Date: 201404
Local time of day: 1801-2400
Location: ZBW.ARTCC, NH
Light: Daylight
Aircraft: Small Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZBW
ATC / advisory: Center ZBW
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Communication Breakdown; Confusion; Human-Machine Interface
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance
Contributing factors: Airspace Structure; Equipment / Tooling; Procedure
Primary problem: Procedure

Narrative: Aircraft X arrived in the sector on a VFR flight plan; destined to ACK. A few minutes after arriving in the sector; he requested an IFR clearance. The Radar Controller (R-side) acknowledged his request and told him to expect the clearance shortly; due to traffic in the vicinity. An IFR clearance was given to Aircraft X shortly after his request and the Radar Controller (R-side) entered the assigned altitude into the data block (17;000) while I updated the route to reflect what had just been issued.I got busy with landline coordination; checking routes and scanning the scope to ensure separation. During the time; the Radar Controller (R-side) must have issued an altitude of 15;000 to Aircraft X. I was likely on a coordination line as I do not recall hearing this assigned altitude. Shortly after; the data block indicated an interim assigned altitude of 11;000 with the aircraft actually at 15;000. I noticed the altitude; it is the bottom of our airspace and initiated the hand off to Cape Approach (K90) as the aircraft was approaching their boundary and the radar controller was busy. The hand off was accepted and the Radar Controller subsequently gave Aircraft X the frequency change. Aircraft X was sequenced and spaced properly with other arrivals into Cape Approach's airspace.As the Aircraft X flight was descending out of 10;500; our BDR 07 line (normally only a shout line with a few towers) rang. Cape Approach called to let us know that the normal shout line between ZBW and Cape Approach appeared to be out of service. They also questioned the flight plan status of Aircraft X telling me that they showed him VFR. Additionally; the Cape Approach Controller told me that Aircraft X checked-in with him level at 15;000; which is 5;000 FT above the top of their airspace. The Cape Approach Controller asked me if he had issued Aircraft X an IFR clearance. I told him that we had and he questioned the flight plan status in the computer and the assigned altitude of 15;000. Since I must have been on a coordination line at the time the lower altitude was given to Aircraft X; I told the Cape Approach Controller that I would ask the Radar Controller (R-side) and get back to him. I was unable to get back to him immediately since the normal shout line had failed and there was no alternate contact info available at the sector. I informed the Supervisor of the situation and the status of the shout line.While looking into the situation (we were unsure if the problem was related to ERAM initially) we discovered that the Radar Controller had only put an INTERIM altitude in the database but never changed the hard altitude from VFR. Since Cape Approach does not get interim altitude information; this lead to them thinking the aircraft was still VFR.To prevent future occurrences of this; I would advise against using interim altitudes when aircraft are descending. This would have prevented the system from masking the VFR altitude in the data block and alerted us that the flight plan needed to be updated to reflect the aircraft's new status of IFR. A contributing factor to the situation was that the sector had just been split when I was assigned the D-side position. The previous D-side opened the R-side position of the split sector. The R-side of the sector where I was working was very busy at the time. I would recommend that the Cape/Nantucket (17/18) sectors be split earlier and not left combined. Even though it is not summer yet; the Cape sector can get very busy all of a sudden and it's usually too late to split the sector when it happens. Cape is particularly busy on today's afternoons and the Supervisor should have known to split the sector earlier. Additionally; I would recommend that procedures be changed to leave these two sectors split more often. This is especially important with so many recently-certified controllers working these sectors. I'm surprised the Controller at Cape Approach (K90) did not question of the flight planstatus of Aircraft X earlier. Even if he could not reach us by shout line; a simply query to the pilot to confirm his IFR status would have been sufficient. Since the pilot checked in with Cape Approach level at 15;000 (5;000 FT above their upper airspace limit) and the weather at ACK indicated that an IFR clearance would be required; this should have raised red flags with the Cape Approach Controller that the aircraft was IFR already and he did not have control to descend the aircraft out of 15;000 FT.This type of confusion unfortunately occurs too often in the busy summer months with Cape Approach. Carriers (like Aircraft X) often depart NYC metro airports VFR and expect to pick up an IFR clearance as get closer to ACK. This creates countless problems and unnecessary complexity especially when lengthy mile-in-trail restrictions to ACK exist in the summer. Often clearances are given last minute and Cape Approach's equipment has already acquired the data block and it does not update to reflect the new flight plan status.Another recommendation to prevent problems like this from occurring again is to update the ERAM software to prevent interim altitudes from being assigned to a VFR aircraft. There's no reason to give a VFR aircraft an interim altitude since altitude is entirely at the pilot's discretion.




Synopsis: ZBW ARTCC enroute Controller is off line when altitude is assigned to aircraft. Adjacent facility calls up and queries Center if aircraft is IFR or VFR.