Arresting F-35s & Brake Testing

spazsinbad · by **spazsinbad** » 07 Aug 2010, 01:48

RED HORSE Airmen literally bring safety to JSF brake testing
8/4/2010 by Kenji Thuloweit - 95th Air Base Wing Public Affairs

"8/4/2010 - EDWARDS AIR FORCE BASE, Calif. -- During developmental testing and evaluation at Edwards, safety is a core priority. When base resources are unavailable to make flight tests the safest they can possibly be, commanders here do not hesitate to search throughout the Air Force for assistance.

With the Joint Strike Fighter currently undergoing braking tests, which include wet and dry brake testing, the 416th Flight Test Squadron and the Air Force Flight Test Center decided they needed an additional safety barrier.

That's where the 823rd and 820th RED HORSE Airmen come in.

RED HORSE stands for rapid engineer deployable heavy operational repair squadron engineers.

These highly deployable Airmen and their equipment travel the globe providing the Air Force with a mobile civil engineering capability.

"We go all over," said Tech. Sgt. Michael Fralick, 823rd RED HORSE Barrier Maintenance noncommissioned officer in charge.

Here in the high desert, an 11-man team consisting of five Airmen from 823rd RED HORSE out of Hurlburt Field, Florida and six from 820th RED HORSE out of Nellis Air Force Base, Nev., arrived in late July to support the JSF taxiing and braking tests.

The two teams merged due to the short notice of the deployment and the fact that equipment can be driven down from Nellis AFB, which is relatively nearby.

The team set up the mobile aircraft arresting system on Edwards' 12,000-foot inside runway.

The MAAS was installed in case, for whatever reason, the JSF had an emergency and would not be able to stop. It consists of two mobile braking systems, one on each side [END?] of the runway, with a cable laid across the runway between them. Specifically, the braking system is made from a modified B-52 braking system.

The mobile barrier is used for any jet equipped with a tail hook. If a jet could not stop, the tail hook would catch the cable and the MAAS' braking system would engage then slow down and stop the airplane. It's similar to the way planes land on aircraft carriers.

"The aircraft carrier uses just steel cables and steam power to stop their jets," said Sergeant Fralick. "We also use a nylon tape to absorb some of that energy and then the B-52 brakes to stop the plane."

The MAAS is held in place with more than 150 66-inch spikes driven into the ground. The team took just two days to set it up, which was notable given the short notice of their deployment. They were able to set up the MAAS in time for the JSF runway testing.

"We were anticipating it would take about four days because of the type of soil on Edwards," Sergeant Fralick said. "We heard it was really hard, which makes it harder to drive the stakes in the ground, but we ended up knocking it out in two days."

"They basically set up the MAAS in a weekend, which was amazing," said Bruce Strong, 412th Operations Support Squadron, Director of Operations for the Airfield Operations Flight. "Those guys are something."

Once the JSF brake testing is finished the RED HORSE team will break down the MAAS and transport it back to Nellis AFB.

Sergeant Fralick said RED HORSE teams set up these MAAS barriers everywhere from air shows to Afghanistan and Iraq.

"We did two installs down range this year and we also support the Thunderbirds and Blue Angels," said Sergeant Fralick. "We have an air show in Sacramento coming up where we will do the same thing. We'll set the barrier up for the duration of the air show then we'll pull it back up - it will be like we were never there."

Source: http://www.edwards.af.mil/news/story.asp?id=123216369

Links to HiRes Photos:
http://www.edwards.af.mil/shared/media/ ... 9T-001.JPG
http://www.edwards.af.mil/shared/media/ ... 9T-002.JPG

f35phixer · by **f35phixer** » 07 Aug 2010, 02:00

you call that AF tail hook a tail hook !

BWAHAHAHAHAHHAHAHAHAHA :devil:

spazsinbad · by **spazsinbad** » 07 Aug 2010, 02:38

'neptune' posted: http://www.f-16.net/index.php?name=PNph ... c&p=160651

"Thanks to Graham Warwick and Bill Sweetman; Aviation Week, Ares: http://www.aviationweek.com/aw/blogs/defense

AA-1 - is now at Edwards AFB for arrestor-hook testing before heading to China Lake to end its career in live-fire testing. Its 2.8h flight to Edwards on Sep. 10 [2009]..."

spazsinbad · by **spazsinbad** » 07 Aug 2010, 03:00

http://news.directindustry.com/press/bi ... 42500.html

"For the F-35 Lightning II JSF Fokker Landing Gear is system design responsible for the Arresting Hook of the F35 Conventional Take Off and Landing (CTOL) and the Carrier Version (CV). For the reliability of this arresting hook system Fokker needs to do climate testing. One of the parts of the arresting hook system is the Upswing Damper. It is mounted right under the engine of the F-35. This Upswing Damper adsorbs the energy during the landing from the hook.

At their location in Helmond (NL), Fokker Landing Gear investigates and tests the reliability of this Upswing Damper. They have test- and qualification facilities where technology demonstrators and preliminary- or final design prototypes are tested on strength, fatigue, environmental and endurance test rigs. The testing facility is completed by a drop test rig on which gears can be drop tested up to 22.5 tons with a vertical speed of up to 8 m/s. Fokker was searching for a test chamber with a wide temperature range. According to Sem Cornelissen (Engineering Manager Testing & Test Facilities), `BINDER is the perfect partner for the job`. The professional look, quality and the short response time made BINDER with its BINDER MKT the best candidate."

spazsinbad · by **spazsinbad** » 19 Aug 2010, 10:26

I'm interested in the F-35A & C hooks. From this PDF comes a 'zoom photo on cover' JPG. Green arrows indicate where I think the hook will be on AA-1 but I don't see it except perhaps a very thin 'rod'. Is this what the F-35A hook looks like? Or has the hook been airbrushed out of the picture? (Perhaps the hook has just been raised - but then the wire would be on the deck?) PDF here: http://esco.zodiac.com/downloads/docume ... mmer10.pdf (1.2Mb)

"The F-35 Joint Strike Fighter comes to a slow, smooth rest following a barrier engagement with the ESCO BAK-12. The JSF performed arresting barrier tests at Ewards AFB in February 2010."

spazsinbad · by **spazsinbad** » 19 Aug 2010, 19:43

Here is how the FSX FlightSim modeller has done the job showing the 'hook down' on AA-1 F-35A. I'm guessing that this is close to the mark.

Lightndattic · by **Lightndattic** » 20 Aug 2010, 00:29

I'm thinking in the arresting wire pics above were just running over the wire without the hook down to see what the wheels do to the wire first.

Prinz_Eugn · by **Prinz_Eugn** » 20 Aug 2010, 01:14

spazsinbad wrote:I'm interested in the F-35A & C hooks. From this PDF comes a 'zoom photo on cover' JPG. Green arrows indicate where I think the hook will be on AA-1 but I don't see it except perhaps a very thin 'rod'. Is this what the F-35A hook looks like? Or has the hook been airbrushed out of the picture? (Perhaps the hook has just been raised - but then the wire would be on the deck?) PDF here: http://esco.zodiac.com/downloads/docume ... mmer10.pdf (1.2Mb)

"The F-35 Joint Strike Fighter comes to a slow, smooth rest following a barrier engagement with the ESCO BAK-12. The JSF performed arresting barrier tests at Ewards AFB in February 2010."

That looks more like an access gate from the background.

spazsinbad · by **spazsinbad** » 20 Aug 2010, 03:24

Having another guess from replies above, I'm guessing that yes we see a 'side opening' hook door (hinge on left side) with the very thin hook (outlined in green) barely visible in the photo. The wire is showing the strain of arrest with the right side straight out from the hook point at arrest. Meantime the left side of the wire has warped temporarily a bit, as it flails during pullout. The wire is under strain, not bouncing high as suggested (refer to the first/second pic above). This 'bouncing without arresting' wire would be extremely dangerous otherwise IMHO.

Remember in the BAK-12 arrangement seen here the wire is above the runway supported by the rubber grommets. Later BAK-14 gear have the wire below runway level - being raised by Air Traffic Control as required. A BAK-12 wire will bounce slightly when run over but not as shown in the pic above IMHO. This is an arrest. Thanks for your input - much appreciated. If anyone has a pic of the arrest hooks for both A & C aircraft these would be nice to see. TIA.

BAK-12 & 14 info here: http://www.boeing.com/commercial/airpor ... ystems.pdf (1Mb)

Pics in above PDF show difference between how the wire is strung across runway - at rest.

spazsinbad · by **spazsinbad** » 20 Aug 2010, 04:16

Also because (apparently) this is a 'low speed' arrest then perhaps that accounts for the 'more than usual wire bounce' as seen above. Probably a normal arrest speed will keep that wire more taut. Anyhoo here is this old news [31 August 2009]:

http://www.aviationweek.com/aw/blogs/de ... d=blogDest

"AA-1, meanwhile, is due to return to Edwards AFB, Calif., for low-speed arrestor-hook testing in advance of the first F-35C carrier variant flying around year-end. The A-model's lightweight hook, designed for only limited land-based use, will be used to gain early experience with arrested landings."

spazsinbad · by **spazsinbad** » 20 Aug 2010, 05:38

Unfortunately this F-35C 'tailhook servicing' graphic is not too good: http://www.catiacommunity.com/images/lockheed5.jpg

http://www.catiacommunity.com/print_art ... reid=23325

spazsinbad · by **spazsinbad** » 20 Aug 2010, 09:32

F-35C hook (CF-01 rollout ceremony): http://www.flickr.com/photos/lockheedma ... 875816736/

spazsinbad · by **spazsinbad** » 05 Sep 2010, 22:39

USAF Arresting Systems described very well in this (0.25Mb) PDF: http://www.keesler.af.mil/shared/media/ ... 20-083.pdf

johnwill · by **johnwill** » 06 Sep 2010, 01:55

spazinbad,

Thanks for all the information you supplied about barrier systems.

You are batting .500 on your comments about the F-35 arresting tests. The wildly flailing wire in the photo is an actual engagement as you say, but it is not a low speed engagement. The wire goes through those wild gyrations on all but the slowest engagements, and the faster the engagement, the wilder the gyration. The impact of the hook on the wire and the almost instantaneous acceleration of the center of wire up to airplane speed causes waves to form in the wire, which are reflected back and forth across the wire until the entire wire is moving at airplane speed. Want to see a really wild gyration? Then do an off-center engagement, up to 50 ft, so the reflecting waves are out of sync left and right and the hook is pulled to one side, thus pulling the aft end of the airplane to one side and pointing the airplane at the rapidly approaching edge of the runway, and the airplane also tries to roll over due to skidding down the runway with one main gear off the ground.

I observed these and many more exciting events during 96 F-16 engagement tests in 1979, where I was the structures engineer responsible for not breaking the airplane. Limit loads are reached on main and nose gear and the hook during the tests. The tests included a wide range of gross weights, external store loadings, engagement speeds (up to 135 kt), and runway offsets (0, 30, and 50 ft).

The only structure we broke was the wire itself. On one run, the hook point impacted the wire precisely on its centerline and tore the top half of the wire completely out,

spazsinbad · by **spazsinbad** » 06 Sep 2010, 02:58

johnwill, thanks for info. Yes there are limits to 'off centreline' and speed engagements as well as weight. However sometimes some decel is better than 'no decel' if something is going to break worse otherwise! A long or usually short field engagement for practice has no comparison to an onboard arrest. Below are some USN carrier arrest stats. An A4G on HMAS Melbourne pulled up in around 200 or so feet. The entire runway flat deck was just under 300 feet. Older Sea Venom and Gannet aircraft used 6 wires where the last wire pullout had them 'nose over' the other end with aircrew screaming profanities! This wire was removed for A4G/S2 ops.

http://www.globalsecurity.org/military/ ... a_2002.pdf (1.5Mb)