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-   -   F-35C Accident - USS Carl Vinson (https://www.pprune.org/military-aviation/644821-f-35c-accident-uss-carl-vinson.html)

SpazSinbad 8th Feb 2022 01:27

EXTERMINATE EXTERMINATE EXTERMINATE USN Blackshoe equivalent to WAVE OFF WAVE OFF WAVE OFF!
Navy Investigating Leaked Footage of F-35C Lightning II Ramp Strike 07 Feb 2022
https://news.usni.org/2022/02/07/nav...ii-ramp-strike
"...While the Navy has released few official details about the ramp strike, the service did not order advisories or warnings to the fleet on technical aspects of the F-35 and its landing system nor did it call for a safety stand down like the service has done following other aviation accidents...."

RAFEngO74to09 8th Feb 2022 19:34

Analysis from former USN aviators here:


tartare 8th Feb 2022 21:24

So... at the risk of incurring the wrath of the `wait for the investigation' crowd - what does the hive mind think may have happened here?
Could this have been an incorrectly flown approach?
That would seem hard to believe given how capable anyone flying a $100m jet should be...
Or some sort of power degradation, or weird microburst thing off the back of the deck at the last second?
Just curious...

RAFEngO74to09 8th Feb 2022 21:46


Originally Posted by tartare (Post 11181762)
So... at the risk of incurring the wrath of the `wait for the investigation' crowd - what does the hive mind think may have happened here?
Could this have been an incorrectly flown approach?
That would seem hard to believe given how capable anyone flying a $100m jet should be...
Or some sort of power degradation, or weird microburst thing off the back of the deck at the last second?
Just curious...

There is a lot in their earlier video on the same channel regarding how carrier landing training & qualification has been dumbed down following huge incremental improvements in the degree of automation of the carrier landing procedure.


With the F-4 and F-14, it was pretty much all pilot skill with constant control adjustments - from the F/A-18 onwards, the degree of automation has been vastly increased leading to a completely different prioritisation of the information the pilot is scanning.
They all agree there is something badly wrong with the approach - which could have been caused by any of / a combination of the following:
- Out of parameters by so great a margin that automatic systems did not take over correctly.
- Failure of the automatic systems and the pilot failing to notice and react in time or noticing and having insufficient time to react.
- Spool up time on the engine when Mil Power applied.
- Helmet information problem.
Note in the PLAT video how the Wave Off signal "W" has been activated before the LSO can even finish shouting Power for the first time as it is going badly wrong so quickly.

tartare 8th Feb 2022 22:45

Wow.
So the children of the magenta line are now slamming jets onto decks as well.
Crikey...

SpazSinbad 8th Feb 2022 22:46

A lot to ponder. Firstly the video from HOOK 2014 demonstrates 'how quickly things can go pear-shaped' when the auto throttle is mistakenly 'clicked out' [deactivated] whilst this senior pilot (but NOT very current in the F-18E at night) has to eject because the aircraft becomes so UNDER powered in the groove. Note how the LSO goes from Power to WAVE OFF. Pilot rescued by helo OK.

Hook 2014 PLAT/ILARTS Night Eject F-18E Super Hornet Approach USS CARL VINSON Pilot Rescued OK HELO


SpazSinbad 8th Feb 2022 23:00

As noted in the WARD CARROLL video above there was no grounding of F-35Cs so it is likely a 'pilot problem' not a 'system' problem. The F135 spools up fine but when actuated too late from a very low RPM it may take longer than usual. The Pilot may have been slow to react to the LSO calls also. The LSO may have been slow (recall the video LSO 'HOZER' says often the 'controlling LSO' is under training). The supervisor LSO may have actuated WAVE OFF lights as the control LSO gets to verbalise it. Because it is a shorter than usual straight away (Groove) perhaps the pilot missed setting up PLM Precision Landing Mode properly or opted to just use AUTO throttles (which he did not actuate?) thus ending up, once he lined up, perhaps a little high but going down with lower than usual RPM which he thought would be picked up by auto throttle when nose raised. Thus he was in the spud locker with LOW RPM - LOW in close - being lowered more perhaps by the burble - not reacting quick enough to the situation including LSO calls - to wind up in a RAMPstrike (which may have been a very hard landing before reaching the wires (when an arrest made whilst landing before No.1 wire this is called a TAXI ONE) - I find it difficult to say one way or tuther). Recall these are just my guesses from very limited information about the accident. I'll guess once investigations complete that the USN will be more forthcoming than usual about this F-35C loss due to the amount of material about it already online. Enquiring minds want to KNOW.

golder 8th Feb 2022 23:07

I'm wondering if it was a practice, manual landing. It would also explain why the system didn't land it.

tartare 8th Feb 2022 23:52

Poor gal or guy.
Can't even imagine the `oh Jesus, fvck!' feeling as the throttle was firewalled to mil power.
And the shock while swinging under the chute.

SpazSinbad 9th Feb 2022 00:48


Originally Posted by golder (Post 11181787)
I'm wondering if it was a practice, manual landing. It would also explain why the system didn't land it.

What is a 'practice, manual landing'?

SpazSinbad 9th Feb 2022 02:32

Thankfully this detailed (but old) article is still online. Must admit to not remembering a lot of it (why? because I ain't gonna be flyin' the C anytime soon). So there is a button on the stick which may have been inadvertantly deselected but as usual I can only GUESS.

Tailored to Trap 01 Dec 2012 Frank Colucci http://www.aviationtoday.com/av/mili...rap_77964.html
"“F-35C control laws give Navy pilots Integrated Direct Lift Control for easier carrier landings, and they open the door for future landing aids.

Joint Strike Fighter (JSF) test pilots in July [2012] began using an Integrated Direct Lift Control (IDLC) scheme meant to improve approach performance and reduce pilot workload in carrier landings. Tailored control responses in part differentiate the carrier-based F-35C from its runway [F-35A] and small-deck [F-35B] siblings. Lockheed Martin test pilot Dan Canin at Patuxent River Naval Air Test Center, Maryland, explained, “What IDLC does is improve the flight path response of the airplane, allowing the pilot to make almost instantaneous corrections to glideslope while maintaining a constant angle of attack.” “The landing approach in the F-35C is flown with the stick only,” noted Canin. “The throttle is automatic.”... [Don't know if it is possible to 'manually control the 'thrust request']

...…“With IDLC, we change the symmetric deflection of the flaps and the ailerons in response to pitch and throttle commands by the pilot. The glideslope response is immediate, and doesn’t require a speed or alpha change. This is a tremendous advantage over a stiff-wing airplane.”….

…“It’s an integral part of the flight control system and responds to the pilot’s normal stick and throttle movements, without requiring a separate control.” The flight control system also compensates for the pitching moments induced by the lifting surface deflections — F-35C ailerons pitch the airplane on approach almost as much as the big horizontal stabilizers — to maintain the proper angle of attack.

IDLC is commanded by an Approach Mode Control button on the F-35 active inceptor stick. “You really could have done this with any other airplane,” acknowledged Canin, “but the implementation would have been more complicated.” He added, “It’s easier and cleaner to do this with a flight control system that’s naturally a pitch-rate-command system.

...All three variants of the F-35 provide some measure of IDLC. “Glideslope is always important,” observed Canin. “Anything you can do to improve flight path control on approach is a good thing. Waveoff performance is also improved with IDLC, since it can stop or reduce your rate of descent while you’re waiting for the engine to spool up.”

The IDLC function is not identical in all the three F-35 variants, however. “The IDLC gain is much higher in the C-model than the other two,” said Canin. “We only have one release of software for the three variants. It configures itself when it wakes up and discovers which type of F-35 it’s in.” The F-35B does not use IDLC at all in jetborne (vertical landing) mode, when aerodynamic control surfaces are fixed.

Even with its innovative flight controls, the F-35C, from the pilot’s perspective, is relatively conventional coming aboard the carrier. “Determining where you are with respect to lineup and glideslope is all visual,” acknowledged Canin. “For lineup, you look at the ship and line up on centerline … easy enough if the ship’s heading is steady, but tricky if the ship is wallowing,” noted Canin. “As for glideslope, you have to watch the meatball and see small deviations. Then you have to put the ball back in the middle, with the right rate of descent so it stays there. None of that’s changed with this airplane, but what we’re giving the pilot is more responsiveness and bandwidth to do that.”..."
_____________________________

DFP quotes from DOT&E report 2016: http://www.dote.osd.mil/pub/reports/ FY2016/pdf/dod/2016f35jsf.pdf
"...The VFA-101 pilots reported that the Delta Flight Path mode of operation made carrier approaches easier on pilot workload and touchdown points more consistent. During the qualifications, pilots made 154 approaches and landings with 100 percent boarding rate and no bolters…."
______________________________

"...The JSF, in a low speed approach to a carrier landing, will descend at about 11 fps [seen on the ILARTS screen low right corner], and will withstand sink rates up to almost 18 fps. By comparison, the typical sink rate for an Air Force JSF will be about two ft/sec.... The Navy JSF currently flies landing approaches at about 130 to 135 knots, about 25 knots slower than the Air Force version....”
http://machinedesign.com/article/the...l-reasons-0307 [2002]

golder 9th Feb 2022 07:14


Originally Posted by SpazSinbad (Post 11181808)
What is a 'practice, manual landing'?

I would say a practicing a manual landing is. So as if the auto system goes down, the jet can be landed. I'll assume they could need to stay carrier qualified in that.

dead_pan 9th Feb 2022 07:59

Watching the leaked footage of the crash it was miraculous the F35 went straight down the flight deck and didn't veer after that mega bounce. Could have been sooo much worse, given how crowded the deck was at the time.

BEagle 9th Feb 2022 08:45

Personally it looked to me like a sudden and total loss of thrust......

Easy Street 9th Feb 2022 09:41


Originally Posted by BEagle (Post 11181933)
Personally it looked to me like a sudden and total loss of thrust......

The sound from the first leaked video (taken with a smartphone from the fantail) disproves that idea. Engine noise normal throughout and clearly spooling up during the final couple of seconds.

SpazSinbad 9th Feb 2022 09:43


Originally Posted by BEagle (Post 11181933)
Personally it looked to me like a sudden and total loss of thrust......

When? The F135 engine was 'spooling up'. I thought I heard the 'HOWL' as it goes into burner just before the smoke in the first video from the fantail view. Yes it is puzzling I think because we do not have details of the accident. One day we may see a report. [OK now I see the other reply to 'beagle' as I replied here]

Just to add: after lining up I think I see the smoke from the engine disappear and the smoke does not appear again until we hear the engine revving up as noted by 'easy street'.

42go 9th Feb 2022 15:22

Beagle - I would recommend "Personally it looked to me like" insufficient thrust?

RatherBeFlying 9th Feb 2022 17:37

The sink rate once lined up is severe; so, how did it develop and what was the pilot doing about it once perceived (timely or delayed)? How was the airframe and engine responding to the pilot inputs?

So if the approach suddenly deteriorates past recoverable, would it help to bank away to miss the carrier and crew before ejecting? Perhaps recovery would have been possible before hitting the water, but with that sink rate it didn't look likely.

typerated 9th Feb 2022 19:11

Hard to judge without seeing a normal approach.
But it does seem slow - is it effectively stalling on? - power just to late to save?

One interesting thing I saw was watching a violent movement of the stabilator just before touch down - and it was a pitch forward - why?


RAFEngO74to09 9th Feb 2022 19:21

Normal landing of an F-35C



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