TBM 900 / TBM 930
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Flight Instructor
Flight Crew Last 90 Days 200; Flight Crew Total 20000; Flight Crew Type 3500
Situational Awareness; Confusion; Communication Breakdown; Training / Qualification
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Human Factors
I was conducting an instrument training flight. I was on an assigned heading of 360 and altitude of 10;000 feet. ATC asked if I could take 11;000 feet. I read back climb 11;000 feet. He quickly said that he was just asking it was not yet a clearance. I remained at 10;000 feet.A few moments later he gave me a heading of 320 and 11;000 feet. I read back left 320 and climb 11;000 feet. He made no further transmission. As I leveled off at 11;000 feet. ATC said that he did not climb me and told me to descend back to 10;000 feet. I apologized and told him I had read back 11;000 feet. There were no aircraft on TCAS within 20 NM at the time of the altitude deviation. ATC continued on with giving me vectors. The frequency was very busy and there were many people stepping on each other. The same Controller was vectoring me to ZZZ when my destination was IMM that is in the opposite direction. I called it to his attention and he apologized twice; it was not problem. The Controller was very busy and in my opinion his use of none standard language was causing me to listen and decipher his intent on a couple times.
TBM 900 instructor pilot reported communication problems with ATC which led the pilot to an altitude excursion.