B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Situational Awareness
ATC Issue All Types; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Procedure
Originally cleared JOTBA.HHOOD2 to PDX.  About 100 miles prior to JOTBA received Radar Vector.  Later received [a descent to] FL240.  Started descent.  After about 5 minutes re-cleared direct HHOOD with a frequency change.  Since I did not consider us on the arrival until HHOOD I did not consider the 280KIAS arrival restriction as applicable to us yet.  No mention of speed was given when we were re-cleared direct HHOOD or at any time between Present Position (PPOS) and HHOOD.  About 20 miles prior to HHOOD asked by ATC what our IAS was.  After I told them; we were told that we were in violation of the arrival because we were not supposed to exceed 280 KIAS.  I'm not sure if we violated the restriction on the arrival or not since up until that point we had not crossed any fixes along the arrival due to the Radar Vector and Direct HHOOD clearance previously. It seems vague when we are not actually on the arrival if we must comply with the 280 or not.
Approaching Top of Descent (TOD) for the HHOOD2; we were given a vector that took us off course before initiating the arrival. There was a frequency change and after a few minutes we were cleared direct HHOOD. Our speed was well above the 280 Kt restriction for the HHOOD2 descent but with the vector off course there was confusion as to whether we had to comply with the HHOOD2 since we were never technically on the HHOOD2. In retrospect; we should have conservatively reduced to 280 kts regardless. ATC asked what our speed was and then told us to slow down and indicated what the restriction for the arrival was. I [the pilot monitoring] was in back using the LAV when the Pilot Flying (PF) got the vector and was quite busy as a single-pilot. Misinterpretation of the restrictions of an arrival.
A B737 flight crew reports being vectored off course before actually beginning the HHOOD2 RNAV arrival. They are then cleared direct to HHOOD but do not comply with the RNAV speed restriction of 280 knots since they are not on the STAR until HHOOD. ATC is not happy with this interpretation of the speed restriction.