Forum: F-35 milestones

"Of all the technical challanges facing the F-35 program the tail hook problem gives me the most worry. "

Personally, I'm not going to lose any sleep. The launch bar origionally did not hook up during launch tests. It was modified and
they have been shooting them regularly.

Modifying the damper and hook angle, to me, is not an unusual problem. Hooks have been reconfigured before in Naval aviation.

Failing the rollovers, is a [Link pending approval] it is part of the testing process.

I believe on the C model they are still 20% ahead of testing.

I also believe a few bolters will [Link pending approval] always do.

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Wouldn't it be great if the only "Big" problem the Sea will experience is the tailhook. I've yet to see a tailhook problem that wasn't fixed. Other than the rocket scientist; all others agree, "Important but not rocket science"! Laughing

Actually I wasn't worried about the tail hook problem before but when I see how long it is taking to fix the problem I am now starting to worry because the fix isn't going to be a simple one. It "could" end up being a major modification that ends up affecting the mold lines of the aircraft.

Repeated from 'Sticky: Overview of F-35 test flights' thread but best posted here. OK?

How well is F-35 testing going? 07 June 2012 by Barry Graff

http://whythef35.blogspot.com.au/2012/0 ... going.html

"...All numbers and events are as of May 31st....

...CF-3 performed a total of 18 successful roll-in arrestments [MK-7 (6 with risers and 4 with no risers) and E-28 (8 arrestments)] at Lakehurst from 80 to 100 knots ground speed...." Cheers

spazsinbad wrote:

Repeated from 'Sticky: Overview of F-35 test flights' thread but best posted here. OK?

How well is F-35 testing going? 07 June 2012 by Barry Graff

http://whythef35.blogspot.com.au/2012/0 ... going.html

"...All numbers and events are as of May 31st....

...CF-3 performed a total of 18 successful roll-in arrestments [MK-7 (6 with risers and 4 with no risers) and E-28 (8 arrestments)] at Lakehurst from 80 to 100 knots ground speed...." Cheers

Good feedback..,the redesigned hook tip seems to be fine, looking forward to actual traps,to,see,if the modified damper,keeps,the,hook from bouncing over the wires upon contact withthe ground.

Re " For the Mission Systems software, 8.1M of 9.3M Software Source Lines of Code (87%) flying today. Conducting Radar, Electronic Warfare, Electro Optical sensor employment. 95% of airborne software now operating in flight and ground labs".. what block software are they referring to?

"E28 Emergency Runway Arresting Gear. An aircraft arrestment using the E28 Emergency Runway Arresting Gear is accomplished by the engagement of the aircraft’s tailhook with a deck pendant that spans the runway. During run-out, the kinetic energy of the arrested aircraft is absorbed by the rotary hydrodynamic arresting engines. The arrestment is entirely automatic. The arresting gear engines are activated when the aircraft’s tail-hook engages the deck pendant, thereby pulling out the attached purchase tapes. As each tape unwinds, a splined shaft turns a vaned rotor located between vaned stators in a housing filled with fluid. The turbulent fluid resistance decreases the rotational speed of the drums, thereby slowing down the purchase tape pay-out that in turn applies a braking force on the aircraft....
&
E28 Emergency Runway Arresting Gear. The E28 Emergency Runway Arresting Gear general arrangement consists of two arresting engine assemblies and two runway edge sheave assemblies installed on concrete foundations on opposite sides of the runway. Purchase tapes from each arresting engine assembly are coupled to a common deck pendant assembly. Major components include a tape drum and capstan assembly, a retrieve drive sprocket and bearing assembly, and a vaned rotor, mounted on a common shaft assembled in a vaned housing. An engine absorber unit is mounted on a steel base, on which are also mounted a retrieve engine, an arrester sheave, and a tape pressure arm pivot. Leading E28 Emergency Runway Arresting Gear particulars are as follows:"

Development of a Mathematical Performance Prediction Model for Rotary-Hydraulic-Type Arresting Gears - Phase Report 23 March 1972 by George M. Leask, Computer Division NAVAL AIR TEST FACILITY NAVAL AIR STATION LAKEHURST, NEW JERSEY

http://www.dtic.mil/dtic/tr/fulltext/u2/893157.pdf

DESCRIPTION OF THE E-28 ROTARY-HYDRAULIC-TYPE ARRESTING GEAR
A. Purpose: The Navy E-28 arresting gear is a shorebased emergency arresting gear designed to arrest all U.S. Navy arresting-hook-equipped airplanes under conditions of aborted takeoff or landing overrun.

B. Capabilities: An airplane engaging the arresting gear will be stopped within a runout distance of approximately 1,000 feet. The maximum energy absorbing capacity of the gear is 76 million foot-pounds (nominal). Engagements can be made from either runway direction and at points up to 40 feet on either side of the runway centerline.

C. General Description of the Arresting-Gear Operation: As shown in Figure 1, two identical energy absorber units and runway-edge sheaves are located on opposite sides of the runway and are connected, through nylon purchase tapes, to a steel wire-rope deck pendant. Arrestment of a landing aircraft is accomplished by engagement of the aircraft arresting hook with a pendant stretched across the runway. The attached purchase tapes are pulled off the six-foot-diameter drum on each arresting gear. Each drum is splined to a shaft which turns a vaned rotor between vaned stators in a housing filled with a water/glycol mixture. The turbulent fluid resistance caused by the stator and rotor interaction (water brake) decreases the rotational speed of the drums, thereby slowing down the purchase-tape payout which in turn applies a braking force on the aircraft. The ensuing fluid turbulence converts the landing aircraft's kinetic energy into heat. A cooling system is provided to dissipate this heat during rapid-cycle operations. After the aircraft has been safely brought to a stop, and the arresting hook disengaged, the pendant and nylon tapes are returned to battery position by an air-cooled gasoline engine driven retraction system."

F-18 Arrested Landing E-28 Gear Hornet Arrest Video

http://www.youtube.com/watch?v=de7WnuqTx08

"Uploaded by TheHillmanater on Oct 10, 2010
F-18 trap on Marine Corps E-28 gear at MCAS Futenma"

Perhaps the confirmation of 'CVN hook testing slippage' testing from previous bottom of page 'alloycowboy' entry 18 May 2012 article:

F-35 Testing Progresses; UK Rethinks Switch to F-35C AIN Defense Perspective 16 Mar 2012

http://www.ainonline.com/aviation-news/ ... itch-f-35c

"...This combined solution should ensure that the hook catches the wire, O’Bryan said. But the hook problem has probably delayed the first F-35C test flights on a carrier from late 2013 into 2014, he added...."

MANAGING, OPERATING, AND MAINTAINING AIRCRAFT ARRESTING SYSTEMS March 2012 AIR FORCE INSTRUCTION 32-1043

http://wbdg.org/ccb/AF/AFI/afi_32_1043.pdf (1.8Mb)

"...A2.2.8. Mobile Aircraft Arresting System (MAAS). The MAAS (Figure A2.11) is
essentially a BAK-12 AAS mobilized through installation on a specially developed trailer. It is configured for a maximum aircraft runout of 302 meters (990 feet). This system was initially developed and tested to accommodate recovery of fighter aircraft returning to a battle-damaged airfield. Such cases require rapid deployment and installation and may require that only the minimum essential anchoring hardware be installed to accommodate this scenario. When installed for this purpose, the MAAS is installed using a 19-stake anchoring scheme. This configuration is limited to unidirectional engagement capability with a maximum aircraft weight and speed of 18,144 kilograms (40,000 pounds) at 150 knots (Table A2.1). For detailed instructions on this system, refer to T.O. 35E8-2-10-1, Operation and Maintenance Instructions, Arresting Systems, Aircraft, Mobile. Figure A2.11. Mobile Aircraft Arresting System (MAAS) in Set-Back Configuration." [below here]

Latest Inductees [1994 Grand Order of Tape Dragons]

http://www.esco.zodiacaerospace.com/news/2011/tazz.php

Testimonial by Joe “Tazz” Katuzienski
“From 1993-1996 I was assigned to the 67th Fighter Squadron, 18th Fighter Wing, Kadena Air Base in Okinawa Japan. I was a young Air Force Captain, F-15 flight lead, and one of a handful of Desert Storm Combat Veterans assigned to Kadena at that time. During one mission, I lost hydraulic pressure in my aircraft’s utility-A hydraulic system. This is not good in the F-15C. When this happens, the pilot loses his ability to normally extend the landing gear, and cannot stop on the runway using normal braking procedures. The best course of action – and that recommended in the Dash-1 Technical Order – was to blow the gear down with the manual gear extension system, drop the hook, and snag the approach end cable – stay there in the cable until the landing gear gets pinned – then shut down, and ride the walk of shame back to the chocks – essentially staying in the cockpit as the Coleman tug tows your jet back to the ramp. Anyway – that’s what happened to me.

One night in early spring 1994, during a routine night intercept training sortie, my aircraft lost all utility A hydraulic pressure. My course of action was decided to dump gas, manually lower the gear, and catch the arrestment gear on the approach end to runway 23R. It was a dark night, thunderstorms were in the area, and the runway was wet (not good). Departure from the working area and vectors to ILS final were uneventful. I shot the ILS and planted the jet 500 feet in front of the first approach end cable. There were two approach end cables available on 23R – one was at 1500 feet (ish) from the approach end, and the other something like 2500 feet (ish) down the runway. For an Air Force guy – not flaring prior to touch down is not a natural act – but it was the only way to achieve the recommended “three-point attitude” to engage the cable. And I then I waited. And so were the fire trucks – they were waiting – waiting for my jet to stop after snagging the cable. At night, at roughly 180 KIAS – trundling along on a wet runway with no brakes in an F-15C is not a great feeling. My jet blew past the first cable – nothing. Not even a tug on my shoulder straps. Uh – oh – plan B soon to take effect: advance throttles into Full AB, take-off and try again. But wait – cable number #2 – it’s only 2500 feet down the runway. But it was dark and I could not see it to try to straddle the cable donuts to ensure my hook would catch. Dammit Jim – this is not good – was the only thing I could think of at the time. But wait- Okay – here comes the next cable – cable #2 – all the while still blitzing along at a happy 185KIAS on a wet runway at night and in a thunderstorm. Perfect. No pucker factor yet, but I know it’s gonna start soon. Okay – there it was – two quick thuds I feel and hear as my landing gear goes over cable #2 – and there it is – wait for it, wait for it, - nothing….okay now as I began to think about going around I could feel a sharp tug on my shoulder straps as the jet came to a rapid stop on the runway – 3,000 feet down 23R. Now the fire trucks pull-up, they pin my gear safe, and connect the tug. The walk of shame went well. And all I could think of at the time was that the arrestment gear on the runway worked as advertised – and why in the Hell Navy guys do this crap at night on a carrier. That just didn’t make any sense.

Thanks to you and your company for making those BAK-12/14’s. I only took one cable once as described above, but many of my squadron buddies took cables in much more urgent emergencies than mine – and a lot of jets (at least 2-dozen in my 24 year USAF career) were saved. Your company helps to preserve American airpower every day.
- Joe Katuzienski

(Joe Katuzienski, Lt Col USAF (ret) completed 24 years of honorable military service. He currently resides with his family in Yorktown VA, and works for Futron Corporation as Lead Aerospace Operations Analyst)”

http://www.esco.zodiacaerospace.com/images/tazz..jpg
&
ESCO arrestor gear ideal installation diagram from:
http://www.esco.zodiacaerospace.com/dow ... 007_SF.pdf (0.7Mb)
Bunch o'stuff here:
http://www.esco.zodiacaerospace.com/downloads/

Arresting Gear Delays Not Expected to Hold Up Carrier Delivery Jun. 18, 2012 By CHRISTOPHER P. CAVAS

http://www.defensenews.com/article/2012 ... nav%7Chead

“Development of the new advanced arresting gear (AAG) for the U.S. Navy’s Gerald R. Ford CVN 78-class aircraft carrier has hit a few snags and delays, the Navy said, but delivery of systems to the carrier’s shipyard should not delay the ship....

...“The AAG program has adjusted several delivery dates to the shipyard based on the redesign of the water twister components,” Koon added. “However, these delays have not impacted the CVN 78’s scheduled delivery.” The water twister is a device that absorbs energy by circulating water around an enclosed loop, according to information provided by General Atomics, prime contractor to develop the system....

...The AAG will replace the Mark 7 hydraulic system in use aboard all other U.S. aircraft carriers. The AAG’s electric motor-based system, according to GA, replaces the mechanical hydraulic ram of the current system with energy-absorbing water turbines which, coupled with a large induction motor, should provide better control of the arresting forces....

...The AAG program, he added, “is scheduled to complete performance testing in 2013 and Runway Aircraft Landing Site testing in 2014.”

The testing site would be Lakehurst. More info at URL about CVN specific effects of AAG delay.

[quote="spazsinbad"][b]......[b]The AAG program, he added, “is scheduled to complete performance testing in 2013 and Runway Aircraft Landing Site testing in 2014.”[/...quote]

No F-35 in the testing schedule, at this time! Smile

Another quote from same article does not mention F-35C either.

"...GA claims the new system will handle a broader range of aircraft, reduce manning and maintenance, and feature higher reliability and safety margins.

So far, Koon wrote, 138 dead-load recoveries have been conducted at the JCTS [Jet Car Track Site which is not the same as actual AAG for aircraft test site] at Joint Base McGuire-Dix-Lakehurst, N.J.

“System performance to date has correlated well with our models,” Koon wrote. “As in any test program, we’ve found things that we’ve had to address via design changes, and we are currently redesigning the water twister to ensure that it meets dynamic loads experienced during heavy aircraft arrestments. Dead-load testing will resume early this summer.”

The dead-load weights, he said, represented an F/A-18 C/D Hornet, F/A-18 E/F Super Hornet, EA-18G Growler, E-2 C/D Hawkeye, T-45C Goshawk and UAVs...."

Lockheed’s comprehensive Q&A on the F-35 By Philip Ewing, June 19th, 2012

http://www.dodbuzz.com/2012/06/19/lockh ... -the-f-35/

Q: All right, we’ve talked about the helmet and the software. What about the C’s tailhook redesign?

A: Here’s what O’Bryan said: “The distance between the main landing gear and the tailhook on the F-35C is the shortest of any naval aviation carrier airplane that we’ve had. Because we have to hide the hook — because if you had a hook exposed you wouldn’t be as stealthy airplane, that distance is tighter than any other. So it means when you roll over the wire when you land on the deck, the wire goes flush to the deck, and then you have to pick that wire up as it’s generally on the deck. So what we’ve had to do is re-design the hook shank.

Every airplane’s hook shank — as you’d imagine, you ground those things down, dragging it around, so it’s a remove-and-replace kind of thing. It has a bolt through the back of it and it holds on to the hook and we’ve redesigned that to have a lower center of gravity, or in a more mundane way, to make it a sharper hook point. And that allows us to pick up the wire. And we’ve already done testing on that. We’ve done it at 80, 90 and 100 knots and we’ve got a good design for the hook point now.

The other thing we need to do is, we need to make sure that the hook stays flush on the deck. So what you don’t want — and I was a Navy pilot, so I apologize if I’m using a lot of vernacular here – you want to keep that hook on the deck so it doesn’t bounce, or the words we used was skip. It can do that a couple different ways. It can move laterally and it can hit other stuff and just bounce, if you will. Another technical term. So what we’ve done is we’re going to modify what’s called the hold-down damper, kind of a good name for a thing because it does exactly that, it holds the hooks down, it dampens any oscillation. We’ll increase pressure on hook to do that.

The whole thing is a remove-and-replace assembly so any modifications we make to it is an easy fix.”

Q: So when will we actually see an F-35C make its first trap aboard an aircraft carrier?

A: O’Bryan: “We’re accumulating loads; we’ve done rolling arrestments; we’ll do field arrestments next year and the plan is to go to the boat in early 2014, well in time to make the US Navy [initial operational capability]...."

Forum: F-35 milestones

F-35C Lands at Lakehurst For Testing