Commercial Fixed Wing
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Communication Breakdown; Confusion
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Procedure; Human Factors; Environment - Non Weather Related
We were given takeoff clearance including climb to 7;000 and not including 'RNAV (first fix).'  I am accustomed to hearing 'Cleared for takeoff RNAV (first fix)' at other airports with RNAV departures.  I perceived the instruction; and verified with the other pilot; that we were given 'fly runway heading.'  On takeoff; we flew runway heading until questioned by Departure.  Departure gave us multiple instructions; including turn to a heading; stop the climb at 6;000; navigate to the first fix; resume the SID; and climb to 7;000.  The 6;000 level off instruction came as we were rapidly approaching that altitude (Departure assigned expedite climb through 5;000); and we ascended through it to about 6;400 before starting the descent back to 6;000.  This is when we were given 7;000.  Once out of sterile flight deck; we started debriefing the event; and were given an altitude higher than our assigned.  The aircraft was downgraded from RVSM per MEL; but we climbed into RVSM airspace before noticing and then promptly requested a return to our filed altitude.We expected the takeoff clearance to contain 'RNAV (first fix).'  Lacking that; we perceived the takeoff clearance to contain 'fly runway heading;' though it may not have.  That caused confusion which led to rapidly changing ATC instructions; busting the level off; which may have been unavoidable based on the late instruction and good climb performance; and further distraction of debriefing leading to a climb to an altitude above the aircraft's MELed RVSM limitation.RNAV departure clearances should either always or never contain 'RNAV (first fix).'  Being used to hearing that; we perceived the lack of that instruction to mean fly runway heading.
Arrived at assigned report time.  Cabin fogging for COVID was not completed in time; we had to leave the plane and did not gain access to the flight deck until about 20 minutes to departure.  Plane was short approximately 1;000 pounds; CA was busy in back; I called ops but no answer;  so I had to go out to the ramp to find operations; PDC was not received so I sent a message code.  While I built the flight plan; got weather. I noticed at about 15 minutes to departure we still did not have our PDC.  I called clearance but had to wait; once we contacted we received a clearance different from the release.  Received and read back.  We pushed on time; so I asked the CA if we could go over the route one more time before we taxied.  Which we did.  When we were cleared to take off on [Runway] XXR.  The Tower did not give us RNAV takeoff instructions; I thought I heard runway heading.  During initial climb the Tower told us to expedite climb to 5;000 feet; so I bugged 200 knots. We did the climb sequence and after TO check and were handed to departure.  Departure asked were we going to turn south; we responded runway heading. She immediately told us to turn south direct ZZZZZ and climb to 6;000 feet; we were already at 5;500 feet expecting to level at 7;000 feet for the SID.  We did not have time to level at 6;000 and leveled about 6;500 feet then Departure told us to climb to 7;000. ATC very busy.  Additionally; we accepted an altitude in RVSM airspace; but were MEL no RVSM.  We realized at the assigned altitude that we needed to be below RVSM airspace.  We immediately requested our filed altitude of 27;000...we did receive any altitudes in our clearance.We received fuel late; clearance late; cabin sanitizing late this forced me to compress many preflight steps into an inadequate time.  I should have asked for more time to prepare and realized being late was less important than properly performing my preflight duties.We need adequate time for COVID cleaning;  I work very hard at being prepared; methodical and thorough in my duties as a FO.  Recognizing that things are being rushed is very important and I need to do a better job of identifying those times.
Air carrier flight crew reported track heading and altitude deviations during departure and cited confusing ATC instructions as a contributing factor.