F-35 Cancelled, then what ?

[SpazSinbad]

East of Suez

From the main NAO PDF report there is this quote:

"...3.10 An important enabler of the UK’s STOVL Carrier Strike capability will be the ability to conduct Ship-borne Rolling Vertical Landings (SRVL). This landing technique will be necessary where a conventional vertical landing is less likely to be possible without jettisoning large weapons or fuel load when in hot, humid or low pressure weather conditions. [East of Suez when youse fall off the edge - there be dragons?] At present the technology is not proven with redesigns required to the carrier deck and aircraft software. The capability will be required for operations by 2020 and the Department included a provision to complete development as part of the cost of reverting to STOVL. The Department is confident it will develop the technique within the required timescale...."

I have seen many references to "East of Suez" and "hot humid conditions" in reference to the apparent inability of F-35B to do VLs according to KPP requirement (hence SRVL). [Otherwise for purposes of the KPP the F-35B does meet the requirements.] It seems to me that everyone in the UK knows what the temperature referred to means - would someone let me know what these 'East of Suez' conditions are please? All temps etc. would be at sea level or whatever deck height for CVF is appropriate. Thanks.

[Courtney Mil]

I'd never really thought about it before, Spaz, but had always assumed it was a rather vague expression to mean the hot places in the Empire once you get to the Middle East and beyond. I don't think it refers to a specific set of conditions, it's not an ICAO standard. At least, I don't think it is.

[eaglemmoomin]

I remember seeing something about 50 degrees (can't remember where) I've no idea if that was Celcius or Farenheit which seemed plenty hot enough for a VL with VL bring back muntions and fuel.

[Stitchbitch]

I seem to remember another hovvering war budgie that couldn't VL with stores in the heat. Not until it was upgraded. And then sold off.

QQ still have the VAAC Harrier if the navy needs to trial RVL'ing?

[SpazSinbad]

F-35B VLBB Info Today and Past

Some 'old' VLBB F-35B info with temps and current KPP with old 2002 conjecture below...

Scorecard: A Case study of the Joint Strike Fighter Program by Geoffrey P. Bowman, LCDR, USN — April 2008

http://www.f-16.net/f-16_forum_download-id-14791.html (0.3Mb)

"The USMC has added STOVL performance as a service specific key performance parameter. The requirement is listed as follows: With two 1000# JDAMs and two internal AIM-120s, full expendables, execute a 550 [now 600] foot (450 UK STOVL) STO from LHA, LHD, and aircraft carriers (sea level, tropical day, 10 kts operational WOD) & with a combat radius of 450 nm (STOVL profile). Also must perform STOVL vertical landing with two 1000# JDAMs and two internal AIM-120s, full expendables, and fuel to fly the STOVL Recovery profile = ["...2,200 lbs of fuel for an approach, vertical landing, and reserve (Killea) see below]."
_______________

The STOVL Variant of Joint Strike Fighter: Are its’ Tactical Compromises Warranted? Written by: Captain G.M. Beisbier, 01 March 2002

http://www.dtic.mil/cgi-bin/GetTRDoc...c=GetTRDoc.pdf (54Kb)

“...STOVL JSF DESIGN REQUIREMENTS [pages 5-6]
The design requirements for the STOVL JSF mandated a Vertical Lift Bring Back (VLBB) capability of 5,000lbs of fuel and ordnance on a tropical day. The STOVL JSF’s empty gross weight is 29,735 lbs, and it is equipped with a lift fan design capable of producing 39,800 lbs of vertical lift at sea level on a tropical day. An ability to produce 39,800lbs of thrust minus 29,735 lbs gross weight and 3,000 lbs of thrust to safely maneuver the aircraft equals 7,065 lbs of VLBB. As a result the STOVL JSF thirty percent more VLBB then the requirements document mandated (Killea). This means in a worst case, sea-based scenario the STOVL JSF is more than capable of conducting a vertical landing with 4,000 lbs, vise 2,000 lbs, ordnance, plus two 325-lb radar missiles, and 2,200 lbs of fuel for an approach, vertical landing, and reserve (Killea)....”
__________________________

Graphic from: Strike Fighter – From a Harrier Skeptic Captain A.R. Behnke, Mar 2002

http://dodreports.com/pdf/ada520417.pdf (129Kb)

[CoffmanStarter]

Interesting piece from British Forces News ...

Abandoned plans to switch the fighter aircraft for the Royal Navy's new carriers will cost taxpayers £74 million, according to a public spending watchdog.

More here ...

BFBS News

Just love this phrase/quote from the article ...

Although the department "acted quickly" once it had realised the problems with switching, the decision made in the defence review was based on "immature data and flawed assumptions", and the subsequent work cost about £74 million, the National Audit Office (NAO) said.

When I was responsible for multi £m projects in the Private Sector I would have been sacked for even thinking of using those lines as an excuse

[Engines]

Guys,

Perhaps I can help here on the subject of STOVL bringback.

This has always been a KPP for the F-35B, set so as to stress the STOVL design. The KPP was framed as a requirement to carry out a VL to a ship with a full internal payload of 2 1000lb JDAMs and 2 AIM-120, plus enough fuel to carry out a full IMC circuit and landing.

There are a number of conditions that apply to the calculation of the actual 'VLBB' value, not least the required operating temperature and pressure limits. I can't remember the actual figures (sorry Spaz), but the JSF JORD (which the UK signed up to) used a US Mil Spec definition of a 'tropical day'. That applies to this day, and the F-35B must be able to achieve a VLBB with the specified load on that 'hot day'. The actual VLBB number, though, has changed with changes to a number of other design parameters.

The VLBB target is actually pretty tough, as it also makes a number of pessimistic (or realistic, depending on your point of view) assumptions about achieved engine thrust and weigh growth.

However, in around 2002, the UK requested that LM look at the effect on VLBB when operating at even higher temperatures (and lower pressures), such as those that had been experienced in the Gulf in summer. These studies showed that there would be a shortfall in VLBB when operating outside the requirement, and the studies into SRVL started in around 2003.

So, the F-35B can do a VL with stores 'in the heat'. It just can't do it in 'even more heat'. In those extreme cases, the SRVL is being worked on as a solution, and in my view it's a sensible idea. the F-35B has outstandingly clever and effective control systems that give it very good handling qualities throughout the envelope right through transition, unlike the Harrier. It's also got a decent set of brakes. (again unlike the Harrier) Early assessments by the TPs were quite positive, and indicated a good increase in bring back for quite modest speeds over the deck, especially when the ship supplied a bit of WOD.

Hope this helps

Best regards as ever

Engines

[SpazSinbad]

HOT/Tropical Day Temps US Mil STD

Thanks 'Engines'. I have not followed the minutiae of eventual CVF and F-35B selection over the last decade, so a lot of terms, perhaps common to UKers, escape me. Onesuch is 'KUR' - I think that term can be found on the 'Beedall' CVF website; and I will follow that up. Anyhoo here are some temperatures defined:

"There are four specific "non-standard" atmospheric models that are defined in MIL-STD-210A. They each have their own temperature vs altitude profiles, but at sea-level:
(US, 1962)
Standard : 59 deg F
"Cold" : -60.0 def F
"Polar" : -15.7 deg F
"Tropical": 89.8 deg F
"Hot" : 103.0 deg F
____________________________

Future Aircraft Carrier (CVF)
Queen Elizabeth Class Part 4

Navy Matters | Future Aircraft Carrier Part 4

"Key User Requirements
Nine top-level Key User Requirements (KURs) for CVF have been laid out, which define the capabilities required. They are as follows:
- KUR 1, Interoperability: CVF shall be able to contribute to joint/combined operations;
- KUR 2, Integration: CVF shall be able to integrate with the joint battlespace to the extent required to support air group operations, command, control, communications, computers and intelligence (C4I) functions and survivability;
- KUR 3, Availability: CVF shall be able to provide one operational and available platform at all times;
- KUR 4, Deployability: CVF shall be able to deploy for operations worldwide;
- KUR 5, Sustainability: CVF shall be able to sustain operations;
- KUR 6, Aircraft operation: CVF shall be able to deploy offensive air power to the sortie-generation profile specified without host-nation support;
- KUR 7, Survivability: CVF shall be able to achieve a high probability of survival;
- KUR 8, Flexibility: CVF shall be able to operate the largest possible range of aircraft; and
- KUR 9, Versatility: CVF shall be able to operate in the widest possible range of roles.

Each of these is supported in more detail by a series of so-called user requirements documents (URDs), and there are typically 10 of these per KUR.

A solution is developed which meets each of these URDs but, almost invariably, the result is too expensive or too difficult to achieve. It is the responsibility of the IPT, in conjunction with the customer and the supply chain, to examine these capability requirements and seek a solution that would measure trade-offs, and meets the available budget. This is necessarily an iterative and lengthy process, requiring both analysis and synthesis of a complex set of variables...."

[dat581]

A quick question: If the F35B is used at a high operational tempo in a theatre so hot as to require SRVL's how long are the brakes going to last? How easy is it to change the brake pads? Can it be done easily with out removing the main wheels to do it or will the aircraft need to be struck down to the hangar deck and jacked up and have a fresh pair of wheels with new pads swapped in taking a fair bit of down time to do?

[SpazSinbad]

Wet brakes

'dat581' on another thread this reply by 'Engines' seems to be a good one (carbon brakes etc.) although your other concerns not answered:

http://www.pprune.org/military-aircr...ml#post7160694

I'll guess that earlier concerns in 2010-11 have been fixed? Lots of aircraft at Eglin AFB now with no concerns about wet runways voiced so far....

DOD PROGRAMS F-35 Joint Strike Fighter (JSF) page 6

http://www.dote.osd.mil/pub/reports/...2011f35jsf.pdf

"... - The program previously discovered deficient aircraft braking performance during landing on wet runway surfaces. The program tested new brake control unit hardware and software intended to improve performance. The program accelerated testing of the capability to stop the aircraft after landing on wet runway surfaces to 2011 to support the military flight release for aircraft ferried to the training center [Eglin AFB coastal subtropical wetness?]. Changes to the wheel brake controller improved this capability, but the program has not determined if the deficiency is resolved. Effective use of the latest design depends on the adequacy of simulations used to train pilots in maintaining directional control while activating differential braking. This requires precise control of brake pedal deflection, [twas ever thus - try braking an A4G on a wet 6,000 foot runway] which will be difficult if not impossible during non-instrumented flight...."

[SpazSinbad]

F-35 Stealth Coat OK + Block 2A & More Secure ALIS 1.03

Stealth coatings on F-35 'easier to maintain' than on older jets 10 May 2013 Dave Majumdar

Stealth coatings on F-35 'easier to maintain' than on older jets

"US Air Force maintenance troops working on the Lockheed Martin F-35A Joint Strike Fighter at Eglin AFB, Florida, say the stealth coatings on the new fifth-generation type are proving easier to work on than those on earlier low-observable (LO) platforms.

Maintaining the LO coatings on the new aircraft marks "a significant improvement", says Senior Master Sgt Eric Wheeler, a maintainer assigned to the 33rd Fighter Wing at the base. "Typically, [it] has not caused us a whole lot of downtime on this jet."...

...One significant recent development at Eglin AFB is that the maintenance is upgrading the autonomic logistics information system (ALIS) version 1.03 with the delivery of the base's first Block 2A configuration F-35.

The new system, which is also being used at MCAS Yuma in Arizona, Edwards AFB in California and Nellis AFB, Nevada, is able to handle classified data, unlike the older ALIS version."

[dat581]

The real test for the stealth coatings is when the F35B or F35C deploy for an extended period at sea. Super Hornets come back looking very shabby after a long deployment but seem to handle it better than the Hornets do. The Tomcats looked even worse. Don't know if it's better paint or better airframe materials in the Supers.

[peter we]

If the F35B is used at a high operational tempo in a theatre so hot as to require SRVL's how long are the brakes going to last?

They will be required to stop about 20tonnes at about 60mph. How long to truck or car brakes last? They are designed to work at three times that speed so will be under-stressed.

SRVL is also an emergency/exceptional use not standard operating.

[BBadanov]

Don't know if it's better paint or better airframe materials in the Supers.

I guess the Supers do have an improved finish, and probably other enhancements.

[SpazSinbad]

For 'dat581' as indicated earlier the stealth coatings are baked on and ruggedised already for sea / deck conditions...

Lockheed Gives a Peek at New JSF Stealth Material Concept by Amy Butler May/17/2010

Lockheed Gives a Peek at New JSF Stealth Material Concept

"It is called "fiber mat," and Tom Burbage, executive vice president of F-35 program integration for Lockheed Martin says it is "the single, biggest technological breakthrough we've had on this program." He says that a new process to blend stealth qualities into composite material avoided the need for stealthy appliqués and coatings. Using a new process, Lockheed officials are curing the stealthy, fiber mat substance into the composite skin of the aircraft, according to Burbage. It “makes this airplane extremely rugged. You literally have to damage the airplane to reduce the signature,” he said in an interview with Aviation Week in Fort Worth. This top-fiber mat surface takes the place of metallic paint that was used on earlier stealthy aircraft designs. The composite skin of the F-35 actually contains this layer of fiber mat, and it can help carry structural loads in the aircraft, Burbage adds. Lockheed Martin declined to provide further details on fiber mat because they are classified...."

[dragartist]

paint

Whenthese LO coatings get maintained (touched up or resprayed) do they need tocheck the RCS? I can imagine the porous nature picking up dirt (hence theshabby looking frames after a long detachment) this dirt probably carbon/ sootmust have an effect on the RCS.

[PhilipG]

How often is the RN going to use SRVL

SRVL is also an emergency/exceptional use not standard operating.
I am confused, as I understood it the B has to be able to land vertically with 2,000 of bombs and 2 AMRAAMs stowed internally, together with a specified amount of fuel.
I understood the RN/MoD did not think that it was a good move to have to dump such weapons systems as Storm Shadow, if it had not been safe or necessary to use the weapon, thinking that it weighs in at 2,700 lb, just about the total designed bring back weight for a VL.
It thus seems very sensible for the RN/RAF F35B force to be trained in SRVL, as well as having the deck layout of the QEC Carriers designed for it.
What the USMC is going to do with the unexpended ordnance is a question for them, without ski jumps of course the USMC aircraft cannot take off with as many weapons as the UK aircraft, so possibly it is not so much of an issue for them..

[dat581]

How did the A4G hold up at sea Spaz? I've never seen a photo of a RAN Skyhawk looking shabby.

[Engines]

dat581:

Perhaps I can help. The F-35's brakes are designed against a fairly tough set of requirements for repeated conventional touchdowns at high weights at very high ambient temperatures. That drove in some fairly massive brake units and wheels, which were revisited during the weight reduction studies, but still left as very substantial units. F-35B has always had slightly smaller brakes to save weight.

During the first SRVL studies in 2003, I remember that braking performance was looked at. The wheel and brake units were never an issue, as peter we quite correctly points out. The bigger issue was wet decks, which were being carefully analysed a while back. The modern computer controlled brake units offer very good performance, once the software is tuned, but there will be extensive trials before the aircraft gets anywhere near a deck.

Best Regards as ever

Engines

[SpazSinbad]

'dragartist' which aircraft do you refer to in your post?

If I can make a comparison to A4G brakes (quite good really but had to be controlled precisely with toe differential braking rudder pedals) with Sea Venom brakes. It was easy to burst a tyre (depending on tyre pressure) in the A4G. A4G tyre pressures doubled for embarked ops; when ashore from the deck things could be tricky (when working up for example [carqual]). Like most high pressure tyre aircraft it was also easy to aquaplane on water covered runways in an A4G - the wing spoilers were useful of course but if forgotten during first runway landing from embarked ops (not used on deck) then things got tricky quickly depending on w/x.

The Sea Venom had Girling Maxaret Brakes. These were excellent in any circumstance I encountered - but never embarked - the Venom was at the end of days when I flew them (second last RAN FAA sortie ever) only ashore. Sorties were banner tow, Delmar Target Tow and other Fleet Support with a bunch of sorties against A4G OFS students (as an aggressor) or whatever. I'm guessing the F-35s will have equivalent anti-lock capabilities for excellent brake performance.
_______________

'dat581' if you download the different sized examples of PDFs online you will see 'shabby A4Gs'.

https://skydrive.live.com/?cid=cbcd6...6&sa=822839791

The early A4Gs had original dull paintwork that caught all the oil/hydraulic leaks and whatnots. However this original paintwork (anti glint) was not hard wearing so gradually the paint was changed with bits being painted in gloss to stop the paint peeling off. By the time the second batch of second hand A-4Fs converted to A4Gs arrived in their high gloss paint scheme it was decided this was the way to go. The high gloss paint was rugged (compared to dull) and it resisted the oil/hydraulic leak stains. They could still look shabby - especially underneath when embarked. Or when in later years when 'tram tracks' installed aft of the island so that A4Gs were parked their during landing ops, the funnel gas would quickly corroded the paint finish. Have a look at 'A-4 Alley Photos' for this especially:

The A-4 Alley - RAN A-4 Skyhawk Operations 1968-1984

http://a4-alley.x90x.net/A4-Alley/RA...tramtracks.JPG

"“Down chains, off brakes, come ahead slowly !” Newly promoted LEUT ‘Bruiser’ Baddams RAN nervously applies generous throttle to get N13-154903 (side number 882) rolling forward as the ship (HMAS ‘Melbourne’ CVS-21) starts a roll to stbd, threatening to tip his lightly loaded (note the lack of external fuel tanks or armament) a/c backwards over the side. That single white line the a/c’s nosewheel is about to cross is the flight deck safety line (the edge of the landing path visible to the upper right), illustrating how narrow the ship’s flight deck was and just how far the WIDE wingspan of the RAN’s twin prop S-2G Tracker ASW a/c reached …That’s why the ship was modified to add what we called the ‘tram tracks’ jutting out over the ship’s side. These allowed a number of Skyhawks to be parked along (over) the ship’s side aft of the ‘island’ … which is also why they ended-up with that curious (and hopelessly ineffective) yellow paint all over their leading edges, as may be seen on 882). It probably also accounts for why 882 has another a/c’s nose cone … the ‘control’ part of corrosion control was almost non-existent aboard ship. (Text and Picture Laurie Hillier)."
_______________________

For 'Engines' the original "Spastic" Al Hickling is in the A4G overhead whilst that other lad is pretending to YAK (and he is 6 foot - to qualify for the 'six foot yak') on the radio:

http://a4-alley.x90x.net/A4-Alley/RA...croftRange.jpg