28 votes
Accepted

How do aircraft on the deck of a moving aircraft carrier align their INS/IRS?

The aircraft carrier has its own inertial navigation system, (SINS - Ship's Inertial Navigation System) and this information is transmitted to each individual aircraft INS by either cable or datalink. ...
Michael Hall's user avatar
  • 25.8k
25 votes

How did the gyro gunsights of WW2 get the range and lead of a target?

You are seriously over estimating the technical capabilities of the time. The gun-sight is not much more than an intricate slide-rule. You had to feed it information about the target size/aircraft ...
Trevor_G's user avatar
  • 4,876
16 votes

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

They are not calibrated for a certain speed. If by "calibrated", you mean they deflect together / to the same side, then you're using the instruments wrong. The two instruments have are not linked to ...
kevin's user avatar
  • 39.7k
14 votes

How did the gyro gunsights of WW2 get the range and lead of a target?

Other answers here describe the functionality of such gunsights; the "calculation" was done by mechanical analog computer, made up of gears, cams, shafts, and linkages. Here's part of a Sperry K-3 ...
Russell Borogove's user avatar
14 votes
Accepted

Why does the attitude indicator gyro not precess the same way that a directional gyro does?

The self erection device in the attitude gyro that levels it when you start up on the ground also keeps it erect (its axis pointed at the center of the earth) when precession tends to send it off ...
John K's user avatar
  • 130k
12 votes

How did the gyro gunsights of WW2 get the range and lead of a target?

I don't understand how it computed range/position to the target and then calculated how much lead is needed. Reading the Wikipedia article you linked, it didn't, but both assertions are unsourced. ...
Federico's user avatar
  • 32.4k
12 votes
Accepted

What do a "sheared pump drive" and a "possible sticky vacuum regulator" mean?

There is a small vacuum pump attached to the engine by a small rotating shaft which generates vacuum whenever the engine is running. That vacuum is used to spin up the gyro instruments in the plane. ...
niels nielsen's user avatar
10 votes
Accepted

Do air-driven gyroscopic instruments suffer from icing or any blockage of filter?

From all that I have seen on that type of aircraft, there is merely a filter. If one was operating in a dusty environment (eg the bush) then I would add those to a 100 hour check. But honestly, I ...
mongo's user avatar
  • 17.7k
9 votes
Accepted

Why is the Inertial Reference System not used to determine true altitude?

IRS will drift over time. Decision altitude is 200ft for ILS CAT I approach. 0.5nm drift is not to much for navigation but it will be huge difference in altitude and you can hit obstacles if your ...
Andrius's user avatar
  • 3,854
8 votes

During "partial panel" flying, in what ways is a turn rate indicator more useful than a turn coordinator?

A turn coordinator's axis of rotation is tilted around 30 degrees and rotates in the opposite direction. Because of this, looping errror is reversed and it under-reads at more than 1g. This makes it ...
Juan Jimenez's user avatar
  • 12.8k
8 votes
Accepted

Is the pod on the right wing of the PC-12 and Cessna 208 a gyrocompass?

Its not the gyrocompass. Its where the weather radar unit is mounted since the prop prevents it from being mounted in the nose like on many larger aircraft. You can find a nice instructional video on ...
Dave's user avatar
  • 101k
7 votes
Accepted

How does a horizontal situation indicator (HSI) work?

Your understanding is partly right. Usually HSI indicators are associated with a slaving transmitter that includes the flux gate (the magnetic sensor), but also other elements such the directional ...
Daniel Mavrakis's user avatar
7 votes

How does the control-board on small drones govern their flight?

Maneuverability with this kind of drone comes with their small size and high thrust-to-weight ratio. When you scale such a dynamic system, the time scales with the square root of size, so the smaller ...
Peter Kämpf's user avatar
7 votes
Accepted

Has this type of "gyrocompass" ever been used in an aircraft?

I think the answer is "no and yes". Bear with me... That sort of device as a stand alone heading sensor has never been used in an aircraft and if you parse the Wikipedia article carefully it becomes ...
John K's user avatar
  • 130k
7 votes
Accepted

How do you realign a directional gyro in an area of magnetic unreliability?

You initially align it while on the ground, using a known reference like the runway. While in flight, you'll need to use an astrocompass or sextant, if you have one and know how to use it and can see ...
John K's user avatar
  • 130k
6 votes
Accepted

How does a gyro compass indicate true heading?

The directional gyro (DG) does not know about heading. Its gyroscope will hold its position (e.g. the heading you set from the magnetic compass) in space. The plane is turning "around it", but DG is ...
Stefan's user avatar
  • 186
6 votes
Accepted

How do modern avionics work without vacuum pumps or gyroscopes?

If you haven't already done so, you should have a look at section 7 of the C162 POH. That section gives an overview of all the aircraft's systems and the information is at a good level of detail for a ...
Pondlife's user avatar
  • 71.7k
6 votes
Accepted

Artificial horizon - "horizon bar" or "symbolic airplane adjust"

Instrument parallax has to do with viewing position of the pilot compared to the instrument. You adjust the symbolic airplane to the horizon bar on the outside of the instrument, not the part that ...
GdD's user avatar
  • 53.7k
6 votes
Accepted

Why is the turn coordinator gyro tilted?

The turn coordinator is a rate gyro. Unlike attitude and heading gyros that are free to rotate and the instrument senses the orientation of their axis, the turn coordinator (and the turn indicator one)...
Jan Hudec's user avatar
  • 56.2k
6 votes
Accepted

What is gimbal error in DGI compass gyroscopes?

Short answer The gimballing error is the mechanical error introduced by the cardan design of a gyro DI. A cardan joint is linear only when its input and output axes are aligned. In the gyro DI axes ...
mins's user avatar
  • 71.8k
6 votes
Accepted

Why would older jets and turbo props use electric gyros vs vacuum driven?

Electric gyroscopic systems provide redundancy to vacuum powered instruments. "Older" (and modern) jets and turboprops are required to fly in all kinds of weather, including iceing ...
Robert DiGiovanni's user avatar
5 votes

How do modern avionics work without vacuum pumps or gyroscopes?

Looks like the following link takes you to the G300 user manual. You'll find your answers here, and this document would be a good one to be familiar with for exactly the sorts of questions you're ...
Ralph J's user avatar
  • 51.1k
5 votes
Accepted

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. It is largely related to the instruments in your ...
Dave's user avatar
  • 101k
5 votes

What instruments are used to indicate aircraft attitude in acrobatic airplanes?

The basics: Acro airplanes don’t have attitude indicators because they don’t need them. The airplanes are certified at Day/Night VFR flight only and gyroscopic instruments are not required equipment ...
Romeo_4808N's user avatar
  • 73.5k
5 votes

During "partial panel" flying, in what ways is a turn rate indicator more useful than a turn coordinator?

You have the yaw/roll switched. The TC's canted gyro adds roll to the yaw rate sensing, not the other way around. The biggest drawback to the turn coordinator was the presentation of the aircraft, ...
John K's user avatar
  • 130k
5 votes

How do AHRS systems meet the "gyroscopic" requirement of 14 cfr 91.205.d?

In regulations, instruments are always defined functionally. They say what the instruments must measure, not how. Any actual implementation then has to be certified, but that certification concerns ...
Jan Hudec's user avatar
  • 56.2k
5 votes
Accepted

Is it possible for an indirect (Russian) attitude indicator to work in 3D without tumbling?

Yes. It's actually easier. Just consider the fact that an indirect indicator consists of two separate moving parts with one degree of freedom each, rather than one with two (or even three for navball) ...
Zeus's user avatar
  • 9,053
5 votes
Accepted

Can you fly with INS/ IRS at higher lattitudes?

Yes this would be possible. The limitation is for gyro-compassing only (alignment). However being technically possible is only one aspect, there are associated regulations. Going into polar regions is ...
mins's user avatar
  • 71.8k
5 votes
Accepted

Is the attitude gyro (artificial horizon) equipment on our DA40NG aircraft powered by electricity?

That attitude gyro is electric, and having a standalone emergency battery power supply, is your last resort to get to VFR conditions if you have a primary flight display failure and/or total ...
John K's user avatar
  • 130k

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