Phl controller and flight crew reported altitude deviation during descent on the BOJID2 STAR.

Attributes
ACN	1601691
Time
Date	201812
Local Time Of Day	1201-1800
Place
Locale Reference	PHL.Airport
State Reference	PA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 9
Person 2
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

Narrative:

This is the second pilot deviation I have been involved in in the exact same location and altitude in two months' time. Aircraft X had been cleared to maintain 6;000 and direct to bojid to resume the BOJID2 arrival STAR. The aircraft was observed descending through 5;300 between the waypoints bojid and hifal. The flight crew misread; as had happened before; the 4;000 expect altitude charted at ferus and began their descent as if they were issued a 'descend via' instruction and as if the ferus altitude was a requirement and not informational only. Remove all 'expect' altitudes and speeds from this STAR.

Original NASA ASRS Text

Title: PHL Controller and flight crew reported altitude deviation during descent on the BOJID2 STAR.

Narrative: This is the second pilot deviation I have been involved in in the exact same location and altitude in two months' time. Aircraft X had been cleared to maintain 6;000 and direct to BOJID to resume the BOJID2 Arrival STAR. The aircraft was observed descending through 5;300 between the waypoints BOJID and HIFAL. The flight crew misread; as had happened before; the 4;000 Expect altitude charted at FERUS and began their descent as if they were issued a 'descend via' instruction and as if the FERUS altitude was a requirement and not informational only. Remove all 'expect' altitudes and speeds from this STAR.

Data retrieved from NASA's ASRS site 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.