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

quicksilver · by **quicksilver** » 29 Dec 2018, 16:29

"Difficult to imagine any of it just viewing a few videos..."

I know; first time I flew a jet w a HUD (close to four decades ago) I thought it was the greatest thing since sliced bread. Makes sooo many things that much easier, so much so that some become HUD-crippled. No-HUD EPs get lotsa attention in the sim as a result.

In the case of SRVL, the HUD and HOTAS mech is not unlike DFP in the 'C'. One dials in the GS reference and the ship velocity and then flies the SRVV to the intended touchdown point. The depiction you provided above illustrates, but the rest of the story is how the flight control/HOTAS mech contribute to the ease of flying. Add to that a 35kt approach speed (relative) and one has plenty of time to correct for deviations. Night time probably a bit more sporty, but still monumentally simpler.

spazsinbad · by **spazsinbad** » 29 Dec 2018, 16:48

Notwithstanding your explanation (I have flown only using an F-18 HUD in MsFlightSims which of course is LUDICROUS) one needs to account for ship movement in the 'six degrees of freedom' mostly the PITCH & HEAVE as illustrated above. It is 0255 here, I have been working on making a better SRVL PDF but I'll have to stop and get going again later this morning.

However there is a recent SRVL 200 page PDF from whence came the illustrations above along with heaps of explanations.

viewtopic.php?f=22&t=20304&p=403872&hilit=reprinted#p403872

F-35B SRVL INFO 18 Oct 2018 PRN pp 200.PDF (9.7Mb) download/file.php?id=28580

quicksilver · by **quicksilver** » 29 Dec 2018, 17:30

‘...one needs to account for ship movement in the 'six degrees of freedom...’

SRVV does that.

spazsinbad · by **spazsinbad** » 29 Dec 2018, 17:58

I'll guess if the PDF is perused one may see that there is more to it than my cryptic remark. I'm back but not for long. NOT having seen the simulator with the SRVL etc and as described having to 'imagine' how it all works it then becomes difficult to describe accurately & succinctly what the SRVL entails in all the glory of the real deal in conditions that are not great.

Having some olde schoole deck landings without using modern aids except a mirror and an AoA Indexer I could describe an A4G carrier approach well enough using few words that could be understood - but notso the SRVL - I can only imagine.

And yet the PDF in many ways does describe how various factors are taken into account: braking distance, ramp clearance, safe not exceed descent rate and on and on - not all of these are accounted for by the SRVV - the Ship Referenced Velocity Vector. Given time later I could mash up an explanation from all the various references in the latest PDF as indicated above (the new PDF yet to be uploaded just ices dat cake). So my cryptic explanation matches other 'only SRVV cryptic' explanations for the moment. How many pages in this thread? Most of the material refernced in this thread is in the latest PDF made available recently. Sure 200 pages is a lot to read and absorb - but there it is.

spazsinbad · by **spazsinbad** » 29 Dec 2018, 21:59

As good an explanation as any (wordy perhaps) about the need for the BEDFORD ARRAY for SAFE SRVLs aboard CVF S.S.6:

BRIEFING: SHIPBORNE ROLLING VERTICAL LANDING [SRVL]
c.2008 Richard Scott

"...Landing aids
With SRVL now likely to he used as a primary recovery technique on board CVF, there is an additional requirement to augment the baseline landing aids suite with a landing aid appropriate to the SRVL approach manoeuvre. To this end QinetiQ has been contracted to research, conceptualise and prototype a new VLA concept, known as the Bedford Array, which takes inputs from inertial references to stabilise against deck motions (pitch and heave). The software-controlled lighting pattern provides an aim-point for the recovering pilot.

Justin Paines, development test pilot for QinetiQ, said: “Study work and simulator flying have shown that the F-35B has a critical vulnerability to deck motion for the SRVL manoeuvre. So while there is confidence that SRVLs can he performed safely in benign conditions with good visibility, it was apparent that the real task drivers for the manoeuvre were higher sea states and night/poor weather conditions.”

Simulator flying undertaken on both sides of the Atlantic, including work at BAE Systems’ Warton Motion Dome Simulator in December 2007, had brought the problem into sharp relief. “Quite simply, these simulations showed that pilots would crash in high sea state conditions without a suitable stabilised visual reference,” said Paines. “The need for some sort of VLA optimised for SRVL was therefore apparent.”

Although an unstabilised approach aid was looked at early on, the ‘top end’ (recovery in Sea State 6) requirement saw it ruled out on grounds of pilot workload and risk. So a stabilised VLA quickly emerged as a sine qua non. [SEA STATE 6: “4 to 6 metres wave height - Very rough & Surface Wind speed from Table can be from 27-33 knots” Sea State Table: http://www.syqwestinc.com/support/Sea%2 ... 0Table.htm & http://en.wikipedia.org/wiki/Sea_state ]

Existing systems were evaluated, including the US Navy’s Improved Fresnel Lens Optical Landing System (IFOLS). “However, the verdict on IFOLS was that it was reasonably expensive, not night-vision goggle compatible and, as a mechanical system, presented an additional maintenance burden to the carrier,” says Paines. “So the concept of the Bedford Array was conceived, developed and fully tested in around a year in direct response to MoD requirements.”

The science behind the Bedford Array – so called because it was brainstormed at QinetiQ’s Bedford lab – is deceptively simple. A linear array of software-controlled lights is installed along the centreline of the axial flight deck, using a simple mathematical algorithm to switch on the appropriate lights according to the ship motion references input to the system. These provide a stabilised glideslope indication for the pilot’s helmet display SRVV symbology.

“The system ensures that the pilot flying the ‘rolling landings’ makes an accurate approach to the deck, even in rough sea conditions,” said Paines. “It takes inputs from external passive references and when combined with information in the pilot’s Helmet Mounted Display, allows for a low-workload, stabilised pilot approach in even the worst conditions.”

A trial of the Bedford Array concept was undertaken aboard the aircraft carrier HMS Illustrious in November 2008, with QinetiQ using the VAAC Harrier test bed to fly approaches to a demonstration Bedford Array mounted on the ship, in order to evaluate its ability to accurately indicate an SRVL glideslope aim-point. For the purposes of the trial, the lighting array was installed in the port catwalk adjacent to Illustrious’ flight deck.

The VAAC Harrier did not actually perform SRVL recoveries to the ship, owing to the limited dimensions of the flight deck. Instead, it flew representative SRVL approach profiles to the catwalk array (down to a safety height of about 40 ft above deck) and then performed a low go-around.

QinetiQ’s VAAC Harrier flew a total of 39 sorties in the southwest approaches between 12 and 19 November 2008 to prove the Bedford Array concept. In all, 67 vertical landings and around 230 SRVL approaches were flown.

A second lighting array was rigged on the carrier flight deck itself. This was used for a parallel evaluation of the visual acuity of the lighting system, in different ambient conditions, on deck.

“This series of trials was designed to refine the operational concept, mitigate failure cases and optimise the Bedford Array visual landing aids arrangement,” said Lieutenant Commander Chris Götke, VAAC project pilot and one of the six assessor pilots participating in the trial. “The solution was first tested in QinetiQ labs and has now been proved by successful trials, and will be implemented on the new carriers.”..."

Source: http://www.zinio.com/reader.jsp?issue=3 ... v=sub&p=28 [no worketh now] so go here: viewtopic.php?f=22&t=20304&p=265112&hilit=Paines#p265112 [& not quite the same article: http://militarynuts.com/index.php?showtopic=1507&st=120 ]

spazsinbad · by **spazsinbad** » 30 Dec 2018, 04:23

Attached is a 222 page PDF of UK F-35B SRVL goodness via Warton Sim & VAAC Harrier Program + SHOL explained a bonus.

F-35B SRVL INFO 30 Dec 2018 PRN pp 222.pdf (11Mb)

quicksilver · by **quicksilver** » 30 Dec 2018, 12:38

Spaz, I don’t have to imagine; I’m trying to help you imagine.

spazsinbad · by **spazsinbad** » 30 Dec 2018, 12:57

Again: being cryptic is NOT helpful. I have given you the explanation for the Bedford Array. I can imagine deck spotting to get onboard with my own SRVL - no other aids needed except eyeball it. However as the screed makes clear 'good luck' doing that in bad weather (and I have simplified there are lots of considerations - found in the PDF uploaded). This story says it all - anything is possible: An old bold ex-Sea Venom pilot turned A4G driver arrested aboard MELBOURNE when the mirror was still covered (an error by Mirror Control Officer helper) in unusual circumstances. This pilot called the ball and only after arresting OK did the LSO realise there was NO BALL to be seen. Harsh words ensured. Said pilot (unknown to most) wore glasses when flying (not done in my day) so he may or may not have been wearing same during the approach.

quicksilver · by **quicksilver** » 30 Dec 2018, 23:05

“I can imagine deck spotting to get onboard with my own SRVL - no other aids needed except eyeball it.”

Recommend you re-imagine w a vHUD, a GS reference and an SRVV. If the vHUD fails, overlay HUD symbology on the DAS in a PCD window.

quicksilver · by **quicksilver** » 30 Dec 2018, 23:19

Obtw, some air forces call the ‘velocity vector’ a ‘flight path marker’; it makes lotsa stuff really easy because one just places the fpm over the intended point of landing, presses a button and monitors/corrects for deviations...and the jet responds to one’s most subtle inputs (or not). It’s that easy.

spazsinbad · by **spazsinbad** » 31 Dec 2018, 00:19

quicksilver wrote:Obtw, some air forces call the ‘velocity vector’ a ‘flight path marker’; it makes lotsa stuff really easy because one just places the fpm over the intended point of landing, presses a button and monitors/corrects for deviations...and the jet responds to one’s most subtle inputs (or not). It’s that easy.

I'll get to the DAS window later, however 'AIR FORCES?!' WTF?! Who cares wot 'AirForces' do. 'AirForces' land (usually) on runways that are LOONNGG, not displaying any SIX Degrees of Freedom, in sometimes ADVERSE Sea STATES. GameOver.

I have read about USN Hornet pilots placing the VV on the CROTCH during a CVN approach for the LINE UP innit [and getting to a good start from a LONG WAY out] (straight in I guess because otherwise WAVE OFF; LONG IN GROOVE by LSO), however they must take out the crab misalignment at some point but it is helpful. Sure experienced carrier pilots can do ANYTHING as I pointed out earlier but woebetide any problems occurring - I would not like the PLEASE EXPLAIN. I think already I have posted an NAN Winter 2011 GranPawPettibone story about a NU-GENT using the NEEDLES to carrier land (he thought it was the GOUGE). The rampstrike that ensued DID NOT CARE but he survived to tell the tale - thank goodness.

I'll guess that you still not have cottoned on to MOVING T/D AIM POINT indicated by Bedford Array to ensure SAFETY?!

VV / crotch mention: viewtopic.php?f=62&t=16223&p=241162&hilit=needles#p241162

More crotchiness mit graphic ilLustStration: viewtopic.php?f=62&t=16223&p=234249&hilit=needles#p234249

GRAMpaw NEEDLESS: viewtopic.php?f=22&t=20505&p=233738&hilit=needles#p233738 The OMNITECH url here noworkee so I'll have to post the PDF 'bout it.... NOW attached below. An HUGE amount of info/stories about Naval Aviation (NavAv) are contained in PDFs (or 1 HUMUNGOUS PDF): https://www.faaaa.asn.au/spazsinbad-a4g/

spazsinbad · by **spazsinbad** » 29 Apr 2019, 23:13

One for 'stevieTheWondering' to ponder. Is this an SRVL max weight on LHA 'MERICA going RONG? :mrgreen:

from:

F-35 JOINT STRIKE FIGHTER April 2019 p 43-4 Action Needed to Improve Reliability and Prepare for Modernization Efforts
https://www.gao.gov/assets/700/698748.pdf (2.2Mb)

quicksilver · by **quicksilver** » 30 Apr 2019, 00:36

They got figure 9 wrong; that is a takeoff on a wet flight deck.

I think that pic is from 2016 testing. But, here’s a video link w sto on wet deck during the combat sorties flown in recent months. Watch the segment from 2:20-2:40 to see what happens under the jet during a launch on a wet flight deck.

https://m.youtube.com/watch?feature=you ... Dd0b6sl-b4

spazsinbad · by **spazsinbad** » 30 Apr 2019, 01:09

I am pleased to know WHY the F-35B tyres are wearing out - HeavyWeightSRVLs TESTin' on LHAs IS MADNESS! :doh:

How usual is the STERN Approach to VL? Is it because darkness afoot? OR just part of the mixture (rather than translate).

USS Wasp 31 Jan 2019: https://www.dvidshub.net/video/657464/f ... nal-pylons

F-35B Ops WASP Stern Approach to Vertical Landing 31 Jan 2019 https://www.youtube.com/watch?v=ncp9yqMkRCY

quicksilver · by **quicksilver** » 30 Apr 2019, 01:47

The former PEO remarked something to the effect that “tires weren’t rocket science...”. Turns out they are a lot more difficult to get right than he thought. When you add up the competing requirements for a 35-40k# STOVL jet (heat tolerance with all that engine and roll post exhaust nearby, weight (of the tire), durability for relatively high ROD rolling landings and, of course, cost) things are apparently a bit challenging.