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A fokker 100 reported alternate brake pressure bleed down was excessive but could find no limits in the fom.
| Attributes | |
| ACN | 458397 |
| Time | |
| Date | 199912 |
| Day | Tue |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Fokker 100 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : parked ground : maintenance |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 458397 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial pilot : multi engine |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : published procedure |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | other |
| Factors | |
| Maintenance | contributing factor : engineering procedure performance deficiency : training |
| Supplementary | |
| Problem Areas | Company Chart Or Publication |
| Primary Problem | Chart Or Publication |
| Situations | |
| Publication | Flight Operations Manual |
Narrative:
After sitting in XXX for approximately 2 hours, we readied the aircraft for the flight to ZZZ. The alternate brake pressure was lower than normal, but I believe it was still in the green band. Out of habit, I turned on the system #1 hydraulic pump to pump up the brake pressure. As we approached departure time, the pressure had bled down again, but was still in the green band. I attempted to look in the volume #1 for any guidance on the limits on alternate brake bleed down rate. I could not find it anywhere. Now it was departure time, and with the brake pressure still in the green band, I decided to depart, and inquired once we got to ZZZ. ZZZ maintenance checked out the aircraft when we arrived and ended up taking the aircraft OTS. In hindsight, I probably should have had XXX maintenance come out and consult with them. What I would really like to know is -- where is it written for the pilots what the limits are for the alternate brake bleed down rate?
Original NASA ASRS Text
Title: A FOKKER 100 RPTED ALTERNATE BRAKE PRESSURE BLEED DOWN WAS EXCESSIVE BUT COULD FIND NO LIMITS IN THE FOM.
Narrative: AFTER SITTING IN XXX FOR APPROX 2 HRS, WE READIED THE ACFT FOR THE FLT TO ZZZ. THE ALTERNATE BRAKE PRESSURE WAS LOWER THAN NORMAL, BUT I BELIEVE IT WAS STILL IN THE GREEN BAND. OUT OF HABIT, I TURNED ON THE SYS #1 HYD PUMP TO PUMP UP THE BRAKE PRESSURE. AS WE APCHED DEP TIME, THE PRESSURE HAD BLED DOWN AGAIN, BUT WAS STILL IN THE GREEN BAND. I ATTEMPTED TO LOOK IN THE VOLUME #1 FOR ANY GUIDANCE ON THE LIMITS ON ALTERNATE BRAKE BLEED DOWN RATE. I COULD NOT FIND IT ANYWHERE. NOW IT WAS DEP TIME, AND WITH THE BRAKE PRESSURE STILL IN THE GREEN BAND, I DECIDED TO DEPART, AND INQUIRED ONCE WE GOT TO ZZZ. ZZZ MAINT CHKED OUT THE ACFT WHEN WE ARRIVED AND ENDED UP TAKING THE ACFT OTS. IN HINDSIGHT, I PROBABLY SHOULD HAVE HAD XXX MAINT COME OUT AND CONSULT WITH THEM. WHAT I WOULD REALLY LIKE TO KNOW IS -- WHERE IS IT WRITTEN FOR THE PLTS WHAT THE LIMITS ARE FOR THE ALTERNATE BRAKE BLEED DOWN RATE?
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.