I have downloaded the errata sheet for Descent:journeys in the dark on support page.When I readed the first page,I could‘t sure which razorwing corresponding that was shown on the phrase "In the first quest,one of the razorwings in Area 3 is placed off the map.It should be placed one space to the south."

Which is it? The next phrase shown ".......These instances are detailed on the errata sheet available on FFG's website"

but I didn't searched it on this website

It's the razorwing which is printed in a position off the edge of tile map. =P

If you have a newer print run copy of Descent it's entirely possible they corrected it already in your quest guide.

I think so. some of content on errata sheet already corrected in my rulebook&quest guide,but some not. OH GOD!!!!