# NTSB ATL94IA001: Boeing 757-232, N638DL, Fort Lauderdale, FL, October 4, 1993 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: October 4, 1993, 17:20 local (21:20 UTC) - Place: Fort Lauderdale, FL - Location: 26.0717° N, 80.1497° W: Placed by OpenAirDocs at FORT LAUDERDALE/HOLLYWOOD INTL (FLL), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=26.0717&lon=-80.1497&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 95 uninjured - Status: Completed, report November 10, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 3309 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL94IA001 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3309/pdf - Page: https://openairdocs.org/ntsb/ATL94IA001 ## Probable cause FAILURE OF THE CAPTAIN TO USE THE PROPER ROTATION AND LIFT-OFF SPEEDS, WHICH RESULTED IN OVER ROTATION OF THE AIRCRAFT DURING TAKEOFF AND A SUBSEQUENT TAIL SCRAPE. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water encounter with terrain/water, takeoff - roll/run - airspeed(vr) - improper, pilot in command (cause) - airspeed(vlof) - improper, pilot in command (cause) - rotation - excessive, pilot in command (cause) - lift-off - premature, pilot in command ## Analysis ACCORDING TO THE PILOTS, DURING THE TAKEOFF ROLL, THE AIRPLANE BEGAN TO BOUNCED FORWARD & BACKWARD, & AT ABOUT 128 KTS, THE NOSE PITCHED UP. INFO IN THE FLIGHT DATA RECORDER SHOWED THAT AT 95 KTS, THE ELEVATOR BEGAN A POSITIVE DEFLECTION; AT 108.5 KTS, PITCH ATTITUDE BEGAN TO INCREASE; THEN AT ABOUT 126 KTS, THE PITCH ANGLE REACHED A MAXIMUM VALUE OF 11.25 DEG & THE AIRCRAFT BECAME AIRBORNE. ABOUT 3 SECONDS AFTER INITIAL LIFT-OFF, THE AIRCRAFT TOUCHED DOWN MOMENTARILY. THE CAPTAIN STATED THAT AFTER BECOMING AIRBORNE, HE APPLIED FULL POWER & CONTINUED THE CLIMB. SUSPECTING A POSSIBLE TAIL STRIKE, HE ELECTED TO RETURN TO THE AIRPORT & LAND. A POST-FLIGHT EXAM REVEALED A 6' SCRAPE MARK AFT OF THE PRESSURE BULKHEAD. COMPUTED TAKEOFF SPEEDS FOR THIS FLIGHT WERE: DECISION SPEED (V1) 128 KTS, ROTATION SPEED (VR) 130 KTS, AND TAKEOFF SAFETY SPEED (V2) 135 KTS. THE PREVIOUS FLIGHT'S LIFT-OFF OCCURRED AT 151 KTS & 6.855 DEG NOSE UP PITCH. NO MECHANICAL PROBLEM WAS DISCOVERED WITH THE AIRPLANE. ## Factual narrative On October 4, 1993, at 1720 eastern daylight time, a Delta Air Lines Boeing 757-232, Flight 594, N638DL, collided with the runway during an attempted takeoff from International Airport, Fort Lauderdale, Florida. The scheduled, domestic, passenger flight operated under 14 CFR Part 121 with an instrument flight clearance. Visual weather conditions prevailed at the time of the incident. The airplane sustained minor damage, and none of the 95 occupants was injured. The flight departed Fort Lauderdale, at 1720 hours. According to the pilots, during the takeoff roll, "the aircraft bounced forward and aft" (rearward), and as the airspeed approached 128 knots, the nose pitched up. At this point the pilot stated that he applied full power and continued the climb (see attached airworthiness release). Seconds later, a flight attendant seated in the rear of the airplane reported that she thought that the tail of the airplane struck the runway (see attached NTSB Form 6120.1/2 with crew statements). The flight returned to Fort Lauderdale and landed without further incident. Examination of the airplane revealed a six-foot long scrape mark on the bottom of the fuselage near the aft pressure bulkhead. Further examination revealed a buckle in the lower panel of the pressure bulkhead assembly. Examination of the aircraft flight control systems failed to disclose a mechanical malfunction or component failure. The aircraft digital flight data recorder (DFDR) was removed for data readout and evaluation. The recovered data disclosed that, at 0039:30 elapsed time, at an indicated airspeed of 95 knots, elevator deflection began to change from a negative to a positive value. Three seconds later, at an indicated airspeed of 108.5 knots, pitch attitudes began to increase as well. At 0039:37 elapsed time, elevator deflection angles attained maximum values, and one second later, at an indicated airspeed of 126 knots, pitch angle reached a maximum value of +11.25 degrees nose up while the air/ground parameter changed to the "air" state. Pitch angle values then decreased concurrently with elevator deflection angle value. At 0039:41 elapsed time, the air/ground parameter changed back to the "ground" state. At 0039:42 elapsed time, at an indicated airspeed of 140 knots, the air/ground parameter changed to "air" and remained in that state for the remainder of the flight. Data from the previous take-off was also examined. The data revealed that elevator deflection began to move from negative to positive values at an indicated airspeed of 136.5 knots. Additional review of the DFDR data revealed no N1 engine speed changes until after the aircraft had established a positive rate of climb. Further review of the DFDR data did not disclose a pitch angle in excess of +10.0 degrees on the previous flight until the aircraft was well into the positive rate of climb; a corresponding reduction in engine N1 speed was also noted at that time. The previous flight liftoff occurred at 151 knots and at 6.855 degrees of nose up pitch. A review of the final weight and balance data revealed the following computed takeoff airspeeds for Flight 594: V1-128, VR-130 and V2-135 (see attached V speed definitions). ## Aircraft - Registration: [N638DL](https://openairdocs.org/deregistered/N638DL-2014-06-23), registration cancelled 2014-06-23, S/N 23761, built 1988 (OpenAirDocs) - Reported make and model: BOEING 757-232 - Registry model: [Boeing 757-232](https://openairdocs.org/model/boeing-757-232) (registry code 1384965) (OpenAirDocs) - Registry engine: [Pratt & Whitney PW2037](https://openairdocs.org/engine/pratt-whitney-pw2037) (registry code 52117, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 23761 - Airframe hours: 18266 - Engines: P&W 2037 37530 lbs thrust turbo fan - Damage: Minor damage - Flight: Part 121 - Registered owner: Delta Air Lines - Last inspection: Continuous airworthiness, October 3, 1993, 9 hours before - Departed: FLL - Destination: BOS, BOSTON, MA - Flight plan: IFR - Airport: FLL, Fort Lauderdale, runway 27R, 9,001 × 150 ft ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; airline transport, commercial; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 1,881 in this make and model, 227 in the last 90 days, 12 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: 7,000 ft broken - Temperature: 81 °F, dew point 73 °F - Altimeter: 29.00 inHg - Observed at: FLL ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19931004043879I](https://openairdocs.org/incident/19931004043879I), Oct 4, 1993: Boeing 757232, Ft Lauderdale, FL, Minor damage. Experienced porpoise effect on takeoff roll. Tail section contacted runway. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.