MD-80 Series (DC-9-80) Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
Flight Crew Returned To Gate; Flight Crew Rejected Takeoff; Flight Crew Became Reoriented
Human Factors
While performing First Officer (FO) preflight duties; it was time to calculate the flight's weight and balance. Unlike the other flights; all passengers have been removed so the flight was now just crew. The Captain (CA) preferred I call the automatic WB (Weight and Balance) number to get the flights details instead of the manual way. I called and reached an operator and gave the flight number and began to read the weights and positions for the flight. When complete; the operator repeated the flight number but somehow had the wrong N number. I quickly corrected the error; and the operator read off the numbers. If I remember correctly; like everyone does; the operator read some numbers as individual and others as groups (i.e. one; two; three or ten; twenty; sixteen). I jotted down what I believed to be correct; and read the numbers back in the same fashion. I handed the load report to the CA and he reviewed it and we were on our way.On the takeoff roll; even at seventy knots I could tell something was wrong. The nose seemed to be bouncing and the whole big picture seemed just wrong. I expressed something like 'this isn't normal' or 'something odd' and at about 80 knots the nose seemed to be flying off the runway. That is when the CA decided to reject the takeoff and we reached about 90 knots on the abort. We safely exited the runway and returned to the gate.After a review by the company it seems that I somehow heard the operator incorrectly and noted a CG (Center of Gravity) of 3 instead of 30. I read back the incorrect 3 and the operator missed it and said 'all correct'.I realize that experienced MD80 crew would know that 3 is probably not the correct CG for an empty aircraft. However; I don't believe I've ever flown an empty plane; or if I did I could have been the manual fashion. At any rate; I had no idea that 3 was an incorrect CG for being empty. Unfortunately; the CA was also very new and he also did not know the 3 was not a good CG for being empty.But the good news is due to both my and the CA's years of experience in jets; we knew on the takeoff roll that something didn't feel right and we both prevented a further problem.I would suggest a more standard way of the weight details. Maybe a small training course for both pilots and WB operators to know usual positions? I don't recall ever being made aware of empty MD80 characteristics.
The previous day involved two missed approaches and two diversions. The weight/balance form was incorrectly completed and read back with an automated CG (Center of Gravity) calculation of 3.59 for verification by the flight crew. This read back was not challenged by weight/balance personnel. The actual CG was later discovered to be 30.59. The stab trim was therefore incorrectly set. During takeoff the nose wheel began to rise at 70 knots and could not be controlled by elevator inputs. The takeoff was aborted at approximately 90 knots. The aircraft returned to the ramp and a maintenance inspection was completed and noted in the logbook. An incorrect release was sent to the flight crew with a load of approximately 160 passengers. The flight crew requested a new release reflecting a full crew and no passengers with the new fuel load. This was given to the flight crew. The flight blocked out with an automated CG calculation of 31.19. The flight was then conducted without incident.More attention by flight crew to weight/balance information disseminated by weight/balance personnel. More attention by weight/balance personnel to read back information of flight crew. Approximated CG printed along with release information for check against gross errors (to be finalized after load/passenger count). Better flight crew awareness of MD80 CG/ stab trim tendencies given load/passengers.
MD80 flight crew reports copying incorrect Weight and Balance information during a phone call. The center of gravity (CG) is copied as 3.59 instead of 30.59; resulting in an incorrect stab setting. During takeoff roll the nose begins to lift at 70 knots and the takeoff is rejected.