Good evening Geof,A question about trim in the F33 Bonanza, about how much trim should one give this plane for takeoff? I started using the 3 above U, went to 6 then I have been going almost but not quite up to 9. That is the point that will give me a 90 knot climb.By the way, I did a climbout from 1300 feet to 10000 ft, started with 28 inHg and at 10000ft had 22.5 in.HG. So the pressure is droping it just that the lapse rate is a little slow. I figure the 28 in.Hg is because this is a brand new plane. :(

I usually left the trim neutral unless I had someone in the back-I'd crank just a little in. To tell you the truth I never looked at the numbers-you couldn't see them real well from the pilot position...90 knots sounds good till above 1000ft agl-25" and 2500 rpm-then I would go to cruise climb which was 120 mph (I guess that would be 104 knts or so). I'll have to check out the manifold again...

Good evening Geof,A question about trim in the F33 Bonanza, about how much trim should one give this plane for takeoff? I started using the 3 above U, went to 6 then I have been going almost but not quite up to 9. That is the point that will give me a 90 knot climb.By the way, I did a climbout from 1300 feet to 10000 ft, started with 28 inHg and at 10000ft had 22.5 in.HG. So the pressure is droping it just that the lapse rate is a little slow. I figure the 28 in.Hg is because this is a brand new plane. :(

Slow change in lapse rate = good flying weather! You should put in some bad weather and see if the lapse rate is normal to fast! In a stronge High Pressure system, I'v seen similar MP changes in a real Turbo 182. If taking off in a stronge Low pressure system, the rate should be much faster.

Sounds good, I've been giving quite a bit of up trim on takeof. I guess a habit, I nearly had a disaster in an Archer once, by for foetting to check the trim. I toook off at KGPM pulled back on the yoke, became airborne, and couldn't get the nose up. Whoever had it last left a lot of down trim on it, if I hadn't been an extremely strong person, I would have went right into WalMart shopping center building at the north end of runway 17. I gave it everything I had on the yoke and then a whole lot more, to get that nose up. I've never forgotten trim since. LOL

Sounds good, I've been giving quite a bit of up trim on takeof. I guess a habit, I nearly had a disaster in an Archer once, by for foetting to check the trim. I toook off at KGPM pulled back on the yoke, became airborne, and couldn't get the nose up. Whoever had it last left a lot of down trim on it, if I hadn't been an extremely strong person, I would have went right into WalMart shopping center building at the north end of runway 17. I gave it everything I had on the yoke and then a whole lot more, to get that nose up. I've never forgotten trim since. LOL

Yeah-bo's are notorious for that-takes a lot of strength in that condition-definately would check it at neutral before takeoff.

Thats a good idea VegaSS, I was flying real weather the altimater was around 30.33 or so. I know we've had good weather in OKC for the last week or so, I've been flying real world weather with winds 12 to 15 knots, and no turbulence in X-Plane 10, A real joy or a change. If turbulence is too stiff in this sim I just get a metar and put it in myself minus the turbulence.

Well here is a shot I had of the plane the highest I ever had it outside Wilcox, Az just outside Tuscon. The temps on the ground were about 25 F. Same temps, location, pressure set...Notice the manifold on both...

Yes, I've noticed most of the planes in about any of the sims are a bit on the optimistic side. I don't worry overly about it though, I pretend these are brand new planes etc. etc. we can still get pretty good practice and have close ideas.

Hi Geof,I think there is something weird going on with the manifold pressure. I have changed the default Baron58 to not having a turbocharger in planemaker (it really doesn´t, only some variants do).Then I took the plane up to 12000 feet and shot the following picture.As you can see in the data-display that is put out by X-Plane itself, the absolute outside atmospheric pressure is 19.14inHg. Close enough.The manifold pressure is at 22.09inHg, though. How can the manifold air pressure be higher than the absolute pressure on a non-turbocharged reciprocal engine? Ok, some factors will influence MAP - ram effect, propeller slipstream, venturi effect etc. But almost 3 inHg?I used to fly the Bonanza F33 in the late 90´s for about 200 hours, and while I was usually more occupied with flying holding patterns with partial instruments over Stanfield VOR I do not remember such a discrepancy... and your picture seems to validate that memory. At 12.500 feet the pressure should be around 19.00 inHgJan

Ok... So I have a stupid question. Where do you see the trim settings?

Remember, most of the engine data in any sim is just "fictional" APART from thrust/power as a function of N1/RPM/ALT/MACH/TEMP etc.So all the other engine readings (that I can think of) are just that - visual readings. I mean, there is actually no Manifold Pressure in the sim, EGT, N2 etc... these are just for instrument readings, not part of the "flightmodel".All of these will vary with type of engine.My point is, IF you know how it should be, it's pretty easy to make a good MP gauge using generic instruments - keyframes in PlaneMaker.M

Edited January 6, 201214 yr by MortenM

yes - but they weird thing is that the MAP equals total outside air-pressure almost perfectly at sea-level. Then as altitude increases, the discrepancy increases. Sure, you can work around that with a plugin (as you can with almost every fault) - but it´s still not working as intended I think.Jan

Right Jan, looks like a bug.Anyway, X-Planes generic instruments (no plugin) are made exactly for things like this,- if you need an instrument to read different than the default I mean...M

Ok... So I have a stupid question. Where do you see the trim settings?

I'm not sure whether you mean the trim settings on the control panel of the plane or you want to change the trim settings in planemaker, so I will answer both ways.If you mean how can I tell how much trim I have put in there is a guage on the panel that has a sliding scale, usually a needle that will slide up or down,the gauge will be in different places on different planes, if the needle goes up,(on most planes), that wil be trim down, if the needle goes down, then the trim is up. Actually a lot of the planes have a sliding tape that move under a fixed set point.If you mean how can I change the rate of trim, either faster or slower, open PlaneMaker and follow this path in the menu at the top click FileOpen browse to the plane you want to change, then StandardControl GeometryTrim & Speed. Be careful making adjustments, write down the defaults first, but first make a backup of the .acf file. In fact I would make a backup copy of the entire plane folder yoou want to work on.

Sounds good, I've been giving quite a bit of up trim on takeof. I guess a habit, I nearly had a disaster in an Archer once, by for foetting to check the trim. I toook off at KGPM pulled back on the yoke, became airborne, and couldn't get the nose up. Whoever had it last left a lot of down trim on it, if I hadn't been an extremely strong person, I would have went right into WalMart shopping center building at the north end of runway 17. I gave it everything I had on the yoke and then a whole lot more, to get that nose up. I've never forgotten trim since. LOL

That's why we use Check lists !