Narrative:

After intercepting the localizer to runway 4R at ord, we were told by approach control to 'cross degan at 8000 ft at 250 KTS, cleared for the approach.' we were about 10 mi southwest of degan at 10000 ft, 250 KTS. The copilot was relatively new and armed the approach coupler on the MCP. After capturing the GS, the aircraft descended and I was involved with seating the passenger and getting ATIS when I looked at the instrument panel and saw '264 KTS' on the airspeed indicator. The aircraft continued descending and I immediately told the copilot to disconnect the autoplt and fly the aircraft manually with speed brakes deployed. As this was done, it took several seconds, the aircraft was slowed. However, during this process of advising the copilot how to correct properly, we in manual flight, descended to 7700 ft MSL 1 1/2 mi southwest of degan intersection. We corrected slowly back to 8000 ft and crossed degan at the assigned altitude based on the FMC map display. Since we were both in manual on our navigation/ILS for approximately 5-10 mins and since the approach was started approximately 42 mi southwest of ord, we had no radio updates. The display could have developed an error. Although we never deviated more than 1 DOT from the GS at 23 DME, that could easily be 300-400 ft, which caused us to not comply with the restr of 8000 ft at degan intersection. I should have been a bit more cautious with the first officer by evaluating the experience level this person had and by suggesting that drag was going to be needed to comply with the airspeed restrs if the autoplt and approach coupler were to be used. I assumed too much and once the deviations began, several other parameters were in jeopardy which I talked about when I should have taken control of the aircraft as the captain. Although safety was not jeopardized, I think I went a little too far in instructing the copilot so some positive learning could occur. Nonetheless, the copilot finally got the approach within limits and a debrief was conducted after the flight. Supplemental information from acn 443890: at 11000 ft MSL, on the localizer for runway 4R at ord, approaching rahnn, ord approach cleared air carrier for the ILS 4R approach. We were instructed to maintain 250 KTS, and 8000 ft or above until degan. We were at 250 KTS, 1 1/2 dots below GS when cleared for the approach, and I armed the approach mode. The aircraft captured the GS, clean at 250 KTS. Passing through 10000 ft on GS, the aircraft had accelerated to 263 KTS, and the captain prompted me to deploy the speed brakes. The aircraft decelerated back to 250 KTS by 9300 ft. We extended the landing gear to further aid in airspeed control. With the speed brakes extended, and landing gear down, the autoplt followed approach mode/GS indications to descend the aircraft to 7700 ft about 1 NM prior to degan. The captain announced the altitude deviation and I disconnected the autoplt and autothrottle, and corrected expeditiously back up to 8000 ft. I flew the remainder of the approach manually (with flight director, without autoplt or autothrottle). I feel that the altitude and airspeed deviations were pilot error on my part (ie, less experience with extremely fast GS's). During postflt, the captain debriefed the entire approach and offered further techniques for this type of approach.

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Original NASA ASRS Text

Title: B737 CREW HAD ALT AND SPD DEV.

Narrative: AFTER INTERCEPTING THE LOC TO RWY 4R AT ORD, WE WERE TOLD BY APCH CTL TO 'CROSS DEGAN AT 8000 FT AT 250 KTS, CLRED FOR THE APCH.' WE WERE ABOUT 10 MI SW OF DEGAN AT 10000 FT, 250 KTS. THE COPLT WAS RELATIVELY NEW AND ARMED THE APCH COUPLER ON THE MCP. AFTER CAPTURING THE GS, THE ACFT DSNDED AND I WAS INVOLVED WITH SEATING THE PAX AND GETTING ATIS WHEN I LOOKED AT THE INST PANEL AND SAW '264 KTS' ON THE AIRSPD INDICATOR. THE ACFT CONTINUED DSNDING AND I IMMEDIATELY TOLD THE COPLT TO DISCONNECT THE AUTOPLT AND FLY THE ACFT MANUALLY WITH SPD BRAKES DEPLOYED. AS THIS WAS DONE, IT TOOK SEVERAL SECONDS, THE ACFT WAS SLOWED. HOWEVER, DURING THIS PROCESS OF ADVISING THE COPLT HOW TO CORRECT PROPERLY, WE IN MANUAL FLT, DSNDED TO 7700 FT MSL 1 1/2 MI SW OF DEGAN INTXN. WE CORRECTED SLOWLY BACK TO 8000 FT AND CROSSED DEGAN AT THE ASSIGNED ALT BASED ON THE FMC MAP DISPLAY. SINCE WE WERE BOTH IN MANUAL ON OUR NAV/ILS FOR APPROX 5-10 MINS AND SINCE THE APCH WAS STARTED APPROX 42 MI SW OF ORD, WE HAD NO RADIO UPDATES. THE DISPLAY COULD HAVE DEVELOPED AN ERROR. ALTHOUGH WE NEVER DEVIATED MORE THAN 1 DOT FROM THE GS AT 23 DME, THAT COULD EASILY BE 300-400 FT, WHICH CAUSED US TO NOT COMPLY WITH THE RESTR OF 8000 FT AT DEGAN INTXN. I SHOULD HAVE BEEN A BIT MORE CAUTIOUS WITH THE FO BY EVALUATING THE EXPERIENCE LEVEL THIS PERSON HAD AND BY SUGGESTING THAT DRAG WAS GOING TO BE NEEDED TO COMPLY WITH THE AIRSPD RESTRS IF THE AUTOPLT AND APCH COUPLER WERE TO BE USED. I ASSUMED TOO MUCH AND ONCE THE DEVS BEGAN, SEVERAL OTHER PARAMETERS WERE IN JEOPARDY WHICH I TALKED ABOUT WHEN I SHOULD HAVE TAKEN CTL OF THE ACFT AS THE CAPT. ALTHOUGH SAFETY WAS NOT JEOPARDIZED, I THINK I WENT A LITTLE TOO FAR IN INSTRUCTING THE COPLT SO SOME POSITIVE LEARNING COULD OCCUR. NONETHELESS, THE COPLT FINALLY GOT THE APCH WITHIN LIMITS AND A DEBRIEF WAS CONDUCTED AFTER THE FLT. SUPPLEMENTAL INFO FROM ACN 443890: AT 11000 FT MSL, ON THE LOC FOR RWY 4R AT ORD, APCHING RAHNN, ORD APCH CLRED ACR FOR THE ILS 4R APCH. WE WERE INSTRUCTED TO MAINTAIN 250 KTS, AND 8000 FT OR ABOVE UNTIL DEGAN. WE WERE AT 250 KTS, 1 1/2 DOTS BELOW GS WHEN CLRED FOR THE APCH, AND I ARMED THE APCH MODE. THE ACFT CAPTURED THE GS, CLEAN AT 250 KTS. PASSING THROUGH 10000 FT ON GS, THE ACFT HAD ACCELERATED TO 263 KTS, AND THE CAPT PROMPTED ME TO DEPLOY THE SPD BRAKES. THE ACFT DECELERATED BACK TO 250 KTS BY 9300 FT. WE EXTENDED THE LNDG GEAR TO FURTHER AID IN AIRSPD CTL. WITH THE SPD BRAKES EXTENDED, AND LNDG GEAR DOWN, THE AUTOPLT FOLLOWED APCH MODE/GS INDICATIONS TO DSND THE ACFT TO 7700 FT ABOUT 1 NM PRIOR TO DEGAN. THE CAPT ANNOUNCED THE ALTDEV AND I DISCONNECTED THE AUTOPLT AND AUTOTHROTTLE, AND CORRECTED EXPEDITIOUSLY BACK UP TO 8000 FT. I FLEW THE REMAINDER OF THE APCH MANUALLY (WITH FLT DIRECTOR, WITHOUT AUTOPLT OR AUTOTHROTTLE). I FEEL THAT THE ALT AND AIRSPD DEVS WERE PLT ERROR ON MY PART (IE, LESS EXPERIENCE WITH EXTREMELY FAST GS'S). DURING POSTFLT, THE CAPT DEBRIEFED THE ENTIRE APCH AND OFFERED FURTHER TECHNIQUES FOR THIS TYPE OF APCH.

Data retrieved from NASA's ASRS site as of July 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.