How do I change altitude with an active flight plan?

Question

I've activated a flight plan, turned on AP and Nav and set altitude. I've tried changing altitude by turning off AP and/or Nav, but I end up crashing.  Seems that the Garmin 530 on the stock 172 ignores pitch inputs.   How can I change altitude, but maintain on course according to the FP?

Answer 1

Hi, with the C172, to change altitude, you click on VS on the autopilot to activate Vertical Speed mode. You can select the vertical speed with the knob. +/-500 ft/min is good. You then need to adjust the throttle : 90 kts during climb or 120 kts during descent. When you reach your target altitude, click on ALT again and your autopilot will maintain the current altitude.

Comments

What if I want to cancel Nav from controlling my altitude, but stay on course according to the FP?

---

Can't you stay in Nav mode while selecting VS or Alt? Can you attach a video?

---

I'm not able to change altitude. In any case once you are close to your destination I would like to disengage AP and fly the landing.  So far I haven't found how to quit AP and the FP without crashing.

---

Hi again, I just tried the C172 to understand the problem, and thanks to you I discovered the vertical navigation section on the "G530". Nice!

This  vertical navigation page helps you manage your top of descent and helps you adjust your vertical speed if you set it right, in order to make your chosen constraint. I think you understood how to use it.

But you have to manually engage VS mode and manually adjust the vertical speed. Once you reach your altitude, you will have to press ALT on the autopilot, otherwise your Autopilot will remain in vertical speed mode.

Now, if you want to fly manually for altitude and automatically for lateral guidance (ie NAV only), I thought you just had to press ALT again so that the autopilot is in NAV mode only. Somehow it didn't work, the autopilot still wanted to remain at the previous target altitude. So the only option seems to be to deactivate the autopilot by pressing AP and making sure the digital screen is blank. Then you have full manual control, which is the proper way to do when there is no ILS.