New answers tagged

6

The function of the form is to act as a throttle stop when the part is in the position shown in the picture. It prevents full movement of the throttle when canopy is not securely closed and sealed. When the canopy is closed, the latch is moved by pushing the bottom part of the latch towards the outside of the plane. This moves the throttle stop out of way ...


1

Let's consider an infinite swept wing with a sweep angle $\Lambda$. We can divide the freestream velocity ($V_\infty$) into two components: the component perpendicular to the sweep ($V_{\perp}$) and the component parallel to the sweep ($V_{||}$). Similarly, we will divide the exo-boundary layer velocity field around the wing ($V_e$) into the perpendicular ...


-1

My guess would be to keep the pilot relaxed but at the same time the orientation in night time be easy to look out back in without eyes getting strained and easy to look at dials and gizmos which would be difficult if flying in inclement weather at night.


1

Shock waves form where air can no longer "get out of the way" and begins to compress. Sweeping the wing effectively increases the chord and reduces the rate of wing thickness increases as airflow moves across it, essentially making the body longer and more "streamlined". Instead of running into a steep hill and compressing, it can flow over a more gently ...


1

"Lock-on" just refers to a unit receiving multiple different response signals in response to its interrogation broadcasts, scanning for the signal it's looking for, and when it finds the signal who's encoding matches its channel selection, it starts to process that signal and ignores all others. It's locked on to that signal.


0

If you are not afraid of UFOs, you can check MHD principles and plasmas. The idea is to interact with the ambient fluid to improve the flow, thus reducing the shockwave Real results are very limited and it requires too much power to be airworthy.


1

Since few years, flight data is used to improve predictive maintenance. This Big Data approach is apparently very popular among airlines. But structural damage must still be evaluated by hand (and torchlight) from reports.


0

Anoher advantage of side by side is INSTRUMENT COMPARISON. If the two >2< Instruments are the same, it is a good bet the system is working correctly.


0

This answer will approach the question by focusing on a more narrow case: "In a conventional wing + tail configuration, is it possible for an aircraft to be stable even if the tail is creating an upforce rather than a downforce?" The Center of Lift (or Center of Pressure) is the point where we can treat the wing's lift vector as acting, without having to ...


4

Most supersonic aircraft have points where the cross-section suddenly changes, such as the fuselage nose, the wing root leading edge or the wing trailing edge. The points of sudden change produce sharp changes in air pressure, i.e. loud sonic booms. Concorde was one example. By designing the plane's cross-section to vary smoothly from end to end, the ...


0

This might work better thinking on the x,y, and z axes. I am seeing a dihedral upper wing, a straight lower wing, and a t-tail. A dihedralled upper wing, with a little sweep, would interfere with the lower wing first near the front, causing the plane to pitch down before it stalled if AOA became too great. There should be some gap between the two. The ...


0

It would depend on the relationship between span and separation. The dihedral would be too great on a short-span wing, as drawn, leading to all sorts of issues. Since the separation needs to be more than usual, approaching two chord lengths, you would need a very high aspect ratio, maybe 15 or so. But if you were to leave out the middle wing and cross-brace ...


19

While the other answers are correct they are missing a key point: Because it was certified that way When an aircraft is certified with particular equipment, changing that can be difficult and may require the filing of a MAJOR REPAIR AND ALTERATION form. Its likely cheaper for Boeing to keep the trim wheels the way they are. The common 737 type certificate ...


9

The leading edge of the horizontal stab on jets is driven up and down for trim using a very large acme thread style screw jack. The Cessna 180/185 family and the Piper Cub/Super Cub/Pawnee family also do nearly the exact same thing, just with much smaller cable operated screw jacks. The early jets using jackscrew driven stabs included electric motors but ...


30

Trim pitch "wheels" as you describe date back to the time when turning that wheel actually pulled on steel cables that were connected to the hinge mechanism for the control surface itself. This mechanical/manual system was a simple and robust method of manually trimming the aircraft and was very widely used before electronic/fly-by-wire control systems were ...


6

This statement is using "plane" in the mathematical-geometric sense, which is of course very confusing when we talk about a part of a "plane" in the "flying machine" sense. So, a "one-plane" thrust vectoring nozzle can only move up and down or left and right (typically up and down). So, this gives you pitch control using the thrust, without requiring ...


0

For those who don't know "thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket, or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to control the attitude or angular velocity of the vehicle. In rocketry and ballistic missiles that fly outside the atmosphere, aerodynamic control ...


3

@George already gave a correct answer, but I'll expand it a bit and show the source. Indeed, the lower load limit is for trans- and supersonic flight (formally M > 0.85) and the higher limit is for subsonic conditions. The AoA redline at 15° also relates to M > 0.85. At subsonic speeds, the max AoA is 26°. I can only speculate why it is not shown on the ...


2

Ilyushin Il-80 Source: Wikipedia The "canoe" is thought to house "advanced" satellite communications equipment. This is a classified aircraft though, so there isn't a lot of publicly available information on exactly what other equipment might be contained in that hump.


7

There are many factors going into the sizing of elevators, and they are all interconnected with other considerations such as CG envelope, static margin, flight controls, etc. Here are some factors that will influence up-sizing the elevators. Usually, the minimum elevator sizing is determined by low speed requirements: Ability to perform early rotation in ...


2

The line that is at the 9 G's is limit of maximum amount of G's( 9) until 0.85Mach (that is subsonic speed) and the lower line@7.5 is the limit for supersonic flight.


1

“What is the maximum height for deploying a parachute?” Probably somewhere in the neighborhood of 60,000 feet MSL. I have no citation for this opinion. Based on what I have seen and experienced, there will be some limiting factors that will not make a parachute effective beyond that. As a matter of fact, a better plan would be to fly the plane as long as ...


1

Not for large passenger aircraft. Single engine failure flies on. 2 engine failure? I'd rather have a (shielded) 3rd engine, perhaps doubling as a very robust APU. Probability of a major structural failure in a commercial aircraft is not high enough. Both pilots incapacitated, same. Saving people from a loss of control due to spatial disorientation or ...


0

I'm assuming this is for something like the BMFA Payload Challenge where you design a model plane to carry a payload. You need to increase the wing area, as lift is a function of wing area and speed (and speed requires power, so you can't increase it). As your span is limited, you can add chord, or add another wing (i.e. turn it into a biplane). More ...


0

Why are fuel tanks located in wings? Because it is hard to fit the passengers or their baggage into the wings.


2

I'm not sure what you mean by 'payload capacity'. Airplanes have what's termed a 'useful load' which is the maximum combined weight of the passengers, baggage and cargo, and useable fuel. If you wanted to increase useful load, you would have to make the airframe and all systems aboard the airplane which constitute useful load lighter. This does have the ...


0

"Is there a maximum possible size for an airplane?" Assuming the context of the question is airplanes that fly in the skies of planet earth, the answer is "yes". An airplane vastly larger than the earth could never fly within the earth's atmosphere.


1

Yes, it is possible and variable-incidence wings have been used. The only production example was the Vought F-8 Crusader, used primarily by the US Navy. It had a variable-incidence wing, which tilted nose-up by about 7 degrees to give increased lift for takeoff. The conventional solution of a lengthened nose undercarriage was deemed impractical for the ...


0

All it means is the deck angle of the fuselage will be lower for a given speed. Weight being the same, the wing will fly at the AOA it needs to fly at to support the weight. By increasing the incidence, the fuse will just be pointing down more because AOA will be the same for a given flight condition. You have a downstream problem as well because the ...


0

In short, no. But it depends... Angle of incidence does not increase or decrease lift, only angle of attack and airspeed affect lift. Let me explain - If you had an aircraft with a variable angle of incidence you could fly at a constant angle of attack while varying the incidence and have no effect on lift. Picture the wing steady with respect to the ...


0

If I am thinking about this correctly, increasing angle of incidence would increase lift because you would also be increasing angle of attack. Increasing the angle of attack would increase lift until you reach the critical angle where you have airflow separation and aerodynamically stall the wing. It’s the angle of attack that’s important. A better ...


0

I can’t comment on the MiG exactly, but most fighter aircraft have maneuvering limitations when heavily loaded with external stores. If I recall correctly, the F-16 is limited to ~7Gs with a loadout. A good guess is that the MiG has similar limitations; this would be verified by looking at a MiG-29 flight manual under operational limitations listed therein....


1

Yes. Angle of Attack is included in the Lift formula. Lift generally increases with angle of attack in a linear fashion until AOA reaches stall. This is why it is not a good idea to fly at too high an AOA. Better to increase Velocity. Lift increases with Velocity squared. The Navy Vought F-8 Crusader had a "variable incidence wing" that was raised to a ...


5

One big reason is to make room for external stores such as fuel, weapons and electronics packs. A low-wing design must have longer and therefore heavier and bulkier undercarriage if ground access to the underwing hard points is to be adequate. Also, the upper surface of a high wing is larger and cleaner, providing better lift over the fuselage and reducing ...


5

By inclined, do you mean that the conventional (taildragger) landing gear configuration angles the propeller? If that is in fact your question, know that the propeller is not “inclined” in flight any more than a tricycle landing gear aircraft. Straight and level is basically (very roughly) the same between the P-40 and the SR-22. And, P-factor is only ...


5

Yes, the Su-34 does technically include a food ration warmer, a "sanitary container", and some room that allows for sleeping. However, all three are much less impressive than the terms might suggest: The food ration warmer is not a microwave. It's just a small can heater: There is also some dedicated room for extra cans. The "sleeping room" is just a bit ...


1

No, there is neither a toilet nor a kitchen on an SU-34. The first picture in your post is of the "relief tube", which the crew can urinate into. It's not a toilet, though, and can't handle feces. There is a small area behind the crew seats just big enough for one person to stretch their legs, which can be used to store food if the crew so desires. It even ...


1

The answer is no. The SU-34 is a tactical jet with ejection seats. There is no room for such amenities. Most fighter type aircraft only have a relief tube of the type in your upper photo.


3

Ejection of the tipjet exhaust streams in different directions creates a reactive torque on the rotor. This causes the rotor to spin up until aerodynamic drag exactly opposes the jet reaction. So in a way you can say that tipjet helicopters cancel the rotor torque through aerodynamic drag. But no torque is applied to the rotor through the rotor hub. Its ...


8

Think of 2 scenarios: in one you are holding a rocket shaped projectile that is inert and you throw this projectile using your arm. In the second scenario you hold a real rocket, which is then launched. In the first scenario you throw the projectile, and you have to counter the twisting motion of your arm because your arm is imparting a force. In the ...


32

This is a basic physics question, involving Newton's third law of motion (For every action, there is an equal and opposite reaction.) When a centrally mounted engine applies force to turn the rotor, the equal and opposite reaction creates torque on the fuselage. With a tip jet, the force is applied by the jet shooting its exhaust perpendicular to the blade,...


11

Think of the aircraft engine as one isolated system and the rotor as another isolated system. In its simplest terms, torque is the force required to move mass in a circular motion. Torque is caused by the engine providing power to the rotor shaft which moves the mass of the blades. The torque is the interaction of the stationary engine trying to move the ...


2

Trapezoidal wings have advantages and disadvantages: Better performance than delta wings at transonic speed Good stealth performances Flaps can be easily used. drag reducing better Lift/Drag ratio than delta wings The problem is that they stall at much lower angles of attack than delta wings. Edit:this problem is overcome using leading edge,LERX,and/or ...


0

To add to the answers of @Meower68 and @rbp The craft's configuration is basically a conventional wing with a biplane tail. Such tails date from the pioneer days of aviation. The exact variant here is a cantilevered inverted seqsuiplane; both cantilever biplanes and inverted sesquiplanes have since flown successfully. Another concept dating from those days ...


-2

18 HP is more than good enough. Wright Brd's proves it. Your plane seems perfect. However, %35-40 of the propulsion will be lost as "fuselage drag", where your HP's are valuable . If you can split the power into two, like that in the "Colombon Cri Cri". (You can do it with proper Gates belt drive), you can use lighter props (0,7m) and nacalle drag loss ...


0

Re tailskids versus tailwheels-- Tailskids are inferior to tailwheels for directional control on hard-surfaced runways, even if said tailskids are steerable. Of course this is a negative advantage (disadvantage), not an advantage. (Re steerable tailskids-- see https://en.wikipedia.org/wiki/Conventional_landing_gear ) Especially on a grass or dirt ...


2

Does joystick position control bank angle rather than directly controlling aileron/spoileron deflection in some Airbus aircraft? To complement @Bianfable's answer, in Normal Law Flight Mode, Airbus FBW families (including A220) command roll rate via lateral stick position up to the artificial spiral stability limit of 33 deg bank (for A220 it's 30 deg). ...


1

The sidestick (they don't like it when you call it joystick) is not controlling bank angle, but roll rate in flight. On the ground, the control surfaces are deflected proportionally to sidestick movement in order to perform a check of all surfaces before takeoff. The details may vary, but this is generally true for all full fly-by-wire Airbuses. From the ...


61

It's called 'toe-in' and it's done basically to match the local airflow which is slightly divergent (heading outboard along the underside of the wing). If the engines were mounted exactly parallel to the fuselage, they would be moving slightly obliquely through the local airflow and therefore incurring extra unnecessary drag. Another view of a 777 showing ...


-1

the reason for two vertical tails is so the plane can maneuver during high angle of attack situations. With a single vertical tail, you cannot turn ( maneuver ) during a high angle of attack situation, making the plane a strafing target.


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