FS simulates some what aircraft icing.  I have had similar experiences of loss of altitude and engine failure due to what seemed appropriate, icing.  Otherwise there would be no real other explanation of this occuring.  This usually occurs when temp. is freezing and you are in the clouds.  If that was your case, you probably experienced icing....

Happens in jets too. I was climbing in an Airbus A320 the other day, and the airspeed indicator dropped to zero, and elements of the autopilot stopped working. Then I remembered that I hadn't turned the pitot heat and engine deicer switches on! After a while the plane recovered, but it was 'flying by the seat of your pants' for a while, I can tell you!

It's all been explained very nicely above so I won't add further useless comment to the main question.

Just a small point though - the default Baron panel de-icing switched for "Boot De-Ice" and "Prop De-ice" are dummies. They don;t do anything apart from move and click.

These aspects of flight dynamics are modelled in FS2002 and I managed to fix the switches in my own version of the Baron Panel to have an actual effect. If you fly the Baron, you might want to download my panel and crib the gauges, even if you don't like the panel itself.

I remember bringing this subject up regarding carburettor icing, just after FS 2002 came out.
I mainly fly small single engine piston aircraft, (Lycomings, Continentals, etc), and have always applied carburettor heat when closing the throttle prior to landing, to prevent carburettor icing, and also applying it regularly under low temperature conditions during normal cruise, as you should.... ...!
But I have always found that the only way I could simulate actual engine failure due to low temperature icing was to go to Menu > Aircraft > System Failures and set an "actual time" for an engine failure to occur, which it does, to the minute!
Obviously this is not very realistic, in that the failure does not occur randomly when NOT applying carburettor heat..!
I have tried all sorts of weather conditions to generate icing in the carburettor but have never got it to work realistically and cause the engine to cut-out!!
I rather think it was something that was not programmed into FS 2002?
I hope it will appear in the next FS 2004 version, as it is a vital action which piston engined pilots must always be aware of....
...apply carburettor heat regularly, or your engine WILL cut-out when you least expect it... ...!

Cheers...
Paul.
(Engine).

Might have happened to me in a 727 last night ???
Climbing through FL150 over Frankfurt (sp) speed fell to 120knts, engines 2 and 3 failed  and I stalled ???
however this was in summer

haha i was more going on about the original icing question there:)
but yes indeed i do remember during those lessons, i even got yelled at once for forgetting
great fun really i just find it fascinating it can happen at upwards of 20 degrees celcius or somewhere in that region but i would like to see it included properly in 2004

Quote:

hahaha:)
sounds like you need cooling off lol