# Tag Info

### Can TCAS and GPWS work at the same time?

Yes they can work together. It's not particularly sophisticated. Essentially there is a priority list for all alerts. For TAWS/GPWS and TCAS, the TAWS/GPWS alerts will take precedence over a TCAS RA (...
• 17.6k
Accepted

### At what angle to the ground track does wind become favorable to lower fuel consumption?

To solve this problem, let's look at the vector diagram of TAS, GS and Wind Speed (WS): (image source) In this diagram, the angle between the desired course (ground track) and the wind is $\delta$ (...
• 44.5k

### Do airlines record the plane roll, yaw, pitch angles during a landing? (eg every 100 milliseconds)

Yes, the type of data you are asking about does exist, but it isn't available for curious passengers to critique. Most modern airlines have within their safety programs a means to record and analyze ...
• 16.3k
Accepted

### Do symmetrical airfoils generate induced drag?

It depends on the angle of attack. If it is non-zero there will still be a different airflow on both sides - leading to different pressures and thus induced drag.
• 2,495

### Do symmetrical airfoils generate induced drag?

If an airfoil is producing lift, then it will be producing induced drag. Both cambered and symmetrical airfoils have an angle of attack at which they produce no lift, no induced drag, and no pressure ...
• 337
Accepted

### If while landing ,a surface inversion occured close to the ground would atc or atis know?

Probably not unless a pilot reported it. METARs and TAFs only include ground temperature/pressure so presumably that's all they know.
• 196

### CoG Envelope Calculation - Am I Doing Something Wrong?

First, the reference datum for the spar is of no consequence in W&B calculations. For Empty Weight and Moment, you have to refer to the actual W&B record for the specific aircraft. It is part ...
• 17.6k

### CoG Envelope Calculation - Am I Doing Something Wrong?

Yes, you are doing something wrong. Your biggest mistake is using 154.75 as the empty weight moment. As shown in my last image (from the Icon A5 user manual), 154.75 is just a reference datum marking ...
• 32k
Accepted

### Ice Protection System for supersonic aircraft

Depends on the aircraft. Concorde, for instance used electrical deicing system on its engine inlets, air data probes and wing leading edges to prevent ice accumulation during subsonic climb and ...
• 65.5k

### If you are in a terrain escape maneuver, would you be able to see traffic above you displayed in the cockpit of airliners

Yes, if you are in an aircraft with good upward visibility, and you tilt your head upwards, it is reasonable to presume that you could see traffic above you within your filed of view as you pitched up....
• 16.3k
1 vote

### Which countries use qfe field pressure?

I learned PPL and IFR in the USA. QFE was briefly mentioned in training but everything else at all times was QNH. ATC always reported in QNH as did inflight and online weather services (I have seen a ...
1 vote

### Which countries use qfe field pressure?

Also why doesn't everyone use it? Isn't qfe field pressure better than qnh local pressure... Advantage of QFE is that it will read 0 on the field (and therefore approximately height in the pattern), ...
• 54.1k
1 vote

### How does maximum speed vary with altitude?

From sea level to Ionospheres, it first increases because air drag decreases with altitude, until at a certain altitude the maximum velocity starts to decrease because engine performance decreases.

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