Navy F-35C DT-III Testing

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Conclusions from the previous page paper by CMDR Wilson:

F-35 Carrier Suitability Testing
17 May 2018 Tony Wilson

"...VI. Conclusions
Designing an aircraft that will operate from the decks of seagoing vessels is not easy. The design space is filled with a myriad of constraints and intricacies such as sizing for deck space considerations, wing fold capabilities to reduce that size factor, and the proper sizing of control surfaces for the tasks of launching and recovering. The F-35C couples those baseline constraints with the additional requirements of low observability and commonality with two other variants which affected such things as arresting hook geometry that had second order effects on arresting gear dynamics (perturbations of kink waves). These engineering challenges were faced by the multidiscipline specialization team of carrier suitability that combines theories from aircraft loads, flying qualities, and performance in a system of systems approach to assess the suitability of an aircraft to operate from ships and austere sites. In addition to flight sciences, carrier suitability includes many other nuances and facets such as navigation and guidance, sensor integration, data link interoperability, pilot-vehicle interface, supportability, maintainability, and night evaluations, that were all beyond the scope of this paper.

Aircraft that are launched from and perform arrested landings to the deck of a ship require enhanced structure to withstand the loads to which they are subjected. As such, a majority of the carrier suitability process was spent on conducting specialized loads testing in the form of shore-based catapults and arrested landings. During the structural survey, the F-35C faced and overcame many challenges such as the AHS. The original tailhook is proof that while designs may work on paper, they do not always go right the first time. The AHS redesign process was validation of the engineering problem solving process.

Additionally, strides towards the improvement of the carrier suitability discipline were also made by challenging the current assumptions and philosophies. The F-35C was approached with a “blank canvas” mentality that paved the way for the use of automation in the pursuit of CVS testing that increased efficiency. The advanced approach modes and IDLC provided the pilot with an unprecedented ability to control the aircraft. This technology, specifically DFP, and FTAs provided tools that allowed challenging test points to be achieved with a high level of repeatability without relying on a test pilot’s skill to finesse aircraft performance.

Undeniably, the CLAW, which provides the basis for the advance approach modes and FTAs, demonstrated many benefits to both the F-35C and the entire F-35 program. Delta Flight Path is a game changer. It was an instrumental tool in allowing the test team to complete the structural survey efficiently, effectively, and safely. DFP, which has only been attainable with the implementation of fly-by-wire controlled aircraft and advances in computing power, will be the basis for changes in how the discipline of CVS flight test is approached in the future. Not only has DFP been beneficial to flight test, but it has also provided the fleet aviator with an unprecedented ability to control the aircraft during shipboard approaches which will increase operational capabilities and make Naval Aviation safer."

Source: F-35 Carrier Suitability Testing PDF

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10 page PDF of article below attached.

A Flight Deck REVOLUTION

"...INTO SERVICE...
...Four squadron F-35Cs then embarked the USS George Washington on August 14, directly from Eglin, to begin the first fleet pilot CQs. Of the 15 pilots on squadron strength, a total of 12 deployed to the carrier. LT Graham Cleveland, lead LSO at the ‘Grim Reapers’, said: “It’s awesome to see that everybody performs so well. We are on the boat less than 24 hours and almost everybody is qualified without a single ‘bolter’ [when the tailhook misses all of the arresting wires]. We’ve not heard any screaming calls from the LSOs and not a single pilot has caught the one-wire, which is less safe than a two- or the preferred three-wire. We also haven’t seen any waveoffs due to unsafe approaches.”

New F-35 technology had a large part to play. The Delta Flight Path (DFP) has been developed by the US Navy in close co-operation with Lockheed Martin. It partly automates the precise flying phase in the final seconds before touchdown. Without DFP, an average pilot makes 200 to 300 minor corrections with the throttle, stick and rudder in the last 18 seconds before touchdown. DFP, along with the Magic Carpet software developed simultaneously for the F/A-18 Hornet, dramatically decreases these corrections to just 20 for an average pilot. It is expected that this number could even drop below ten inputs!

“With DFP we have reduced FCLPs to between four and six days”, said LT Cleveland. “I expect the navy to reduce day requirements to six traps”....

...Some of the specific navy testing that CDR Anderson [CDR Ernest ‘Big Ern’ Anderson, executive officer (XO) of VX-9 Det Edwards] mentions includes aircraft carrier testing. “We CQ’d our first pilot from VX-9 last September and three more are currently working with VFA-101 and 125 to get qualified,” Anderson explains. “There are already multiple boat detachments going on but we will run OT-I – our first formal operational test period on the boat – in summer 2018. For this we will embark on the carrier and execute specific test points to assess suitability for mission readiness.”

Typically, US Navy pilots must complete ten daylight ‘traps’ and six at night aboard the carrier in order to achieve an initial qualification. Night launches and recoveries have been successfully demonstrated by the NAS Patuxent River Integrated Test Force, initially during DT-II in November 2014. Anderson continues: “Coming back to an airfield at night is very different to coming back to the ship. The night-vision camera [in the helmet] is already very capable in the tactical environment but flying around the carrier at night is a unique situation. So there are some things we’d like to see improved before we move forward with it. It really comes down to how dim you can get the symbology in the helmet. US Navy guys are notorious. At night we turn everything in the cockpit down in brightness in order to open up the aperture in our eyes for better night vision. This is so you can see the landing area and see the [Fresnel] lens.

“Delta Flight Path makes the F-35C considerably easier to land aboard the carrier,” says Anderson. “The data we saw from VFA-101’s last detachment was eye-watering in terms of how accurate they were at landing without bolters, or high or low passes.”

CDR Tony Wilson, a development test pilot with VX-23 said: “Delta Flight Path is an innovative leap in aircraft flight controls – this command enables the F-35 to capture and maintain a glide slope, greatly reducing pilot workload, increasing safety margins during carrier approaches and reducing touchdown dispersion.” CDR Anderson adds: “The jet knows the ship’s speed and the wind speed over the deck. The pilot still flies the line-up, but the jet is assisting you with the glideslope corrections.” Testing revealed an extraordinary reduction in the level of pilot inputs in the final approach phase to the carrier. It has huge implications for the future of carrier aviation.

“Pilots have felt confident to go to the ship in half the amount of ‘looks’ that it would have previously taken,” says Anderson. “Even for first-time pilots going to the boat, it will undoubtedly reduce their time to prepare.”..."

Source: F-35 Lightning II The Fighter Evolution Magazine July 2018