Narrative:

Our departure clearance had an assigned altitude of 5000 ft, which the captain dialed into the digital altitude alerter. Unfortunately, the captain had selected 'MDA' mode on the altitude alerter, rather than the normal mode. In MDA mode, the aural and light indications for the altitude alerter are enabled when the aircraft is descending towards the selected altitude. In the normal mode of operations, the aural and light indications for the altitude alerter are enabled when the aircraft is climbing towards the selected altitude. The 'MDA' annunciator on the face of the altitude alerter is a very small digital display and its brightness is controled by the same light rheostat that controls the digital display of the captain's altimeter. The captain had the lighting intensity of his altimeter turned down very low, making the 'MDA' annunciator on the altitude alerter almost impossible to see, particularly in the dawn or sunrise light conditions we were experiencing that morning. After a normal takeoff, the first officer began calling for incremental flap retraction and accelerating per our aircraft operations manual (aom) profile. During flap retraction from 5 degrees to 2 degrees, the flaps 'stalled' approximately halfway between 5 degrees and 2 degrees, resulting in the illumination of the amber 'led' annunciator light. This occurred at approximately 3000 ft MSL. When I pointed out the illumination of this light and the condition of the flaps to the captain and first officer, the first officer realized the aircraft was rapidly accelerating beyond the 230 KT limit speed for our led and flap confign. He initiated a pitch up to reduce speed and the aircraft assumed a 15 degree nose up pitch attitude and a rate of climb in excess of 6000 FPM (we were not carrying any cargo, so our takeoff weight was a relatively light 136700 pounds). Within a very short period of time, the aircraft climbed through our assigned altitude of 5000 ft MSL with no aural or light indications from the altitude alerter because it was in 'MDA' mode. I was the first crew member to realize we had climbed through our assigned altitude and immediately called out 'altitude.' by the time the first officer initiated corrective action, we had reached an altitude of approximately 5800 ft MSL and chicago approach was issuing us a vector and asking us to verify our assigned altitude. Our aircraft was equipped with an operating TCASII system and at no time did we get a TA or RA from the TCASII nor did chicago approach indicate we were in conflict with other traffic. Among the mitigating factors of this altitude bust are the following: 1) the improper set-up of the altitude alerter. It should be noted that our air cargo company does not authority/authorized the use of 'MDA' mode and therefore provides no training or guidance to flight crews regarding this mode of altitude alerter operation. 2) the lighting set-up for the altimeter and altitude alerter. Because the altimeters and altitude alerter are liquid crystal displays (LCD's), they should each have their own, independent lighting rheostat or automatic dimming/brightening function (perhaps utilizing a photoelectric cell) so low or bright light conditions do not compromise the readability of these important displays. 3) the flap problem. This aircraft had been written up several times for flap anomalies and each time, the discrepancy was 'pencil whipped' with an 'operations check good' or 'within limits' or 'could not duplicate' corrective action. At no time during the many write-ups of the flap system on this aircraft did our maintenance personnel actually work on the system or perform meaningful diagnostic work. Had we not been distraction with a flap malfunction, the altitude bust likely would not have occurred. 4) the aom climb profile. Our company air cargo flight profiles place heavy emphasis on accelerating the aircraft as rapidly as possible to 250 KTS. The maximum speed for led extension and for flaps 2 degrees is 230 KTS. A lightly loaded B727 accelerates very rapidly in this speed regime and it is quite easy to exceed flap and led limit speeds while adhering to the flight profile. Perhaps the profile should include heavy emphasis on situational awareness rather than acceleration. Supplemental information from acn 618222: airspeed was kept at 210 KTS to comply with flap position airspeed while abnormal procedure was being accomplished. After completing the procedure, the flaps retracted normally. During the procedure, the aural and visual warning system that was selected on the altitude selector failed. Also, as the aircraft approached assigned altitude we entered VMC conditions and the display on both digital altimeters were barely readable.

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Original NASA ASRS Text

Title: A CLBING B727F OVERSHOOTS ITS ASSIGNED ALT WHEN THE CREW IS DISTR WITH A LEADING EDGE FLAP PROB 2 MI E OF ORD.

Narrative: OUR DEP CLRNC HAD AN ASSIGNED ALT OF 5000 FT, WHICH THE CAPT DIALED INTO THE DIGITAL ALT ALERTER. UNFORTUNATELY, THE CAPT HAD SELECTED 'MDA' MODE ON THE ALT ALERTER, RATHER THAN THE NORMAL MODE. IN MDA MODE, THE AURAL AND LIGHT INDICATIONS FOR THE ALT ALERTER ARE ENABLED WHEN THE ACFT IS DSNDING TOWARDS THE SELECTED ALT. IN THE NORMAL MODE OF OPS, THE AURAL AND LIGHT INDICATIONS FOR THE ALT ALERTER ARE ENABLED WHEN THE ACFT IS CLBING TOWARDS THE SELECTED ALT. THE 'MDA' ANNUNCIATOR ON THE FACE OF THE ALT ALERTER IS A VERY SMALL DIGITAL DISPLAY AND ITS BRIGHTNESS IS CTLED BY THE SAME LIGHT RHEOSTAT THAT CTLS THE DIGITAL DISPLAY OF THE CAPT'S ALTIMETER. THE CAPT HAD THE LIGHTING INTENSITY OF HIS ALTIMETER TURNED DOWN VERY LOW, MAKING THE 'MDA' ANNUNCIATOR ON THE ALT ALERTER ALMOST IMPOSSIBLE TO SEE, PARTICULARLY IN THE DAWN OR SUNRISE LIGHT CONDITIONS WE WERE EXPERIENCING THAT MORNING. AFTER A NORMAL TKOF, THE FO BEGAN CALLING FOR INCREMENTAL FLAP RETRACTION AND ACCELERATING PER OUR ACFT OPS MANUAL (AOM) PROFILE. DURING FLAP RETRACTION FROM 5 DEGS TO 2 DEGS, THE FLAPS 'STALLED' APPROX HALFWAY BTWN 5 DEGS AND 2 DEGS, RESULTING IN THE ILLUMINATION OF THE AMBER 'LED' ANNUNCIATOR LIGHT. THIS OCCURRED AT APPROX 3000 FT MSL. WHEN I POINTED OUT THE ILLUMINATION OF THIS LIGHT AND THE CONDITION OF THE FLAPS TO THE CAPT AND FO, THE FO REALIZED THE ACFT WAS RAPIDLY ACCELERATING BEYOND THE 230 KT LIMIT SPD FOR OUR LED AND FLAP CONFIGN. HE INITIATED A PITCH UP TO REDUCE SPD AND THE ACFT ASSUMED A 15 DEG NOSE UP PITCH ATTITUDE AND A RATE OF CLB IN EXCESS OF 6000 FPM (WE WERE NOT CARRYING ANY CARGO, SO OUR TKOF WT WAS A RELATIVELY LIGHT 136700 LBS). WITHIN A VERY SHORT PERIOD OF TIME, THE ACFT CLBED THROUGH OUR ASSIGNED ALT OF 5000 FT MSL WITH NO AURAL OR LIGHT INDICATIONS FROM THE ALT ALERTER BECAUSE IT WAS IN 'MDA' MODE. I WAS THE FIRST CREW MEMBER TO REALIZE WE HAD CLBED THROUGH OUR ASSIGNED ALT AND IMMEDIATELY CALLED OUT 'ALT.' BY THE TIME THE FO INITIATED CORRECTIVE ACTION, WE HAD REACHED AN ALT OF APPROX 5800 FT MSL AND CHICAGO APCH WAS ISSUING US A VECTOR AND ASKING US TO VERIFY OUR ASSIGNED ALT. OUR ACFT WAS EQUIPPED WITH AN OPERATING TCASII SYS AND AT NO TIME DID WE GET A TA OR RA FROM THE TCASII NOR DID CHICAGO APCH INDICATE WE WERE IN CONFLICT WITH OTHER TFC. AMONG THE MITIGATING FACTORS OF THIS ALT BUST ARE THE FOLLOWING: 1) THE IMPROPER SET-UP OF THE ALT ALERTER. IT SHOULD BE NOTED THAT OUR AIR CARGO COMPANY DOES NOT AUTH THE USE OF 'MDA' MODE AND THEREFORE PROVIDES NO TRAINING OR GUIDANCE TO FLT CREWS REGARDING THIS MODE OF ALT ALERTER OP. 2) THE LIGHTING SET-UP FOR THE ALTIMETER AND ALT ALERTER. BECAUSE THE ALTIMETERS AND ALT ALERTER ARE LIQUID CRYSTAL DISPLAYS (LCD'S), THEY SHOULD EACH HAVE THEIR OWN, INDEPENDENT LIGHTING RHEOSTAT OR AUTOMATIC DIMMING/BRIGHTENING FUNCTION (PERHAPS UTILIZING A PHOTOELECTRIC CELL) SO LOW OR BRIGHT LIGHT CONDITIONS DO NOT COMPROMISE THE READABILITY OF THESE IMPORTANT DISPLAYS. 3) THE FLAP PROB. THIS ACFT HAD BEEN WRITTEN UP SEVERAL TIMES FOR FLAP ANOMALIES AND EACH TIME, THE DISCREPANCY WAS 'PENCIL WHIPPED' WITH AN 'OPS CHK GOOD' OR 'WITHIN LIMITS' OR 'COULD NOT DUPLICATE' CORRECTIVE ACTION. AT NO TIME DURING THE MANY WRITE-UPS OF THE FLAP SYS ON THIS ACFT DID OUR MAINT PERSONNEL ACTUALLY WORK ON THE SYS OR PERFORM MEANINGFUL DIAGNOSTIC WORK. HAD WE NOT BEEN DISTR WITH A FLAP MALFUNCTION, THE ALT BUST LIKELY WOULD NOT HAVE OCCURRED. 4) THE AOM CLB PROFILE. OUR COMPANY AIR CARGO FLT PROFILES PLACE HVY EMPHASIS ON ACCELERATING THE ACFT AS RAPIDLY AS POSSIBLE TO 250 KTS. THE MAX SPD FOR LED EXTENSION AND FOR FLAPS 2 DEGS IS 230 KTS. A LIGHTLY LOADED B727 ACCELERATES VERY RAPIDLY IN THIS SPD REGIME AND IT IS QUITE EASY TO EXCEED FLAP AND LED LIMIT SPDS WHILE ADHERING TO THE FLT PROFILE. PERHAPS THE PROFILE SHOULD INCLUDE HVY EMPHASIS ON SITUATIONAL AWARENESS RATHER THAN ACCELERATION. SUPPLEMENTAL INFO FROM ACN 618222: AIRSPD WAS KEPT AT 210 KTS TO COMPLY WITH FLAP POS AIRSPD WHILE ABNORMAL PROC WAS BEING ACCOMPLISHED. AFTER COMPLETING THE PROC, THE FLAPS RETRACTED NORMALLY. DURING THE PROC, THE AURAL AND VISUAL WARNING SYS THAT WAS SELECTED ON THE ALT SELECTOR FAILED. ALSO, AS THE ACFT APCHED ASSIGNED ALT WE ENTERED VMC CONDITIONS AND THE DISPLAY ON BOTH DIGITAL ALTIMETERS WERE BARELY READABLE.

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.