Narrative:

We were cleared canal 3 departure off midway runway 31L. First officer dialed in 3000' in our altitude alert counter. On takeoff brief I doublechked departure plate altitude and verified 3000' assuming that altitude was assigned by clearance delivery. After takeoff in a climbing righthand turn to the heading assigned by the tower, departure control told us to descend from 2500' back down to 2000'. After later discussing the situation on the telephone with departure's supervisor I agreed that we should have only climbed to 2000' at that point. Two problem areas exist at midway airport associated with departures: 1) depending on whether you are given canal 3 or midway 3 departure you may climb to 2000' or 3000' and often times on the takeoff roll midway tower will change the altitude clearance from one to another. Solution: assign only 1 altitude to climb to (probably 2000') when departing midway airport. Then after talking to departure control allow them to clear to climb higher. There always seems to be confusion between departure, tower, pilot as to exactly how high to climb. 2) the departure plates are ambiguous! It appears on canal #3 (incorrectly) that DME equipped aircraft may be cleared up to 2000 or 3000' and that non DME equipped aircraft on the right side of the page must adhere to wbound and southbound and wbound altitude restrictions. Since we were DME equipped I assumed we were to climb to 3000' as per instructions. Please help standardize the climb procedures at midway no matter what runway you takeoff on!!!

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Original NASA ASRS Text

Title: CLIMBED TO 3000' VERSUS 2000' ON THE MDW CANAL 3 SID.

Narrative: WE WERE CLRED CANAL 3 DEP OFF MIDWAY RWY 31L. F/O DIALED IN 3000' IN OUR ALT ALERT COUNTER. ON TKOF BRIEF I DOUBLECHKED DEP PLATE ALT AND VERIFIED 3000' ASSUMING THAT ALT WAS ASSIGNED BY CLRNC DELIVERY. AFTER TKOF IN A CLBING RIGHTHAND TURN TO THE HDG ASSIGNED BY THE TWR, DEP CTL TOLD US TO DSND FROM 2500' BACK DOWN TO 2000'. AFTER LATER DISCUSSING THE SITUATION ON THE TELEPHONE WITH DEP'S SUPVR I AGREED THAT WE SHOULD HAVE ONLY CLBED TO 2000' AT THAT POINT. TWO PROB AREAS EXIST AT MIDWAY ARPT ASSOCIATED WITH DEPS: 1) DEPENDING ON WHETHER YOU ARE GIVEN CANAL 3 OR MIDWAY 3 DEP YOU MAY CLB TO 2000' OR 3000' AND OFTEN TIMES ON THE TKOF ROLL MIDWAY TWR WILL CHANGE THE ALT CLRNC FROM ONE TO ANOTHER. SOLUTION: ASSIGN ONLY 1 ALT TO CLB TO (PROBABLY 2000') WHEN DEPARTING MIDWAY ARPT. THEN AFTER TALKING TO DEP CTL ALLOW THEM TO CLEAR TO CLB HIGHER. THERE ALWAYS SEEMS TO BE CONFUSION BTWN DEP, TWR, PLT AS TO EXACTLY HOW HIGH TO CLB. 2) THE DEP PLATES ARE AMBIGUOUS! IT APPEARS ON CANAL #3 (INCORRECTLY) THAT DME EQUIPPED ACFT MAY BE CLRED UP TO 2000 OR 3000' AND THAT NON DME EQUIPPED ACFT ON THE RIGHT SIDE OF THE PAGE MUST ADHERE TO WBOUND AND SBND AND WBOUND ALT RESTRICTIONS. SINCE WE WERE DME EQUIPPED I ASSUMED WE WERE TO CLB TO 3000' AS PER INSTRUCTIONS. PLEASE HELP STANDARDIZE THE CLB PROCS AT MIDWAY NO MATTER WHAT RWY YOU TKOF ON!!!

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.