Incident on 2/7/2015 12:00:00 AM in Eagle, CO
Tail Number: N701DB
Aircraft Type: GULFSTREAM AEROSPACE G IV
Serial Number: 1036
Visibility: 10 statute miles
Wind Velocity: knots
Wind Gusts: knots
Sky Condition: NONE at feet
Total Injuries: 0
Total Fatal Injuries: 0
NTSB No.: CEN15IA139
HISTORY OF FLIGHT
On February 7, 2015, about 2136 mountain standard time, a Gulfstream Aerospace G-IV airplane, N701DB, sustained minor damage during a rejected takeoff on runway 25 (9,000 feet by 150 feet, asphalt) at the Eagle County Regional Airport (EGE), Eagle, Colorado. The five passengers and two pilots were not injured. The airplane was registered to GOAT Airways LLC and operated by Executive Air Charter of Boca Raton, Inc., dba Fair Wind Air Charter, under the provisions of 14 Code of Federal Regulations Part 91 as an executive/corporate flight. Night visual meteorological conditions prevailed for the flight, which was operated on an instrument flight rules (IFR) flight plan. The flight was originating at the time of the incident. The intended destination was the Bob Hope Airport (BUR), Burbank, California.
The incident occurred during the second flight of the day. The previous flight departed the McCarran International Airport (LAS), Las Vegas, Nevada, and arrived at EGE at 2049. The incident flight crew also operated the LAS to EGE flight, and no anomalies were reported with respect to that flight.
The pilot reported that before taxing the airplane a flight control check was performed. He noted that the flight control check was "normal," with "no binding or resistance issues." He added that the flight control forces seemed "normally loaded." During the initial takeoff attempt, the pilot engaged the auto-throttles. He stated that about 75 knots, a triple chime sounded and a master warning illuminated. He immediately rejected the takeoff with "light" brake pressure and coasted to the end of the runway. The flight crew reported that they did not observe any message on the Crew Alert System (CAS), nor were there any exceedance events recorded. In addition, they did not observe any tripped circuit breakers.
Based on this information, the pilot elected to attempt another takeoff. During this takeoff, he did not use the auto-throttles, electing to set the engine power manually. He reported that as the airplane accelerated through approximately 75 knots, the triple chime/master warning activated again. He observed that the engine low pressure (LP) turbine speed indicated within the yellow arc. He subsequently reduced engine thrust slightly in order to return the LP turbine speed to the white arc (normal operating range). The pilot continued the takeoff. At rotation speed, he pulled back on the control yoke but the flight controls did not seem to respond normally. He added that the controls had no "noticeable pressure resistance and felt unloaded with hydraulic pressure." He noted that the yoke was moved "forward and then back further aft" with the same result.
The pilot subsequently rejected the takeoff, applying maximum braking and full reverse thrust. The pilot taxied off the runway at taxiway A7 and brought the airplane to a stop on taxiway A. The flight crew requested response by aircraft rescue and firefighting (ARFF) crews due to high brake temperatures. A right brake fire subsequently ensued, which was promptly extinguished by the ARFF crews already on-scene. Airplane damage was limited to the right main landing gear. The flight crew and passengers evacuated the airplane without injury.
The pilot-in-command (PIC), age 50, held an airline transport pilot certificate with single and multi-engine airplane ratings. The single engine rating was limited to commercial pilot privileges. The PIC held type ratings for Gulfstream G-1159 (G-II/III), Gulfstream G-IV, and Aero Commander IA-Jet airplanes. He was issued a first class airman medical certificate with a restriction for corrective lenses on December 2, 2014.
The PIC was hired by the operator on November 4, 2014. At the time of his employment, the PIC reported a total flight time of 5,720 hours, with 108 hours within the preceding 90 days. He reported a total of 2,459 hours in G-IV airplanes, including 1,027 hours as PIC.
The PIC reportedly met the requirements for a flight review (14CFR 61.56), recent flight experience (14CFR 61.57), and a PIC proficiency check (14CFR 61.58) at the time of his employment. He completed the operator's Part 135 Basic Indoctrination training on November 14, 2014, with recurrent and instrument proficiency training in the G-IV in January 2015 (14CFR 135.293 / 14CFR 135.297). A line check (14CFR 135.299) was pending, but had not been accomplished at the time of the incident. His employment was terminated on February 28, 2015, in conjunction with the incident airplane owner's decision to transfer management of the airplane.
The second-in-command (SIC), age 47, held an airline transport pilot certificate with single and multi-engine airplane ratings. The single engine rating was limited to commercial pilot privileges. The SIC held type ratings for Gulfstream G-1159 (G-II/III), Gulfstream G-IV, and Canadair CL-600 airplanes. He was issued a first class airman medical certificate without restrictions on August 6, 2014.
The SIC was hired by the operator on November 4, 2014. At the time of his employment, the SIC reported a total flight time of 8,105 hours, with a total of 2,711 hours in G-IV airplanes. He had accumulated about 38 hours within the 90 days preceding the incident.
The SIC reportedly met the qualifications for SIC (14CFR 61.55) at the time of his employment. He completed the operator's Part 135 Basic Indoctrination training on November 14, 2014, with recurrent (135 CFR 135.293) and instrument proficiency training for the G-IV (14CFR 135.297) on January 10, 2015. A line check (14CFR 135.299) was pending, but had not been accomplished, at the time of the incident. His employment was terminated on February 28, 2015, in conjunction with the incident airplane owner's decision to transfer management of the airplane.
The incident airplane was a 1987 Gulfstream Aerospace G-IV, serial number 1036. It was powered by two Rolls-Royce Tay 611-8 turbo-fan engines. At the time of the incident, the airplane had accumulated 12,473 hours and 7,319 cycles. The left and right engines had accumulated 11,953 hours and 12,232 hours, respectively.
The airplane flight log included the inbound flight from LAS to EGE, with departure and arrival times of 1940 and 2049, respectively. The log also included discrepancies attributed to the incident flight as: "Flight control failure on takeoff" and "Both main gear tires flat (RH)." Those discrepancies were reported by the incident PIC.
The incident PIC reported that on three separate occasions, the crew had received a configuration warning horn upon selecting the landing gear up after takeoff. The horn subsequently stopped after the wing flaps were raised. The most recent occurrence was on February 3, 2015, at which time the airplane entered maintenance.
A preceding log entry denoted a flight from Van Nuys Airport (VNY) to LAS on February 3, 2015. The flight log included 3 discrepancies reported by the incident PIC, dated February 3, 2015. These included: (1) "Configuration horn activates on takeoff after gear retraction and stays on until flaps are retracted," (2) IRS #2 fault/fail," and (3) "VOR #2 fail (intermittent)."
The airplane was maintained under an approved continuous aircraft maintenance program. The most recent inspection and maintenance activity was completed on February 7, 2015, the day of the incident, prior to departure from LAS. The maintenance work included the replacement of an inertial reference unit and the flight guidance computers. In addition, three switches located in the cockpit pedestal switch bank -- speed brake flap control warning (S11), speed brake takeoff alarm (S12), and speed brake lever autopilot control (S13) -- were replaced. Based on the documentation provided by the operator, the next inspection under the maintenance program was due at 12,586 hours and/or 7,428 cycles.
The EGE Automated Weather Observing System (AWOS), at 2150, recorded conditions as: clear sky, calm wind, 10 miles visibility, temperature 1 degree Celsius, dew point -4 degrees Celsius, altimeter 30.20 inches of mercury.
The incident airplane was equipped with a cockpit voice recorder (CVR). The unit was removed from the airplane and shipped to the National Transportation Safety Board (NTSB) Recorders Lab for download. The recording consisted of four channels of audio information; however, none of the audio was pertinent to the incident investigation. Conversations that were captured were consistent with maintenance personnel working in or near the cockpit, and with the airplane taxiing after the incident.
The airplane was not equipped, nor was it required to be equipped, with a flight data recorder.
TESTS AND RESEARCH
A postincident examination was conducted under the direct supervision of Federal Aviation Administration (FAA) Flight Standards inspectors. The examination was directed and monitored by an NTSB aircraft systems engineering specialist. The examination was conducted on February 10, 11, and 12, 2015, at EGE with the assistance of the airplane manufacturer and the operator.
The airplane configuration was documented before beginning any system evaluations or functional testing. At the time of the initial examination, no electrical circuit breakers were tripped (open/extended), the Flight Power Shutoff Valve (FPSOV) handle was stowed, and the gust lock handle was down (disengaged). The FPSOV unit, located in the right main landing gear wheel well, was observed in the normal/flight position. The elevator pitch trim indicated approximately 9 units Nose UP. The wing flap selector handle was at the zero degree (flaps up) position, and the horizontal stabilizer position corresponded to the flaps up setting.
An inspection of the flight control system was conducted without any electrical or hydraulic power supplied to the airplane. Movement of the cockpit control column and control yoke was smooth throughout the required range of motion (stop-to-stop). Movement of the flight control surfaces corresponded to the inputs from the cockpit controls. With the elevator rig pins installed, the control cable tensions measured 113 lbs. and 160 lbs. at the inboard and outboard cables, respectively. The required minimum cable tension was 135 lbs. [Aircraft Maintenance Manual (AMM) 27-01-00]. The rig pins were subsequently removed in order to allow the system to balance. With the rig pins removed, the control cable tensions measured 129 lbs. and 140 lbs., respectively. The elevator trim cable tensions measured 40 lbs., which was within the specifications (AMM 27-04-00).
An operational test of the gust lock was completed without any anomalies or adverse findings (AMM 27-05-00). A general examination of the elevator gust lock hook was unremarkable. Inspection of the elevator input bungee, input bungee attachment bolt, elevator actuator load relief bungee assembly, and elevator actuator damper shaft (AMM 27-01-00) revealed no anomalies. Indexing of the horizontal stabilizer corresponded correctly at all flap settings in accordance with the Wing Flap/Stabilizer Operational Test (AMM 27-06-01). Operational testing of the stall barrier/angle of attack system and the stall barrier dump valve (AMM 27-01-01) did not reveal any anomalies. The FPSOV operated normally in accordance with the Flight Control Manual Shut-off Valve – Operational Test (AMM 27-08-00).
Electrical power and hydraulic power were subsequently supplied to the airplane. Operational tests of the elevator control system (AMM 27-01-00) and the elevator trim system (AMM 27-04-00) were completed with no anomalies observed. The elevator control surface deflections were measured at 24.3 degrees (left) and 24.9 degrees (right) trailing edge up, and 11.7 degrees (left) and 12.0 degrees (right) trailing edge down. The required deflections were 24.0 +/- 0.5 degrees trailing edge up, and 13.0 +0/-1 degrees trailing edge down (AMM 27-01-00).
The elevator trim deflections were 21.4 degrees (left) and 20.9 degrees (right) trailing edge up, and 7.8 degrees (left) and 7.1 degrees (right) trailing edge down. The required trim deflections were 22.0 +/- 1.0 degrees trailing edge up and 8.0 +/- 1.0 degrees trailing edge down (AMM 27-04-00).
Thrust reverser operational testing (reverser deployment and retraction) was performed and found to be satisfactory. Hydraulic system fluid quantity (AMM 12-01-05) and accumulator pressures (AMM 29-17-00) were inspected and found to be within normal limits. The hydraulic manifold differential pressure bypass indicators were inspected with no anomalies noted (AMM 29-14-00). The brake system electronic control unit (ECU) did not have any faults recorded. Braking system antiskid wiring electrical continuity was confirmed between the brake pedals and the brake system ECU, and between the wheel speed sensors and the brake system ECU. Brake antiskid functional checks were completed and found to be satisfactory (AMM32-45-20).
Additional maintenance action was completed to address the damage at the right main landing gear due to the brake fire.
The Fault Warning and Performance Computers were forwarded to Honeywell Aerospace for download of the non-volatile memory. The left (no. 1) Fault Warning Computer did not have any data available. The right (no. 2) Fault Warning Computer memory included two items. The first was generated by an engine exceedance in October 2014 and was unrelated to the incident flight. The second was takeoff trend data, recorded on February 7, 2015, at 2131 (February 8th/0431 UTC), as the airplane reached 105 knots. The data was provided as follows:
Gross weight: 56,810 lbs.
Autothrottle: Armed/Not Engaged
CAS: 105.4 knots
Press Alt: 6,292 ft
Engine HP: 92.9/91.4
Engine LP: 88.7/87.3
Engine TGT: 674/677
SAT: 2.0 deg C
Wing/Cowl Anti Ice: Off
The performance computer data included normal power up cycles, with no anomalies being logged. The autothrottle (A/T) computer logs did not contain any recorded errors. The most recently recorded A/T operational data included:
AT1 (Left/Captain's side A/T unit)
Engage SW: False (State of the A/T engage switch at the time the data was captured.)
Quick SW: True (State of the quick disconnect switch at the time the data was captured.)
Man Dis: True (Type of A/T disconnect causing that data to be captured.)
Spd Tgt: 134.000
Cur Spd: 67.8979
Alt Tgt: 15000.0
Cur Alt: 6304.25
EPR: 1.75230 / 1.74253
PLA: 31.9919 / 31.3098
The recorded A/T data cannot be directly associated with a specific takeoff event. In addition, if the A/T system is not armed for a particular takeoff, no data will be captured.
On March 3, 2015, an evaluation flight was completed by Gulfstream Aerospace Corporation Production Test Pilots. The evaluation flight was conducted without any adjustments to the flight control system following the rejected takeoff event. A maintenance preflight inspection and ground engine run-up were performed the day before the flight. During the engine run-up, at a takeoff engine pressure ratio (EPR) of 1.75, the left engine low pressure (LP) turbine speed approach the exceedance limit of 95.5-percent, which would intermittently trigger a master warning. The flight crew elected to complete the takeoff with a slightly reduced EPR of 1.73 in order to avoid the possibility of a nuisance warning message on takeoff.
The flight control check conducted before takeoff was normal. Airplane flight manual procedures specify an elevator control check at 60 knots during the takeoff roll. Specifically, the airplane flight manual included a note with the Line Up checklist stating, "At sixty (60) knots, the pilot shall confirm that the elevators are free and the yoke has reached the neutral position." Due to the flight control issues reported as part of the incident, the evaluation flight crew elected to conduct an additional control check at 80 knots. During the takeoff roll, at both 60 and 80 knots, the elevator response was "positive, obvious, and 100% normal." The takeoff continued normally and the flight crew completed a left-hand traffic pattern to return for a full stop landing. The pilot subsequently executed a landing without any anomalies; the brakes and thrust reversers functioned normally during the rollout. No anomalies were identified during the evaluation test flight.
The airplane was subsequently released to the owner/operator for return to service.
The pilot reported that the pretakeoff flight control check was “normal” with “no binding or resistance issues.” During the initial takeoff, the pilot used the autothrottles. Shortly after, a triple chime and master warning indication activated, so he rejected the takeoff. However, the pilot observed no messages on the crew alert system nor any tripped electrical circuit breakers, so he chose to attempt another takeoff. During this takeoff, he did not use the autothrottles. As the airplane accelerated through 75 knots, the triple chime and master warning indication activated again. The engine low-pressure turbine speed was within the yellow arc, so the pilot reduced the engine thrust slightly to return to the normal operating range and continued the takeoff. At rotation speed, he pulled back on the control yoke, but the flight controls did not seem to respond normally. The pilot added that the controls had no “noticeable pressure resistance and felt unloaded with hydraulic pressure.” He noted that the yoke was moved “forward and then back further aft” with the same result. The pilot subsequently rejected the takeoff and applied maximum braking and full reverse thrust. He taxied the airplane off the runway and stopped it on the parallel taxiway.A postincident examination of the airplane, including the flight control system, did not reveal any anomalies that would have compromised the effectiveness of the flight control system. Although minor variations in the inboard elevator control cable tension and elevator control surface deflections were noted, these variations also likely existed during the initial flight of the day; the pilots of that flight reported no discrepancies. After repairing the fire damage to the right main landing gear, the airplane manufacturer had two test pilots conduct an evaluation test flight. The pilots reported that the elevator response during takeoff was “positive, obvious, and 100% normal.” The pilots continued the takeoff and subsequently returned for a full-stop landing. They reported that no anomalies occurred during the evaluation test flight.
The pilot's rejected takeoff due to perceived flight control system anomalies, which led to excessive brake temperatures and resulted in a right main landing gear brake fire.