ERA24LA041

The pilot reported that, just after rotation during takeoff, he began to accelerate the airplane to 120 knots. About 20 ft above the runway, he noticed that the airplane’s airspeed and altitude started to decrease, though he reported no issues with either engine. Assessing the length of runway remaining, the pilot chose to abort the takeoff and lowered the landing gear using the normal method. The airplane touched down on the runway before the gear was fully extended, and the landing gear collapsed. The airplane came to rest upright about 1,000 ft before the end of the runway and incurred substantial damage to the airplane’s wings. The pilot stated that there was nothing mechanically wrong with the landing gear, which operated satisfactorily during recovery of the airplane using the emergency extension system. The departure runway was about 8,000 ft long. The airplane’s flight manual indicated that, given the airplane’s gross weight near its maximum and the environmental conditions present at the time of the accident, a minimum of 3,100 ft was required to accelerate, rotate, and climb to 50 ft; however, flight track data was not available to determine the maximum altitude the airplane reached during the takeoff or the point at which the pilot decided to abort the takeoff. The pilot attributed the loss of airspeed and altitude to a microburst during takeoff. Review of weather conditions revealed that a quasi-stationary front passed through the area around the time of the accident with a resulting slight wind shift; however, there was no significant wind shear associated with the front. Additionally, no convective echoes associated with microbursts or outflow boundaries were detected in radar data or satellite imagery, and recorded weather observations did not detect any strong gusting winds until well after the accident. Thus, there was no available evidence to support that wind shear or microburst conditions existed at the time of the accident. Although a reason for the airplane’s degraded climb performance could not be determined, its operation near the maximum gross weight and the ambient temperature at the time of the accident were likely factors. Any delay in the pilot’s recognition of the airplane’s reduced performance and aborting the takeoff would have resulted in the airplane continuing about 200 additional feet along the runway every second.

On November 11, 2023, about 1357 eastern standard time, a Cessna 421B, N977SM, was substantially damaged when it was involved in an accident near Lake City, Florida. The commercial pilot and five passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that he had landed at Lake City Gateway Airport (LCQ) to refuel the airplane, and after fueling, he performed weather and flight planning for the next leg of the flight. The pilot taxied to runway 10, an 8,003-foot-long runway, and after lining up on the runway centerline for departure, set the power and started the takeoff roll operating about 45 lbs below the airplane’s maximum gross weight. Data from an airport operations and tracking system (AOTS) captured a portion of the takeoff roll, with the airplane attaining 80 knots groundspeed about 1,544 ft down the runway. No more data points from the AOTS, or ADS-B, were available for the accident flight. The pilot stated that, after rotation, he transitioned to a climb airspeed of 120 knots and retracted the landing gear (no information was available in the airplane’s Federal Aviation Administration [FAA] Approved Aircraft Flight Manual [AFM], airplane maintenance manual, or component maintenance manual that specified how long gear retraction or extension would take). When the airplane was about 20 ft above ground level with the engines developing normal rpm and manifold pressure, the airspeed started to decrease with a corresponding loss of altitude, which the pilot later attributed to be from a “microburst on takeoff.” He assessed the length of runway remaining versus continuing the flight and aborted the takeoff. He used the normal method to extend the landing gear, but it was not fully extended and collapsed upon touchdown. The airplane came to rest upright near the aiming point markings for runway 28. Postaccident review of pictures of the airplane revealed substantial damage in the form of abrasion to the wing carry-through structure, and damage to ribs in both wings. The pilot also stated that he did not perceive any issue with either engine during the flight and that there was nothing mechanically wrong with the landing gear extension system. He also indicated that in the previous 90 days, in which he had flown that airplane on 40 flights accruing about 58 hours, he had not experienced any issues with the landing gear or engines. During recovery of the airplane from the runway, the landing gear was extended via the emergency extension system with no discrepancies reported. Safety concerns due to potential fuel leakage prevented application of electrical power to extend the gear using the normal system. According to the airplane’s AFM, for the existing environmental conditions that day, operating at gross weight, no wind, and a takeoff speed of 106 knots indicated airspeed, the distance to take off and climb to 50 ft was about 3,100 ft. The AFM also indicatedthat the calculated rate of climb performance for the temperature that day and with the flaps and landing gear up, maximum continuous power and climbing at 106 knots calibrated airspeed, was about 1,559 ft per minute and the distance to land over a 50 ft obstacle and stop was about 2,218 ft. Review of weather information indicated that an east-to-west quasi-stationary front extended in the vicinity of the accident site about the time of the accident. The surface weather observations surrounding the time of the accident depicted a slight wind shift, but there were no significant weather echoes within 5 miles of the accident site at the time of the accident. Further, there was no support for significant low-level wind shear or turbulence below 10,000 ft outside of any potential convection, and there were no Convective SIGMETs, SIGMETs, Center Weather Advisories, or Graphic-AIRMETs over the airport surrounding the period between 1400 through 1600.