Even I selected Clear Weather ( no wind ) . My aircraft still losing airspeed when climbing .

What plane? Do you have your gear and flaps up? Does the plane have spoilers? What is your rate of climb? What is the airport altitude?  More information is always better when you ask for help

Yeah they do that... Physics.

 

Agree with him though? What specific FSX aircraft is it?

Make sure you aren't in vertical speed mode. That will drop your airspeed in a second. Also, airplanes climb at constant airspeeds. Keep that in mind. Also, as the you go higher, te air becomes less dense which means you have less air molecules hitting the pitot tube (dynamic pressure). That being said, this causes a drop in INDICATED airspeed. I'm order for the plane to continue to fly in the less dense air (and due to other factors such as temperature), your TRUE airspeed will rise.

There is nothing "shocking" about your initial statement, Ken.  Climbing can kill airspeed.  In GA aircraft you can build airspeed with enough power in a shallow climb or you can kill it just as well with too steep a climb or not enough power.  As stated above, you also have altitude effects coming into play.  The higher you are, the less power you will generate with a normally aspirated engine unless you are leaning the mixture appropriately and even then you will reach an altitude at which you can't lean it any more, the service ceiling.  All that as well as the effects higher altitudes will have on your indicated air speed.

 

I forget what altitude my instructor and I climbed up to on a nice clear day just for some sightseeing in a 152.  We were well below the service ceiling of 14,700 ASL, probably not even that close to 10,000 ASL (i'm thinking it was around 7,000 ASL) and it was a dog slow climb.

 

.... and then he pulled the throttle, told me I was on fire and I had to rapid decend to 50 AGL.  Fun days those were.

As you climb teh air gets thinner, the indicated air speed will decrease, but your ground speed will increase, its physics.as mentioned previously.

IAS: on the gauge

 

TAS: True airspeed adjusted for altitude, temp, etc

 

GS: TAS adjusted for wind

Even I selected Clear Weather ( no wind ) . My aircraft still losing airspeed when climbing .

You haven't really given much information. So one has to guess as to what you are doing. Most probably you have selected a constant rate of climb e.g. 2,500 fpm and/or a constant angle of attack. In both these cases your IAS will gradually fall the higher you get until the a/c will stall.

If you climb at a constant IAS say 290kts then the aircraft will gradually reduce the climb rate until you end up with a nose down attitude to maintain airspeed at high altitude.

Really no information given to really be able to know what's going on. If you're using the default aircraft, you're probably using vertical speed hold on the autopilot, in which case the higher you get, the higher the chances of losing speed since at high altitudes, the air is less dense and the engines can't produce nearly as much thrust as it can at sea level. On the more complex add-ons, like the PMDG Boeing 747-400, for instance, you would normally use VNAV or I guess FLCH, which would maintain a constant thrust and speed, then adjust the vertical speed accordingly, but we don't get this option in the default aircraft.

 

Also, the airspeed reading you get on the airspeed indicator is the speed in which the air is hitting the pitot tubes. At higher altitudes, there is less pressure, so less air hitting the pitot tubes, therefore a lower airspeed reading. Doesn't necessarily mean you're going too slow, but at that point, you would use Mach rather than airspeed, which you would see increasing. If you checked your ground speed, which is different than airspeed, you would see it is much higher.

 

Of course, this is assuming you are referring to a commercial jet. Since you haven't told us anything other than you're losing speed during climb, we can only guess with the information we don't have.

I have just the opposite problem. It gains speed when descending. What, gravity you say?

I have just the opposite problem. It gains speed when descending. What, gravity you say?

 

A tractor beam maybe?

You will be assimilated.

Thanks everyone, problem solved . i have adjusted some settings

Thanks everyone, problem solved . i have adjusted some settings

Um....oKay....would be nice to know what the actual issue was in the first place and what you did to resolve it....

 

 

would be nice to know what the actual issue was in the first place and what you did to resolve it...

 

Just a guess, but I suspect he turned off the weather effects in FSUIPC.  Go check out recent posts on the Hifi forums.

 

It's really hard to tell what his problem might have been.  IAS vs TAS?  Failure to lean a piston engine?  Doesn't know that aircraft fly slower when climbing?  Aircraft building up ice due to a thick atmospheric icing layer (you lose prop efficiency and lift if it ices up)?  "Poor climb performance" is kinda generic.

 

Hook