EMALS & JPALS for the JSF

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Corsair1963

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Unread post31 Jan 2019, 04:54

So, that's 20 failures compared of several hundred successful launches???
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spazsinbad

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Unread post31 Jan 2019, 05:10

The Count says 700+ successes fordem EMALS.
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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steve2267

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Unread post31 Jan 2019, 05:53

How does that performance compare to the requirements?

How does that performance compare to the steam system and conventional arrestor gear on the Nimitz boats?
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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usnvo

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Unread post31 Jan 2019, 06:12

Corsair1963 wrote:So, that's 20 failures compared of several hundred successful launches???


10 were EMALS and 10 were AAG, only 2 required suspension of flight op.
Last edited by usnvo on 31 Jan 2019, 16:00, edited 1 time in total.
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Unread post31 Jan 2019, 06:23

Corsair1963 wrote:So, that's 20 failures compared of several hundred successful launches???


Not really. We know there were 747 successful launches. There were ten critical failures on EMALS and of those, "There were, he added, two “mission aborts” associated with the catapult launch system. In both cases, flight operations were briefly suspended and “a correction was implemented.”...

Any numbers of things could cause critical failures from hardware to software and obviously they have different impacts and repair times. So, if only 2 failures required a brief interruption of flight operations, by inference the other 8 didn't. So operational impact was really limited to 2 of 747 launches.

In any event, given that the design requirement is something like a MTBF of 4000 launches, and they have only completed 747, as indicated in the article they need a bunch more cycles before they can start to draw valid conclusions on reliability. Of course, it is hard to tell if any of the failures constitutes a failure in terms of calculating MTBF since they only required a "brief" suspension of flight operations, what ever that means.
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Unread post01 Feb 2019, 10:05

There is a new DOT&E 2018 report on CVN 78 which includes EMALS - I'll get to that later - meanwhile some JPALS DOT&E.
Joint Precision Approach and Landing System (JPALS)
01 Feb 2019 DOT&E

"...Executive Summary
• As of the end of FY18, DOT&E’s analysis of the data and results for the Joint Precision Approach and Landing System
(JPALS) Block 0 is ongoing; however, preliminary observations from the Navy’s IOT&E period indicate JPALS Block 0 will meet the Program Office’s objectives to support an Early Operational Capability decision.

• The Navy’s Operational Test and Evaluation Force (OPTEVFOR) conducted the JPALS Block 0 IOT&E. This consisted of an at-sea period with an F-35B, an at-sea period with an F-35C, and one pier-side test period.

• The Navy will conduct an operational assessment of the JPALS Block 1 Full Operational Capability in 3QFY19....

System
...• JPALS Block 0 is an interim solution/Early Operational Capability of JPALS, specifically to support the F-35B. Block 0 uses an ultrahigh frequency data broadcast to transmit a subset of the JPALS precision approach data and on-deck Inertial Navigation System alignment from ship to aircraft.

• JPALS Block 1 will further support the F-35B/C and MQ-25A with a two-way datalink capability by providing the accuracy, integrity, and continuity required for future F-35C and MQ-25A autoland capability on CVN-type ships and F-35B coupled flight capability on LH-type ships …."

Source: http://www.dote.osd.mil/pub/reports/FY2 ... 8jpals.pdf (0.5Mb)
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JPALShiLevelOpGraphicDOT&E.gif
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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Unread post01 Feb 2019, 11:25

CVN 78 Gerald R. Ford-Class Nuclear Aircraft Carrier FY 18 NAVY PROGRAMS
01 Feb 2019 DOT&E

"Executive Summary
• The DOT&E assessment of CVN 78 remains consistent with previous assessments. Poor or unknown reliability of systems critical for flight operations including newly designed catapults, arresting gear, weapons elevators, and radar, could affect the ability of CVN 78 to generate sorties. Reliability of these critical subsystems poses the most significant risk to the CVN 78 IOT&E timeline.

• CVN 78 completed eight Independent Steaming Event (ISE) at-sea periods in support of developmental test and ship certification. Four of these at-sea periods included fixed-wing flight operations for a total of 747 F/A-18E/F launches and arrestments. Mechanical problems forced CVN 78 to return to port early on three of the eight ISE events.

• CVN 78 will probably not achieve the Sortie Generation Rate (SGR) (number of aircraft sorties per day) requirement. Unrealistic assumptions underpin the SGR threshold requirement. These assumptions ignore the effects of weather, aircraft emergencies, ship maneuvers, and current air wing composition on flight operations. DOT&E plans to assess CVN 78 performance during IOT&E by comparing it to the demonstrated performance of the Nimitz-class carriers as well as to the SGR requirement....

... • The Navy previously identified an inability to readily electrically isolate Electromagnetic Aircraft Launching System
(EMALS) and Advanced Arresting Gear (AAG) components to perform maintenance. This limitation precludes some types of maintenance during flight operations.

• The Navy continued performance testing of the AAG at the Jet Car Track Site at Join Base McGuire-Dix-Lakehurst, New Jersey, with 2,230 arrestments completed as of September 30, 2018. Runway Arrested Landing Site (RALS) testing with manned aircraft continues and has completed a total of 928 aircraft arrestments as of September 30, 2018. RALS testing began on E-2 and C-2 on May 24, 2018, with the first propeller aircraft fly-in arrestment occurring on the C-2 on July 18, 2018....

... • CVN 78 exhibits more electromagnetic compatibility problems than other Navy ships. The Navy continues to characterize the problems and develop mitigation plans.

• The development and testing of AWE, EMALS, AAG, DBR, and the Integrated Warfare System will continue to drive the Gerald R. Ford timeline as it progresses toward IOT&E....

...SYSTEM
... • CVN 78 incorporates a more efficient flight deck layout, dedicated weapons handling areas, and an increased number of aircraft refueling stations designed to enhance its ability to launch, recover, and service aircraft. The Navy set a sortie generation requirement for CVN 78 to sustain 160 sorties per 12-hour fly day for 26 days and surge to 270 sorties per
24-hour fly day for 4 days....

...ACTIVITY
...EMALS
• The Navy conducted 747 F/A-18E/F launches from CVN 78.

• As of September 30, 2018, the program conducted 3,807 dead loads (non-aircraft, weight equivalent sled) and 523 aircraft launches at the land-based test site.

AAG
• The Navy conducted 747 F/A-18E/F arrestments on CVN 78.

• The Navy continues to test the AAG on a jet car track at Joint Base McGuire-Dix-Lakehurst, New Jersey. Earlier testing prompted system design changes that the program is now testing. The jet car track testing examined the F/A-18E/F performance envelope with the new design, and initial E-2C/D and C-2A testing. As of November 3, 2018, land-based jet car track testing accomplished a total of 2,230 dead load arrestments and land-based RALS testing accomplished a total of 456 F/A-18E/F, 65 EA-18G, 226 C-2A, 84 E-2C+, and 140 E-2D aircraft arrestments....

...Reliability
• Four of CVN 78’s new systems stand out as being critical to flight operations: EMALS, AAG, DBR, and AWEs.

Overall, the poor reliability demonstrated by AAG and EMALS and the uncertain reliability of DBR and AWEs could delay CVN 78 IOT&E. The Navy continues to test all four of these systems in their shipboard configurations aboard CVN 78. Reliability estimates derived from test data for EMALS and AAG are discussed in following subsections....

...EMALS
• Testing to date involved 747 shipboard launches and demonstrated EMALS capability to launch aircraft planned for the CVN 78 Air Wing.

• Through the first 747 [JUMBO? Wait WUT!?] shipboard launches, EMALS suffered 10 critical failures. This is well below the requirement of 4,166 Mean Cycles Between Critical Failures, where a cycle represents the launch of one aircraft.

• The reliability concerns are exacerbated by the fact that the crew cannot readily electrically isolate EMALS components during flight operations due to the shared nature of the Energy Storage Groups and Power Conversion Subsystem inverters onboard CVN 78. The process for electrically isolating equipment is time-consuming; spinning down the EMALS motor/ generators takes 1.5 hours by itself. The inability to readily electrically isolate equipment precludes EMALS maintenance during flight operations.

AAG
• Testing to date included 763 attempted shipboard landings and demonstrated AAG capability to recover aircraft planned for the CVN 78 air wing.

• The Program Office redesigned major components that did not meet system specifications during land-based testing. Through the first 763 attempted shipboard landings, AAG suffered 10 operational mission failures (which includes one failure of the barricade system). This reliability estimate falls well below the re-baselined reliability growth curve and well below the requirement of 16,500 Mean Cycles Between Operational Mission Failures, where a cycle represents the recovery of one aircraft.

• The reliability concerns are magnified by the current AAG design that does not allow electrical isolation of the Power Conditioning Subsystem equipment from high power buses, limiting corrective maintenance on below-deck equipment during flight operations...."

Source: http://www.dote.osd.mil/pub/reports/FY2 ... 8cvn78.pdf (372Kb)
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
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