# All Questions

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6 views

### Professional CFD softwear for aerodynamics?

What is best profi CFD softwear for aerodyanmics?
19 views

### How safe are commercial airliners from gallium infiltration?

I recently saw a video on gallium infiltration on YouTube. Gallium is a metal with a melting point somewhere between standard room temperature and human body temperature, meaning if you pick up a ...
20 views

### Are there any automated path planner algorithms for indoor drones?

I am developing a drone for sanitization, I am looking for a middle layer Software/Algorithms/Method which decides the flight path. The needs are as follows: Need to cover whole indoor area, for ...
9 views

### What are the expected vibration frequencies in a co-axial rotor system with contra-rotating propellers?

I am trying to understand the frequency spectrum of a co-axial rotor system. Form now i have a RC helicopter with two sets of three gear systems arranged in parallel, The number of teeth are 7,23,27) ...
5k views

### What are the bumps in the F-22 Raptor wing for?

As you can see in the picture there are several bulges or bumps in the wing that are located in the aileron and flaps. Somebody told me these are to hide the linear actuator, pushrod, and control horn....
1k views

### How does the fuel pump work in a PA-28 and when should I use it?

Just started flying again after 14 years and I'm taking this to the finish line this time. All my time, up till 10 am today, is in a C172. I did fly a PA 28-151 today and liked it. I do have some ...
34 views

### Stability Analysis of Aircraft

How can we do the complete lateral, longitudinal, and directional stability analysis of an aircraft by drawing appropriate geometry? I tried DATCOM+ but it has certain limitations. Is there any other ...
94 views

### What materials form the structural elements of the Boeing 737?

What materials form the structural elements (leaving the spars, ribs etc) of the B737? It was tough to get any information on the kind of composites used on the 737 structure. Hoping to get some ...
46 views

### What is physically happening when you use a bypass nozzle on a turbofan?

I am having trouble understanding how a fan affects the flow of air through the bypass in a turbofan engine. Solving for the flow of air using thermodyanic states requires using a bypass nozzle to &...
1k views

### How can I easily keep track of my landing count during pattern work?

PPL Student pilot, ~20 hrs Hi, whilst doing some pattern work I frequently find myself unable to keep accurate track of the number of landings. There's an AFIS at my home airport who keeps track (...
70 views

### 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 ...
48 views

### I'm looking for a flight school near Manhattan. What are the best options around within commuting distance? [closed]

I see a few airports on Long Island, in NJ, and in Westchester. Some seem to have flight schools. Can anyone recommend area flight schools or resources to research them other than Google? I'm a bit ...
568 views

### For the CFIs, CFIIs, MEIs, and AGIs - How often do you find students that utilize your ratings?

I am curious. Out of 100 new students that walk into the average flight school, how many only need a standard CFI, how many do instrument training, and how many do multi-engine training? Additionally, ...
42 views

### Airbus A321 CFM56 Engine - Engine Anti-Ice Valve

For Airbus A321 - CFM56 engine, is there any maintenance task or trouble shooting procedure that require to removal Engine Anti-Ice valve and its hose? (except remove engine and remove the valve ...
59 views

### What is the theory of the ram's horn yoke? [duplicate]

Embraer tend to use a Ram's Horn yoke in the Phenom and many of their RJ aircraft: And Cessna uses a more standard yoke with vertical sides: What is Embraer's reasoning for the Ram's Horn Yoke? Are ...
81 views

### Where can I find airport diagrams for the Philippines?

I would like to have airport map, just like the one that pilots can see when they are taxiing. Is it possible to get such a map, even if you are not a pilot? Perhaps there are applications which a ...
41 views

### Does thrust depends on rocket chamber shape? [migrated]

i mark with green part of rocket which produce forward thrust and with red backward thrust. integration of pressure around rocket walls gives total thrust,which allways act in forward direction.. Does ...
88 views

### How do rotor tangs lock into wheel keyways?

How do the rotor tangs lock into wheel keyways? Are there special keys on the outboard wheel half that allow locking the tangs in place? Also would be great if anyone could provide me with a image of ...
680 views

### Why do Dassault Falcons only have one thrust reverser?

Using all 3 engines would slow it down much faster. No?
2k views

### What is the best procedure for landing at my destination if I have a full electrical failure at night?

What is the best procedure for landing VFR at the intended destination airport and I have an electrical failure, in the following scenario? Let's assume this is a VFR flight and I'm 50 miles from the ...
99 views

### Is it possible to upgrade old Mirage-III and Mirage-V variants with thrust vectoring engines?

Is it possible to upgrade old Mirage-III and Mirage-V variants with thrust-vectoring engines so that they can match the maneuverability of F-16s?
78 views

### Why did South African Air force get rid of Atlas Cheetahs? [closed]

If Pakistan can fly Mirage-III and Mirage-V variants for 50 years, why did SAAF get rid of their Atlas Cheetahs? Ecuador is still flying Atlas Cheetahs.
4k views

### Plane that always flies into the wind?

Suppose that you dropped an uncontrolled, dummy glider into the air. You want it to always face into the wind by design. Would it be possible? If so, what would such a plane look like?
37 views

### Can climbing above RVSM airspace cause temporary loss of separation with an aircraft in RVSM airspace?

Consider Aircraft A cruising at FL400 and Aircraft B cruising at FL410. Both in close proximity, heading in the same direction. Ignore altitude for direction of flight issue. When aircraft B requests ...
194 views

### How calculate water rocket thrust? [closed]

both nozzle is 2cm diameter one "rocket" has air pump which hold constant 5 bar second "rocket" it has water inside and also air pump which hold cosntant 5 bar,(water column is ...
164 views

### When flying on a glide slope, does the G meter show 1G or less?

If your angle of attack in landing pattern is 14 degrees but your vertical velocity is 600 feet/minute, does the HUD show you 1G or not? Why?
121 views

### What are the names of the antennas which I have marked in this picture of a Boeing 737?

I have taken the picture from PMDG 737NGX Microsoft flight simulator X. I am really curious to know what this antennas are. These antennas are behind the nose gear.
64 views

### Does DA/DH refers to ceiling?

If airport is reporting FEW001 or SCT001 and RVR is above 600m, does it means that there will be no LVO because ceiling is defined as more than 4/8 and DA/DH will be more than 100ft because DA/DH is ...
72 views

### What is the difference between ILS and VOR/DME?

I have wondered many times about the difference between VOR/DME and ILS and which one is better for carrying out approaches. Why do pilots use VOR/DME when the ILS is a better option because it is ...
291 views

### Is a jet engine's shaft neutral in the direction of thrust?

I think I read somewhere that the forces on a jet engine shaft is neutral because the forces at the turbine and compressor cancel out. This means that the axial bearings don't have force on it in ...
129 views

### Other than the 747, are there any other current, recent or planned airliners with a nose door option?

Boeing has recently announced that the 747 program is coming to an end. One of the key features of the freight 747s was the nose door, which facilitated faster loading of freight and allowed the ...
110 views

### What is relation between Reynolds number-turbulent flow-flow separation? [duplicate]

can some explain conection betwen re number -turbulent flow -and flow separation ,in example at wing in the air and water? 1)does high numbers= turbulent flow mean higher resistance to flow separation ...
23 views

### Why is hybrid laminar flow control preferred for swept wings over other options?

As I understand it, a (the?) major form of laminar-to-turbulent transition on the swept wings of large jets is the crossflow caused by the sweep. One way to control this is laminar flow control by ...
167 views

### Is/why isn't the Antonov 124 to 225 wing upgrade method common?

I'm told that wing redesigns (edit: for tapered, swept wings) are difficult, so variants of a model often do with a common wing optimized for the middle member. But then I read the following: Based ...
44 views

### Why does a steady-state non-zero body yaw and/ or roll rate induce side force?

An answer on ASE states The presence of steady-state non-zero body yaw and roll rate induces side force ($C_{y_p}$ and $C_{y_r}$). What is a non-mathematical explanation of why this is so? Is it ...
1k views

### What is this “Supersonic French” aircraft?

To celebrate Bastille Day, Ubisoft released the below (2D) in-game charm for their game, Tom Clancy's Rainbow Six Siege. Despite frantic searching on Wikipedia, I cannot for the life of me figure out ...
396 views

### Why does the UK CAA restart its page numbering with every new chapter of their CAP publications?

Every CAA Publication (CAP) seems to restart its page numbering when starting a new chapter. Does anyone know why they have decided to do this? For example, the CAP413. Instead of a logical page ...
47 views

### How does wing shape impact shock structure?

I am trying to understand what the 3D shock structure would be for a wing in supersonic flow. Suppose we have a wing which is made of double-wedge airfoil cross-sections. If we view the shock ...
207 views

### Is PVC tubing a good material for helicopter airframes?

Been thinking of getting into the hobby of building ultralight helicopters, and would PVC tubing be a good choice to build the overall airframe?
98 views

### CH-37 Mojave Helicopter decibels

What was the decibels level for the Sikorsky CH-37 Mojave Helicopter? 1956 --1959. I need this information for the VA, to process my hearing claim. I was a crew chief in the Army.
240 views

### Can Airbus A320 doors be opened mid-flight?

Today I learned how airliner doors are typically an outward facing plug and cabin pressure would make them nearly impossible to open mid-flight. It's easy enough to see that for the shape of Boeing ...
94 views

### Does the strength of a wingtip vortex generated by an airfoil peak at the critical angle of attack?

I know that generally, wingtip vortices increase in strength as the angle of attack increases. Is the critical angle of attack/Cl Max the peak strength, or do the vortices generally continue to ...
5k views

### Are there any remaining flying boat or seaplane airliners in operation?

Is there anywhere in the world that still offers scheduled air carrier service using flying boat / seaplane types of aircraft - something akin to a proper airliner? Or are they all limited to charters ...
99 views

### Is there a 'common courtesy' distance that should be complied with when initiating contact with ATC for class D airspace?

Some background: I'm a student pilot preparing for an upcoming stage check involving XC diversions and have been trying to visualize different scenarios of what I'd need to do when diverting. One case ...
987 views

### What is this thing on a FDX MD11 (MD10?)?

I assume something forward looking; not sure why there and how they got this to play nicely with radar
282 views

### Is it feasible to replace a C152's engine with multiple small turbine engines?

If I wanted to remove the piston engine from a cheap plane like a Cessna 152 and add small turbine engines with an equivalent thrust but weighing less, where would be the best place structurally to ...
92 views

### Why does a banked aircraft create sideslip?

Below is an excerpt from Raymer (Aircraft Design) where he explains the dihedral effect. He states that a banked aircraft (due to say a roll disturbance) will have a sideslip which leads to a ...
89 views

### RC airplane required engine power

I'm going through the process of designing an RC airplane. I know that probably most calculations on scale models might be non-precise ones, but I'm trying to do it as correct as possible (it's a ...