Hi veteran pilots, this noob needs some help. I am attempting to make my first IFR flight, and had come across a tutorial that guides you through the process on a trip from Stillwater, OK, to Amarillo, TX in a C-172. I learned to properly taxi, request ATC clearance, ATC handoffs and such as that. It's about a 3, or 3.5 hr flight, and I'm about midway. I've had trouble with one thing since leaving the ground. I can't get the 172 up to a decent cruising speed, and it keeps wanting to sink.FYI, I'm on full realism settings. I have made sure flaps are up. The current situation is that I'm at about 10,000 feet, and a heading of 240. The plane wants to fall (sink, I guess) regardless of being at full throttle. It will not hold a nose up trim. I can set the elevator trim at 10 degrees, and within 20 seconds or so, it will dip back to the horizon line. I'm going only about 70knots, and maybe a top of 90. My cousin, who's a pilot and FAA had to leave and didn't have time to go over it, but said I was definitely flying way too slow. Any ideas? Here are links to screenshots of the upper and lower panels:http://img2.pict.com/03/d5/d0/3125615/0/c172panelupper.jpghttp://img2.pict.com/f7/fe/3a/3125616/0/c172panellower.jpgThanks for any help!

Try leaning the mixture (pull back on the mix knob).

Your flying too high. The air isn't dense enough for a C172. You got to get more powerful aircraft (with pressure cabin) if you wanna fly higher. Don't forget the oxygen if the aircraft isn't pressurised :(

Your flying too high. The air isn't dense enough for a C172. You got to get more powerful aircraft (with pressure cabin) if you wanna fly higher. Don't forget the oxygen if the aircraft isn't pressurised :(

That was my first thought. I fly the 172, the Scout, and other smaller GA craft at much lower altitudes and never have this kind of problem. I was just following the guy's tutorial, which I think had me at 8000 feet, and then ATC ordered me to climb to 10,000. Is there a way to request a drop in altitude from ATC? CharlieChew, I tried that mixture knob and that made the engine even weaker. Thanks for the replies.

Some good charts here:-http://www.dmjwilliams.co.uk/gbsep_perform...ise_performance

If you use FSX Flight Planner to create the IFR flight you may set the cruise altitude to a lower altitude before saving the flight plan.

If you use FSX Flight Planner to create the IFR flight you may set the cruise altitude to a lower altitude before saving the flight plan.

I mean is there a way to request a lower altitude mid-flight? or is that once it's set at the start, that's it?Paul, excellent charts, thanks. I printed those out.CharlieChew, I went back and tried the mixture knob again. When i tried it last, I think i pulled it all the way out, and that weakened the engine, this time I found a 'sweet spot' somewhere between all the way in and all the way out, and that seemed to improve things. I'm up to around 90 knots now, and am able to maintain altitude.

Ok, is this normal? I'm flying from Stillwater, which is just N or OK.City, to Amarillo. The red "A" marker is where I am now. The green line is what I thought I'd be flying, and the red line is what I actually flew (with a few minor heading changes). Is it normal to be routed so far south? I haven't heard from ATC in a while. I did speed up the sim rate for a bit, could that mess up ATC and/or the whole flight?

On an IFR flight using FS ATC, you should be able to hit the tilde key to open the ATC window and 'request lower'. If you are on accelerated time and you fail to respond to ATC, they will cancel your IFR, but you should see an option in the ATC window to open a new IFR flight plan, which can be the one you are presently on, effectively 'reopening' it.One of the problems with FS ATC, is that it will often vector you to set you up for an ILS approach when you are still miles away from the destination. It should detect what type of aircraft you are in and what height you are at, and adjust its timing of when it vectors you for approach, unfortunately, what it instead often does, is treat your Cessna as though it was a Boeing 747 at 37,000 feet, which obviously would need to start vectoring for an ILS approach when 60 miles away from the destination. This is one of the main reasons why people buy add-on ATC programs for FS.Al

10,000 feet is still below the service ceiling for a 172 (I did my first real-world cross country in a 172 at that altitude), and you should be able to fly up there with no problem. As you discovered, you have to lean the mixture considerably when you're up high, though. Watch your engine RPM gauge and pull back the mixture slowly until you see the RPMs dip, then put back in just a little and you should be at a workable mixture.The other thing to consider is that your airspeed indicator reads in knots indicated, not the ground speed. As you climb and the air pressure decreases, the indicated airspeed will begin to drop off. Your ground speed, however, is actually faster - sometimes significantly faster, depending on how high you fly and what the wind conditions are.

Thanks for the info, Al. I tried to re-open my flight plan, but it reset me to the beginning. I must have done something wrong. I think I'll abandon ship here and just try a new one in PNW. Frankly, I'm tired of looking at Oklahoma :( I did learn quite a bit on this flight, even if I did end up 100 miles south of my target. I guess it's a big no-no to use accelerated time during an IFR flight?Any recommendations for add-on ATC?

10,000 feet is still below the service ceiling for a 172 (I did my first real-world cross country in a 172 at that altitude), and you should be able to fly up there with no problem. As you discovered, you have to lean the mixture considerably when you're up high, though. Watch your engine RPM gauge and pull back the mixture slowly until you see the RPMs dip, then put back in just a little and you should be at a workable mixture.The other thing to consider is that your airspeed indicator reads in knots indicated, not the ground speed. As you climb and the air pressure decreases, the indicated airspeed will begin to drop off. Your ground speed, however, is actually faster - sometimes significantly faster, depending on how high you fly and what the wind conditions are.

Good stuff, Bill. Thanks. Yes, I was able to fly at 10,000 np, once I got that mixture right. It got to 90 knots, and that's pretty much exactly what the chart that Paul posted said it should be. Once I got that mixture right, I no longer had to fight the plane from sinking. Thanks for the info on groundspeed too. I'm learning a lot, and appreciate the help.

This is fantastic ! :( .. you're taking the time to learn this stuff in a trainer, and using realistic settings .. before posting questions like, "Why won't my 737 fly faster that 250 knots at 33,000ft ?" But in that same vein of getting ahead of yourself.. you're trying to fly IFR before understanding flight-planning and navigation (and I don't mean using the FSX flight-planner, nor the GPS).You've already gotten a good lesson about why you need to lean the mixture as you gain altitude.. next lesson would be about the difference between indicated and true, airspeed... and that a C172 can't climb at 1500fps at 10,000ft. :( I'd suggest that you concentrate on planning your flight by charts.. and then use radio nav-aids to find your way to the airport (no GPS yet). As soon as you're confident about keeping track of where you are, and can get yourself from A-to-B by VOR/NDB.. then start learning about instrument approaches.. and THEN start flying IFR.

This is fantastic ! :( .. you're taking the time to learn this stuff in a trainer, and using realistic settings .. before posting questions like, "Why won't my 737 fly faster that 250 knots at 33,000ft ?" But in that same vein of getting ahead of yourself.. you're trying to fly IFR before understanding flight-planning and navigation (and I don't mean using the FSX flight-planner, nor the GPS).You've already gotten a good lesson about why you need to lean the mixture as you gain altitude.. next lesson would be about the difference between indicated and true, airspeed... and that a C172 can't climb at 1500fps at 10,000ft. :( I'd suggest that you concentrate on planning your flight by charts.. and then use radio nav-aids to find your way to the airport (no GPS yet). As soon as you're confident about keeping track of where you are, and can get yourself from A-to-B by VOR/NDB.. then start learning about instrument approaches.. and THEN start flying IFR.

I completely agree with Brett. Besides which, radio navigation is lot of fun. I guess we avgeeks get our kicks in odd ways, sometimes. :(

http://www.navfltsm.addr.com/... is the best navigation tutorial site I've found.It will take you through all the NDB/VOR basics, then into nasty IFR attempts, all with downloads to help.Can't recommend it enough.

There are quite a few add-ons for ATC that are worthy of consideration, look out for things such as Pro Flight Emulator, Radar Contact, Vox ATC and Multi Crew Experience, that sort of thing, some of them incorporating voice recognition so that you can actually talk to ATC with a headphone microphone. Remember that the Avsim reviews section is worth a look for things like that, as most programs of that kind have been reviewed by Avsim, and if not, there are of course other flight sim sites that do reviews too.However, I would concentrate on getting the basics of learning to fly your Cessna ship shape first before worrying about all that ATC procedure too much, or you might get overwhelmed. In the real world when learning to fly, you often find that the instructor will handle ATC for you whilst you concentrate on getting the aircraft under your command, and when you have that sussed out, they start letting you loose on the radio as well, so it is probably worth emulating that with your sim outings and not worrying too much about obeying everything ATC decrees, after all, that is one of the nice things about it being a simulator.Keep in mind that Flight Simulator has many built-in lessons, and if those are not enough, there are even 'instructor program' add-ons for FS you can get, such as FS Flying School. Some of those ATC programs I mentioned above have built-in instructor options too, for example MCE. Of course because FS is essentially very realistic, you can also use real aviation tutorial sources, such as books, websites and what not too, and of course this forum, since there is in fact a tutorial section with many articles in it, and there are many very knowledgeable people who frequent Avsim's forums who are more than willing to answer questions.But as I say, I'd stick at what you are doing for the moment and worry about all that 'proper ATC stuff' when you are happy with flying the thing, which will certainly not take too many flights to accomplish if you approach it methodically, and it seems that you are.I think you are going about things in the right way, trying out the Cessna and learning stuff properly; too often people crank up FS and jump in the jets or choppers only to find frustration, so don't get frustrated if IFR flight seems complex, maybe try a few simple circuits and climbs to get your hand in: Take off, climb straight ahead to 400 feet, make a 90 degree turn, keep climbing to 600 feet, make another 90 degree turn still climbing to about 800-1000 feet as you pass by the runway leveling off, and when you've passed the runway parallel and you can see it over your shoulder, descend and make a couple more ninety degree turns at about 600 and 400 feet to line yourself back up with the runway (basically a box pattern with the runway along one of the box lines). That sort of thing. Doing that precisely will get you good at turning onto exact headings and controlling the throttle and flaps.Like anything else, a good solid foundation pays dividends later on when you start getting to more advanced stuff. Above all, make sure you are having fun.Al