Date: 201501
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Regional Jet 900 (CRJ900)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Parked
Aircraft component: PMC; Performance/Thrust Management Computer
Component problem: Design
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Human-Machine Interface; Time Pressure
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Weight And Balance; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Procedure; Aircraft; Human Factors
Primary problem: Ambiguous

Narrative: At the gate the ACARS was going in and out of connection. In an effort to get the flight off the gate close to scheduled departure time; I decided to start filling out the ACARS back-up form. Once the bridge was moved off of the aircraft; the ACARS reconnected and the First Officer quickly grabbed the paperwork (CLR and passenger load information) and entered it in an effort to receive takeoff data before the ACARS could possibly lose connection again.We received our data; programmed it and closed the door for departure. We verified the takeoff data was set; accomplished all normal checklists and were cleared for takeoff. I called; 'V1; Rotate' as indicated by the speed bugs and the FO pulled back on the yoke. When the wheels left the ground; I felt what seemed like the tail sinking down. The FO slowed his rotation and the aircraft began to climb. During climb; I observed the low-speed warning tape on the bottom of the airspeed indicator. Normally; it is not visible. I believe the FO noticed this also and adjusted pitch to allow the aircraft to fly at a higher speed. After 10000 FT; we talked about it and he described how he had noticed the green line on the airspeed tape. I talked about the low-speed tape. The FO described how he allowed the aircraft to climb at a higher speed because of his realization of the speed issue. As we investigated the speeds and realized they were set at the correct speeds from the ACARS; we noticed that the passenger loadout was incorrect. The correct loading was: 12 in zone 1; 31 in zone 2 and 31 in zone 3. What was entered into the ACARS was 12 in zone 1; 11 in zone 2 and 11 in zone 3 - FORTY passengers less than were actually aboard. We calculated that the aircraft was almost 8000 lbs heavier than the v-speeds that were set.We manually calculated a correct weight for landing and entered this into the landing-data request to provide accurate landing speeds.The desire to get the flight going. The in-and-out nature of the ACARS communication. The rushed data-entering error that the FO made in the ACARS. The unknowingly set incorrect v-speeds.Cross-check of the entered data. The correct action was taken (in-flight) once a problem was realized; but the error occurred at the gate and more attention to the details of data-entry would have eliminated this situation.




Synopsis: Delayed in receipt of their performance numbers due to recalcitrant ACARS operation the flight crew of a CRJ-900 were able to quickly programmed load data immediately after pushback. During the subsequent takeoff climb response and acceleration were noticeably degraded and the aircraft was retrimmed to climb at a higher speed. Subsequent review of the transmitted passenger load compared to those actually on board showed 40 more passengers than utilized in the V speed computations. The flight crew utilized the 'actual' data for the subsequent approach and landing.