# NTSB WPR15LA253: Beech C90, N959MC, Las Vegas, NV, August 28, 2015

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 28, 2015, 10:10 local (17:10 UTC)
- Place: Las Vegas, NV
- Coordinates: 36.099445, -115.162498 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.0994&lon=-115.1625&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Defining events: [Standing-engine(s) not oper: Ground collision](https://openairdocs.org/ntsb-events/200); [Standing-engine(s) not oper: Ground collision](https://openairdocs.org/ntsb-events/200)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report March 23, 2017
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: SC Aviation, Inc., Dassault Aircraft Services, Federal Aviation Administration
- NTSB case key (mKey): 91887
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR15LA253
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91887/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91887
- Page: https://openairdocs.org/ntsb/WPR15LA253

## Probable cause (aircraft 2)

The jet flight crew's use of an inappropriate checklist to resolve a parking brake hydraulic system pressure anomaly, which resulted in the airplane rolling down a slight incline and colliding with a parked twin-engine turboprop airplane. Contributing to the accident was the defective parking brake check valve.

## Probable cause (aircraft 1)

The jet flight crew's use of an inappropriate checklist to resolve a parking brake hydraulic system pressure anomaly, which resulted in the airplane rolling down a slight incline and colliding with the parked twin-engine turboprop airplane. Contributing to the accident was the defective parking brake check valve.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Knowledge: knowledge of procedures](https://openairdocs.org/ntsb-findings/02032010): Personnel issues › Experience/knowledge · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Beech C90, 2 cases](https://openairdocs.org/ntsb-findings/02032010/cases.md?model=1152913), [All aircraft, 41 cases](https://openairdocs.org/ntsb-findings/02032010/cases.md)
- [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Beech C90, 3 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=1152913), [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md)
- [Use of equip/info: use of checklist](https://openairdocs.org/ntsb-findings/02063030): Personnel issues › Task performance · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Beech C90, 2 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md?model=1152913), [All aircraft, 336 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md)
- [Landing gear system: master cylinder/brake valve](https://openairdocs.org/ntsb-findings/01023243): Aircraft › Aircraft systems · Malfunction (probable cause), aircraft 1; cases with it: [Beech C90, 1 case](https://openairdocs.org/ntsb-findings/01023243/cases.md?model=1152913), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01023243/cases.md)
- [Knowledge: knowledge of procedures](https://openairdocs.org/ntsb-findings/02032010): Personnel issues › Experience/knowledge · Pilot (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/02032010/cases.md?model=2730170), [All aircraft, 41 cases](https://openairdocs.org/ntsb-findings/02032010/cases.md)
- [Knowledge: knowledge of procedures](https://openairdocs.org/ntsb-findings/02032010): Personnel issues › Experience/knowledge · Copilot (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/02032010/cases.md?model=2730170), [All aircraft, 41 cases](https://openairdocs.org/ntsb-findings/02032010/cases.md)
- [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Pilot (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=2730170), [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md)
- [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Copilot (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=2730170), [All aircraft, 440 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md)
- [Use of equip/info: use of checklist](https://openairdocs.org/ntsb-findings/02063030): Personnel issues › Task performance · Pilot (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/02063030/cases.md?model=2730170), [All aircraft, 336 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md)
- [Use of equip/info: use of checklist](https://openairdocs.org/ntsb-findings/02063030): Personnel issues › Task performance · Copilot (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/02063030/cases.md?model=2730170), [All aircraft, 336 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md)
- [Landing gear system: master cylinder/brake valve](https://openairdocs.org/ntsb-findings/01023243): Aircraft › Aircraft systems · Malfunction (probable cause), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-findings/01023243/cases.md?model=2730170), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01023243/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Standing-engine(s) not oper: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event), aircraft 1; cases with it: [Beech C90, 2 cases](https://openairdocs.org/ntsb-events/200/sequence.md?model=1152913), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md)
- [Standing-engine(s) not oper: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event), aircraft 2; cases with it: [Dassault FALCON 2000, 1 case](https://openairdocs.org/ntsb-events/200/sequence.md?model=2730170), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md)

## Analysis (aircraft 2)

During the initial preflight checks of the jet before departure, the first officer (FO) observed the BRAKE ACCU light illuminated, which indicated insufficient hydraulic pressure to the parking brake. The FO then referenced the quick reference handbook (QRH) Abnormal Checklist, which noted "Residual pressure normally allows six brake applications to the first detent. No further action required." When the pilot-in-command (PIC) entered the flight deck, the FO advised him of the anomaly and what the QRH Abnormal Checklist stated, which the PIC confirmed. After the ground crewman removed the wheel chocks, the airplane began to roll down a slight incline. Attempts by both flight crewmembers to stop the airplane by applying toes brakes and pulling the emergency brake handle were unsuccessful. The airplane continued to roll down the incline before colliding with a parked twin-engine turboprop airplane, causing substantial damage to the turboprop airplane and minor damage to the jet. The investigation revealed that the jet's flight crew had used the inappropriate checklist for the BRAKE ACCU light anomaly. Rather than using the QRH Abnormal Checklist, the flight crew should have been familiar with, based on their training, and referenced the Normal Operations Pre-Flight Interior Inspection checklist. This checklist specifically states that, if the BRAKE ACCU light is on, the accumulator should be charged using the standby pump or by monitoring engine #2 and the chocks should not be removed until the light is extinguished. The flight crew maintained that they had no recollection during their simulator type-rating training that the QRH Abnormal Checklist was to be used for in-flight anomalies only. However, two simulator instructors employed by the firm that conducted the training for both flight crewmembers stated that all of their instructors are taught to stress that the QRH Abnormal Checklist is to be used only for in-flight anomalies. Had both of the jet's flight crewmembers thoroughly understood the correct checklist to use, the parking brake system, and how to appropriately resolve the BRAKE ACCU light anomaly, this accident would have not occurred. The investigation also revealed that the jet's parking brake check valve was faulty, which was most likely the reason for the illumination of the BRAKE ACCU light. A design improvement to the valve had been developed about 7 years before the accident, which resulted in a new check valve to replace the previously defective check valve. However, the new check valve was never installed on the accident airplane.

## Analysis (aircraft 1)

During the initial preflight checks of the jet before departure, the first officer (FO) observed the BRAKE ACCU light illuminated, which indicated insufficient hydraulic pressure to the parking brake. The FO then referenced the quick reference handbook (QRH) Abnormal Checklist, which noted "Residual pressure normally allows six brake applications to the first detent. No further action required." When the pilot-in-command (PIC) entered the flight deck, the FO advised him of the anomaly and what the QRH Abnormal Checklist stated, which the PIC confirmed. After the ground crewman removed the wheel chocks, the airplane began to roll down a slight incline. Attempts by both flight crewmembers to stop the airplane by applying toes brakes and pulling the emergency brake handle were unsuccessful. The airplane continued to roll down the incline before colliding with a parked twin-engine turboprop airplane, causing substantial damage to the turboprop airplane and minor damage to the jet. The investigation revealed that the jet's flight crew had used the inappropriate checklist for the BRAKE ACCU light anomaly. Rather than using the QRH Abnormal Checklist, the flight crew should have been familiar with, based on their training, and referenced the Normal Operations Pre-Flight Interior Inspection checklist. This checklist specifically states that, if the BRAKE ACCU light is on, the accumulator should be charged using the standby pump or by monitoring engine #2 and the chocks should not be removed until the light is extinguished. The flight crew maintained that they had no recollection during their simulator type-rating training that the QRH Abnormal Checklist was to be used for in-flight anomalies only. However, two simulator instructors employed by the firm that conducted the training for both flight crewmembers stated that all of their instructors are taught to stress that the QRH Abnormal Checklist is to be used only for in-flight anomalies. Had both of the jet's flight crewmembers thoroughly understood the correct checklist to use, the parking brake system, and how to appropriately resolve the BRAKE ACCU light anomaly, this accident would have not occurred. The investigation also revealed that the jet's parking brake check valve was faulty, which was most likely the reason for the illumination of the BRAKE ACCU light. A design improvement to the valve had been developed about 7 years before the accident, which resulted in a new check valve to replace the previously defective check valve. However, the new check valve was never installed on the accident airplane.

## Factual narrative (aircraft 2)

On August 28, 2015, about 1010 Pacific daylight time, a Dassault Falcon 2000, N187AA, and a Beech C90, N959MC, were damaged during a ground collision at McCarran International Airport (LAS), Las Vegas, Nevada. The Falcon 2000 was registered to Anton Air LLC of Henderson, Nevada, and operated by SC Aviation, Inc., of Janesville, Wisconsin. The Beech C90 was registered to and operated by Nebraskaland Tire Inc., of Lexington, Nebraska. The Beech C90 sustained substantial damage, and the Falcon 2000 sustained minor damage. The airline transport pilot, the sole occupant of the Beech C90, and the two airline transport pilots and two passengers aboard the Falcon 2000 were not injured. Visual meteorological conditions prevailed for the proposed cross-country flights, both of which were to be operated under the provisions of Title 14 Code of Federal Regulations Part 91. IFR flight plans had been field for both flights, with Wheeling, Illinois, as the planned destination for the Falcon 2000, and Lexington, Nebraska, the Beech C90's destination.In a statement submitted to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot of N959MC, reported that after completing his preflight checklists in preparation for a proposed cross-country flight, the Falcon 2000, N187AA, caught his eye as it started to move. The pilot assumed that the pilots had started the engines and were beginning to taxi out of the ramp, but as they started to move, instead of turning into the designated turning lane, they continued mostly straight ahead. The pilot further reported that as the Falcon continued to roll ahead its right wing passed under the left wing of a Falcon 20, lifting it up about a foot or so. The Falcon 2000 then continued to roll forward toward the C90, subsequently colliding into its left wing, outboard of the engine. The pilot stated that the collision moved the C90 backward about 20 feet, and spun the airplane left about 70 to 80 degrees, which resulted in the ground power unit becoming lodged under the tail section of the airplane. In a statement submitted to the NTSB IIC, the pilot-in-command (PIC) of the Falcon 2000, N187AA, reported that in preparation for the cross-country flight, the first officer (FO) had completed the checklist procedures up to the Before Start Checklist. The PIC further reported that the SIC had previously noted the airplane's BRAKE ACCU light was illuminated, and stated that he had referenced the [Abnormal] Checklist, which noted "The system allows six brake applications to the first detent. No further action required." The PIC acknowledged what the SIC had said, then initiated the Before Start Checklist. The PIC reported that he then set the parking brake, looked out of the left side screen and observed the lineman standing next to the aircraft, at which time he signaled for chock removal. The PIC stated that as he continued the Before Start flow and was reaching down for the Fuel Eng[ine] switches onthe center pedestal, the FO said, "We're rolling." The PIC opined that he immediately pressed the toe brakes and [received] no brake response, after which he pulled the emergency brake handle, but again received no response. The PIC stated that the airplane was now without steering or brakes, as it was rolling across the aisle (ramp) in an easterly direction. "The airplane veered slightly left, and our right wing clipped the left wing of a Falcon 20 parked ahead of us." The PIC concluded that the airplane continued rolling in an eastbound direction across a second aisle and collided with a King Air C90, which was parked ahead and to their left, and facing in the opposite direction. In a statement submitted to the NTSB IIC, the FO of N187AA, reported that in preparation for the cross-country flight he had completed the checklist procedures up to the Before Start checklist, and that he had previously noted that the BRAKE ACCU light was illuminated and referenced the [Abnormal] Checklist for the BRAKE ACCU light. The FO stated that he informed the PIC of the light, and that the checklist read, "Residual pressure normally allows six brake applications to the first detent. No further action required," to which the PIC acknowledged. The FO further stated that as they initiated the Before Start checklist the PIC set the parking brake, and as he continued to read the Before Start checklist he noticed the airplane begin to roll. When he advised the PIC that the airplane was rolling, the PIC immediately pressed the toe brakes, however, there was no braking response. The PIC then pulled the emergency brake handle, but there was still no response to braking. The FO opined that he also applied his toe brakes, but with no response. He then asked the PIC if he had any steering, to which the Captain replied, "I've got nothing." The FO stated that at this point the airplane had rolled across the ramp and their right wing clipped the left wing of a Falcon 20 that was parked ahead of them. The airplane then veered slightly left before colliding with the C90, which was parked ahead and to their left, and facing in the opposite direction. During the investigation the operator of the Falcon 2000, SC Aviation, submitted to the NTSB IIC two checklists, one of which was the Simuflite "for training purposes only" checklist, while the other was the manufacturer's checklist, both of which were in the airplane at the time of the accident. Both checklists were identical, and labeled, "F2000, QRH2, ABNORMAL – 11." With respect to a BRAKE ACCU – PARK BRAKE SYSTEM anomaly, i.e., the BRAKE ACCU light being illuminated on the cockpit annunciator panel, the information provided in the checklist states that for such an anomaly, "Residual pressure will normally allow at least six brake applications to first detent after MASTER + GONG with BRAKE ACCU lighting. No further pilot action required." This checklist was consistent with the checklist the flight crew referred to when theanomaly with the BRAKE ACCU light presented itself. With respect to the Dassault Aviation Falcon 2000 NORMAL OPERATIONS PRE-FLIGHT, INTERIOR INSPECTION, CODDE 2, DGT125663, the checklist denotes the following for the check of the parking brake handle: • Set PARK BRAKE to 1st detent prior to removing chocks. Check its operation by: • BAT………………………………………………………………............................... On • BRAKE PRESS light………………………………………………………………… On - Checked • BRAKE ACCU light…………………………………………………………………. Out - Checked If BRAKE ACCU light on: • Charge the accumulator using ST-BY PUMP or by motoring Engine 2. • Do not remove chocks until BRAKE ACCU light is extinguished. With respect to the Dassault Aviation Falcon 2000 NORMAL OPERATIONS, PREFLIGHT, BEFORE START; START checklist, CODDE 2, DGT125663, the BEFORE START DO-LIST calls for the pilot flying (PF) to perform the following: PARK BRAKE…………………………...1st detent Chocks……………………………………Removed Additionally, the checklist stipulates that if the BRAKE ACCU light is on, for the crew to: • Chock airplane • Charge the accumulator using the ST-BY PUMP or by motoring Engine 2. • Do not remove the chocks until BRAKE ACCU light is extinguished. During the investigation the Director of Operations (DO) for SC Aviation, the operator of N187AA, stated in a letter to the IIC, that based on information the IIC had previously provided him, he understood that use of the Abnormal QRH was not an appropriate reference for a ground-based anomaly. The DO further stated, "Considering the actions of both crewmembers during the accident, it appears that they may have been unaware of the consequences relative to removing the chocks with the BRAKE ACCU light illuminated. Our internal investigation revealed that neither crewmember had a recollection of any reference during training that the Abnormal QRH Checklist was to be used as an 'in-flight only' checklist. In fact, following the accident, the crew reviewed their training notes, and did not find any reference that the Abnormal QRH Checklist is to be used in-flight only. Nevertheless, after discussing the accident with the CAE Simuflite instructors, it has been confirmed that the Abnormal QRH Checklist is intended for in-flight use only. Both pilots reported the lack of any recollection from their Initial Aircraft Type-rating training that it was an error to reference the Abnormal QRH Checklist to resolve a BRAKE ACCU light anomaly. Furthermore, it should be noted that the pilots attended separate Initial Type-rating courses, and neither pilot reported having any notes or recollection of an emphasis area warning them that the Abnormal QRH Checklist is intended for in-flight use only." In an interview conducted by the NTSB IIC with a Lead Instructor for CAE Simuflite, Dallas, Texas, the instructor, whose name was provided by SC Aviation, reported that he had 18 years of experience as a simulator instructor, of which about 7 years was as an instructor on the Dassault Falcon 2000airplane. The instructor stated that during initial and recurrent training, all CAE instructors instruct all Falcon students that the Falcon 2000 Abnormal QRH Checklist is to be used for in-flight anomalies only, and not for ground-based anomalies. The instructor also confirmed that if the BRAKE ACCU light is illuminated on the ground, that the wheel chocks are not to be removed until the BRAKE ACCU light is extinguished, which is noted in the Normal Operations Preflight – Interior checklist, and reiterated in the Normal Operations Before Start – Start checklist, each of which is part of the instructional curriculum for the Falcon 2000 airplane. In an interview conducted by the NTSB IIC with a second CAE Simuflite instructor, also assigned to the Dallas, Texas training facility, and whose name was also provided by SC Aviation, the instructor stated that he had been employed by CAE Simuflite for 15 years as a simulator instructor, 12 of which had been as a Falcon 2000 instructor and check airman. Additionally, the instructor stated that he had more than 4,500 hours of pilot-in-command time in the Falcon 2000, which he currently flies. When queried by the IIC about when the Falcon 2000 Abnormal QRH Checklist should be used, the instructor stated that it is to only be used for in-flight anomalies, which is stressed during training with all pilots. He also opined that while BRAKE ACCU light anomaly cannot be replicated in the simulator, this anomaly is discussed in detail during both ground and flight simulator training. He further stated that if the BRAKE ACCU light is on before starting engines, the Normal Checklist, both in the PRE-FLIGHT phase and the BEFORE START phase, instructs the flight crew not to remove the chocks. He also related that both checklist instructs the crew to charge the parking brake accumulator by using the standby pump or motoring the #2 engine. Further, when asked by the IIC if he had any knowledge of any previous events where a Falcon 2000 had started rolling when the flight crew used the Abnormal QRH Checklist to resolve a similar BRAKE ACCU light anomaly, he said he could not recall anything like this happening previously. During the investigation, and under the supervision of a Federal Aviation Administration aviation safety inspector, the airplane's parking brake check valve, Part Number L95H07-202, serial number 20667, was examined for functionality. The inspector reported that during the bench flow test, the check valve failed, as it was observed to be leaking. It was further revealed during the investigation, that Falcon Service Advisory (FSA) 32-40-032-R01-A, dated November 19, 2009, was issued for Park Brake Check Valve P/N L95H07-202, as there had been previous failures with the check valve; the purpose of the check valve is to sustain hydraulic pressure to keep the park brake energized. The FSA noted that a design improvement had been developed to improve the reliability of the unit, by introducing a new sealmaterial, along with revised tolerances to assure proper seal retention. The new park brake check valve, P/N L95H07-204, which incorporated the new improvement, was available for Falcon 2000 operators at the time the FSA was published in 2009, about 7 years prior to the accident. There was no record that the improved check valve had ever been installed on the accident Falcon 2000, N187AA. In an incident that was reported to the NTSB IIC by Dassault Aviation, on August 11, 2014, at the Calgary Airport, Alberta, Canada, the flight crew of a Falcon 2000LX, serial number 129, experienced a parking brake failure after shutdown with the park brake set to the first detent. After the passengers had deplaned, the airplane began moving backward. At this time the pilot pulled the park brake to the second detent, which did not stop the airplane. The pilot then turned on the batteries and standby pump, after which he applied the brakes and successfully stopped the airplane 10 meters from a Boeing 737. Maintenance personnel subsequently found that park brake check valve P/N L95H07-202 was faulty, and replaced it with park brake P/N L95H07-202.

## Factual narrative (aircraft 1)

On August 28, 2015, about 1010 Pacific daylight time, a Dassault Falcon 2000, N187AA, and a Beech C90, N959MC, were damaged during a ground collision at McCarran International Airport (LAS), Las Vegas, Nevada. The Falcon 2000 was registered to Anton Air LLC of Henderson, Nevada, and operated by SC Aviation, Inc. of Janesville, Wisconsin. The Beech C90 was registered to and operated by Nebraskaland Tire Inc. of Lexington, Nebraska. The Beech C90 sustained substantial damage, and the Falcon 2000 sustained minor damage. The airline transport pilot, the sole occupant of the Beech C90, and the two airline transport pilots and two passengers aboard the Falcon 2000 were not injured. Visual meteorological conditions prevailed for the proposed cross-country flights, both of which were to be operated under the provisions of Title 14 Code of Federal Regulations Part 91. Instrument Flight Rules (IFR) flight plans had been field for both flights, with Wheeling, Illinois, as the planned destination for the Falcon 2000, and Lexington, Nebraska, the Beech C90's destination.In a statement submitted to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot of C90, reported that after completing his preflight checklists in preparation for a proposed cross-country flight, the Falcon 2000 caught his eye as it started to move. The pilot assumed that the pilots had started the engines, and were beginning to taxi out of the ramp; but as they started to move, instead of turning into the designated turning lane, they continued mostly straight ahead. The pilot further reported that as the Falcon continued to roll ahead its right wing passed under the left wing of a Falcon 20, lifting it up about a foot or so. The Falcon 2000 then continued to roll forward toward the C90, subsequently colliding into its left wing, outboard of the engine. The pilot stated that the collision moved the C90 backward about 20 feet, and spun the airplane left about 70 to 80 degrees, which resulted in the ground power unit becoming lodged under the tail section of the airplane. In a statement submitted to the NTSB IIC, the pilot-in-command (PIC) of the Falcon 2000, N187AA, reported that in preparation for the cross-country flight, the first officer (FO) had completed the checklist procedures up to the Before Start Checklist. The PIC further reported that the SIC had previously noted the airplane's BRAKE ACCU light was illuminated, and stated that he had referenced the [Abnormal] Checklist, which noted "The system allows six brake applications to the first detent. No further action required." The PIC acknowledged what the SIC had said, then initiated the Before Start Checklist. The PIC reported that he then set the parking brake, looked out of the left side screen and observed the lineman standing next to the aircraft, at which time he signaled for chock removal. The PIC stated that as he continued the Before Start flow and was reaching down for the Fuel Eng[ine]switches on the center pedestal, the FO said, "We're rolling." The PIC opined that he immediately pressed the toe brakes, and [received] no brake response, after which he pulled the emergency brake handle, but again received no response. The PIC stated that the airplane was now without steering or brakes, as it was rolling across the aisle (ramp) in an easterly direction. "The airplane veered slightly left, and our right wing clipped the left wing of a Falcon 20 parked ahead of us." The PIC concluded that the airplane continued rolling in an eastbound direction across a second aisle and collided with a King Air C90, which was parked ahead and to their left, and facing in the opposite direction. In a statement submitted to the NTSB IIC, the FO of the Falcon reported that in preparation for the cross-country flight he had completed the checklist procedures up to the Before Start checklist, and that he had previously noted that the BRAKE ACCU light was illuminated, and referenced the [Abnormal] Checklist for the BRAKE ACCU light. The FO stated that he informed the PIC of the light, and that the checklist read, "Residual pressure normally allows six brake applications to the first detent. No further action required," to which the PIC acknowledged. The FO further stated that as they initiated the Before Start checklist the PIC set the parking brake, and as he continued to read the Before Start checklist he noticed the airplane begin to roll. When he advised the PIC that the airplane was rolling, the PIC immediately pressed the toe brakes, however, there was no braking response. The PIC then pulled the emergency brake handle, but there was still no response to braking. The FO opined that he also applied his toe brakes, but with no response. He then asked the PIC if he had any steering, to which the Captain replied, "I've got nothing." The FO stated that at this point the airplane had rolled across the ramp, and their right wing clipped the left wing of a Falcon 20 that was parked ahead of them. The airplane then veered slightly left before colliding with the C90, which was parked ahead and to their left, and facing in the opposite direction. During the investigation the operator of the Falcon 2000, SC Aviation, submitted to the NTSB IIC two checklists, one of which was the Simuflite "for training purposes only" checklist, while the other was the manufacturer's checklist, both of which were in the airplane at the time of the accident. Both checklists were identical, and labeled, "F2000, QRH2, ABNORMAL – 11." With respect to a BRAKE ACCU – PARK BRAKE SYSTEM anomaly, that is, the BRAKE ACCU light being illuminated on the cockpit annunciator panel, the information provided in the checklist states that for such an anomaly, "Residual pressure will normally allow at least six brake applications to first detent after MASTER + GONG with BRAKE ACCU lighting. No further pilot action required." This checklist was consistent with the checklist the flight crewreferred to when the anomaly with the BRAKE ACCU light presented itself. With respect to the Dassault Aviation Falcon 2000 NORMAL OPERATIONS PRE-FLIGHT, INTERIOR INSPECTION, CODDE 2, DGT125663, the checklist denotes the following for the check of the parking brake handle: • Set PARK BRAKE to 1st detent prior to removing chocks. Check its operation by: • BAT…………………………………………………………………………………....On • BRAKE PRESS light………………………………………………………………… On - Checked • BRAKE ACCU light…………………………………………………………………. Out - Checked If BRAKE ACCU light on: • Charge the accumulator using ST-BY PUMP or by motoring Engine 2. • Do not remove chocks until BRAKE ACCU light is extinguished. With respect to the Dassault Aviation Falcon 2000 NORMAL OPERATIONS, PREFLIGHT, BEFORE START; START checklist, CODDE 2, DGT125663, the BEFORE START DO-LIST calls for the pilot flying (PF) to perform the following: PARK BRAKE…………………………... 1st detent Chocks…………………………………… Removed Additionally, the checklist stipulates that if the BRAKE ACCU light is on, for the crew to: • Chock airplane • Charge the accumulator using the ST-BY PUMP or by motoring Engine 2. • Do not remove the chocks until BRAKE ACCU light is extinguished. During the investigation, the Director of Operations (DO) for SC Aviation, the operator of N187AA, stated in a letter to the IIC, that based on information the IIC had previously provided him, he understood that use of the Abnormal QRH was not an appropriate reference for a ground-based anomaly. The DO further stated, "Considering the actions of both crewmembers during the accident, it appears that they may have been unaware of the consequences relative to removing the chocks with the BRAKE ACCU light illuminated. Our internal investigation revealed that neither crewmember had a recollection of any reference during training that the Abnormal QRH Checklist was to be used as an 'in-flight only' checklist. In fact, following the accident, the crew reviewed their training notes, and did not find any reference that the Abnormal QRH Checklist is to be used in-flight only. Nevertheless, after discussing the accident with the CAE Simuflite instructors, it has been confirmed that the Abnormal QRH Checklist is intended for in-flight use only. Both pilots reported the lack of any recollection from their Initial Aircraft Type-rating training that it was an error to reference the Abnormal QRH Checklist to resolve a BRAKE ACCU light anomaly. Furthermore, it should be noted that the pilots attended separate Initial Type-rating courses, and neither pilot reported having any notes or recollection of an emphasis area warning them that the Abnormal QRH Checklist is intended for in-flight use only." In an interview conducted by the NTSB IIC with a Lead Instructor for CAE Simuflite, Dallas, Texas, the instructor, whose name was provided by SC Aviation, reported that he had 18 years of experience as a simulator instructor, of which about 7 years was as an instructor on the Dassault Falcon 2000airplane. The instructor stated that during initial and recurrent training, all CAE instructors instruct all Falcon students that the Falcon 2000 Abnormal QRH Checklist is to be used for in-flight anomalies only, and not for ground-based anomalies. The instructor also confirmed that if the BRAKE ACCU light is illuminated on the ground, that the wheel chocks are not to be removed until the BRAKE ACCU light is extinguished, which is noted in the Normal Operations Preflight – Interior checklist, and reiterated in the Normal Operations Before Start – Start checklist, each of which is part of the instructional curriculum for the Falcon 2000 airplane. In an interview conducted by the NTSB IIC with a second CAE Simuflite instructor, also assigned to the Dallas, Texas, training facility, and whose name was also provided by SC Aviation, the instructor stated that he had been employed by CAE Simuflite for 15 years as a simulator instructor, 12 of which had been as a Falcon 2000 instructor and check airman. Additionally, the instructor stated that he had more than 4,500 hours of pilot-in-command time in the Falcon 2000, which he currently flies. When queried by the IIC about when the Falcon 2000 Abnormal QRH Checklist should be used, the instructor stated that it is to only be used for in-flight anomalies, which is stressed during training with all pilots. He also opined that while BRAKE ACCU light anomaly cannot be replicated in the simulator, this anomaly is discussed in detail during both ground and flight simulator training. He further stated that if the BRAKE ACCU light is on before starting engines, the Normal Checklist, both in the PRE-FLIGHT phase and the BEFORE START phase, instructs the flight crew not to remove the chocks. He also related that both checklists instruct the crew to charge the parking brake accumulator by using the standby pump or motoring the #2 engine. Further, when asked by the IIC if he had any knowledge of any previous events where a Falcon 2000 had started rolling when the flight crew used the Abnormal QRH Checklist to resolve a similar BRAKE ACCU light anomaly, he said he could not recall anything like this happening previously. During the investigation, and under the supervision of a Federal Aviation Administration aviation safety inspector, the airplane's parking brake check valve, Part Number L95H07-202, serial number 20667, was examined for functionality. The inspector reported that during the bench flow test, the check valve failed, as it was observed to be leaking. It was further revealed during the investigation, that Falcon Service Advisory (FSA) 32-40-032-R01-A, dated November 19, 2009, was issued for Park Brake Check Valve P/N L95H07-202, as there had been previous failures with the check valve; the purpose of the check valve is to sustain hydraulic pressure to keep the parking brake energized. The FSA noted that a design improvement had been developed to improve the reliability of the unit, by introducing a newseal material, along with revised tolerances to assure proper seal retention. The new parking brake check valve, P/N L95H07-204, which incorporated the new improvement, was available for Falcon 2000 operators at the time the FSA was published in 2009, about 7 years prior to the accident. There was no record that the improved check valve had ever been installed on the accident Falcon 2000, N187AA. In an incident that was reported to the NTSB IIC by Dassault Aviation, on August 11, 2014, at the Calgary Airport, Alberta, Canada, the flight crew of a Falcon 2000LX, serial number 129, experienced a parking brake failure after shutdown with the parking brake set to the first detent. After the passengers had deplaned, the airplane began moving backward. At this time the pilot pulled the park brake to the second detent, which did not stop the airplane. The pilot then turned on the batteries and standby pump, after which he applied the brakes and successfully stopped the airplane 10 meters from a Boeing 737. Maintenance personnel subsequently found that park brake check valve P/N L95H07-202 was faulty, and replaced it with park brake P/N L95H07-202.

## Aircraft 1

- Registration: [N959MC](https://openairdocs.org/deregistered/N959MC-2015-12-10), registration cancelled 2015-12-10, S/N LJ-821, built 1979 (OpenAirDocs)
- Reported make and model: BEECH C90
- Registry model: [Beech C90](https://openairdocs.org/model/beech-c90) (registry code 1152913) (OpenAirDocs)
- Registry engine: [Pratt & Whitney Canada PT6A-60A](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-60a) (registry code 52043, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: LJ-821
- Year built: 1979
- Airframe hours: 13087
- Engines: Pratt & Whitney PTA-135A 750 horsepower turbo prop; Pratt & Whitney PT6A-135A 750 horsepower turbo prop
- Damage: Substantial damage
- Flight: Business, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Condition, August 21, 2015
- Departed: LAS, Las Vegas, NV
- Destination: LXN, Lexington, NE
- Flight plan: IFR
- Airport: LAS, McCarran International
- Equipment: Onboard weather, Stall warning system, Auto-pilot, Electronic flight bag or handheld device, Electronic multifunction display

## Aircraft 2

- Registration: [N187AA](https://openairdocs.org/aircraft/N187AA), registered now, S/N 156, built 2001 (OpenAirDocs)
- Reported make and model: DASSAULT FALCON2000
- Registry model: [Dassault FALCON 2000](https://openairdocs.org/model/dassault-falcon-2000) (registry code 2730170) (OpenAirDocs)
- Registry engine: [Alliedsign CFE-738 series](https://openairdocs.org/engine/alliedsign-cfe-738-series) (registry code 02500, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 156
- Year built: 2001
- Airframe hours: 6641.2
- Engines: Honeywell CFE-738-1-1B 5600 lbs thrust turbo jet; Honeywell CFE-738-1-1B 5600 lbs thrust turbo jet
- Damage: Minor damage
- Flight: Business, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, June 17, 2015
- Departed: LAS, Las Vegas, NV
- Destination: PWK, Chicago, IL
- Flight plan: IFR
- Airport: LAS, McCarran International
- Equipment: Angle of attack indicator, ADS-B, Stall warning system, Electronic primary flight display, Electronic multifunction display, Electronic flight bag or handheld device, Data recorder, Auto-pilot

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot, aircraft N959MC; age 52; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review January 21, 2015; seat: left; restraint: 3-point; flight hours: 6,362 total, 1,794 in this make and model, 5,317 as pilot in command, 42 in the last 90 days, 8 in the last 30 days
- Pilot, aircraft N187AA; age 54; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review May 15, 2015; seat: left; restraint: 5-point; flight hours: 7,802 total, 133 in this make and model, 7,277 as pilot in command, 108 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours
- Co-pilot, aircraft N187AA; age 31; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review January 31, 2015; seat: right; restraint: 5-point; flight hours: 2,737 total, 188 in this make and model, 1,870 as pilot in command, 65 in the last 90 days, 28 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 3 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 93 °F, dew point 52 °F
- Altimeter: 29.97 inHg
- Observed at: LAS

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20150828019291A](https://openairdocs.org/incident/20150828019291A), Aug 28, 2015: Falcon 2000, Las Vegas, NV, Substantial damage. On August 28, 2015, at approximately 1028 PDT, while parked on the signature flight support ramp at the Las Vegas mccarren airport (las) the flight crew of a…

## Docket (14 files)

The files NTSB released with the investigation on January 24, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91887.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (N959MC) (item 1, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448601&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20(N959MC)-Master.PDF
- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (N187AA) (item 2, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448602&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20(N187AA)-Master.PDF
- Record of Interview - CAE Simuflite Falcon 2000 Simulator Instructors (item 3, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448603&FileExtension=.PDF&FileName=Record%20of%20Interview%20-%20CAE%20Simuflite%20Falcon%202000%20Simulator%20Instructors-Master.PDF
- Falcon 2000 Captain's Statement - Helmeid (item 4, .PDF, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448604&FileExtension=.PDF&FileName=Falcon%202000%20Captain%27s%20Statement%20-%20Helmeid-Master.PDF
- Falcon 2000 First Officer's Statement - Quade (item 5, .PDF, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448605&FileExtension=.PDF&FileName=Falcon%202000%20First%20Officer%27s%20Statement%20-%20Quade-Master.PDF
- Excerpts from Pilot Training Records (Falcon PIC and FO) (item 6, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448606&FileExtension=.PDF&FileName=Excerpts%20from%20Pilot%20Training%20Records%20(Falcon%20PIC%20and%20FO)-Master.PDF
- Dassault Event Report #4699 (item 7, .PDF, 153 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448607&FileExtension=.PDF&FileName=Dassault%20Event%20Report%20%234699-Master.PDF
- Falcon Service Advisory Letter FSA-32-40-032-R01-A (item 8, .PDF, 310 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448608&FileExtension=.PDF&FileName=Falcon%20Service%20Advisory%20Letter%20FSA-32-40-032-R01-A-Master.PDF
- Review of Falcon 2000 Normal and Abnormal Checklists (item 9, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448609&FileExtension=.PDF&FileName=Review%20of%20Falcon%202000%20Normal%20and%20Abnormal%20Checklists-Master.PDF
- Submission - SC Aviation (item 10, .PDF, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448610&FileExtension=.PDF&FileName=Submission%20-%20SC%20Aviation-Master.PDF
- Statement of Party Representatives to NTSB Investigation (item 11, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448611&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF
- Release of Aircraft Wreckage, NTSB Form 6120.15 (N959MC) (item 12, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448612&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15%20(N959MC)-Master.PDF
- Release of Aircraft Wreckage, NTSB Form 6120.15 (N187AA) (item 13, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448613&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15%20(N187AA)-Master.PDF
- Evidence Control Form (item 14, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448614&FileExtension=.PDF&FileName=Evidence%20Control%20Form-Master.PDF

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.

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