Ask The Pilot

[tgh]

VFR int IMC
I have read many many reports in Aviation safety digests with this subject line.
The desire to press on and "get home" was often a best guess diagnosis for otherwise inexplicable cloud related accidents

I offer that clouds look pretty innocent when out in the blue.
Glider pilots in the 60's often drifted into a bit of cloud.
Trying to get a few hundred feet more out of a thermal was a common causation.
I recall the transition as quite confronting , switching to instruments was easy but the aural and gravitational inputs to the brain are amplified as the horizon vanishes and this was extremely difficult to overcome.
To that end many glider pilots have had spin recovery practice out of the bottom of cloud base.
Sadly some were lost after coming out inverted and failing to recover.

 

[straitman]

VFR int IMC
I have read many many reports in Aviation safety digests with this subject line.
The desire to press on and "get home" was often a best guess diagnosis for otherwise inexplicable cloud related accidents

I offer that clouds look pretty innocent when out in the blue.
Glider pilots in the 60's often drifted into a bit of cloud.
Trying to get a few hundred feet more out of a thermal was a common causation.
I recall the transition as quite confronting , switching to instruments was easy but the aural and gravitational inputs to the brain are amplified as the horizon vanishes and this was extremely difficult to overcome.
To that end many glider pilots have had spin recovery practice out of the bottom of cloud base.
Sadly some were lost after coming out inverted and failing to recover.

The problem with spinning is that even if the pilot is rated, many aircraft (big & small) are not and consequently can break up and become uncontrollable in a spin.

 

[jb747]

VFR Into IMC

over there years there has been a number of fatalities relating to pilots flying light aircraft while VFR into IMC.
This one is a Cessna inflight breakup in a NT wet season coughulonimbus:

In-flight breakup involving Cessna 210, VH-HWY, 22 km east of Darwin Airport, Northern Territory, on 23 October 2017 | ATSB

www.atsb.gov.au

Why do pilots fly VFR into IMC?

When I first saw the question, I expect it to be a simple VFR pilot in IFR accident. This is a bit different, in that both of these pilots actually had instrument ratings (though I doubt that the aircraft was all that well equipped). Even though they had ratings, they were very inexperienced.

The upshot though, is that convective cloud is dangerous. You don't even need to be in it to be affected by it.

VFR int IMC
I have read many many reports in Aviation safety digests with this subject line.
The desire to press on and "get home" was often a best guess diagnosis for otherwise inexplicable cloud related accidents

I offer that clouds look pretty innocent when out in the blue.
Glider pilots in the 60's often drifted into a bit of cloud.
Trying to get a few hundred feet more out of a thermal was a common causation.
I recall the transition as quite confronting , switching to instruments was easy but the aural and gravitational inputs to the brain are amplified as the horizon vanishes and this was extremely difficult to overcome.
To that end many glider pilots have had spin recovery practice out of the bottom of cloud base.
Sadly some were lost after coming out inverted and failing to recover.

Instrument flying is not easy. I suspect one of the problems is that VFR pilots sit in coughpits with instruments that would allow IFR flight, and they look at them all the time. After a while they start to think that they understand what they are seeing, and hey, how hard can it be. But, as soon as they enter cloud, they suddenly find that whilst they were looking at the instruments, they were mostly using cues that they were seeing outside the coughpit. Now those cues are gone. But, something that they probably never noticed before suddenly appears. Their sense of balance. Normally their view outside the aircraft overwhelms the inner ear, so their eyes are constantly recalibrating any erroneous balance signals. Without that correction the signals from the ears become magnified. You know you're turning, so they correct it. But then they realise that the attitude indicator doesn't agree, so they correct back to its level. Now the inner ear is screaming at them. And so on. I think I read that it takes about 100 seconds before the average non rated pilot loses control. Not long anyway.

 

[Quickstatus]

But why do they get themselves into an IMC situation?.

 

[jb747]

But why do they get themselves into an IMC situation?.

There’s plenty of ways to do it. The edges, especially when above you, aren’t necessarily all that easy to discern. But, probably the most common would be allowing yourself to be boxed in. You won’t necessarily see it coming, Try flying up a valley, which is climbing, or in which the cloud is slowly lowering...now what are your choices?

 

[straitman]

But why do they get themselves into an IMC situation?.

There’s plenty of ways to do it. The edges, especially when above you, aren’t necessarily all that easy to discern. But, probably the most common would be allowing yourself to be boxed in. You won’t necessarily see it coming, Try flying up a valley, which is climbing, or in which the cloud is slowly lowering...now what are your choices?

An example:

In September 1981 I was flying lead of a pair of Iroquios Helicopters transiting Arthurs pass in New Zealand. As we approached the pass it was all clear through and we decided to proceed. Half way through and the weather closed in ahead and behind us and all in a matter of 30 seconds. #2 closed in tight and we did a quick turn and exit. Not a whole lot of fun for a bunch of professionals let alone anyone else. (There was a QFI in each aircraft.)

 

[kookaburra75]

VFR int IMC
I have read many many reports in Aviation safety digests with this subject line.
The desire to press on and "get home" was often a best guess diagnosis for otherwise inexplicable cloud related accidents

I offer that clouds look pretty innocent when out in the blue.
Glider pilots in the 60's often drifted into a bit of cloud.
Trying to get a few hundred feet more out of a thermal was a common causation.
I recall the transition as quite confronting , switching to instruments was easy but the aural and gravitational inputs to the brain are amplified as the horizon vanishes and this was extremely difficult to overcome.
To that end many glider pilots have had spin recovery practice out of the bottom of cloud base.
Sadly some were lost after coming out inverted and failing to recover.

The major issue with glider pilots in the 60's and also the 70's and 80's was trying to chase that bit extra, but none had any instrument training. If you lost the horizon, then things weren't good. Coupled with flying any aircraft that was inherently slippery (Libelle, Cirrus, ASW15 etc) simply pulling full air brakes wouldn't get you to stay within Vne. The problem wasn't spins, but spiral dives where you can very quickly get too fast too quickly. I would take pupils up into the cloud base to get them to understand how quickly they could lose track of things, and get to know what not to do. It's probably the same today though, where people don't think it could happen to them.

 

[Quickstatus]

Do you get the same disorientation in a large aircraft like a double decker when in IMC compared to say a Cessna?

 

[jb747]

Do you get the same disorientation in a large aircraft like a double decker when in IMC compared to say a Cessna?

Potentially you could. But, I think that for those of use who have spent thousands of hours looking at the various instruments, they eventually supplant the visual sense that you have in VMC. I recall feeling the effects early in my flying life, but not for many years.

 

[Quickstatus]

If I as a passenger sense that an aircraft is banking say to the right (without any visual cues), what is the aircraft actually doing?.

 

[AviatorInsight]

If I as a passenger sense that an aircraft is banking say to the right (without any visual cues), what is the aircraft actually doing?.

Initially? Probably a turn to the right. The problem becomes when the turn is kept at a constant bank at around the 30sec mark that the vestibular system catches up. The pilot may now feel that they’re straight and level adjusting themselves and the aircraft when in fact the turn is still going.

The next problem occurs when that turn had been going longer than 30sec that when there’s a nice gradual roll back to straight and level the pilot may feel a turn in the opposite direction.

It’s one of the first things taught in basic instrument flying, always trust your artificial horizon. I had the leans on one of first flights after being checked out with a brand new instrument rating. Luckily I took another pilot with me just in case something like this happened and I tried so hard to forget what I was feeling and just fly the AH. I never got that feeling again.

 

[Quickstatus]

How does the artificial horizon work?

 

[jb747]

If I as a passenger sense that an aircraft is banking say to the right (without any visual cues), what is the aircraft actually doing?.

Just about anything.

You may have felt the aircraft bank to the right, but it may have been banking left (and you hadn't noticed), and what you perceive as a right bank was simply the correction back to wing level. Your senses are totally unreliable in this situation.

 

[jb747]

How does the artificial horizon work?

Magic.

All you never wanted to know about them:

Attitude indicator - Wikipedia

en.wikipedia.org

Laser ring gyros make interesting reading too:

Ring laser gyroscope - Wikipedia

en.wikipedia.org

 

[Quickstatus]

Ah ok thx. So current artificial horizons have no moving parts?
So they are just a fancy application of Einsteins special theory of relativity.

 

[tgh]

Your senses are totally unreliable in this situation.

Indeed .. I sometimes play games to pass the time in my magic tin tube..
Invent a turn and bank in my mind, listen to the aural and balance inputs from my little brain...and decide if we are still turning or no
The judge and Jury is a peek out the window and (with a bit of knowlege).. I am wrong much of the time …duuuuhhhh…..
Folks with no flying experience at all can play this game and learn a bit about seat of pants -v- Instrument flying

 

[Quickstatus]

Yes I play that game by looking only at the seat in front of me and try to predict which was the bank is. Sometimes it doesn’t work due to the moving shadows/sunlight coming in through the windows. When there are no external visual cues, I’m wrong more than half the time.

 

[AviatorInsight]

Ah ok thx. So current artificial horizons have no moving parts?

On the PFD, yes. They're part of the IRS system now and align themselves. The old gyro type AHs still feature in the older 737s that Virgin have and as such they still need manual realignment by pulling out a lever and it'll centre it. I'm on 2 weeks leave now (a much needed break!) but when I get back I'll try and get a video of it.

 

[jb747]

Yes I play that game by looking only at the seat in front of me and try to predict which was the bank is. Sometimes it doesn’t work due to the moving shadows/sunlight coming in through the windows. When there are no external visual cues, I’m wrong more than half the time.

And there’s a simple way to make you wrong all of the time. If we were to very gently roll the aircraft into a 30º bank in one direction (using a couple of degrees per second roll rate), leave it in that bank for a short while (so that becomes the normal), and then roll the bank off (using about 15º per second), you’d be utterly convinced that you’re in a bank, even though we’re wings level. This is how you can induce an issue called “the leans”, which all pilots experience at some point.

Instrument training in the military was fairly extreme. The Macchi (and PC9 too, but I’ve had nothing to do with it) are fully aerobatic, so there were some interesting setups used in the training. The instruments used when flying partial panel (i.e. without an attitude indicator) were fairly cryptic, and had some interesting errors that the instructors could induce. For instance pitching the Macchi slightly nose high, rolling inverted, and then pulling around half a G positive, would for a short period look as if you were right way up and wings level. The instructors would hand over at that point, and for a few moments it all looked nicely under control, before you realised you’re now inverted, nose low and increasing, speed rapidly rising. You were expected to fix this, but there were some cases were admitting defeat and ejecting was a solution.

 

[Borisdog]

I don’t know what defines rare. I was on the 767 at the time, and operated to Hong Kong, Bangkok, and various other ports in Asia in similar conditions fairly regularly. But the 767 did many more cycles than the 747, so I guess there was more opportunity to keep in practice. Really poor conditions aren’t that common, simply because we do our best to avoid them. Holding isn’t always initiated by ATC.

The weather was much less of an issue than was the mindless application of an ill conceived company procedure. It was the cause of much angst at the time, with more than one of the “old and bold” predicting it would end in tears. They were simply fobbed off by the management and training heavies of the day, as being “resistant to change”. That’s another MBA term that’s as worthless as “world’s best practice”.

I regularly got "Worlds' Best Practice" rammed down my neck in the mining game.

Doesn't mean it's not mind-bendingly stupid though does it!!