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Re: F-35B UK SRVL info - Updated when new/old info available

30 Apr 2019, 02:38

Until HMDS 'green glow' fixed for individual HMDS then apparently night stuff done without it but in any individual case I guess no one knows except if the whole embarked F-35B pilots carry out the same SOP. Perhaps all those now have modified 'greenglowless' HMDS? Interesting about Harrier night ops etc. Few people know how BLACK it is out there.

We may have old articles about F-35B 'tyres' on this thread - certainly elsewhere. However GAO info seems OUTdated?
2015 BOGDAN: ...…"Another hiccup in the F-35B have been the tires. An aircraft that takes off from short runways and lands vertically requires tires with enough bounce but also must be sufficiently rugged to maintain their form in 170 mph takeoffs. “We have been working hard to find the right balance between float and durability for vertical takeoff,” Bogdan said. “Our fourth tire is now in test. It appears to be working better than any of the others.” Tire manufacturer Dunlop has had difficulties producing the correct specs, he added, “But we’re moving in the right direction.”..." viewtopic.php?f=61&t=26629&p=288071&hilit=tire+Bogdan#p288071

Of course things are complicated with tyres (tires) and the F-35B:
viewtopic.php?f=22&t=27345&p=291912&hilit=tire+wear#p291912

Good searcharoonie: search.php?st=0&sk=t&sd=d&sr=posts&keywords=tire+wear&fid%5B%5D=65&ch=-1
Dragon029

Re: slow landing vs normal landing

14 Jan 2018, 22:31

There's various reasons it could have been done:
1. To please the crowd and their hosts.
2. To reduce brake and tire wear (in the last DOT&E report, one of the components affecting aircraft availability across all 3 variants were the main landing gear tires).
3. For ease and safety - the pilots likely just finished an ~8 hour flight, so being able to land at <1/2 the airspeed would make the pilots' life easier (particularly if reason #1 mentioned above is in their mind). You can hit your desired point of the runway you want more easily, you can steer via the nosewheel pretty much immediately to help keep in the middle of the runway, you don't have to worry about flaring at the right time, etc.
johnwill

Re: F-35 landing gear

31 Oct 2016, 06:25

I can think of at least two reasons to sweep the gear strut forward. First is to change the distribution of load between the main and nose gears. By sweeping forward, the main gear contact point is closer to the CG, thus reacts more gear load proportionally than the nose gear. At landing touchdown, if the main gear contact point is moved aft, the airplane will rotate nose down faster, thus increasing the load on the nose gear and vice versa. Adjusting the sweep angle allows optimum balancing of main and nose gear load.

The other reason to sweep the gear strut forward is to reduce the bending load in the strut at impact. Here's what happens. At impact there is of course a large load on the tire contact point, perpendicular to the ground. Due to angle of attack, even an unswept strut is tilted back, so the impact load tries to bend the strut forward. But there is another load at the same time of impact, the load parallel to the ground that spins the wheel up to speed very very rapidly, called spin up load. That load tries to bend the strut aft, so impact load and spin up load tend to cancel the bending in the strut. That's good. By adjusting the strut sweep angle, the cancellation of strut bending can be optimized. Reduced strut bending results in a lighter strut and cylinder, along with less friction and wear.
spazsinbad

Re: 6 F-35s land on Wasp for testing

30 May 2015, 11:50

As pointed out succinctly by 'QS' on previous page of this thread the amiable butler had this incorrect statement in the long post: [IF THE 'ON THE SHIP' phrase had been deleted by a good sub editor then things are fine - but no}
"...As of May 26, no tires required changing as a result of a failure on the ship. Officials say they would likely perform a tire change even if one is not required to demonstrate procedures in the confines of the ship’s footprint. Poor tire performance on the ship earlier plagued the program, so the OT performance was welcomed by overseers...."

Here ya go - because I are tired and I want to go to bed (freezing in my part of the world this evenin')... A long uninformative ramble is here: http://defensetech.org/2013/09/19/5th-g ... ion-tires/

ABOUT aircraft tyres in general AND NOT about F-35: http://www.goodyearaviation.com/resourc ... manual.pdf (7.5Mb)

BUT go here for succinct goodness (as per 'QS' retort over page).
F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds
18 Sep 2013 Anthony Capaccio

"Sept. 17 (Bloomberg) -- Tires that wear out too soon are adding to the troubles facing Lockheed Martin Corp.’s F-35, the Pentagon’s costliest weapons system.

Landing-gear tires made by Dunlop Aircraft Tyres Ltd. for the Marine Corps version of the fighter have “been experiencing an unacceptable wear rate when operating as a conventional aircraft,” according to Joe DellaVedova, spokesman for the Defense Department’s F-35 program office.

He said the tire, which costs about $1,500 apiece, demonstrates “adequate wear” when the aircraft performs short takeoffs and vertical landings intended for amphibious warfare vessels and improvised runways...."

Source: http://www.bloomberg.com/news/articles/ ... agon-finds
quicksilver

Re: 6 F-35s land on Wasp for testing

29 May 2015, 03:43

Amy also wrong about tire performance. "On the ship" was not the issue since all ship landings are VLs. The issue was ashore where they were restricted to higher speed rolling landings (i.e. higher touch down spped and thus higher wear per landing).

Re: RE: Re: RE: F-35 Fighter’s Tires Wear Out Too Soon, Pent

27 Sep 2013, 04:13

maus92 wrote:Could it be that the Dunlop tire design was optimized for STOVL ops, and it turning out that most operations are, and will be, in CTOL mode? And was the Dunlop tire ever redesigned to meet certain weight goals?


Generally correct. Jets are used mostly CTOL because few of the jets are yet mod'd for routine STOVL ops. Remains to be seen what eventually constitutes 'normal' conops in routine day-to-day ops.

RE: Re: RE: F-35 Fighter’s Tires Wear Out Too Soon, Pentagon

22 Sep 2013, 14:11

Could it be that the Dunlop tire design was optimized for STOVL ops, and it turning out that most operations are, and will be, in CTOL mode? And was the Dunlop tire ever redesigned to meet certain weight goals?
popcorn

Re: RE: Tire Issues

19 Sep 2013, 14:35

spazsinbad wrote:Skidmarks already on this post in this part of this forum: http://www.f-16.net/index.php?name=PNph ... c&p=259743

F-35 Lightning II » F-35 Design & Construction » F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds


Aaarrghh!!! Not another F-35 subforum icon to clutter up my homescreen.. :x
spazsinbad

RE: Tire Issues

19 Sep 2013, 10:28

Skidmarks already on this post in this part of this forum: http://www.f-16.net/index.php?name=PNph ... c&p=259743

F-35 Lightning II » F-35 Design & Construction » F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds
popcorn

Tire Issues

19 Sep 2013, 09:24

The level of scrutiny of the F-35 is unparalleled, now even tire wear has surfaced as an issue... B tires use asofter compound,resulting in accelerated wear and tear in CTOL mode? A and C tires can damage LHA/LHD deck coatings?
http://mobile.bloomberg.com/news/2013-0 ... finds.html

F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds

Tires that wear out too soon are adding to the troubles facing Lockheed Martin Corp. (LMT)’s F-35, the Pentagon’s costliest weapons system. Landing-gear tires made by Dunlop Aircraft Tyres Ltd. for the Marine Corps version of the fighter have “been experiencing an unacceptable wear rate when operating as a conventional aircraft,” according to Joe DellaVedova, spokesman for the Defense Department’s F-35 program office. He said the tire, which costs about $1,500 apiece, demonstrates “adequate wear” when the aircraft performs short takeoffs and vertical landings intended for amphibious warfare vessels and improvised runways...
DellaVedova said that tires made by Michelin & Cie (ML) and Goodyear Tire & Rubber Co. for the Air Force and Navy carrier versions, while running down sooner “than originally desired, are currently averaging adequate wear rates.”

RE: F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds

18 Sep 2013, 15:39

The Marines need this tire:

RE: F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds

18 Sep 2013, 10:54

F-35 Program Chief Calls For Improved Reliability, Maintainability 17 Sep 2013 InsideDefense.com
"...The general cited problems with aircraft tires, especially on the Marine Corps' F-35B short-takeoff-and-vertical-landing variant of the aircraft, as one example of a "bad actor."

Those tires must be able to support vertical landings, accomplished by designing the tires to collapse somewhat upon impact with the ground. That quality is technically known as "float." On the other hand, the F-35B tires need to be capable of taking off conventionally, which demands durability. Those two characteristics, float and durability, are at odds with one another.

"Wouldn't you know, float and durability are on the opposite ends of the spectrum when it comes to designing a tire," he said...."

http://insidedefense.com/20130917244709 ... id-61.html

F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds

18 Sep 2013, 06:35

F-35 Fighter’s Tires Wear Out Too Soon, Pentagon Finds 18 Sep 2013 Tony Capaccio
"Tires that wear out too soon are adding to the troubles facing Lockheed Martin Corp. (LMT)’s F-35, the Pentagon’s costliest weapons system.

Landing-gear tires made by Dunlop Aircraft Tyres Ltd. for the Marine Corps version of the fighter have “been experiencing an unacceptable wear rate when operating as a conventional aircraft,” according to Joe DellaVedova, spokesman for the Defense Department’s F-35 program office.

He said the tire, which costs about $1,500 apiece, demonstrates “adequate wear” when the aircraft performs short takeoffs and vertical landings intended for amphibious warfare vessels and improvised runways....

...The Pentagon is working with Lockheed Martin and Birmingham, U.K.-based Dunlop Tyres on a new design for the landing-gear tires that will be introduced next year, DellaVedova said in an e-mailed statement. In the meantime, Dunlop has provided a tire that’s “improved but still unacceptable,” he said.

‘Poor Design’
Michael Gilmore, the Defense Department’s director of operational test and evaluation, said the Dunlop tires are “wearing more quickly than expected” because of a “poor design,” according to a statement from spokeswoman Jennifer Elzea.

John Butters, a spokesman for Dunlop Tyres, said in an e-mailed statement that the initial tires “are experiencing high wear rates” and the interim model has “better tread wear.” The company says on its website that it makes “world class aircraft” tires “and nothing else.”

The Marine Corps model of the F-35 “faces a unique and challenging operational environment” demanding a tire “that can operate without damaging the landing surface,” Butters said....

...DellaVedova said that tires made by Michelin & Cie (ML) and Goodyear Tire & Rubber Co. for the Air Force and Navy carrier versions, while running down sooner “than originally desired, are currently averaging adequate wear rates.”

Military personnel at flight test centers and training locations “discovered that the tires were wearing out too quickly or becoming too thin,” Gilmore said.

Goodyear spokesman Scott Baughman said in an e-mailed statement that the company “works closely with its customers to meet tire specifications.” Michelin North America spokesman Brian Remsberg said in an e-mailed statement that “we have not received any complaints or requests for tire redesign.”"

http://www.bloomberg.com/news/2013-09-1 ... finds.html

RE: Re: RE: Re: RE: Re: RE: Re: RE: Canada might contractors

28 Dec 2012, 22:39

'neurotech' asked: "...Did the RAN A-4G have different procedures for CV-only ops ("Blue water") vs CV with runway divert, or runway only, as far as tire pressure and/or strut pressure/tension?

The F/A-18s are usually flown on carriers with significantly higher tire pressure than for land-based ops. We'd sometimes use different tires for non-CV ops to save wear. I suspect this will be the same for F-35Cs in USN or potential allied partners."

The last part of the question / statement "...We'd sometimes use different tires for non-CV ops to save wear. I suspect this will be the same for F-35Cs in USN or potential allied partners." would have to apply at moment only to USN and I gather they will test this possibility.

As for the first part, I would guess every carrier capable USN aircraft according to their NATOPS will have tyre pressure procedures for Ashore/Afloat. In the A4G case as per NATOPS the tyres were about double the pressure on the carrier compared to ashore tyre pressures. As indicated on other threads this discrepancy between coming ashore from the carrier with these high tyre pressures could make landing on the mostly short runways found in Australia at the time an issue (whether there were adequate short/long field arrest gear just in case could be problematic) although alleviated by the temporary use of Phantoms on lease by the RAAF meant that at those RAAF airfields meant to operate Phantoms there was adequate arrest gear and I will concede longer runways.

An unique issue perhaps for A-4s with spoilers was that they were not used on the carrier but necessary for crosswind landings and on short runways. So having the worst combination of short 6,000 foot runways, with a crosswind, and being wet, for the A4G pilot coming ashore, in whatever circumstances, forgetting to arm spoilers with the high tyre pressures meant for an interesting rollout. NAS Nowra had these 6,000 foot runways with many an disembarkation having such a scenario. No excuse though for not being aware of these issues.

In the first few years of new A4G ops at NAS Nowra whilst the Vietnam War was underway the spares situation was not good. We learnt how to (with the CHIEF) use the tyres down the first showing of the many canvas layers underneath the rubber tread, in order to use them to the max. As indicated earlier I burst only one tyre in my career, being silly one hot windless day.

The RNZAF when using NAS Nowra for training with the KAHU A-4K for a decade would not land for touch and goes there - doing a last second waveoff - to save on tyre wear and tear. Not so the RAN - we needed to get that PLONK on the runway and get the nose off again quick smart feeling, for the short deck onboard HMAS Melbourne. This inability to get the nose up quickly with the TA4G was the reason it never went onboard for any reason.

I wonder how the RAAFie CHAPpies operate their Hornets over all these years as we are discussing? I have no idea really.

Re: RE: Re: RE: Re: RE: Re: RE: Canada might contractors out

28 Dec 2012, 21:08

spazsinbad wrote:Unfortunately 'arkadyrenko' such a good idea: "There is a simple solution to Canada's problems with refueling and aircraft hook inadequacy... Just Buy The F-35C Model...." will be lost on the Canuks. If it is taken up then we will only hear another round of moaning about how inadequate the F-35C is in comparison to the Hornet (only one engine blah blah blah). Nevertheless the KISS principle is always attractive - even perhaps if more expensive - but I don't want to rain on your parade. :D

Since they've already planned for a probe on a F-35A then that isn't going to be a compelling reason to switch. One minor detail with regard to the ongoing to the F-35C vs F-35A debate. Did the RAN A-4G have different procedures for CV-only ops ("Blue water") vs CV with runway divert, or runway only, as far as tire pressure and/or strut pressure/tension?

The F/A-18s are usually flown on carriers with significantly higher tire pressure than for land-based ops. We'd sometimes use different tires for non-CV ops to save wear. I suspect this will be the same for F-35Cs in USN or potential allied partners.

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