Accident Investigation Analysis:

Gulfstream GIV - Bedford, MA

ACSF Safety Symposium

8 Mar 2017

Background

• VIP transport from Bedford, MA to Atlantic City, NJ 31 May 2014

– Part 91

– Nighttime, good weather conditions

• Runway overrun and impact with structures/terrain

– 2 Pilots,1 Flight Attendant, and 4 passengers fatally injured

• Investigation Status: NTSB Final Report issued Sep 15 (ERA14MA271)

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History: GIV and Accident Aircraft

• GIV type certificated in 1987

• 526 in service

• Outstanding Safety Record

• 4.2M Flight Hours

• 2.1M Takeoffs/Landings

• N121JM

• Manufactured 2000

• ~4950 Hours

• Normal maintenance history

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Investigation - General

• Luke Schiada – NTSB IIC

• Party Members: FAA, Gulfstream, Rolls Royce, Rockwell Collins,

Honeywell, MA Airport Authority

• Debris field confined to runway extended centerline and perimeter ditch

• ARFF were first responders

• FRD, CVR, QAR recovered and valid data extracted

Loral/Fairchild F1000 FDR L-3/Fairchild FA2100-1020 CVR

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Investigation - Flight Data Monitoring

• FDR - Loral/Fairchild F1000 FDR

– Recorded 41 hours of data (62 parameters)

– Records 64 12-bit words of digital information every second

– Recording initiated with engine oil pressure

• QAR - L-3 Micro QAR

– Recorded 303 hours of data

– 176 takeoff events, including the accident

• Two complete and 16 partial flight control checks

• CVR - L-3/Fairchild FA2100-1020

– 2 hours of digital cockpit audio

– Recording initiated with electrical power

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Gulfstream GIV – Gust Lock System Overview

Gust Lock cable

system

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• Flight Controls

• Mechanical, hydraulically boosted, reversible

• Pedestal Controls

GIV Cockpit Systems

• Gust Lock Engaged

• Flap Handle 10o

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• Gust Lock Design

• Mechanically locks the aileron and rudder in the neutral position

• Mechanically locks the elevator trailing edge down (13°)

• Intended to limit forward throttle movement to 6° (+/- 1°)

GIV Gust Lock System – Center Console

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GIV Gust Lock System – Flight Control Locks

Rudder GL Hook

Spring Bungees

GL Cable Input

Unlock Springs

Elevator GL Hook

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Aircrew Background

• PIC: Age 45, ATP, CSEL, CFII

• Ratings: G-IV, G-1159, BE-400, MU-300, LR-JET

• Experience: 8275 hrs (1400 G-IV)

• G-IV Recurrent: FSI Wilmington (Sep 2013)

• Left seat as PF

• SIC: Age 61, ATP, CSEL, CFII, A&P/IA

• Ratings: G-IV, G-V, G-1159, L-1329

• Experience: 18,530 hrs (2800 G-IV)

• G-IV Recurrent: FSI Savannah (Sep 2013)

• Right seat as PNF

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Investigation Analysis - CVR

Seconds Event Note

00.0 Turn Onto Runway 11

01.1 Pilot: “It says rudder limit light is ON” Unresolved RUDDER LIMIT alert [Vert tail load limit system]

26.6 Pilot: “Couldn’t get (it manually any further)" Plateaued at 1.40

Momentarily achieved EPR 1.62 (Rated 1.70)

31.3 Co-Pilot: “Eighty” EPR 1.53

37.5 Co-Pilot: “V1” EPR 1.53

38.9 Co-Pilot: “Rotate” EPR 1.53

39.9 Pilot: “(Steer) Lock is ON” 1st Reference to Lock being ON

42.7 Pilot: “(Steer) Lock is ON” 2nd Reference to Lock being ON

43.7 Pilot: “(Steer) Lock is ON” 3rd Reference to Lock being ON

44.4 Pilot: “(Steer) Lock is ON” 4th Reference to Lock being ON

45.2 [Sound Similar to Thump and Squeak] Corresponds to Flight Power Shut-off Valve operation

46.6 Pilot: “(Steer) Lock is ON” 5th Reference to Lock being ON

47.5 Pilot: “(Steer) Lock is ON” 6th Reference to Lock being ON

50.0 Brake Pressures start to rise Peak Speed 162 Kt, ~1400’ of runway remaining

52.6 Pilot: “(Steer) Lock is ON” 7th Reference to Lock being ON

54.0 Engine Thrust Reduction Less than 500’ runway remaining (No Ground Spoilers)

54.3 Pilot: “I can’t Stop It”

55.5 Thrust Reverser Deploy

60.0 Exit end of safety area 104 Kt

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Investigation Analysis – FDR/QAR

• Previous 10 takeoffs:

– Manually advanced throttles to achieve Rated EPR then;

– Engaged Auto Throttles

• Accident takeoff:

– Could not manually advance throttles to achieve Rated EPR

– Impeded(~5s) at “plateau” then;

– Engaged Auto Throttles

Pilot: “Couldn’t get (it manually any further)”

60 Knots

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Investigation Analysis

30 (deg) PLA

1.70 EPR

Accident Takeoff Previous 10 Takeoffs

Auto Throttle Engagement

(Example from NTSB FDR Addendum 2)

1.40 EPR

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Gulfstream Flight Manual Procedures

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Gulfstream Flight Manual Procedures

“Elevator Free” Check is clearly delineated in all documentation

and is critical to verify proper elevator movement prior to V1.

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NTSB Probable Cause

• “…flight crewmembers’ failure to perform flight control check before

takeoff, their attempt to takeoff with the gust lock system engaged, and

their delayed execution of a rejected takeoff after they became aware

that the controls were locked.”

• “Contributing…were the flight crew’s habitual noncompliance with

checklists, Gulfstream Aerospace Corporation’s failure to ensure the G-

IV gust lock/throttle interlock system would prevent an attempted takeoff

with the gust lock engaged, and the Federal Aviation Administration’s

failure to detect this inadequacy during the G-IV’s certification.”

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NTSB Final Report Recommendations

• To the FAA:

• To the International Business Aviation Council:

• To the National Business Aviation Association:

A-15-31: “After Gulfstream Aerospace Corporation develops a modification of the G-IV gust

lock/throttle lever interlock, require that the gust lock system on all existing G-IV airplanes be

retrofitted to comply with the certification requirement that the gust lock physically limit the

operation of the airplane so that the pilot receives an unmistakable warning at the start of

takeoff.”

A-15-32: “Develop and issue guidance on the appropriate use and limitations of the review of

engineering drawings in a design review performed as a means of showing compliance with

certification regulations.”

A-15-33: “Amend International Standard for Business Aircraft Operations auditing standards to

include verifying that operators are complying with best practices for checklist execution,

including the use of the challenge-verification-response format whenever possible.”

A-15-34: “Work with existing business aviation flight operational quality assurance groups,

such as Corporate Flight Operational Quality Assurance Centerline Steering Committee, to

analyze existing data for noncompliance with manufacturer-required routine control checks

before takeoff and provide the results of this analysis to your membership as part of your data-

driven safety agenda for business aviation.”

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NBAA Special Project Team

• FOQA service provider data (3yrs, 140,000+ flights)

• Flight control surface deflection analysis

• Caution: not all surfaces got a full sweep

• Warning: no surfaces got a full sweep