JASDF F-35A crashed

[Gums]

Salute!

I am not all that supportive of the above definition of "leans". Maybe Outlaw, Spaz and others can help here.

My experience was that I tilted, or "leaned" my head to get the little gyros and hairs in the ear to agree with what my attitude indicator showed, or just to stay close on the wing during night weather. I swear, many a night in weather I was sure we had done a barrel roll or two. The worst time was when a really smooth lead would be in a turn, then suddently roll out. For a while you were sure that you were turning, but a glance at the ADI said you were wings level. Hence, when a lead, I always called our turns rolling in and rolling out. When solo, the "leans" usually went away after a few moments, especially if you did any turns.

Gums recalls....

[quicksilver]

Salute!

I am not all that supportive of the above definition of "leans". Maybe Outlaw, Spaz and others can help here.

My experience was that I tilted, or "leaned" my head to get the little gyros and hairs in the ear to agree with what my attitude indicator showed, or just to stay close on the wing during night weather. I swear, many a night in weather I was sure we had done a barrel roll or two. The worst time was when a really smooth lead would be in a turn, then suddently roll out. For a while you were sure that you were turning, but a glance at the ADI said you were wings level. Hence, when a lead, I always called our turns rolling in and rolling out. When solo, the "leans" usually went away after a few moments, especially if you did any turns.

Gums recalls....

The description in the doc was a little dense; I had to read it a couple times...

Most memorable case for me at night IMC flying in parade as wingy. After thinking lead had been in a LH 30 degree aob turn for about 20 minutes, I glanced at the HUD and noted that we were actually straight and level...

[spazsinbad]

Not sure about what is required however here is another 'explanation' of the LEANS. There is a page with a quote from A-4 NATOPS about changing radio frequencies. Due to cramped cockpit often the radio changing required twisting and looking to the right and down - then of course doing reverse. NATOPS warns: on PAGE SIX of the SD PDF "“Do not switch the radio or IFF frequency codes below 2,500 feet at night or instrument conditions except for urgent military necessity. If this necessity arises, the aircraft should be in stabilized, level flight before changing frequencies or codes.” Even then one had to be careful about doing the twisting and head moving slowly (not quickly abruptly). YIKES! There I am first downwind at night at 1,000 feet required to change radio frequencies from CCA/LSO back to area radar (IIRC but perhaps NOT for the reason explained). That event is getting too far in the past these days. GOOD descriptions by others above though.

Don’t believe your ears
05 Jan 2018 Staff Writers

"...Somatogravic illusions
There are three versions of the somatogravic illusion. Both involve the body’s inability to distinguish pitch changes from acceleration.
1. The leans
This common illusion is a false sensation of roll. It gets its name because pilots lean to one side in order to cancel out the false sensation. Leaning your body is the right way to counter the leans; rolling your aircraft is the wrong response. The leans often happen when a pilot looks down at a map, radio or instruments, and the aircraft goes into a gentle, banked turn that is too slow for the vestibular system to detect. Typically, the pilot looks up, and corrects the bank. But because this correction is fast enough to be felt by the inner ear, visual and vestibular information get out of sync and the leans occur. This illusion can occur in good visual flight conditions.…

...Myths, busted
Because spatial disorientation is a result of human anatomy, it follows that no human is immune to it. It is a maxim of aviation medicine that spatial disorientation is a normal human reaction to an unnatural situation.

A false and dangerous idea about spatial disorientation is that it can always be felt. Not so. The graveyard spiral can occur without being detectable to the inner ear. In their 2004 magnum opus on sensory illusions, researchers Bill Ercoline and Fred Previc write:

‘ … all too many pilots have gone to their death never feeling or suspecting that anything was amiss with their aircraft’s altitude or trajectory’.

The only advantage skill and experience have when it comes to spatial disorientation is that they may (but do not necessarily) help in recognising the phenomenon. They do not stop the effects. After a session in the disorientation-inducing Barany chair at the RAAF Institute of Aviation Medicine, Qantas pilot Richard Champion de Crespigny summed up the value of experience in one sentence. ‘I have about 16,000 hours,’ he said, ‘and none of it was any use to me in preventing this condition.’..." [I'll add this web page to the next version of the SD PDF]

Source: https://www.flightsafetyaustralia.com/2 ... ur-ears-2/

[outlaw162]

After the centrifuge runs, everyone was offered a ride in the spinning 'somo' chair. It was voluntary and a lot of folks turned it down.

Compared to the 'fuge, I thought it was almost enjoyable. Burp.

[spazsinbad]

One may note how ballet dancers spin - always a quick turn of the head to the front every time whilst body follows later.

IF one can see the horizon that always helps hence my insistence that HMDS is great for carrier landings - for horizon viz. Then of course there are other issues that are highlighted (but being solved by OLED in Gen III+ HMDS) we may gather.

[Gums]

Salute!

Thanks for more, Spaz, but that ain't what I call the "leans". "leans" happen over a period of a minute or more when your gyros and rate sensors do not reflect actual attitude and gee. So you tilt your head so they agree.

A good example is rolling into a turn and then holding the bank and altitude for a full turn. After 30 seconds or so your ear sensors "align". Meanwhile, you "lean" to make actual attitude and gee agree with what your own strapdown inertial referenceis telling you ( no batteries required, heh heh, and standard issue from God). The problem happens when you roll out and have to re-cage your gyros.

As far as changing radios and such, if I was saturated I would tell ground control I am staying on this freq and standby. Old fashioned training procedures for the single seaters, but we had the "blindfold cockpit check" so we could reach out and find the radio knob, then rotate a click at a time to the new freq..IFF changes were a different breed of cat.

Upfront control displays and switches made a helluva difference in the 80's and 90's.

Gums sends...

[spazsinbad]

Blind cockpit checks are nice IF the controls stay in the same place. BUT BEWARE when the bleeding switch panels on the right side (and even some on the left side sometimes) are removed or changed about or both because CONFUCIUS reigns.

It seems 'the leans' can mean many things. As a general term it works whilst medicos insist on defining everything I guess.

Yes, delaying radio changes was common because of reasons 'Gums' gives. After rampstrike I definitely had to change freq.

[mixelflick]

I realize there's a lot more to this, but avoiding spatial disorientation can be done by relying on instruments/the artificial horizon, can it not?

The condition isn't unknown, so why do pilots continue to fall victim to it?? Pilots on average are very disciplined people. Rationale, logical etc.. This spatial disorientation must be some powerful stuff given so many have died. Like JFK Jr.. Was spatially disoriented, but had an auto-pilot button right there that would have saved them.

Easier said than done, I'm sure but the phenomenon is unusual looking at it from the outside in..

[marsavian]

Is it just a higher risk when external visibility is poor and you have to fly by your displays and instruments ? Maybe requires more from the pilot when he can't visibly see what is happening to his plane in the sky. This is why GCAS is needed to be rolled out asap as a fail-safe especially as night missions will be an important part of F-35 operations.

[spazsinbad]

'mixelflick': You probably have not read all the material - or - understood it if you have read it all. On this thread I have highlighted how EVERY PILOT - even in daylight - can suffer SD Spatial Disorientation. Yes when flying in instrument conditions ONLY the instruments can be believed NOT the pilot erroneous sensory input. SHIRLEY this has been made clear. In DAYLIGHT when the horizon is visible one may counteract SD by looking at the horizon. A way to help counter sea sickness is to go on deck to be able to view the horizon (perhaps not possible in a storm etc.).

'mixelflick' said: "...The condition isn't unknown, so why do pilots continue to fall victim to it??…" Firstly pilots are not victims. Pilots fly aircraft in unusual conditions of all kinds especially when in military jets. Knowledge of SD is the first step in dealing with it. At some time it is clear all pilots will encounter SD of some kind. However they have to recognise it. This can be difficult as is explained in the material. Always referencing the horizon - be it artificial or the real one - CAN be the best way to deal with SD. This is easier said than done if the pilot does not recognise the SD as perhaps the example of the POSSIBLE cause of the Japanese dive into the sea.

Read how an S2E/G pilot pushed the controls forward to fly into the sea after a night bolter (his first). Why did he do this. He was suffering from SD when looking at the engine gauges and not the AI IIRC. Read from page 16 in the 75 page PDF: Dark night takeoffs and the “false climb” illusion the quote below is from page 24 then read the conclusion of the second accident enquiry on page 26.

"...The 2nd inquiry explored pilot disorientation and concluded that the pilot of 853 possibly suffered from disorientation due to the acceleration off the ship [I think he means 'aircraft' here - not ship] under full power inducing a sensation of the aircraft pitching up. Barry Bromfield and other crew members of 853 told me that Barry had been calling to ‘get the nose up’ or words to that effect before they hit the water. If the pilot’s instrument scan wasn’t ideal he would have pushed the nose of the aircraft down to respond to his perception of the aircraft pitching up. I also recall that this was the first bolter 853’s pilot had experienced. I think this inquiry concluded disorientation as the most likely cause...."

'mixelflick' said: "...This spatial disorientation must be some powerful stuff given so many have died...." YES it is whilst depending upon circumstances SD can be difficult to correct in the time/space available when flying. Pointing any miljet towards the ground (even if engine at idle etc.) means VERY QUICKLY arrival is guaranteed, this fact is demonstrated to new jet pilots dramatically in various ways early in their jet flight training. I have given this example before elsewhere.

The VAMPIRE had an AI that would precess / undergo precession when accelerating from zero to flight speed of some 100 KIAS approx. When in flight the precession was negligible so the AI could be relied upon then. CATCH 22: when taking off at night straight after wheels off the runway one had to fly roughly some five/ten degrees to the left with a slightly higher nose up attitude than usual. IF this was not done at RAAF Pearce (RAAF basic jet training airfield) when taking off on R/W 36 one would end up in a smoking black hole in the hills to the right of the runway some distance ahead. This FACT was demonstrated time and again to nuggets. However one RAN nugget did this on first night solo - a very real thing to die.

Why tell this story? There may be times perhaps when the AI / artificial horizon does not tell the truth in VERY OLD aircraft however in modern aircraft this is not the case. The AI does tell the truth (whilst IF NOT you are doomed).

Another story. A new civilian prop pilot sillily flew into IMC without an instrument rating at low level, attempting to get over a flat tableland near NAS Nowra with very deep valleys otherwise. He was on the radio advising everyone who could listen that he was feeling some G and every now and then seeing a valley floor below. It was thought he was doing loops in a valley in IMC. Eventually he got out OK with lots of radio advice. One of the lucky ones.

Imagine being catapulted at night suffering from SD immediately (one of my experiences of SD). Even though I was flying on the ABBAJABBA AI which I knew could be relied upon my 'world' was just in turmoil. This had come about because (I think) I could not not NOT view/unview a single bright fishing boat light ahead of the ship. When things were just black for a night catapult then I did not experience SD. In any event I flew UP Straight telling the controller I was not going to obey directions until 'my world' was right again. CO confirmed at the time listening on radio this was the correct action.

[Gums]

Salute!

Thanks, Spaz.....

And to all..... to get my wings I flew the T-33, then I flew it in ADC from 1965 - 67 . It had the J-8 attitude indicator, which was self-contained and used some kinda plumb bob or such to "erect" ( don't get excited, folks). If you flew in a coordinated turn for a long time, the damned thing would finally show wings level and the turn needle was your only big savior, besides the fact that your heading was changing.




Note no blue sky or black dirt !! If level you could pull the "cage" knob and reset/erect the thing. In our ADC training they taught us to use "bar width" pitch corrections on an ILS or GCA. The main symbols were surrounded by thin, black outlines. So a bar width would be about 100 feet per minute or less.

Damn thing was useless if completely dissoriented, so you went to needle, ball and rolled to stop the turn and then pulled to gain altitude.

I gotta tellya. After learning instruments on that kinda stuff, later planes were like cheating.

Gums sends....

[outlaw162]

After learning instruments on that kinda stuff, later planes were like cheating.

I agree, although some of those civvy vacuum attitude references were no trip to Hollywood either.

At Del Rio in mid-60s, our T-37 fleet had a mix of half J-8, half MM-3. Since Del Rio had T-38s and not T-33s, instrument check in the T-37 was required to be done on an MM-3, still somewhat primitive, size about like an SFD. T-38 had a nice layout, basically like an F-4, no tapes though like 105. The T-38 graduates who were assigned to ADC then had to go thru a short T-33 course to learn how to really fly instruments, before going to 101, 102, 106 etc., all-wx fighters.

All of the aircraft with SFD type indicators/displays I flew had at least one training session devoted to flying the SFD or equivalent with the primary instruments covered over or EFI/HUD turned off. I would reasonably think there is a training session of this type in the F-35 simulator? It appears you need to know when and how to use it.

(Our 2 T-33s at Niagara in '71 had a J-8 in one and an MM-3 in the other)

edit: you know the fallback is you can just 'automate' everything and take the pilot out of the loop gradually, which 'preserves' assets but opens pandora's box as far as pilot skills, requiring more automation, a vicious circle

[Gums]

Salute!

To expand upon Outlaw and the good stuff from Spaz....

Before the cosmic flight management systems that could connect to the autopilot, the instrument flying skill and associated training was the major driver of your wings. You had to do all the basic visual stuff, but also navigate and fly without any visual references. Oh yeah, maybe communicate and change IFF codes, radio freq's,, nav stations, required courses on the airways, and the beat goes on.

Air Defense Command missions required great instrument skills because we had to launch and land in any weather condiiton. As a raw nugget, I was cleared to fly at the field minimums, and more than once landed at less than the published numbers. Because I came from Craig ( last of the T-33 bases), I was fully qualified in the T-33. So 3 or 4 rides at Perrin and I was able to fly target missions when my Deuce training schedule allowed. Flew many hours with a T-38 guy in the back seat so he could log "instrument" time while I logged "pilot in command" Therefore, I accumulated many hours in the Lockheed racer before going to 'nam, because ADC let me fly both planes next two years. TAC did not do that except for a very few senior toads, and not for raw nuggets like me.

So I had about 1,000 hours in less than three years counting the Deuce and Voodoo hours. TAC guys also did not get as many hours because they had to have decent weather to go to the range. I also got very good flying close formation by staying 8 or 9 feet from the green or red light on the lead's wing tip. Once above the scud we went our separate ways for intercept practice.

Gums sends...

[spazsinbad]

Thanks for the stories. 'Limited Panel' (just pressure instruments & turn indicator) was fun WITH muchos patience required to master it. Recovery from what we called an 'unusual attitude' was done at high altitude to demonstrate "IF IN DOUBT - EJECT/PUNCH OUT"! I think. I've described 'finding overhead a radio beacon on limited panel in cloud in a Vampire' on another thread here. For me a once only attempt never brought to a conclusion because the instructor got bored with it. "TAKING OVER" & we pointed earthwards as fast as possible for one of few landings I was a passenger.

Oops I see 'Gums' has responded as I typed..... Take a look at an RAN olde style variant of the dual seat Vampire layout. Oh what joy to have the AI hidden under your hand on the control column. Talk about flying with the leans as one leaned usually left to keep the AI in view (when pilot in command in the left seat - PAX usually in right seat being cool).

[outlaw162]

That picture right there is probably partly responsible for the creation of ergonomics.

(BTW just to set the record straight, I've never been to the ballet)