
1
vote
1answer
125 views

How energy efficient is an aircraft take off?

How much work is generally done by an aircraft (e.g. B737NG) in order to reach V_rotate, and how does this compare to the energy content of the fuel that is used?
4
votes
2answers
310 views

Does altitude influence the flight range of an engine driven aircraft?

I'm reading a chapter about flight performance during the cruise phase and the influence of altitude. My book (Aerodynamica, prestatieleer en vliegtuigtechniek by Bas Vrijhof on page 155, written in ...
1
vote
2answers
250 views

Why do the B747 of NASA Shuttle Carrier Aircrafts (SCAs) need additional vertical stabilizer?

Here is picture of B747 SCA of NASA and the AN-225 SCA. There are additional vertical stabilizer in the tip of the elevator to the Boeing's, while the AN-225 is designed with the vertical stabilizer ...
1
vote
2answers
90 views

Which one is more effective produce power of this two turbine's location?

Consider we have the exactly same turbine which is possible to be mounted to the tail (left picture) and to the wing (right picture) as picture below. Which one will produce more power to the airplane?...
1
vote
1answer
83 views

Does heavy air pollution improve takeoff performance?

As you all probably know by now, aircraft have much better takeoff performance when and where the air is denser; this is why flights need to either use longer runways or jettison passengers and cargo ...
3
votes
1answer
132 views

Air flow over an airfoil

We know that in real viscous flow, boundary layer exists around the airfoil and there will be a separation point which flow starts to separate from the back of the airfoil( velocity gradient equal ...
10
votes
3answers
473 views

For how long after the last A380 delivery does Airbus have to provide spare parts for it?

After Airbus's announcement that they plan to discontinue A380 production in 2021 after the last orders are filled, how long will they have to guarantee the availability of A380 spare parts?
0
votes
2answers
179 views

Would this hybrid impeller design create enough thrust for a VTOL aircraft?

I am wondering if combining a centrifugal blower impeller with an Archimedes screw impeller would create a hybrid impeller that would create enough thrust to lift up a VTOL aircraft. Please reference ...
12
votes
6answers
2k views

What is Density Altitude?

I'm trying to get a deep understanding of the term: Density Altitude. So I have read the explanations in my instruction book, and online articles. One source explained it differently then the other ...
2
votes
1answer
231 views

Since when had fighter jet designer stopped caring about Whitcomb's Area Rule?

According to this source, designers of military fighter jets seemed to have stopped centering their design on Whitcomb's Area Rule for quite a while. Yet even the twin series fighters struggle to ...
1
vote
4answers
89 views

Would a propeller extracting air from a cylinder with holes in it be an ideal lift apparatus for a VTOL aircraft?

I am wondering if enough lift can be created for a VTOL aircraft using a propeller that is extracting air from a cylinder which is closed at one end and has holes in the top half of the cylinder. ...
0
votes
1answer
290 views

What's the difference of Vs from Vs0 or Vs1?

Vs: Stall speed or minimum steady flight speed for which the aircraft is still controllable Vs0: Stall speed or minimum flight speed in landing configuration. Vs1: Stall speed or minimum ...
5
votes
1answer
755 views

Why is the A330neo more efficient than the A350 on shorter routes?

For A330neo Wikipedia page, is written: A330neo enables profitability on shorter ranges where the longer-range A350 and Boeing 787 aren't optimized. For what reasons it is true? A330 and A350 ...
3
votes
1answer
79 views

What is a simple way to explain why best range airspeed is below normal cruise airspeed? [closed]

Without using complex mathematics, please explain why best range airspeed is less than normal cruise airspeed.
1
vote
1answer
143 views

What is the most effective of propeller's rotation in a two-propeller engine airplane?

Consider two-propeller airplane as picture below (picture 1 (the above) and picture 2 (the below)). Which one is the most effective configuration to produce thrust power, stability, structural design, ...
0
votes
2answers
135 views

What is the main reason of air-cooled radials producing much less HP/L compared to liquid cooled Vs?

Is it because of the inherent limitations of cooling the cylinder walls, only 2 valves per cylinder, relative ease of scaling up instead of dialing up the boost, or some other reason?
3
votes
1answer
231 views

Are WWII turbochargers reliable?

How reliable are WWII turbochargers? Does adding them to an otherwise reliable engine, e.g. the P&W Double Wasp and the Allison, decreases the overall reliability of the engine? Are they well made ...
3
votes
3answers
139 views

How much clearance is provided when taking off over a 50 foot obstacle?

When performing a takeoff over a 50' obstacle, how much clearance is provided between the obstacle and the aircraft and where can that be found?
0
votes
2answers
174 views

How do you use a flexible drive shaft?

Saw it on a 747 freighter nose door, see it again on an F16's M61A1 gun assembly. How do you design with a flexible shaft? In what situation do you use it to replace a bunch of rigid shafts and gears?...
1
vote
1answer
145 views

How much does the swirl of engine exhaust affect aircraft performance?

Most multi-engine aircraft have engines that rotate the same direction on both sides of the fuselage (e.g. the GEnx rotates clockwise, as viewed from the front, there is no 'mirrored' version). What ...
2
votes
2answers
137 views

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. ...
8
votes
4answers
320 views

Why does elevator input move the turn coordinator ball in steep turns?

When practicing steep turns, I'm running into an unusual phenomenon. If the airplane is losing altitude in coordinated flight and I apply aft stick pressure to pitch up and correct, I notice that the ...
1
vote
4answers
315 views

Is smart phone's GPS accurate enough to calculate airplane speed? [closed]

Around seven years ago, I did airplane speed measurement. I activated the GPS on my tablet and I monitored the speed, especially when the airplane touched the ground (runway). I found that the ...
7
votes
2answers
666 views

Can an Airbus A380 or Boeing B747 fly with only 2 engines?

What would happen if, during cruise at a high gross weight, one of these airplanes suffered a double engine failure: With one failed engine on each side (leaving one working engine on each wing)? ...
4
votes
4answers
333 views

What is the maximum angle between an airplane and runway centerline when touching down at a crab angle in a crosswind landing?

What is the maximum angle between the airplane's heading to the runway when an airplane is being landing sideway due to crosswind?
4
votes
3answers
367 views

Is the MD-11's third engine slightly nose up?

From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is ...
1
vote
0answers
167 views

How much performance penalty is incurred from a WW2-era folding wing mechanism?

I'm interested in WW2-era single-engine piston-prop monoplanes. I'm interested in the folding wing mechanisms from the perspective of performance, chiefly two things: How much extra weight does it ...
1
vote
3answers
216 views

How long can a commercial airliner fly at 90deg roll?

For how long can a commercial airliner fly at a 90deg roll angle ? Or can it at all ?
0
votes
2answers
113 views

How do engines cope with various intake airflow speeds?

On a recent trip out of Washington Dulles to San Francisco, our B777 met with 200+ mph headwinds (as per the passenger entertainment system) at 35,000 ft for the first half of the route, before ...
1
vote
0answers
93 views

How does wind affect takeoff weight limits?

Two days ago I took off from BUR in relatively windy (although dry) conditions. Flightradar showed departure from runway 33, and winds were recorded roughly mid 20s kts from the N-NNE direction. ...
2
votes
1answer
64 views

How have fuel consumption and emissions per passenger/kilometre declined since the first jet airliners?

The efficiency of jet aircraft has improved since the 1960s. Is it possible to chart figures that show how consumption and emissions of pollutants and CO2, per passenger/kilometre, have declined ...
1
vote
2answers
69 views

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 ...
2
votes
4answers
444 views

Why are the leading edges of wings not always made as 'sharp' as possible?

Why is an airplane's wing (the leading edge) not made as sharp as possible to break the air, in the same way that a ship's hull is made sharp to easily break the water? This is unlike Concorde's nose ...
0
votes
1answer
266 views

How to calculate the flight envelope and maneuvering envelope for the B727-200F?

I'm a student and my assignment is to make a flight envelope and maneuvering envelope of the Boeing 727F-223. But I don't find any of the values to calculate the flight envelope and maneuvering ...
-2
votes
4answers
197 views

Could an airplane takeoff with a very strong tailwind if its propeller blades are set to a negative pitch? [closed]

Would it be possible for an airplane to accelerate and takeoff with a very strong tailwind if its propeller blades are set to a negative pitch? For example, let's say that a hurricane was approaching ...
8
votes
2answers
2k views

Why would you NOT lean on takeoff with a Lycoming engine?

There is an excellent question/answer on leaning here. However what I have not yet understood is why one would NOT lean for takeoff below 3000 feet? Why does the Lycoming Service Directive 1497A/B ...