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E-8 Structural Health: Integrity - Service - Excellence

The document discusses the structural health and maintenance challenges of the aging E-8C JSTARS fleet. It notes the aircraft have an average age of 47 years and were previously used commercially, resulting in a lack of maintenance records. Systemic issues include incomplete inspections, corrosion findings, and inconsistent planning. Recent actions have involved improving data access and collection while developing a new MSG-3 maintenance plan to address concerns and ensure structural integrity through 2030.

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puhumight
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58 views

E-8 Structural Health: Integrity - Service - Excellence

The document discusses the structural health and maintenance challenges of the aging E-8C JSTARS fleet. It notes the aircraft have an average age of 47 years and were previously used commercially, resulting in a lack of maintenance records. Systemic issues include incomplete inspections, corrosion findings, and inconsistent planning. Recent actions have involved improving data access and collection while developing a new MSG-3 maintenance plan to address concerns and ensure structural integrity through 2030.

Uploaded by

puhumight
Copyright
© © All Rights Reserved
Available Formats
Download as PDF, TXT or read online on Scribd
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Integrity - Service - Excellence

E-8 Structural Health

Jessie Martin, E-8 ASIP Manager


Alton “Donald” Bell, E-8 Structural Lead
John Dorminey, E-8 Chief Engineer
1
Agenda

• History
• Service Life
• FAA vs Government Type Certification
• SPO Challenges
• Systemic Issues
– Inspections/Tracking
– Corrosion
• Maintenance Findings
• Maintenance Planning

Integrity - Service - Excellence 2


Aircraft History
JSTARS aircraft are NOT “new’ airplanes Multiple owners before the USAF purchased them

 Average JSTARS airframe age: 47 years


 Highest flight hour fleet in the USAF> 58K hrs
Integrity - Service - Excellence
Example: AC 94-0284 History

First Flight conducted on Friday, 9 Dec 1966


Delivered to Robins AFB on 13 Aug 1999
Hours Upon Delivery: 59,473
Qantas Airlines of Australia accepted delivery of this aircraft on 28 January 1967. It remained in service with
Qantas until July 1978, when ITEL International purchased and immediately began leasing it to a number of air
carriers through BMI British Midland Airways over the following three years. Those companies were: Kuwait
Airlines from May to June, 1978; Pakistani International Airlines from July 1978 to January to 1979; Air Algerie
from June to October 1979; Gulf Air from November 1979 to March 1980; and finally Linhas Aereas de
Mocambique from October 1980 to April 1981. GATX Financial Corp., a financier and leaser of aircraft, had
purchased the plane in December of 1980. Ariana Afghan Airlines leased the aircraft for a short period in May of
1981. Afterwards BMI operated it until November 1984 when it was parked and began trading owners four more
times up through 1986. The aircraft would not be operated again until BAX Global, an international freight
shipping company purchased in January 1986. BAX later leased it to Southern Air Transport who operated it
until October 1991 when it was leased again by Buffalo Air. On in June of 1994 Grumman Melbourne Systems
Division purchased the plane for the U.S. Air Force for future conversion and use as an E8-C “Joint-STARS”
aircraft. Northrop Grumman completed the conversion in June of 1996. 94-0284 was delivered to Robins AFB on
13 August 1999.

16 different owners before it became a JSTARS


Integrity - Service - Excellence
707 Service Life Concerns

• 1973: Boeing conducts commercial 707 teardown


inspection
– Lower wing stringer significant cracking
– SB 3226 and 3395 Resulted

• Many Widespread Fatigue Damage (WFD) cases


– Military and commercial aircraft
• Aloha Boeing 737
• KC-135 wing
• C-5A wing
• Commercial 707 fleet

Integrity - Service - Excellence 5


E-8 Service Life Concerns
Joint STARS Teardown Inspection
• 5 Aug 93: Dr. Lincoln published “Comments on Structural
Integrity of the Boeing 707 Aircraft”

• Apr 95 – Jun 96: Lower Wing teardown inspection found


significant cracking

• Sep 96: Dr. Lincoln determined probabilistic loss of


failsafe risk
– Wing repairs recommended
– E-8 Wing Structural Integrity Program initiated

Integrity - Service - Excellence 6


FAA Rulemaking and 707
Service Life
• August 1988: Airworthiness Assurance Task
Force (AATF) created for aging aircraft issues
– Developed 6 aging aircraft initiatives including Program to
preclude Widespread Fatigue Damage (WFD)
• April 2006: FAA proposed establishing transport
aircraft operational limits to preclude WFD
• Sept 2006: Boeing alternate WFD regulatory
proposal
– Boeing recommended the use of an “LOV”
– 40,000 flight cycles Boeing’s 707 LOV estimate
• Nov 2010: FAA publishes “Aging Aircraft
Program: Widespread Fatigue Damage; Final
Rule”
– 20,000 flight cycles defined Limit of Validity (LOV)
Integrity - Service - Excellence 7
FAA vs Government Type
Certification
• Commercial MX not conducive for military ops
– Aircraft usage and environment different

• Current MX plan challenging as fleet ages


– FAA reliance for structural health issues
– Joint STARS 707 fleet hour/cycle leader

• Program Office transitioned MX posture to Air


Force Airworthiness Military Type Certificate
– Puts the OSS&E responsibility on the Program
Office as it should be

Integrity - Service - Excellence 8


Air Force Challenges
• Engineering data lacking
– Drawing Access
• No JEDMICS drawings
• Atypical drawing format

– No Authority on Drawings
• ECO of 707 drawings not viable
• High cost to modernize 1960’s era drawings

– Missing Loads/Stress/Fatigue Documents

– Limited organic Analytical Tools/Models

Integrity - Service - Excellence 9


Air Force Challenges
• Historical data missing
– Prior commercial use; multiple owners
– 707 to E-8 conversion
– Early E-8 PDM maintenance data

• Maintenance data collection


– Operator Maintenance data (IMDS)
– Contractor PDM database
– WUCs not mandatory until recently
– Limited SPO PDM data access - TSSR

Integrity - Service - Excellence 10


Maintenance Planning History
• 707 Maintenance Planning Document (MPD)
– Commercial operators tailored according to individual
needs
– C-checks segmented aircraft into quarters

• 1994: Airworthiness Assurance Working Group


further developed Supplemental Structural
Inspection Documents

• 2014: E-8C C-check interval changed from 18 to


24 months

Integrity - Service - Excellence 11


Maintenance Planning Results
• C-checks inspect/repair a/c subset
• C-1 inspected area not revisited for ~11 years
• SSIDs, SBs, ADs, Repair Inspection Intervals
added over time
– C-checks now partial PDMs
– Average C-check length is >400 days

Integrity - Service - Excellence 12


ASIP Systemic Issues
• No Gov SSID/SB/AD control
– Boeing risk assessment involvement necessary
– Program Office Boeing rep greatly aids evaluation

• Individual Aircraft Tracking Program at a/c level


– Does not account for WSIP in the 2000s
– Pylon overhaul in work
• Require pylon serialization
• IATP unable to track serial numbers

• IATP Control Points not E-8 specific


– Uses similar MDSs

Integrity - Service - Excellence 13


CPCP Systemic Issues
• Increased corrosion findings
– Fastener CAD plating degraded
– No surface sealant at 707 production

• Inconsistent paint

• No visual inspection cleaning cards

• Focused Inspections; not zonal scope

• Lavatory Issues
– Plugged weep holes – hidden problems
– Blue water tanks overfilled
– Incomplete O-level maintenance procedures
Integrity - Service - Excellence 14
Engine Pylons

15 Integrity - Service - Excellence


Stringer 28R & 29R
(Blue Water Induced Corrosion)

Integrity - Service - Excellence


Lower Aft S30L
(Blue Water Induced Corrosion)

Integrity - Service - Excellence


Keel Beam Corrosion

Integrity - Service - Excellence 18


SPO Recent Actions
• Boeing & NGC engineering in Program Office
– Quickly support technical data requests

• Gov engineering & configuration data access

• Increased Gov PDM data oversight

• Improved PDM data collection

Integrity - Service - Excellence 19


Maintenance Planning Way
Ahead
• E-8 MSG-3 Mx plan being developed

• 6-year PDM cycle


– Full aircraft every 6-years
– Major and Minor ISO’s between PDMs

• Additional Integrity Programs


– MECSIP, AVIP, PSIP, CPCP

• Engineering Requirements Review/Logistics


Requirements Determination Process
(ERR/LRDP); Systems Engineering Mx approach
Integrity - Service - Excellence 20
2030 Roadmap
• Safe aircraft operations number one priority

• Ensure structural integrity; keeps planes viable

• Air Force executing 2030 Capability Roadmap

• Boeing contract to establish WFD risks


– Fuselage completed Feb 2017
– No structural concerns
– Extended service life ~12 years
– Wing analysis in work; complete ~Jun 2018
– Wings are current structural service life limiter

Integrity - Service - Excellence 21


Summary

• Commercial Mx plan not compatible with


Military Weapon System lifespan

• Gov overcoming sustainment challenges

• Improved fleet performance expected with


move to MSG-3

Integrity - Service - Excellence 22

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