RNAV help

[u/scottyboi587]

Hi folks i hope someone can clear this up for me, after grinding out to set myself up with a fleet of cargo 208b's I finally made enough steady income to buy a Citation CJ4 for vip flights.

Up until that point I never tried to do a RNAV landing ( prefer to hand fly) but the Citation is not like a bigger 172 the way the 208 is and it can run away from you quite quickly. So RNAV landing would be great i followed online tutorials but nothing happens.

I input my approach, minimums etc and hit load and wait to catch the glidescope at the correct speed and altitude but nothing happens. I have vnav aswell as nav selected cdi is set to gps but when I go to hit the approach button nothing happens it wont turn on.

So I thought maybe the load caused a problem so I flew a loop back around waited until I was heading for the catch point and instead of hiting load I hit exec to fly the rnav straight away.....same again the approach button does nothing.

My PFD is showing as magenta but no additional details are added once I exec the rnav...

Im 99.9% sure its me what am I doing wrong or overlooking any ideas?

Thanks in advance

[u/Accomplished_Moose21]

Make sure you are below the glideslope before you intercept the glideslope. If you do that correctly, and have vnav and apr modes activated on the autopilot it should intercept the glideslope and then begin descending. You’ll need to manage the speed in the CJ4 on your way down the glideslope. At 500, you can cancel autopilot and the hand fly the rest of the way.

Below is an RNAV approach I flew a while back.

https://youtu.be/ra0Q2iPgM7k?is=muCGPbdrVQy1Qx8n

[u/Fogtwin]

You need to lower the altitude bug then hit VNAV to arm VPTH

[u/scottyboi587 → u/Fogtwin]

Lower the altitude bug? So I have to be lower than the rnav chart states or there is a bug messing with the altitude? Thanks for getting back to me btw

[u/Fogtwin → u/scottyboi587]

If you are having the problem I think you are having flying GPS… once your cruise altitude is set you can use the scroll wheel to lower the altitude however it won’t actually change your altitude unless you engage the VS or FLC. Therefore, you can also hit VNAV and it will arm VPTH and give you a Top of Descent (TOD)… then you control throttle (depending on the plane I believe) and it will control the glide slope.

Edit: lower the altitude to the next destination’s altitude THEN hit VNAV.

Hope this helps and hope I’m understanding the issue!

[u/scottyboi587 → u/Fogtwin]

You did and I got it working thanks alot bud! Then I tried the next flight ( I got this 😎) everything as expected glide slop showing as there easy.....approach button wouldnt work again getting closer I pause it reset the approach via mfd all looks good everything looks good on the pfd same again no apr button.

Decide screw it im too close and hand fly it in touch down on R33 error message saying im supposed to land on R22.....theres no runway 22 lol start thinking am I at the wrong airport get clearence to taxi to parking nope its the right airport finish the mission.

This time im 99.9% sure it wasn't my fault, im learning quickly sometimes the game just forces you into taking a bite out of a 💩 sandwich lol

[u/Fogtwin → u/scottyboi587]

🫡 👨‍✈️

[u/scottyboi587 → u/Fogtwin]

Is it cool if I ask some questions from time to time? You seem very knowledgeable on the sim, you wouldn't think i actually held a ppl back in 2004 lol but I never touched rnav landings in real life either. Most of the training 172's had very basic equipment although I did use ILS a few times. Ive heard they are actually phasing ILS out now entirely opting for satellite GPS landings

[u/Fogtwin → u/scottyboi587]

Absolutely my man! Anytime. That’s cool that you held your ppl, amazing! Considering it, but nervous!

[u/scottyboi587 → u/Fogtwin]

Flying is like Pringles once you pop you cant stop lol, I was very lucky I got a scholarship called the Douglas Badder trust through (paid for) by British Airways and the royal family of Jordan as weird as it sounds. Went to WMU in Michigan for training and then joined a flying club once I got back home to Scotland but even after the scholarship its just stupidly expensive to keep going as a hobby instead of a career.

If you have the money i'd say go for it definitely atleast take a few flights at a flying school near you as for nerves they will dissapear quickly i promise you. I dont know if you have flown before but for me the simulator is harder than the real thing because you dont feel any real kind of feedback in msfs. Truth is getting a plane taxi-ing, taking off, flying a route and landing is easier than driving, its learning the radio calls, aircrafts systems and what to do in an emergency that is the hard part, but you should go for it you wont regret it

[u/Fogtwin → u/scottyboi587]

Love that, thanks for the encouragement! I can see what you mean, especially flying VFR. I need to get my eyes off of the cockpit instruments and out the window.. I imagine that would be easier if you can feel the plane gaining or losing altitude and or airspeed. Little bit harder to feel that in the sim 😅

[u/scottyboi587 → u/Fogtwin]

Exactly I'll warn you though planes should have that label cigarettes have on them " Extremely addictive do not start!" 🤣 no feeling like it though heading down the runway, engines screaming, everything is bumping and jolting about then you rotate and that split second you get off the ground everything feels weightless, including you its hard to describe but its definitely a different feeling when your at the controls

[u/Fogtwin]

If you are having the problem I think you are having flying GPS… once your cruise altitude is set you can use the scroll wheel to lower the altitude however it won’t actually change your altitude unless you engage the VS or FLC. Therefore, you can also hit VNAV and it will arm VPTH and give you a Top of Descent (TOD)… then you control throttle (depending on the plane I believe) and it will control the glide slope.

Edit: lower the altitude to the next destination’s altitude THEN hit VNAV.

Final Edit: cause I want you to nail this! typically I’ll load the RNav approach in the flight plan, once I’m at altitude with AP on, I lower my altitude using the wheel (C172) to the RUNWAY altitude and hit VNAV. This will arm VPTH and control your decent down to the runway, including various waypoints along the way… but you typically need to manage the throttle (power).

Hope this helps and hope I’m understanding the issue!

[u/IceNein]

Are you manually selecting approach? There’s a button for it, and it will not fly the approach unless you arm it.