How does reverse sensing work on Hsi?
When using traditional ILS/LOC instrument, the needle moves right when it senses more of the right signal, but since the signal is now on the left, you get reverse sensing. On the HSI, the needle still moves right when it senses more of the right relative to the arrow when it senses more of the right signal.
Is that “reverse sensing”?
Is that “reverse sensing”? Well, not really because the needle just goes to the left when you’re in the shaded area. It doesn’t know front from back courses, or inbound from outbound. It only knows which side of the localizer feather it’s on. It’s actually just your senses that have to be reversed to correct properly.
How does the HSI work?
The HSI combines a heading indicator with CDI needles. As long as you tune the front course for the localizer, you won't get reverse sensing. When configured properly, you can fly the LOC BC approach with normal sensing, and fly "to the needle" like you do in all other navigation.
How do I know if my HSI is from or to?
When an HSI is tuned to a VOR station, left and right always mean left and right and TO/FROM is indicated by a simple triangular arrowhead pointing to the VOR. If the arrowhead points to the same side as the course selector arrow, it means TO, and if it points behind to the side opposite the course selector, it means FROM.
Can an HSI get reverse sensing?
The HSI combines a heading indicator with CDI needles. As long as you tune the front course for the localizer, you won't get reverse sensing.
Can you get reverse sensing on a VOR?
Reverse sensing occurs when the current heading is on the bottom half of the VOR. Taking this theory to the HSI where the currently flown heading is always on the top half and you can never have reverse sensing. It is also proper technique to set in the front course when flying a LOC/BC approach.
How does the HSI work?
Like other cockpit instruments, HSIs can vary in appearance and operation by brand. Fundamentally, however, all HSIs indicate an aircraft's horizontal position relative to a selected VOR or ILS. The HSI works by combining a VOR/DME receiver and an electrically-slaved heading indicator.
What is the difference between RMI and HSI?
1:168:41Radio Nav Aids ADF RMI OBI HSI DME ATPL - YouTubeYouTubeStart of suggested clipEnd of suggested clipWith a turn from indicator to resolve directional ambiguity on the other hand a horizontal situationMoreWith a turn from indicator to resolve directional ambiguity on the other hand a horizontal situation indicator or an HSI combines.
Does CDI have reverse sensing?
In other words, the CDI needle will tell you to turn left when you should turn right and vice versa. This is known as reverse sensing. To avoid reverse sensing, remember that radials are always radiating away from the VOR station.
What is VOR Reverse Sensing?
In “reverse sensing,” the instrument is displaying exactly what you're telling it to display. It takes some effort from the pilot to not become “reversed.” Where pilots get confused and think that the instrument is reversed is when the OBS is set to the reciprocal of the course they want to fly.
What is the difference between a CDI and HSI?
A standalone CDI (Course Deviation Indicator) is an instrument that shows your deviation from a VOR radial that is selected using the OBS (Omnibearing Selector) knob located on the instrument itself. An HSI (Horizontal Situation Indicator) is an entirely separate instrument that combines a CDI and a heading indicator.
Does an HSI have a gyro?
HSIs align themselves with the flux gate and are usually electrically driven (electric gyro) The gyro in a heading indicator is mounted in a double gimbal, as in an attitude indicator, but its spin axis is horizontal permitting sensing of rotation about the vertical axis of the aircraft.
How many degrees is a dot on an HSI?
Each division (dot) represents 1.25 degrees deviation from the ideal ILS flightpath approach.
What is aircraft HSI?
The horizontal situation indicator (HSI) is a key instrument in IFR flight. It combines the functions of a heading indicator and navigational indicator into a single instrument. For HSI questions, first determine the aircraft heading shown at the top of the indicator.
How do you read an HSI aviation?
4:0812:30Horizontal Situation Indicator Explained | How an HSI WorksYouTubeStart of suggested clipEnd of suggested clipNotice the green course selector arrow it's pointed at 0 9 0.. Also notice the white triangleMoreNotice the green course selector arrow it's pointed at 0 9 0.. Also notice the white triangle pointed the same direction as the green arrow marking the two indication.
What two instruments are combined to create an HSI?
The horizontal situation indicator (commonly called the HSI) is an aircraft flight instrument normally mounted below the artificial horizon in place of a conventional heading indicator. It combines a heading indicator with a VHF omnidirectional range-instrument landing system (VOR-ILS) display.
When does positive sensing occur?
For conventional VORs, Positive sensing occurs when the headng currently being flown is on the top half of the VOR. Reverse sensing occurs when the current heading is on the bottom half of the VOR.
What does the VOR instrument tell you?
The instrument always tells you the relative position to the VOR course / localizer, it is up to the pilot to manipulate the plane to the desired position. It's reverse tracking, not reverse sensing. The instrument tells you your deviation from the selected course , it has been and will be doing that all the time.
What is a localizer signal?
The localizer signal actually radiates directly out from the antenna in opposite directions, as if the lighthouse is actually bipolar, with a front beam and a back beam.
How does CDI work?
The CDI works with the ambiguity indicator, while both are determined by the received radial and the OBS setting. You’re still east of the station with 090 in the OBS and a “From” indication. If you drift southward, the CDI will move to the left.
Can you reverse sensing a navigation indicator?
It’s actually just your senses that have to be reversed to correct properly. You can decide if that’s reverse sensing or not. Of course, this is all true if you’re using a conventional navigation indicator. If you’ve got an HSI, well, you never have to fly away from the needle.
Can you fly away from the needle with an Hsi?
If you’ ve got an HSI, well, you never have to fly away from the needle. We’ll talk about that next time. Frank Bowlin was about to risk the ire of that seasoned ATP who was headed into a mountain. Just then, though, the controller interjected vectors to save Frank’s butt—and career.
What is HSI in music?
The HSI is an improvement on the standalone CDI instrument in that it takes into consideration your actual heading. The old CDI would just have a radial set in the OBS and show your deviation (which could have reverse sensing depending on which radial you tuned) in relation to that radial. The HSI serves as a heading indicator as well as a CDI ...
Why is CDI confusing?
The reason the CDI can be a little confusing is because it can either be its own standalone instrument (used for VOR navigation) or it can be a component within an HSI (Horizontal Situation Indicator).
Does the heading bug control HSI?
It’s incredibly flexible because of this and I never have any reverse sensing in the cockpit. The heading bug does not control anything in the HSI per se, but is more of a “target” you can set if you are assigned a heading by ATC or if you are trying to remember your wind correction angle when tracking a VOR.
Is reverse sensing a malfunction?
It isn’t a malfunction of the instrument, just something you have to be keenly aware of particularly when flying IFR. As you can tell (or as you might know from personal experience), the potential to have reverse sensing in the cockpit can lead to some major issues.
Can you reverse sensing a CDI needle?
Because of this there is a real downside to the standalone CDI instrument and that is you can have reverse sensing.
What is reverse sensing?
I understand that many people call that "reverse sensing," but I also understand that the term is a symptom of the fundamental misunderstanding about CDI presentation (i.e., that CDI's give left/right steering information rather than showing cardinal direction location information) which confuses people and makes it harder to learn how to do VOR orientation, interception, and tracking, especially when flying a localizer backwards.
Can you fly a GPS backwards?
Yes, if you set the GPS to a course from point "A" to point "B" and then fly the course backwards (B to A) instead of flying to the needle to intercept the course you'll have to fly away from the needle (or as I like to visualize...drag the needle to you). Everybody understands that as "reverse sensing", .....well, almost everybody
What is an Hsi?
WHAT'S AN HSI? An HSI, or Horizontal Situation Indicator, is a combination of two familiar cockpit instruments: the directional gyro with a heading bug and a VOR/ILS indicator.
Where is the RNAV on a HSI?
RNAV. The legend "RNAV" will appear in the lower right corner of the instrument face when the HSI is part of an area navigation system and that mode is engaged. Slaving Meter. A slaving meter is located in the upper right hand corner of the instrument face on slaved models.
What is HSI on F-15E?
The HSI provides a basic horizontal view of the aircraft's navigation picture. In the F-15E, it can provide navigation data to selected ground navigation facilities (TACAN or Instrument Landing System (ILS)) or to onboard navigation systems like the Inertial Navigation System (INS). Instrument flying without an HSI requires a fair amount ...
Can you fly without an Hsi?
Instrument flying without an HSI requires a fair amount of mental gymnastics; for this reason, the HSI is becoming more prevalent in general aviation since it provides an excellent picture for precise navigation. The HSI may display bearing and distance to a navigation aid, magnetic heading, track/ track deviation and course/course deviation.
Remember Ndbs?
- Perhaps you once learned to fly an NDB approach. (If not, it’s okay. I won’t hold it against you. Bear with me as we explore a little instrument-flying history.) The venerable and once-ubiquitous King KR-86—when it worked—provided an ADF bearing pointer on a user-adjustable compass card. Th…
What’s An HSI?
- The horizontal situation indicator is a rather busy instrument, displaying lots of useful information. For our purposes, just as an RMI combines a bearing pointer with a heading indicator, let’s think of the HSI as a single instrument that combines a gyro heading indicator with a VOR/LOC navigation instrument. Let’s look at one of many reasons that depiction is meaningful. As we explored last …
Fly The Approach
- Say we’re coming from the south and we’re on the localizer south course, headed north. We’ll pass MANZA then make the procedure turn, then head back in on final. Let’s say there’s a stiff wind from the west and we’re not very good at making those wind corrections, so we’re east of course. Remember, I said that the reasoning behind Rule #1 would become evident? Watch. As we set u…
Pretty Simple, Eh?
- Now you can see that if you rigorously follow Rule #1 with an HSI, Rule #2 is still true, but we can pretty much ignore it and can absolutely ignore Rule #3. Having followed Rule #1, all we have to do is chase the needle. On AIS charts it still takes a little mental energy to determine exactly what the inbound front course is. But, if you remember Rule #2, it’s easy. Just orient yourself on the c…