KBWI Altitude Restriction on Departure

Last night I was flying KBWI/KBOS and my PDC cleared me for the SWANN3 departure and CLIMB VIA SID. I looked at the departure and couldn’t see any altitude restrictions on the chart and when I loaded the departure in the FMS (PMDG 737) it didn’t have any altitude restrictions. I therefore thought hat I was cleared to climb without restrictions. I departed using VNAV and when I contacted Potomac Approach after takeoff I was climbing through 6000’. The controller advised me that Baltimore has a 4000’ altitude restriction that I had busted. I am sure that he is right but for the life of me I can’t find where that restriction comes from. I can’t seem to find it anywhere. What am I missing?

I’m not sure if you happen to still have a copy of your PDC handy, but most departure clearances have an initial altitude that you get cleared to.


My theory is that the initial altitude of 4,000 was specified in the PDC.

Is there a way go back and look at a PDC? I don’t think that there was an initial altitude in the PDC but perhaps I missed it.

This is a good question, John. I checked the SWANN SID pretty carefully and agree with you that there are no published altitude restrictions, including a top altitude, on the procedure. Therefore they can’t really assign you a Climb Via altitude clearance. My theory is that the controller may have inadvertently selected the wrong altitude clearance in vTDLS, since they do have a lot of RNAV SIDs with altitude restrictions on them and probably use those far more often.

In this case, however, the best move would have been to query the tower controller at BWI about your initial altitude clearance. After all, there isn’t (or shouldn’t be) any controller out there that minds someone verifying as important as an altitude clearance, no matter how busy they are.

Yes, you are right. When I saw the “CLIMB VIA” I should have questioned the controller before departure. A good lesson learned.

Good point. I missed the part of your original post where you said you had received a CLIMB VIA clearance.