Aviation Accident Summaries

Aviation Accident Summary DCA13CA088

Cocoa Beach, FL, USA

Aircraft #1

CBP113

GENERAL ATOMICS MQ-9

Analysis

On May 10, 2013, at 12:24 pm eastern daylight time (EDT) a General Atomics MQ-9 Predator, serial number CBP-113, operated by the US Customs and Border Protection (CBP), Office of Air and Marine (OAM), under the callsign Omaha 13, experienced a bounced landing and runway excursion on runway 13 at the Patrick Air Force Base Skid Strip (KXMR), Cape Canaveral Florida.  The aircraft was substantially damaged, there were no injuries.  The aircraft was operated as a non-military Public Aircraft in Restricted Airspace. According to the operator, the aircraft had departed from KXMR at 0736 EDT for a routine patrol in the warning areas east of the airport. The aircraft conducted the launch and patrol without incident. The aircraft departed the patrol area at approximately 1142 EDT for return to KXMR. During the initial approach under VFR conditions, the aircraft conducted a go-around after first touching down. During the first landing attempt, the Sensor Operator (SO) called for a go-around when he noticed that the aircraft was slowing below the recommended landing speed based on the weight of the aircraft (computed reference speed was 102 knots) and that the aircraft was floating. The main landing gear contacted the runway, rebounding the aircraft back into the air. The aircraft remained airborne for the go-around procedure. Flight instrumentation in the GCS recorded a G-Load of +3.8 with the hard landing annunciator illuminating momentarily. Flight was re-established in the traffic pattern for a second landing procedure. Winds were reported from the control tower at 140 degrees at 11 knots with no gusts reported. The approach was made to Runway 13. Upon the second landing attempt to Runway 13, the control tower once again reported winds from 140 degrees at 11 knots. No gusts were reported by the control tower. As the aircraft approached its landing area, a flare to land was conducted resulting in the aircraft maintaining an attitude of approximately 20 feet above the runway (based on laser altimeter information) as power was reduced. The indicated airspeed dropped to approximately 89 knots as the landing gear came into contact with the runway nose wheel first. As the aircraft bounced on the nose wheel, the SO called for a go-around. The PIC stated that the aircraft was already on the ground and did not initiate a go-around at that time. The nose wheel bounced a second time with the height of the rebound being greater than the first. Upon the third contact of the nose wheel with the runway, the nose wheel tire failed and the aircraft rebounded with a higher pitch angle resulting in a high angle of attack warning. During the fourth contact with the runway, the landing gear sheared. The aircraft then fell onto its EO/IR payload (located under the nose portion of the fuselage) and veered off of the runway to Its left. The aircraft came to rest on its nose approximately 30 feet to the left side of the runway. The left winglet was in contact with the sod and its right main landing gear was holding up the right side of the aircraft. The G-Load recorded in the GCS during the accident landing sequence was +5.0. During both approaches and landings the LRE PIC utilized the daytime airframe camera for the approach and landing with the SO utilizing the daytime EO/IR system. The aircraft gross weight and center of gravity were within the limits as stated in the Operators Manual with no indication of CG related issue being present. The Ground Control Station(GCS) was configured in a standard setting that was appropriate for the mission being flown. An analysis was completed and it was determined by CBP UAS engineers that the GCS was working properly and did not contribute the accident.

Factual Information

On May 10, 2013, at 12:24 pm eastern daylight time (EDT) a General Atomics MQ-9 Predator, serial number CBP-113, operated by the US Customs and Border Protection (CBP), Office of Air and Marine (OAM), under the callsign Omaha 13, experienced a bounced landing and runway excursion on runway 13 at the Patrick Air Force Base Skid Strip (KXMR), Cape Canaveral Florida. The aircraft was substantially damaged, there were no injuries. The aircraft was operated as a non-military Public Aircraft in Restricted Airspace. According to the operator, the aircraft had departed from KXMR at 0736 EDT for a routine patrol in the warning areas east of the airport. The aircraft conducted the launch and patrol without incident. The aircraft departed the patrol area at approximately 1142 EDT for return to KXMR. During the initial approach under VFR conditions, the aircraft conducted a go-around after first touching down. During the first landing attempt, the Sensor Operator (SO) called for a go-around when he noticed that the aircraft was slowing below the recommended landing speed based on the weight of the aircraft (computed reference speed was 102 knots) and that the aircraft was floating. The main landing gear contacted the runway, rebounding the aircraft back into the air. The aircraft remained airborne for the go-around procedure. Flight instrumentation in the GCS recorded a G-Load of +3.8 with the hard landing annunciator illuminating momentarily. Flight was re-established in the traffic pattern for a second landing procedure. Winds were reported from the control tower at 140 degrees at 11 knots with no gusts reported. The approach was made to Runway 13. Upon the second landing attempt to Runway 13, the control tower once again reported winds from 140 degrees at 11 knots. No gusts were reported by the control tower. As the aircraft approached its landing area, a flare to land was conducted resulting in the aircraft maintaining an altitude of approximately 20 feet above the runway (based on laser altimeter information) as power was reduced. The indicated airspeed dropped to approximately 89 knots as the landing gear came into contact with the runway nose wheel first. As the aircraft bounced on the nose wheel, the SO called for a go-around. The PIC stated that the aircraft was already on the ground and did not initiate a go-around at that time. The nose wheel bounced a second time with the height of the rebound being greater than the first. Upon the third contact of the nose wheel with the runway, the nose wheel tire failed and the aircraft rebounded with a higher pitch angle resulting in a high angle of attack warning. During the fourth contact with the runway, the landing gear sheared. The aircraft then fell onto its EO/IR payload (located under the nose portion of the fuselage) and veered off of the runway to Its left. The aircraft came to rest on its nose approximately 30 feet to the left side of the runway. The left winglet was in contact with the sod and its right main landing gear was holding up the right side of the aircraft. The G-Load recorded in the GCS during the accident landing sequence was +5.0. During both approaches and landings the LRE PIC utilized the daytime airframe camera for the approach and landing with the SO utilizing the daytime EO/IR system. The aircraft gross weight and center of gravity were within the limits as stated in the Operators Manual with no indication of CG related issue being present. The Ground Control Station(GCS) was configured in a standard setting that was appropriate for the mission being flown. An analysis was completed and it was determined by CBP UAS engineers that the GCS was working properly and did not contribute the accident.

Probable Cause and Findings

an improper flare leading to a nose-wheel first touchdown, which resulted in a pilot induced oscillation (PIO). The PIO caused the UAS to pitch up abruptly on the third nose gear contact with the runway, resulting in the separation of the nose wheel assembly from the landing gear strut.

 

Source: NTSB Aviation Accident Database

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