Questions tagged [flight-instruments]

Flight instruments provide the pilot with information about the flight situation of that aircraft, such as altitude, speed and direction; and are of particular use in conditions of poor visibility, such as in clouds, when such information is not available from visual reference outside the aircraft.

Filter by
Sorted by
Tagged with
18
votes
1answer
6k views

What do the yellow lashes/wings on the B737 PFD indicate?

When I was looking at a YouTube clip of a B737 doing a landing, I couldn't help but notice something on the PFD: What do these yellow lashes/wings indicate on the artificial horizon? Image Source (...
10
votes
4answers
1k views

How do instructors simulate instrument failure in basic training aircraft with glass cockpits?

While working towards my private pilot's license in the United States in 2004-2005 (in a steam gauge only airplane), I very much remember my instructor covering one or more instruments to simulate ...
9
votes
3answers
2k views

What prevents a Machmeter from being the standard airspeed indicator?

Airspeed is more accurate when displayed by a Machmeter than when displayed by an airspeed indicator. It isn't affected by ambient temperature / density changes. It is still affected by position error,...
9
votes
2answers
7k views

How does an Airbus pilot decide whether to use HDG-V/S or TRK/FPA guidance?

The Flight Control Unit of modern Airbus aircraft has a pushbutton for selection of either heading / vertical speed (HDG-V/S), or track / flight path angle (TRK-FPA) guidance for the Autopilot and ...
13
votes
1answer
521 views

How should this Bendix course deviation indicator from the '50s be read?

This is a Swissair photo from a DC-7C panel. Source I have seen photos on airliners.net of these in DC-6s, VC-118 and Constellations. It appears that other companies besides Bendix made these ...
1
vote
1answer
4k views

Statute miles to runway visual range [duplicate]

Is there a formula to converting statute miles to runway visual range? If so, what would it be? I'm seeing how 1 mile is equal to 5000 feet, but I am so confused because 1/2 of a mile is equal to 2,...
9
votes
3answers
5k views

What is the difference between a pitot tube and a pitot-static tube?

What is the difference between a Pitot tube and a Pitot-static tube? If an aircraft fitted with Pitot tube and static holes on the fuselage, is it necessary to consider the static pressure ...
28
votes
3answers
3k views

What's the UX in modern airliner avionics for diversion choices, and does it integrate to autopilot?

This question mentions a flight that had to divert, in that case to Iqaluit (YFB). I was wondering: in modern large airliners, what is the user interface like when diverting? How is the case of "what ...
6
votes
1answer
3k views

What are the pros and cons of vacuum and pressure gyros?

Inspired by this question, I would like to know what the pro's and con's of the mostly used vacuum-gyro and the less used high-pressure-gyro is. Side-question: Are there any other ways to make the ...
16
votes
2answers
2k views

What is this nose cowl mounted display?

(YouTube) A crop duster's nose mounted display. It looks like a poor man's HUD to keep the display and the outside view at roughly the same focus distance, but what is its function?
6
votes
1answer
529 views

On an inverted aircraft, is the ILS glide slope sensing reversed?

If I'm halfway through a barrel roll on final descent, on an ILS, will I get reverse sensing on my glide slope indicator?
3
votes
1answer
97 views

Why $\frac{\Delta p}{\overline q}$ is depending by weight, flap deflection and other parameters? Which are other parameters?

As you can see in this link (Roskam, Airplane Aerodynamics and Performance, Chapter 2.5.3 Airspeed corrections) ... ... in the first and second line of page 30 Roskam tells that, in hypothesis of ...
3
votes
1answer
910 views

What caused the loss of "everything" on Swiftair Flight QY-2939?

I found this from a youtube video, and more info from this avherald article. One of the pilots declares an emergency because right after takeoff they lost "everything", as in all instruments. ATC ...
4
votes
1answer
873 views

At what altitude do vacuum powered gyros become ineffective?

Obviously, in space a vacuum powered gyro would not work because there is no air to move, but, how high do you have to go before they are unable to spin fast enough to work properly? would a vacuum ...
3
votes
1answer
214 views

What techniques, tools, or instruments are used while performing zero-g parabolic dives? [duplicate]

There are companies that sell "zero g" rides, where the aircraft is configured specifically to take people and possibly experiments through a parabolic dive to experience a short period of micro-...
20
votes
2answers
5k views

How can pilots lacking instruments interpret vectors given by ATC?

This video is about European Air Transport flight 2939, a Boeing 737, which "lost all the instruments of the aircraft" shortly after takeoff. BCS2939: We are flying heading now, and we don't have ...
5
votes
2answers
1k views

How does altimeter reading vary when departing from ISA conditions?

I am a soon-to-be student-pilot and am struggling with a basic concept that is altitude. After watching multitude of online videos, I feel that most of the people do not have good teaching skills. ...
13
votes
5answers
5k views

What will the pilot do if all the airspeed indicators fail?

Are there any alternate instruments to indicate the airspeed in case of pitot tube failures?
8
votes
2answers
969 views

What causes the phenomenon that pilots don't believe their instruments, while they're working well?

I read in a comment on another question that pilots not believing their instruments while they work perfectly well is common in aviation: The flight leader reported that his compasses had failed [.....
10
votes
1answer
750 views

Why vacuum instead of pressure to power gyros?

Why are most air powered gyro instruments powered by vacuum rather than positive pressure?
7
votes
1answer
441 views

How does Pitot Heat influence airspeed indication (assuming no ice or moisture)?

Should Pitot Heat ON (in dry weather conditions) decrease airspeed indication because warmer (so less dense) air flows through the tube?
8
votes
2answers
868 views

How does a Machmeter behave if the static port is blocked during a constant CAS climb?

Question: How will the machmeter behave in a constant CAS climb if the static source becomes blocked? Answer: The machmeter reading will decrease. Why? I couldn't find any logical reason for the ...
21
votes
2answers
3k views

What does it mean when pitch numbers move all over the HUD screen?

In this video from an F-16: You can see pitch angle move out of screen or be on the side at the end.
3
votes
1answer
3k views

How is the terrain displayed on the ND in a A320?

When you turn on "TERR ON ND" in a A320, you see terrain info on you navigation display (ND), but where does its source come from ? if data comes from FMGS stored inside its memory, then how come it ...
2
votes
1answer
674 views

Does an RMI show true or magnetic north?

Does the compass card of a Radio Magnetic Indicator (RMI) point to true north or magnetic north ?
2
votes
1answer
391 views

How do fighter jets measure how high they are?

I know most of the commercial planes use altimeter to find how high they are. I was just curious in finding out what fighter jets use to to find their height and what are the other technologies that ...
24
votes
13answers
11k views

How did planes measure their speed relative to the ground before GPS?

How did planes measure their ground speed before GPS? If they used some sort of anemometer to measure speed, that would only measure the speed of the plane relative to the air through which it is ...
12
votes
2answers
2k views

How is a conflict between aircraft with TCAS I and II resolved?

Let's say there are two aircraft in a risk of collision, one of them is equipped with Traffic Collision Avoidance System (TCAS) I so it will get only a Traffic Advisory (TA), however the second one is ...
7
votes
2answers
2k views

Are turn rate indicators calibrated to a certain speed? If so, what speed?

Are turn rate indicators calibrated to a certain speed? If they are, what speed are they calibrated to, and why aren't all the turn rate indicators calibrated for the same speed?
5
votes
2answers
610 views

What is the most accurate geometric plane for referencing terrestrial flight attitude?

I have found various definitions for attitude. Merriam Webster: inclination of the three principal axes of an airplane in flight to the relative wind. Wikipedia - Attitude Indicator: the orientation ...
4
votes
2answers
1k views

What type of altimeter is this?

What type Altimeter is an SA-91? It has three pointers 100, 1000, 10000. Don't know if it is Kollsman. I can't find any info as far as repairing unit.
6
votes
1answer
2k views

When do I need to worry about a course deviation indicator reverse sensing?

I understand that if I am tracking a radial inbound I will set that radial as the reciprocal so I don't have to worry about reverse sensing. On an approach however, do I need to set the CDI to the ...
11
votes
3answers
4k views

Why was the WWII RAF fighter joy stick loop design not used widely?

WWII RAF fighters had a loop on top of the joy stick in case of hand loss or injury - Anyone know why the Allies didn't copy this very helpful idea?
0
votes
3answers
336 views

How can I get General Aviation flight data on smartphone and/or tablet?

Is it possible to in-flight receive navigation data on an electronic device (like smartphone and/or tablet) present in the cockpit? I refer to General Aviation aircraft and navigation data like ...
12
votes
2answers
84k views

What are the differences between an OBS, a CDI, a Heading indicator, and an HSI?

What are the differences between an OBS, a CDI, a Heading indicator, and an HSI? As far as I can tell they all use VORs. Why would 4 different version of the same instrument be invented? Is the HSI ...
6
votes
1answer
394 views

What is the Boeing 727 AC Generator Panel Part Number?

Does anyone know the part number for the Boeing 727 AC Generator Drive panel? I have searched the Internet and have not found the part number. (Source)
1
vote
2answers
537 views

How do you set up your nav instruments and coms during ground operations and takeoff? [closed]

I have an HSI, an OBS, and a GPS. I normally set my HSI to runway heading, my bug to the wind direction, and the GPS to destination airport/waypoint (which will give me my turn out heading). I don't ...
4
votes
1answer
9k views

How does a true airspeed indicator work?

How does a True Airspeed Indicator work? I am aware of how the air speed indicator works, but how is the density input being provided to this instrument?
9
votes
1answer
1k views

Where are the locations of the elevators or horizontal stabilizers in a Concorde?

I don't find the horizontal stabilizers or the elevators of a Concorde at the tail section like other aircrafts. Are they fitted beside the ailerons in the wings?
18
votes
2answers
5k views

What types of attitude indicators are there?

Learning to fly in general aviation in the west since the mid 2000s I'm used to the common attitude indicators like this one. I've also seen older ones that are black and white as well as many ...
4
votes
2answers
8k views

What details do EICAS systems provide?

I was reading this article about EICAS: Engine-indicating and crew-alerting system (EICAS) includes instrumentation of various engine parameters, including for example revolutions per minute, ...
20
votes
1answer
2k views

What do these instruments do?

This is sort of the reverse of an aircraft-identifcation question. I am attempting to build a virtual model of a Gee Bee R1 (for fun). Unfortunately I haven't had much luck finding plans or images of ...
8
votes
1answer
3k views

What is the correct crew procedure for an unreliable airspeed alert?

When the crew receives "airspeed disagree" message on the primary flight displays, they may face some hazardous situation. Is there any procedure, using a table containing pitch, power, altitude and ...
2
votes
1answer
326 views

Altimeter disagreement. What's the crew procedure to deal with that?

The crew is facing a situation, in which, the altimeters indicate different altitude (the port and starboard ones - cpt´s and FO´s). Is there any procedure to perform an IFR landing? If we consider a ...
30
votes
1answer
5k views

Can we replace an attitude indicator with a ball half full of liquid?

Attitude indicators (artificial horizons) use a gyro to display pitch and bank. I was wondering if it would work to use a ball half full of liquid to replace the artificial horizon (using the water ...
8
votes
2answers
14k views

How does a horizontal situation indicator (HSI) work?

I am trying to understand the Horizontal Situation Indicator. To my understanding there is a slaving transmitter, usually in a wing (the left wing in the Piper Archer and Seminole), which sends ...
6
votes
3answers
4k views

What does a helicopter "gas prod" gauge measure?

The beginning scenes of the movie "San Andreas" partly take place in a rescue helicopter. One of the panel gauges read "GAS PROD" above it. I googled it but didn't find much. Can someone explain what ...
8
votes
1answer
14k views

How is the wind direction and wind speed measured in flight?

Most large aircraft have a wind direction and wind speed indicator. How is this measured? The vector difference between TAS and ground speed? How accurate is this? In the below picture (taken from ...
16
votes
2answers
2k views

What are these lights above the panel in a Blue Angels cockpit?

I found the following picture on the Blue Angels Facebook page: What is the purpose of the lights over the pilot's panel? (The two on the top are green)
1
vote
2answers
652 views

What dictates the shape of the attitude indicator display on the PFD?

I notice the atitude indicator displayed in the PFD is either squared-shape or truncated-circle-shaped. A good example of the square shape is the B747-400, It looks like a square whose corner are a ...