Date: 201510
Local time of day: 1201-1800
Location: TEB.Airport, NY
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Light Transport; Low Wing; 2 Turbojet Eng
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B NYC
ATC / advisory: TRACON N90
Reporter organization: Corporate
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Confusion; Distraction
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Contributing factors: Human Factors; Procedure; Chart Or Publication
Primary problem: Chart Or Publication

Narrative: Arrival at Teterboro (TEB). Weather at TEB >10 miles vis and Clear sky. Cleared for the Wilks-Barre Four Arrival to TEB followed by vectors to the ILS Runway 6; Circle to land runway 1. FMS setup with Wilks-Barre4 and vectors giving a discontinuity and DANDY as the next fix. Departed STW vector 140 heading; eventually cleared to 2000 feet. To clear the discontinuity on the FMS; DANDY selected as the away from fix (made blue). Approaching the Centerline; cleared to turn left 090 and join the localizer. During the turn to pick up the localizer cleared for the approach and maintain 180 knots to DANDY. Localizer established; and aircraft configured 10 flap and gear selected down with glide path indicating 1.5 dots in anticipation of descent. Approaching DANDY; ATC said; 'I need you at 1500 feet.' The co-pilot replied 'Roger; descending on the glide slope.' To which he replied 'Negative; 1500 feet is mandatory'. Rate of descent was increased to maintain below the glide path to meet the restriction. Cleared to circle at TORBY for Runway 1 and aircraft landed without event.Lesson Learned: The Approach was briefed in good time before the descent. The 1500 feet at DANDY was briefed but neither pilot emphasized it as a mandatory crossing (the Jep chart that we were using does show a step-down to 1500 feet after VINGS; we did not cross VINGS; but '1500 feet mandatory' is annotated at DANDY on the vertical profile. Just intercepting and following the glide path prior to DANDY does not ensure crossing DANDY at 1500 feet. If ATC had been busy and not told us we would have been above 1500 feet at DANDY.We were good VMC visual with the field; and intercepting the localizer at 2000 feet from our position meant that we would intercept the glide path as normal; comfortable with the ILS guidance combined with looking for traffic; planning our circle looking for the towers and Giants stadium (good guide for the circle) all distracted from the rigor of the approach plate.Flying the full approach through the IAF at SBJ or joining the localizer and crossing VINGS would have kept our concentration on the approach plate. As we were joining the approach closer and off a vector; although not officially required a reminder of the altitude restriction as we were given the approach clearance would have helped.


Second narrative: On descent into TEB on the Wilkes-Barre4 arrival; and upon receiving current ATIS info; we briefed on the approach in use; the ILS Runway 06; and set it up in the FMS. Departing STW; the final fix on the arrival we were assigned 140 degrees; and eventually cleared to 2000 feet. To clear a discontinuity in the FMS; DANDY was selected as the away from fix. Approaching the final approach course; we were instructed to turn left to 090 and intercept the localizer. Upon intercepting the localizer we were cleared for the ILS Runway 06 approach; circle to land Runway 01; and maintain 180 knots to DANDY. With the localizer and GS established; we configured the aircraft flaps 10 and gear down. Approaching DANDY; ATC said; 'I need you at 1500 feet. I replied; 'Roger; descending on the glide slope.' To which ATC replied; 'Negative; 1500 is mandatory.' A quick glance at the approach chart and I realized our mistake in not noticing the mandatory altitude of 1500 feet. The Pilot Flying (PF) immediately began descent to 1500. We were then cleared to commence circle for Runway 01 at TORBY; and we landed without incident. I am not sure at what altitude we crossed DANDY; except that the PF was making the correction as quickly as practical. The lesson is learned to go over every detail of the approach during the brief. This approach is a little different in requiring the step down to a mandatory altitude once on the localizer course. It is common practice to descend on the Glide Slope once cleared for the approach; even though the minimum crossing altitude of the final approach fix or other fixes on the final approach course; may allow descent to a lower altitude. That common practice led to complacency on this approach and could have led to an altitude deviation.


Synopsis: Pilots reported of flying an approach; but did not see a mandatory crossing altitude on the approach. The pilots briefed the approach but did not see the mandatory altitude. ATC corrected the problem.