Cessna autopilot acting strangely

Regarding your second problem, turn on pitot heat, it seems your pitot tube freezes over, thus meddling with your readings.

As for the first issue, VOR reception depends on terrain, not necessarily just distance. Make sure you are picking up the station (the needle points on your RMI and you get a DME reading). Also, make sure you are using your OBS to put in the track, not heading.

Let us know if it works.

Thanks for the help Bindolaf.

What exactly does pitot heat do? I don't really understand it but I'll definately turn it on next time (do I turn it on before I start the engine?)

Regarding the "NAV" issue, the VOR is definately tuned correctly, with the correct heading inputted with the OBS knob. Also the DME is reading the correct distance to the VOR. Any other ideas what might be the problem?

Thanks a lot in advance once again for your help.

Pitot heat, heats the pitot tube, which measures your speed. So if it freezes over, you have no way of knowing how fast you are going

Try toggling the NAV/GPS switch the other option that it isn't on, and try again. So if its on GPS, put it on NAV and try it out again. Don't know what else to suggest 😉

Another suggestion I have for using the auto pilot to fly to a VOR is to be on the radial before turning the autopilot to NAV mode. Both in FS9 and the real airplane, autopilots normally installed in light aircraft are relatively inexpensive and do not have the same finess as more expensive ones in heavier a/c. My normal procedure is to use the HDG (heading mode) to fly an intercept course to the radial I want and continue to use it to intercept that radial. Once on the radial, I turn on NAV mode and that works well for me.

You also need to make sure the VOR is receiving the correct signal, either by verifying the morse code identifier or, as a minimum, make sure the FROM/TO flag is showing either From or To. Its best to get in the habit of using the morse identifier since, in the real world, failure to do so will bust a check ride.

The pitot systems feeds more than just the airspeed indicator. It also provides ram air pressure to operate the vertical velocity indicator and the altimiter. Pitot heat should be turned on whenever you are in conditions of moisture and temperature that could cause the tube to ice up. Just for info, if you are ever around a real airplane, it is the small tube, usually mounted on a wing, that is "L" shaped and has a small hole in the center facing the direction of flight.

There are actually two components in the pitot system. The tube is one. The second is a small hole in the surface of the aircraft fuselage. The tube supplies ram air pressure. The side hole supplies ambient air pressure. The three instruments mentioned use both readings to operate their cockpit indicators accurately.

I press the A/Ps "NAV" button so that it will go ahead and fly to that VOR. But what normally happens is the A/P puts the aircraft into a sharp circle, and I just spin around and around again 360 degrees

That also happens to me when I am flying twin engine aircraft, and not just probs, jet engine planes two. It has happened to me in Beech Barons and Boeing 737's

I have no idea why this is 😳

Hmmm... I wonder if it's a bug in the simulator or something?

Don Wood and Bindolaf, thanks for the help. Do you click on the pitot heat switch before you start the engine or can you turn it on in any stage of flight?

Don, I usually do fly with the "HDG" indicator on the approximate course of the radial. But normally when I click "NAV" things go a little crazy. The GPS/NAV switch is on NAV all the time by the way. The only exception is when I fly with the "HDG" button up to reasonable close (maybe 20 miles) from the radial, and the "NAV" button seems to work then.

By the way Don, how do you use the morse code identifier? I didn't even know the plane had one.

Thanks a lot once again.

On your radio stack, if you tune a station and click the "ID" button (on the radiostack, between the buttons there) you will hear the morse code transmitted by the station (may take a minute, it transmits intermittently, not continually). Check the morse code you hear against your chart and you will know for sure which station you have tuned.

The morse code identifier is an audible transmission from the VOR of the three character ID for that VOR in morse code. There are some VOR's that now use voice ID's instead of morse code. There is no equipment in the a/c other than the VOR radio itself that is needed to receive it.

In simpler a/c, like the C-172, you tune the navigation radio to the VOR you intend to use, use the radio panel to turn the audio up for that radio, listen to the morse code identifier being transmitted, then compare that the to morse code characters shown for that VOR on your chart.

The purpose of IDs is to make sure you are navigating from the correct VOR. Since there are a limited number of VOR frequencies, many stations around the world transmit on the same frequency. They are supposed to be separated enough to avoid signal overlap but this is a safety check just to make sure you have the correct station tuned. It is also a safety check to make sure you have not indavertantly tuned the radio to the wrong frequency.

That's great, thanks a lot. One more thing I've learned.

If anyone has any further info on why the A/P acts strangely sometimes (but not always) when I press the "NAV" button, that would be a lot of help as well.

If you hit NAV and you have VORs tuned make sure the (NAV/GPS) switch is switched to NAV. Can't think of anything else right now.