Altitude Autopilot Question

Boeings and airbus' have different systems so that could explain why they're differences. On a boeing i.e. you POSKY model.....you will need to set a vertical speed, in real life pilots use the FMC to control the rate of climb based on the speed they want to fly but this level of realism isnt available in freeware so as far as I know you have to set a vertical speed and the computers will maintain this until the desired altitude is reached.

To answer your second question most pilots will use the autopilot to climb and descend unless they're just about to retire 😉

cheekytrolly wrote:

I have a question concerning Altitude Hold with autopilot on jet aircraft.

I have noticed on some jets, like the iFDG A319 for example, once you have autopilot engaged with alt. hold engaged, you can press the "+" and "-" when hovering over the gauge with your mouse, and change your height from say 20000ft to 25000ft, and the aircraft will automatically pitch its nose up and climb 5000 ft then level off.

In other jets, like the POSKY 737 for example, I could not get this to work.

Is there any reason for this, am I supposed to press anything else before I do this, and does it work in real life- descending and climbing altitude using autopilot rather than the yoke?

If anyone could help me I would be most grateful.

Cheers

PW is right.

When you change the altitude box in some aircraft, it automatically assumes that you want to change to this altitude so will climb or descend accordingly. Some pilots don't like this feature because some like to plan ahead and set their altitude for after the descent, so all they need to do is change the VSI to negative, and it will start descending. On some aircraft, you can't do this and you can only change altitude if you want to descend or ascend straight away.

In POSKY models you don't have to touch the yoke; just change the VSI reading. Personally I prefer to plan ahead 😉

Ahh ok, thanks for explaining that to me you two 😂

Just one more question,

Where can I find out the appropriate rate of climb to enter into the VSI?

On previous flights, I have never touched the VSI gauge, it just automatically changed itself, although the POSKY 737-700 does not work like that, and requires manual input.

There is no one value for VS in an airliner. On a typical flight, I will usually start at 1800 ft/min to maintain 250kts below 10,000 and then 280kts above.
As the craft climbs higher it will begin to struggle in keeping its speed whilst mainatining 1800ft/min and will eventually stall so I usually lower it incrementally. At about 30,000ft im only climbing at 800ft/min. 😉

Hope that helps 😉

Thanks for that info PW.

I noticed iFDG's airbus a319 automatically switches to 700 fpm, climbing from the airport all the way to cruising altitude. Is this wrong?

I'm guessing the higher the VS, the shorter time it will take you to climb to a cruise altitude?

Correct, CT. I usually like to climb at around 1800ft/min VSI until I cruise.

😎

cheekytrolly wrote:

Thanks for that info PW.

I noticed iFDG's airbus a319 automatically switches to 700 fpm, climbing from the airport all the way to cruising altitude. Is this wrong?

I'm guessing the higher the VS, the shorter time it will take you to climb to a cruise altitude?

True, the higher the VS the shorter time it will take you, but the higher fuel flow you will be using - so a balance must be found.

I would have said that V3 is a lot higher in commercial aircraft than 1800fpm - the reason being that the power of some engines on some aircraft, would render the climb at an attitude of around 5-7 degrees pitch up which is very slow. I never normally climb to 10,000 feet less than 2200fpm for small jets, and anything up to 2800-3000fpm in jets such as the 777 - especially the 777. The 777 has a potential V3 of 4500fpm to 10,000 feet and 2000fpm up to FL390 due to it having the worlds most powerful engines - obviously, smaller aircraft can't operate like that but nevertheless, can still climb at fairly high rates.

😉

in an a318 i climb at 2500 to 10,000 - i'm sure the 19 can do the same