Stack Exchange Network

Stack Exchange network consists of 174 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.

2
votes
1answer
151 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
118 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
142 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
95 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 ...
1
vote
2answers
91 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. ...
1
vote
4answers
280 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 ...
3
votes
2answers
249 views

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

If during cruising with full load, these two kinds of airplane got two of their engines failure: With one engines fails in each side (so, only one engine works every side). With 2 engines fail in one ...
4
votes
4answers
224 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?
3
votes
3answers
335 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 ...
0
votes
0answers
132 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
199 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
104 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
75 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
59 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
63 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
204 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
75 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
149 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 ...
2
votes
2answers
80 views

What flaps and throttle settings are used on takeoff, climb, cruise, descent, and landing? [closed]

What degree of flaps and throttle setting are used on takeoff, climb, cruise, descent, and landing? This question is for private and general aviation aircraft. I have looked everywhere for FAA manuals ...
1
vote
1answer
100 views

What is the top speed of the twin seat Hawker Hunter?

Recently I learnt that the Hawker Hunter had a side-by-side twin seat trainer version. This is unusual, since more often the tandem configuration is used. I'm sure the engineers had a good reason to ...
2
votes
1answer
103 views

What would be the power requirements and performance of an Scroggs type of Delta with 250 cm span?

Roy Scroggs, a tailor, patented in 1917, US1250033, and in 1932 US1848578, a Delta Wing plan form machine 'Flying Dart', flight tested with an OX-5 engine, they say ...
0
votes
4answers
161 views

How does scaling of UAV size impact range?

Lets say you have two autonomous small aircraft, one with a wingspan of 200 cm and one with 400 cm. Both have the same general design. They are both optimized for travel distance on one full tank (gas ...
0
votes
3answers
86 views

What factors affect the minimum time to go from point A to point B?

I've created this trajectory for a small RC aircraft to go from 15m to 61m as quickly as possible (e.g. quickest time to get from point A to point B). I'm trying to perform a sanity check for why the ...
5
votes
5answers
219 views

How to recognize the horizontal winglet in the Horten design, or the experimental glider in this video?

Comments below the NASA Armstrong Flight Research Center video Proving Prandtl- With A Twist! incclude: This video is entirely a hidden jewel in youtube, it deserves much more attention than ...
1
vote
2answers
94 views

How can we calculate the fuel that we need?

Let's assume that we are crossing the Atlantic (about 3,878 miles) with a 737-8 MAX. How can we calculate the fuel that we will use during our flight?
0
votes
2answers
91 views

if center of pressure moves forward with angle of attack, then does it move forward of center of gravity also at a particular angle?

Consider an aircraft where- Center of gravity lies forward of Center of Pressure in CRUISE. Now as angle of attack increases, CP moves forward, then for particular angle, it must move forward of ...
1
vote
1answer
108 views

How to calculate the best glide speed if there is none on the POH?

I am studing the POH of Seneca II and could not find the Best Glide Speed. Where can I get this information from? I thought to multiply Vs clean for 1.4 to get an approximate result but I am not sure ...
0
votes
1answer
96 views

Why is A320's CG optimum position at 25% MAC?

I have read a320's optimum CG position is 25% MAC. But, the aerodynamic center is also at 25% of chord. So since CG and aerodynamic center at the same position, there would be no moment arm of lift, ...
0
votes
0answers
24 views

how to simulate the performance parameters wand EGT parameter?where can i get the data? [duplicate]

I went through a lot of research papers and (kind of) understood the parameters needed for Engine Condition Trend Monitoring. From what I've understood, I need N1speed,N2 speed, Pitch, AOA, Exhaust ...
2
votes
7answers
381 views

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 ...
0
votes
2answers
87 views

Why is the normal operating airspeed so much lower than the cruise speed in this table?

I need to work with the following table. I'm interested in vMO which I assume I can simply obtain from converting MMO to vMO through $M = v/ \sqrt{1.4 * 287 * T}$. (Is that correct?) However, I ...
2
votes
1answer
59 views

What is the Relation between Critical AoA with Chordline? [duplicate]

I read here an explanation about angle of attack (AoA) as below: Overly long (forward-back wise) wings will generally have a smaller critical Angle of Attack while smaller ones will have more ...
0
votes
2answers
472 views

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 ...
2
votes
1answer
71 views

What are the potential threats of having the landing gear dirt from mud in a rectractable landing gear airplane?

Recently I have been flying an aircraft with the landing gear very dirt with mud due to the parking area of the airfield on grass and the meteo conditions in recent days. I wonder what are the threats ...
3
votes
1answer
119 views

Is there an ideal air temperature for best performance in a light aircraft?

I know cold air is better for engine performance in general, colder air is also denser making lift components stronger(from what I understand). I was just wondering if there is a temperature or a ...
2
votes
5answers
265 views

Are we changing the angle of attack by changing the pitch of an aircraft?

For example: if I pitch the airplane up, but also increase power and am able to maintain the same speed, then no, the AoA hasn’t changed, although it may have varied in the transition between one ...
7
votes
1answer
264 views

What is the purpose of the serrated trailing edge spoilers on the B52?

At around 50 seconds on the linked video you can see the serrations on the trailing edge of the B52's spoiler. What purpose does it have, and what gives it advantage/disadvantage over the standard ...
0
votes
1answer
164 views

What is fuel consumption of an A330 during climb and descent?

I want to know how to calculate or estimate an aircraft's fuel consumption when climbing from sea level to 15,000 ft, followed by a descent to 10,000 ft. I would like to see an example for an Airbus ...
0
votes
1answer
81 views

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 ...
1
vote
1answer
47 views

Is Vy closer to Vbg with a variable pitch prop

My experience with fixed pitch props is that Vy is generally higher than Vbg due to engine efficiency issues. If I set my prop pitch so optimal engine rpm is at Vbg, will Vy = Vbg?
2
votes
1answer
196 views

Why wasn't Saint-Exupéry able to cover more distance before his 1935 desert crash?

Is there any source that provides more details on Saint-Exupéry's desert crash in 1935 than Wikipedia does: On 30 December 1935, at 2:45 a.m., after 19 hours and 44 minutes in the air, Saint-...
4
votes
2answers
217 views

Would a refueling stop be cheaper than finding lodging for all the passengers?

This is somewhat late followup question to my original question. Basic story was flight got delayed by almost 24 hours because first, technical reasons, secondly temperatures were very high. As far ...
1
vote
1answer
133 views

How far does an A320 travel while climbing to / descending from cruise altitude? [closed]

I am trying to determine how far an A319, A320, and A321 travel horizontally while climbing to / descending from cruise altitude? Would anybody be able to help me calculate this?
3
votes
3answers
319 views

How can I compute the minimum possible bank angle for a turn with a given radius?

I know that I can find an upper bound for the bank angle for a plane, if I know the maximum sustained load factor of that plane because the roll angle and the load factor $n_z$ in a turn are directly ...
15
votes
1answer
3k views

What role did the RAT (Ram Air Turbine) play on US Airways flight 1549?

An article in June 2018 Flying Magazine regarding the RAT by a Rob Mark explains that Capt. Sullunberger deployed the RAT for additional power to guide the plane down to the safe ditching on the ...
0
votes
1answer
688 views

How can I calculate the fuel required for a specific route and aircraft?

Okay, I'm writing a online game. I've got two airports and the equipment. For example: Heathrow - LAX on a 744. What I want to work out is the fuel required, as this will apply a cost to the airline. ...
1
vote
1answer
184 views

What are the typical max range and max flight time (endurance) Mach numbers for the A320?

What are these speeds? Average numbers will be fine.
0
votes
1answer
83 views

Where can I find information on the DC-9's turn radius in flight?

Does anyone know where I can find information on a DC-9-30's turn radius at various altitudes and airspeeds? I've tried Googling it, but all I've found is information about its turn radius while ...
1
vote
2answers
113 views

Is c.g rear or fore of wing leading edge?

This video states that the c.g of most non tapered airplane is 25%-30% of wing chord REAR of the leading edge.The aerodynamic center(a.c) of most wing is 25% rear of the leading edge ....Does this ...