Maximilian_Jenius
Super User
Studying out of the "Red book" on my lunch break and I got to the section on IFR navigation. What is an RMI? They didn't have them in the Cessna's and Pipers (Archer III) I flew for my PPL. It looks like a VOR on crack!
What is an RMI?
- Thread starter Maximilian_Jenius
- Start date
Chris_Ford
Well-Known Member
It's essentially a mix of VOR and ADF technologies... Receives VOR and uses the needle to point to the station, just like an ADF does. This is helpful when doing DME arcs, general awareness of where the station is (it'll help you know when you're about to intersect a radial) and other things.
mtsu_av8er
Well-Known Member
Maximillian_Jenius said:
Ahhh, the fabulous RMI!! You're not going to see one in most of the single engine trainers around. Jump into a souped-up Baron or Seneca, and you just may find one!!
An RMI is a Radio Magnetic Indicator. Think of a Directional Gyro, with one or more needles attached to the middle. That needle is connected to a NAV radio, and that needle will ALWAYS point to the station. You want to go directly to the VOR? Just turn until the needle is at a relative bearing of 0 degrees (assuming no wind).
Here's where it gets even easier - the tail of the needle ALWAYS points to the radial that you're currently on!!!!! SWEET!!!
Many RMI's have switchable needles, so that you can select one VOR or the other, or BOTH! Many will also have an indicator for the ADF.
mtsu_av8er
Well-Known Member
When you're really good, Chris, you'll be able to shoot VOR approaches with them! 
Maximilian_Jenius
Super User
Chris_Ford said:
Thanks guys for the info. If I wanted to go out like a sissy and be one of these new age pilots big MikeD always talks bout I'd say well I don't need to learn that...I'll just use GPS and go direct. But Max doesn't want to "be that guy" I want to be a hardcore stick and rudder guy with hardcore instrument skills.
mtsu_av8er
Well-Known Member
Maximillian_Jenius said:
Not only that, but you're screwed when you want to fly IFR . . . lol. Although it's a nice fantasy that you can just file direct, you'll be shocked when you call for your clearance and you're told, "Advise when ready to copy your full-route clearance", and the word direct isn't anywhere near it!!!
Maximilian_Jenius
Super User
mtsu_av8er said:
Yup...looks like a sweet instrument. Never having flown with one they look tricky. But the formula MH+RB=MB is making understanding it easier. This Gleim book is killer!
Maximilian_Jenius
Super User
Alchemy said:
Wow...thought your EMB's were all Glass with no round dials!
Alchemy
Well-Known Member
Yeah, it is all glass except for the backup instruments on the older planes (even the backups on the new ones are glass).
The HSI/RMI still works the same way and looks the same as its conventional counterpart, although you can do some spiffy things like adjust the size and overlay weather radar on top of it if you want.
The HSI/RMI still works the same way and looks the same as its conventional counterpart, although you can do some spiffy things like adjust the size and overlay weather radar on top of it if you want.
mtsu_av8er
Well-Known Member
Maximillian_Jenius said:
What's even better is that you don't need that formula with an RMI!!
Remember, since the RMI has a slaved gyro card built in, the index is ALWAYS pointing to your heading. This means that although the needle is always pointing at the relative bearing, it's also always pointing at the magnetic bearing! So, in essence, there's no math!
TaterSalad
New Member
mtsu_av8er said:Not only that, but you're screwed when you want to fly IFR . . . lol. Although it's a nice fantasy that you can just file direct, you'll be shocked when you call for your clearance and you're told, "Advise when ready to copy your full-route clearance", and the word direct isn't anywhere near it!!!
Unless you're flying air ambulance 135, where "lifeguard" will get you direct almost* every time.
We took off in front of about 15 waiting USAir flights yesterday, I love that LN prefix.*This does not apply, I've found, when you're headed to the Northeast, ie: Teterboro, etc.
mtsu_av8er
Well-Known Member
BobDDuck said:
TaterSalad said:Unless you're flying air ambulance 135, where "lifeguard" will get you direct almost* every time.
*This does not apply, I've found, when you're headed to the Northeast, ie: Teterboro, etc.
Seem to find that in Utah IHC or "lifeflight" abuse's lifeguard callsign sometimes.
caliginousface
Frank N. Beans
KLB said:
I never thought of using fs to practice on them, until today! It took me 10 mins or so to make sure I wasn't getting ahead of myself, and then did an arc to the ILS. It came out alright, but i'm glad I finally saw it in action (well, pc action), so now I won't be so scared of it in the plane. Thanks man!
You would've figured i would have gotten some NDB action during my instrument rating, however there weren't very many NDB's around Preskit and...yeah!
TaterSalad
New Member
JayAre said:
Just curious, but how do you know they're abusing it? As an example of what you might consider abuse.........sometimes when we come back, sans patients, we still file as lifeguard. Why? Because they may very well have another trip, the other planes are out, and they urgently need our plane with a patient waiting for us to get back.
mtsu_av8er said:Not only that, but you're screwed when you want to fly IFR . . . lol. Although it's a nice fantasy that you can just file direct, you'll be shocked when you call for your clearance and you're told, "Advise when ready to copy your full-route clearance", and the word direct isn't anywhere near it!!!
I'm a bit confused - - what prevents one from flying IFR with nothing but an RMI? I've got more than a few hours flying a T-37 IFR, and it has only an RMI and one VOR/DME. Not only can it be used to fly direct, it can be used to fly a course inbound, or a course ourtbound, or to any given VOR fix. (We called it FIX-TO-FIX navigation, and I believe that topic has been previously discussed on this forum.)
The head falls, and the tail rises...
.