NO!
Integrated graphics is a no go for that heavy piece of game.
Buy a laptop that has GeForce 7XXX go (7300 and up), or ATI Mobility Radeon X1XXX (1600 and up). Its a very heavy game, unless you want to play on lower detail. Even those laptop cards might not be powerful enough. Buy a desktop with a sparkling new GeForce 8800GTX!
good luck!
UPDATE
Ok, mensch201 (the guy below) made a point, but still, if you buy the laptop with intel integrated graphics (I'm not sure what you said "UMA" is, but the best integrated graphics solution from intel is "Intel GMA950") which is indeed supports DirectX 9, but, you can see from this article below why would it equal to saying NO. Again it may still work, but, I don't think you will like slow performance/minimal details.
From the article below you can see a benchmark comparison of Intel GMA950 and a couple of nvidia geforce go generation 6XXXs. You can now find laptops with nvidia geforce go generation 7 (7XXX) and I suppose that would be your best bet for optimum FSX experience in a laptop.
Keep in mind though, even though intel GMA950 (or slower variants) may be slow for 3D games, but it is very energy efficient. Using high powered graphics card in the laptop will make the battery life shorter. My laptop has a radeon X600 in it and battery life is only 3 hours. Comparable intel GMA laptops can have 4-5 hours or more depends on configuration.If you just plug in the laptop to the wall outlet then this will not be an issue.
There is also some laptops that have two types of graphics card, GMA and dedicated graphics (for example, geforce go 7300). This way you can switch to which is more suitable for your needs (longer battery life or faster 3D performance). But these dual-graphics laptops may cost a lot.
I don't know about FSX, but my friend's laptop with Intel GMA950 onboard graphics would not play most newer games, or play them very slowly on low details.