Dear friend, if you read the entry again, you'll find no fly speed is ever mentioned. This is because they cannot fly - the Steelwings are a -weapon-, not a mode of transportation.
[EDIT] For future reference, Savage Species only assigns those stats a +1 LA. And it make sense if you think about it - if you played a Medium race with only those stats as its features, it'd probably be worth that LA. Since none of the abilities really sync together except the possibility of two longsword slashes and a wing slash, each one should be (and is) judged on the basis of, "If a race just had this, what would it be worth?"