ONLY some woids from this excellent 6 page PDF article from Dec 2014 edition of Air International are excerpted below.
Cats, Traps & a Rooster Tail December 2014 Mark Ayton
Air International
"[F-35C Aircraft] “...CF-03/‘SD73’ and CF-05/‘SD75’...
...DEVELOPMENTAL TESTER TEST DIRECTOR
Cdr Shawn Kern is the Director of Test and Evaluation for F-35 Naval Variants and the senior military member within the F-35 Integrated Test Force (ITF) based at Patuxent River. He leads a diverse team comprising 920 members from the US Government, the military and contractors responsible for developmental test of the F-35B and F-35C aircraft during the System Development and Demonstration phase. During DT I, Cdr Kern led the F-35 ITF, provided government oversight of carrier suitability testing and co-ordinated with the USS Nimitz’s captain, executive officers and other F-35 stakeholders.
He told AIR International: “Launch testing included minimum catapult end speed determination as well as performance and handling during high and low energy catapult launches and crosswind conditions at representative aircraft gross weights. Approach and recovery testing focused on aircraft performance and handling qualities during off-nominal recoveries in low, medium, high and crosswind wind conditions. Data and analysis from DT I will support the development of initial aircraft launch and recovery bulletins for F-35C carrier operations and Naval Air Training and Operating Procedures Standardisation (NATOPS) flight manual procedures. Test results from DT I will also influence follow-on developmental and operational testing required to achieve F-35C initial operational capability.”
Lt Cdr Ted Dyckman is a US Navy F-35 test pilot assigned to VX-23 based at Naval Air Station Patuxent River, Maryland: he made the second-ever arrested landing on a super carrier in aircraft CF-05 on November 3 and the first night-time landing on November 13 in CF-03. Speaking about the F-35C’s performance around the carrier, Lt Cdr Dyckman told AIR International: “Everything met expectations and there were no surprises. Going through the burble was a big unknown, but the airplane responded better than we thought it would.
“We saw that the aircraft could trap: the only true bolter was a power call by the Landing Signals Officer when the aircraft touched down long with the hook down but came around and made an arrested landing.
“When the weather started to deteriorate we had such confidence in how the aircraft was flying that we lowered the weather minimums to those used by the fleet. I knew that when I lowered the hook I was going to trap. That says a lot for the airplane.
“Because the autopilots and flying qualities are so good, the workload to fly the jet is reduced and we were confident enough to declare it ready for night-time traps. It flew very well behind the ship and I made two hook-down passes and two traps. It’s unheard of to conduct night ops on a type’s first period at sea.
“We accomplished everything we set out to do, which allows us to go to DT II and conduct maximum speed catapult shots and carry internal and external stores and asymmetric payloads.”...
...Flight testing was split into three phases: day carrier qualification (CQ) and flight deck crew familiarisation; the development of aircraft launch bulletins (ALB) and aircraft recovery bulletins (ARB). In addition DT I also included Logistical Test and Evaluation (LT&E). Subsets of each phase comprised:
Aircraft Launch Bulletins
• Military rated thrust catapult launches
• Minimum catapult launch end speeds
• Low, medium and high excess wind over deck (WOD) catapult launches
• Crosswind catapult launches
• Bow and waist catapult launches
Aircraft Recovery Bulletins
• Approach handling qualities (AHQ) of F-35C approach modes: delta flight path, approach power compensator (APC), and manual
• Low, medium and high excess WOD recoveries
• Crosswind recoveries
• Bolter performance Logistical Test and Evaluation
• Deck handling including taxiing, towing and tie-down
• Weapons loading
• Basic maintenance, including aircraft jacking and landing gear servicing
• Maintenance support
Preparations
Since the author’s previous visit to the F-35 ITF at Pax River in April the main test objectives completed over the summer were arrested landings, touch and goes (a training evolution also known as field carrier landing practice or FCLP) and a structural survey of CF-03. The latter was a methodical check of the aircraft to ensure it was structurally suitable to be flown aboard an aircraft carrier. The survey included testing engineering fixes made to the aircraft’s pitch pivot pin and nose wheel steering motor. Although precautionary, the survey was required because functionality problems had been discovered with each component during the F-35C’s developmental flight test programme. A subset of the structural testing performed on CF-03, known as a shake, was also completed on CF-05 to ensure it was also suitable for carrier trials. No issues were found.
One other pre-deployment test evolution was electromagnetic environmental effects (E3). This required CF-03 to spend two weeks in the shielded hangar at Pax River, to ensure that electromagnetic interference from the ship’s emitters did not affect any of the aircraft’s vital systems and cause them to shut down. The official E3 test report was completed on October 16 which cleared the aircraft to embark onboard the carrier.
All requisite carrier suitability testing was concluded on October 17 and the final FCLPs were completed at Pax River four days later.
One interruption to the test programme over the summer was caused by the temporary grounding order resulting from an engine fire on F-35A AF-27, serial number 10-5015, at Eglin Air Force Base, Florida on June 23. Each engine underwent a rigorous inspection process and because of the priority given to DT I, CF-03 was the first to be inspected, analysed and cleared back to flight: CF-05 followed....
...No modifications were required to the flight deck, not even the Jet Blast Deflectors (JBDs): hydraulic-controlled panels designed to divert hot aircraft exhaust during launches. The panels are raised in preparation for takeoff, protecting the flight deck and aircraft behind from the hot aircraft exhaust. Modification of the JBDs will be required for subsequent DT evolutions, when afterburner will be required to launch aircraft with heavier all-up weights than those used during DT I. Any changes implemented will alter the cooling path of the F-35’s exhaust plume, which interacts with the carrier’s decking differently from that of the twin-engined members of the Hornet family....
...Support Onboard and from Ashore
DT I was supported by a pre-production, nonfleet representative version of the Autonomic Logistics Information System known as ALIS 1.03. According to the F-35 Joint Program Office: “Standard ALIS functions were in place and used to support F-35C operations and maintenance onboard USS Nimitz. The functions were accessible via approved Department of Defense network and cyber security policies and authorisations similar to ALIS support for F-35B STOVL deployments to the USS Wasp (LHD 1)....
...Increased robustness in the aircraft’s control laws refers to:
• Pro-rotation during a catapult and bolter.
• Integrated Direct Lift Control which integrates the control surfaces such that wing camber is altered to increase or decrease lift, thus allowing glide slope changes to be made without a large change in engine thrust.
• Delta Flight Path, which is an innovative leap in aircraft flight controls, that commands the aircraft to capture and maintain a glide slope. The system greatly reduces the pilot’s workload, increases the safety margins during carrier approaches and reduces touchdown dispersion.
Wind Effects
Aircraft carriers are unique in that they have different wind effects that the pilot and the aircraft’s flight control laws must take into account. The overall wind effect is called the burble,...
...“We are evaluating how the control law handles through the burble. Data collected during DT I will now be used by the control law engineers for analysis and to improve our simulator modelling. Because the burble is such a dynamic and integrated wind system there are challenges to modelling it accurately. Future F-35 pilot training will benefit from this work,” said Cdr Wilson....
...We started making intentional errors in our approaches [off-nominal]. This allowed us to see how the aircraft’s flight control laws react to corrections input by the pilot and the effect of the burble while trying to make the corrections. “The pilot intentionally lines up [on approach] on either side of the landing area…starting either high or low, or flying fast or slow to see if there is enough time to input the correction and get back on centreline, on glide slope and on speed [flying a proper approach speed] prior to touch down. “As we fly off nominal approaches, if the LSO [landing signals officer] doesn’t see a timely correction or doesn’t feel that the pilot is going to land safely, he or she will wave them off.
“The LSO [who is located on a platform positioned 120ft (36.6m) from the end of the ship and 40ft (12.2m) from the centreline on the port side] is a pilot trained to observe the aircraft as it flies down the approach watching for deviation in pitch attitude using a camera that shows whether the aircraft is on or off centreline. Listening to the aircraft, the LSO is trained to recognise changes in rates of vertical and horizontal movement to ensure the aircraft is going to clear the ramp at the aft of the ship and recover safely aboard. The LSO plays a vital role in the safe recovery of aircraft aboard the ship.
“Getting aircraft back to the boat is our first concern: our second is [preventing] what we call a long bolter. This occurs if the pilot fails to correct a big deviation and lands well beyond the four-wire [the last arrestment cable along the deck]. For safety purposes any time an aircraft touches down on the deck, the pilot needs sufficient deck to derotate, and get the throttle back to mil[itary] power to fly away. There’s not enough time for the plane to de-rotate with a long bolter, which means it could still have downward direction so when [the aircraft] rolls off the front end of the boat it’s going to sink....
...evaluated approaches with crosswinds behind the ship out to 7kts....
...“We also evaluated approach handling qualities in low and high wind conditions: low is 10 to 20kt, nominal is 20 to 30kt and high is in excess of 30kt. The team’s goal for DT I was to gain as much data with cross winds and various head winds to allow us to start writing our aircraft launch and recovery bulletins.”
What Next? Testing around the carrier gets more complicated with aircraft weight and asymmetry. On subsequent DT events the F-35 ITF will increase aircraft weight and asymmetry by loading stores on one side to create as much asymmetry as possible, which is the complicating factor. Cdr Wilson told AIR International that testing on subsequent DT events is going to look very similar but will evaluate heavier weights and asymmetric lateral weight differences.
OUTCOMES FROM DT I
• Flight test conducted in the operational environment.
• The F-35C demonstrated exceptional handling qualities throughout all launch and recovery conditions tested.
• All four test pilots rated the F-35C to be very easy to operate from the carrier. Arrested landings were consistent: the aircraft caught the optimal three-wire in the majority of the 102 traps. Pilot comments included: “I noticed the burble, but the aircraft just takes care of it”, “It makes flying the ball comfortable” and “This thing is a three-wire machine”....
......STATISTICS FROM DT I
Start date: November 3
Completion date: November 14
Flights: 33
Flight hours: 39.2
Catapult launches: 124
Touch-and-goes: 222
Arrested landings: 124
Bolters: 2 intentional with the hook down
Threshold test points completed: 100%”
pp 42-47 Air International December 2014