Date: 201703
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: PA-31 Navajo/Chieftan/Mojave/T1040
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Reporter organization: FBO
Reporter function: Pilot Flying; Captain; Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Flight Instructor
Human factors: Situational Awareness
Anomaly: Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I have been flying our Cheyenne for six years.  We recently purchased a new plane requiring two crew and since the owner of both planes is a pilot he wants to get qualified as SIC in our new plane. On nice days; I let him practice the SIC duties in our Cheyenne so he can transfer the habits into our new plane after he goes to school.This was a very nice VFR day.  We were running the before taxi checklists and got to the flight instruments set.  I know my boss had listened to the ASOS because I saw him write it down.  I saw him set both altimeters because they were a couple of hundred feet off.  He acknowledged the challenge with 'Altimeters set two times'.  I looked at the pointer on both altimeters and they were within 75' of field elevation (mine was perfect at field elevation.  We finished the check list.  What I didn't look at was the thousand foot altitude.  The altimeter was actually was actually set to -880 feet; which we discovered once we leveled off at 170.We took off and contacted approach with our altitude we were climbing through and climbing to.  The reception and transmissions in that area aren't great down low so there is a chance the controller did not pick up my current altitude we were climbing through. Approach did give me the altimeter setting but I only verified and read back the last two digits rather than the entire four digits. Before we leveled off we were assigned a higher altitude and I only acknowledged the new assigned altitude. We were handed off to Center before leveling off and I checked in with my altitude climbing through and climbing to.  He greeted me; gave me the altimeter setting; and asked me if I was climbing through a given altitude.  Because of my rate of climb; I don't remember the exact altitude but for example he asked if I was at 14;600 and I saw my 100 pointer was just coming up on my next 1000 foot interval; and when I check my thousands feet I was showing 14;000 and didn't make the connection I was actually climbing from 13000 through 140000; not 140000 through 150000.  I think the controller saw the discrepancy and tried to politely point out my mistake.  We were handed off to the next center frequency and I checked on climbing through 16;600 for 17000.  The controller welcomed me.  A short period later the controller called me and asked me to confirm my assigned altitude.  I verified 17;000.  He said my mode C indicated 16;200.  I told him I showed level 17;000.  At that point I looked at my mode C read out and saw 16;200 which prompted me to ask him to verify the altimeter.  This was when I realized I allowed the altimeter to be set 1000' too low before takeoff.  We reset the altimeter properly and climbed to our proper assigned altitude. When I went to school for our new plane they emphasized crew coordination and depending on the second pilot.  They instilled the need to trust he knows what he is doing and broke me of the habit of doing everything myself.  Once I heard the confirmation altimeters set twice and saw the 100' pointer where it should be; I continued with the checklist.  I am not sure why I didn't notice the altimeter was set to 30.72 instead of 29.72 even though the controllers did give me the setting a number of times.  I guess believing the altimeter was set correctly on the ground and the last two digits on the setting didn't change from ATC that I only listened to the last two digits of the setting.  I am also thinking I take the short cut of listening to the hundreds foot position and not the entire altitude when ATC reads off the altitude when I am climbing.In hindsight; I am going to have to rethink how much to trust a second pilot and question them more.  I also realize how strong the feeling is that I knew the altimeter was set on the ground so it didn't register when ATC politely queried me on my altitude. In this case I failed in all four double checks.....The use of checklist; verify actual altitude against altimeter before takeoff; reading back altimeter settings to ATC (I think I read back only the last two digits instead of the full four); and missing the ATC query regarding my actual altitude.  I guess once you believe one piece of the puzzle is correct (I knew the altimeter was set correct on the ground) that the mind makes all the other information fit and ignores the pieces that don't.




Synopsis: PA31 pilot reported ATC alerted him to an altitude deviation resulting from an incorrect altimeter setting.