Airplanes Definition and 49 Threads

  1. P

    B How are fractures in airplane structures detected by ultrasound?

    For applications of ultrasound, detecting fractures using ultrasound is listed in one of my textbooks. According to that, ultrasound cannot travel through air right after it travelled through solid parts of the plane. Therefore if there was a fracture, the sound was supposed to be reflected...
  2. H

    B Some Questions About Drag (for ships in water and airplanes in air)

    I'm interested in the very basics of drag, both for ships in water and airplanes in air. Here's what I have so far : Flow of the medium can be laminar or turbulent. As the relative speed of the vessel increases, the more likely the flow is to be turbulent. Laminar drag increases linearly...
  3. russ_watters

    What are the concerns with 5G and airplanes?

    The basics of this issue is that AT&T and Verizon were set to turn on C-Band 5G service tomorrow, but the roll-out has been halted by the Biden admin because it could interfere with radar altimeters on airplanes...
  4. thommy

    Why don't airplanes explode due to pressure difference?

    My question might sound trivial (I'm just a first year physics student anyways) , however I really feel the need to get an answer. Since the pressurized cabins inside an airplane are regulated at about 0.8 atm while the pressure outside doesn't surpass 0.2 atm (at 35 000+ ft of altitude)...
  5. O

    Doppler effect - two airplanes flying towards each other

    I found it confusing since there is only "mutual" speed of both aircrafts and hence I do not know how to correctly put it into the common Dopplers formula...
  6. C

    MHB Can WGS-84 Coordinates be Used to Calculate Closing Speeds for Airplanes?

    I am trying to calculate closing speeds for airplane traffic. I am using the formula found here-- https://mathhelpboards.com/calculus-10/calculate-closing-velocities-19402.html The question I have is about whether or not I can use wgs-84 coordinates for x and y positions for the planes...
  7. cyboman

    Boeing How Safe is the Boeing 737 Max's MCAS System?

    Hi, I have a question regarding the tragic crash of the latest 737 Max. Is it not a huge error in the flight laws and the MCAS software to execute a nose down maneuver at any altitude? Should the system not have a rule to prohibit such a maneuver below a minimum altitude threshold? I'm also...
  8. Quintijn van Heek

    Using the lift equation, can you make anything fly?

    If I have a contraption with wings that weighs 120 kg, the wings in total are 2 meter squared, and I make it go 60 km/h, will it fly? According to the lift equation (L = (1/2) d v^2 a CL), it should, since L=(1/2)*1.225*277.788*2*3.39 = 1176.789 Weight = 120 kg = 1176.789 N L = lift = 1176.789...
  9. GilGiy

    B Airplanes Landing & Altitude Problem

    First I'm going to say that I was supposed to select a prefix for this thread... I'm not sure what that's for so my apologies if I did it wrong. So here's a problem that I was presented with a bit ago (by a flat earther[emoji849][emoji19][emoji44]) and I'm sort of confused. It's been about a...
  10. Dalton Peters

    Can a Jet Plane Take Off on a Treadmill?

    So I have heard this around the internet before but thought is was a question worth exploring if a jet plane is sitting on a treadmill and the treadmill moves backwards at the same rate the plane is moving forward will it take off? I think no because the plane would have to be moving forward for...
  11. A

    Mechanical gyroscopes -- still used in airplanes?

    I was a bit unsure where to post this, but this one seemed fitting enough. I was wondering about the state of gyros in airplanes, like which type is being used today. Are they all optik/fiber-based or are there mechanical gyroscopes at work. (By mechanical i mean the standard spinning wheel, not...
  12. F

    Delta wing vs standard plane (Paper model)

    I made a few paper airplanes. I noticed that the common paper airplane (shown below) https://i.ytimg.com/vi/v29M7Oa1l-A/hqdefault.jpg flies much further/better than paper planes that look like standard 747s. Any know why ? I expected 747 like plane to be very efficient at generating the lift...
  13. ramzerimar

    How is the moment of inertia of airplanes measured?

    I know it's possible to use a trifilar pendulum to extract information on moments of inertia by measuring the period of oscillation. I've seen this test being executed on small aircraft, like in this video. But I wonder how do is the momement of inertia calculated on big aircraft, like a Boeing...
  14. pug

    B Airplanes stay level at higher velocities?

    Hi, I was wondering- how would a normal winged airplane (jet/propeller) stay level as it increased in speed? In other words, increasing the velocity over an airfoil will generate more lift. But what if a pilot just wants to go faster and not higher? Where does that increased upward force from...
  15. russ_watters

    Collecting News Fails: How Not to Report on Airplanes

    I often post news fails because the media annoys me, so I think I'll start collecting them into one thread. Here's a doozy I saw today on CNN.com : Here's how this happens: Step 1: Two interesting stories about the Airbus A380 happen in 24 hours, which lends itself to a cluster format, with...
  16. P

    Maximizing Lift Through Vortex Generation on Airplanes

    For an airplane, their are multiple types of lift, camber, angle of attack, pressure difference, and vortex lift. I understand that at the end of wings the low pressure at the top, and high pressure on the bottom causes their to be a vortex formed. My question is, how exactly do they use that...
  17. V

    B How do airplanes correct their path

    If a plane has to fly across latitudes as opposed to flying across longitudes, there's also rotational motion of the earth, so if it flies from antarctica to siberia and it takes too long, it is in no way certain whether it lands in siberia, norway or Canada, so it must constantly need to move a...
  18. russ_watters

    What's with CNN and Ridiculous Airplanes?

    http://www.cnn.com/2016/01/27/aviation/antipode-hypersonic-concept-plane/index.html For the love of god, somebody please make it stop!
  19. A

    Physics for Aspiring Aerospace Engineers: A Beginner's Guide

    I'm a brand new physics student. I barely know the subject, but I want to design airplanes for the U.S. army. That's why I want to learn as much physics as possible.
  20. RooksAndBooks

    Avionics Programming Learning Materials?

    I'm an aspiring aerospace engineer. I know that Ada is a language used in many planes today, but I can't find anything to learn about Ada for avionics--I couldn't find books or tutorials. Do any of you guys have any recommendations on how to go about this? I'm very interested in teaching myself...
  21. Y

    Exploring Jet Engine Position: Front or Back?

    Hello. Do you think the idea of placing the jet engine at the front is plausible? Why? Why not? Thanks Yrjosmiel
  22. P

    Solving for Takeoff Distance: Airplanes A & B

    Homework Statement Airplane A, starting from rest with constant acceleration, requires a runway 600m long to become airborne. Airplane B requires a takeoff speed twice as great as that of airplane A, but has the same acceleration, and both planes start from rest. Homework Equations a.)...
  23. L

    MHB Rate of Change of Airplanes in 3D

    One plane is flying due east straight and level at 30000 feet and at 420 mi/h. A second plane flies due north at 40560 feet and at 480 mi/h. The second plane crosses above the flight path of the first plane 2 minutes after the first plane passes that point. How fast were they approaching each...
  24. C

    Time Machines: Can Airplanes Reach the Speed of Light?

    If airplanes' highest speed depends directly on the air it is moving through and not the ground, does it mean we can build a time machine if only the air moves near the speed of light?
  25. P

    How does the weight of airplanes affect atmospheric pressure?

    I was taught that due to Bernouli's theory of air pressure the shape of the wing makes air move faster on the top and slower on the bottom thus creating low pressure above and high pressure below the wing. Now, if this was true, then how do airplanes with identical shape wings fly if both the...
  26. P

    Model airplanes powered by compressed air ? Anyone ?

    Model airplanes powered by compressed air ...?? Anyone ?? Hello, Has anybody explored idea of powering aeroplane models by compressed air? Does this seem to be viable idea? Prima-facie: Let's say a rubber tire tube (old days of car tires - now its all tube less) inflated to say 60...
  27. 3

    Displacement of airplanes in opposite directions.

    An air traffic controller observes two airplanes approaching the airport. The displacement from the control tower to plane 1 is given by vector A, which has the magnitude 220km and points in a direction 32(degrees) north of west. The displacement from the control tower to plane 2 is given by...
  28. J

    Propeller airplanes vs jet airplanes

    why propeller airplanes have superior take-off performance than jet airplanes?
  29. T

    What is the velocity of each plane after three hours?

    Homework Statement Two airplanes leave Dallas at the same time and fly in opposite directions. one plane flies 80mph faster than the other. After three hours, they are 2940 miles apart. What is the velocity of each plane? Homework Equations I don't know what equation to use! The...
  30. B

    Airplanes and Birds-Debunking the Myth of Why They Fly

    My daughter came home from school on Friday and told me that her science teacher mismarked her test. The question was: EXplain the reason thzt birds can fly. she told em that the reason they can flywas Isaac's Third Law. I believed, aqs we weretaught by our elementary school teachers that it waz...
  31. M

    Do Current Theories Fully Explain How Airplanes Fly?

    Hi, I am an airline pilot, with more than 10 years of flying experience, and I would like to know how airplanes fly ;-) This may seem like a strange question for me to ask, so I will elaborate a bit: The theory that was taught to me, and that is still taught to the vast majority of pilots...
  32. Evo

    Are Pay Toilets on Airplanes Becoming a Reality?

    Surely, they wouldn't dare? http://news.yahoo.com/s/ap/20090227/ap_on_re_eu/eu_ireland_ryanair_pay_toilets
  33. L

    2D Kinematics, airplanes crashing wtf?

    2D Kinematics, airplanes crashing wtf?? An airplane is flying with a velocity of 240 m/s at an angle of 30.0° with the horizontal, as the drawing shows. When the altitude of the plane is 2.4 km, a flare is released from the plane. The flare hits the target on the ground. What is the angle...
  34. T

    How Do Planes Calculate Relative Velocities?

    Homework Statement Two airplanes taxi as they approach the terminal. Plane 1 taxies with a speed of 13.4 m/s due north. Plane 2 taxies with a speed of 6.2 m/s in a direction 18.8° north of west. (a) What are the direction and magnitude of the velocity of plane 1 relative to plane 2? (b)...
  35. 5

    Airplane Wing Lift: Bernoulli & Newton's Laws

    Lift ! (airplanes) Hello, I am writing a research paper about the lift generated by the wings of an airplane. It is about the extent to which the Bernoulli effect and Newton's laws each contribute to creating lift. I planned on calculating the actual value of the lift generated by each...
  36. T

    Why do helicopters use a stabilizer rotor while airplanes with propellers don't?

    why do helicopters need a stabilizer rotor but airplanes that use propellers don't?
  37. C

    Why do airplanes pressurize their cabins?

    Why do airplanes pressurize their cabins?
  38. M

    Can Humans Hear Supersonic Airplanes?

    If an air plane flies much faster than a speed of sound can humans still hear it.
  39. P

    Understanding Lift Force on Airplanes

    the force of lift excerted on an airplane is defined as F = Lc * D * v^2 * A where Lc is the lift coefficient, D is the air density, v velocity, and A the lift area of the wing structure. If i use SI units, the Force is expressed in Newtons. What I'm trying to grasp here, is how does this apply...
  40. S

    Revolutionizing Air Travel: The Future of Batwing Airplanes

    This is interesting. I would like to hear comments from the engineers in this forum. http://www.timesonline.co.uk/article/0,,2-1853992,00.html
  41. EnumaElish

    Can Flexible Airline Seating Improve Profitability and Passenger Comfort?

    I hope that is the right forum to post to. What follows may seem like it has more to do with economics than engineering but that is not the case: the economics is straightforward but the engineering may not be. In long-range passenger flights there are 3 classes: 1st, business, and economy...
  42. Pengwuino

    Build WW2 Planes: Is It Possible?

    Seeing as the US is a good and nice capitalist system... and you seem to be able to buy practically anything otherwise... does anyone build WW2 aircraft? Wouldn't it be so cool to buy like an F4 Corsair... Hell if i had the money, id buy one just to stare at outside...
  43. P

    Understanding Flight: Pressure Distribution & the Science Behind Airplanes

    Then what makes an airplane fly?
  44. Les Sleeth

    Relativity and Clocks on Airplanes Calibrated from the Ground

    I asked this question in another thread, but wonder about the answer I got: Question: I bought an atomic-timed clock and wondered if while I am taking off from an airport my clock would record time slower than a clock inside the airport. Since time on the clock is actually maintained by a...
  45. W

    Rubber-band powered toy airplanes

    Any ideas on how to build a vehicle that travels 4m in 20 seconds at a constant velocity and can only be powered by a spring, elastic, or gravitational potential energy? I've heard of mouse-trap cars and stuff but other than that I'm stuck. I'd really appreciate any help i can get.
  46. V

    Rubberband Airplanes: Physics for Takeoff, Flight & Range

    I'm working on a project relating to rubberband power airplanes. I need to know the physics related to it. For my project I need to. Sketch two free-body diagrams: one for the plane accelerating on the ground and another one for the plane flying. Show all the forces in each case and write...
  47. X

    Airplane Velocity and Wind Speed: A Scientific Debate | Xeno's Perspective

    Hey Everyone, I found myself in this scientific debate with my father on our way to the airport about the effect of wind speed on the airplane's velocity. He claimed that if the wind was in the exact direction of the plane, the plane's new speed would be the sum of both speeds. I didnt really...
  48. K

    Airplanes that fly a few feet above the surface of the sea

    Is anyone still developing the airplanes that fly a few feet above the surface of the sea to get increased lift?
  49. lavalamp

    Benouilli Effect: How Airplanes and Paper Fly

    The Benouilli effect, used by aeroplanes, race cars and of course blowing pieces of paper. OK, In the case of an aeroplane wing, the air flowing over the top of the wing has a greater distance to travel than the air flowing under the wing, therefore the air travels faster over the top and has...
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