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RAAFVirt75th
01-28-2004, 06:22 PM
Oleg,

I was speaking with my next door neighbour who was a PBY pilot in WW2 in the RAAF and flew many missions in the Pacific.

He told me about the St. Elmos Light - this is when in certain weather conditons where the atmospheres electrical charge is different than that of an aircraft. All parts of an aircraft are "bonded" to make sure when electical currents (e.g. lightning etc) pass through the plane it does not arc and cause an explosion. What however did occur was that any external fixtures that portruded e.g. pitot, tips of propellor blades, antenna etc used to glow blue - like a gas flame. This effect would continued until the plane left the weather condition. Is there anyway you could put this effect into BoB or FB?

Also clouds "nimcum" or nimbus cummulus could cause updrafts and downdrafts that could send a plane up or down 3000 ft or more. Usually pilots would avoid these types of clouds or as my neighbour pointed out "it would be curtains time' e.g. if flying at night or close to the water and the cloud could not be avoided.

Can these types of weather conditions be built to increase flying realism?

Kind Regards

_RAAF_Schuftie

RAAF website -http://members.optusnet.com.au/raafgames/crest.jpg (http://www.raafsquad.cjb.net)

RAAFVirt75th
01-28-2004, 06:22 PM
Oleg,

I was speaking with my next door neighbour who was a PBY pilot in WW2 in the RAAF and flew many missions in the Pacific.

He told me about the St. Elmos Light - this is when in certain weather conditons where the atmospheres electrical charge is different than that of an aircraft. All parts of an aircraft are "bonded" to make sure when electical currents (e.g. lightning etc) pass through the plane it does not arc and cause an explosion. What however did occur was that any external fixtures that portruded e.g. pitot, tips of propellor blades, antenna etc used to glow blue - like a gas flame. This effect would continued until the plane left the weather condition. Is there anyway you could put this effect into BoB or FB?

Also clouds "nimcum" or nimbus cummulus could cause updrafts and downdrafts that could send a plane up or down 3000 ft or more. Usually pilots would avoid these types of clouds or as my neighbour pointed out "it would be curtains time' e.g. if flying at night or close to the water and the cloud could not be avoided.

Can these types of weather conditions be built to increase flying realism?

Kind Regards

_RAAF_Schuftie

RAAF website -http://members.optusnet.com.au/raafgames/crest.jpg (http://www.raafsquad.cjb.net)

VW-IceFire
01-28-2004, 09:40 PM
Never heard of it but after reading about Sprites and Blue Towers or whatever they are calling some of these strange atmospheric effects I can believe it.

What kind of conditions set this up?

I doubt it'd be modeled...but its definately cool to hear about.

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!

RAAFVirt75th
01-28-2004, 11:38 PM
Gidday,

Yeah I too was fascinated by what St Elmos meant. So went looking on google. I found an article by an everyday private pilot in NZ who recently encountered the "St Elmo effect" . Now I can really picutre what my neighbour was on about as he had encountered the same type of thing on return from a bomb run and flying between "the gap" in the hills just before Pt Moresby, but not only was St Elmo present - but he copped an updraft in the storm at the same time which sent the PBY up an extra 3000ft banking to starboard at the same time. Both himself and other pilot fought to control the plane. He said "that was the only time in my life that I wanted to reach for my parachute" (located under his seat).
This occured at about 3.00am in the pitch black - with zero visibility (also due to heavy cloud)flying in a gully "the gap" between the mountain ranges coming into Pt Moresby. So you can imagine how he probably felt (personally I reckon I would have pooped my pants).

Anyway I am putting a link that I found for you to look at regarding the "St Elmos effect" which happens in stormy/thunder/lightining type conditions.
http://www.billzilla.org/flying1.html

Also when this fine gentleman used to fly PBY missions out from Cairns crossing the coral sea (often in the middle of the night)the "nimcum" used to be all over the place in this area "the cloud formation being "shaped like an anvil". "Trouble is you cant see it at night". This is the same type of weather condition you hear about where fish and other matter are transferred from the sea and deposited on nearby towns e.g. raining fish. Apparently, if you fly into the "funnel" of the nimcum" it can "break the funnel" then what happens is that the water above the plane(you can imagine thousands of litres worth and each litre I think equals a kilogram) this then comes down on the plane like a dam wall being ruptured. Sadly some RAAF and USAAF pilots were lost in this unfortunate type of siutation -when going out on night bombing raids across the coral sea. So not only was it dangerous flying around in a PBY (big and slow easy target for flack and fighters)but also had to do so in pitch dark with these types of weather conditions. In my estimation very brave lads.

Anyway, I am certainly finding my neighbour has a lot of interesting stories about being a RAAF PBY Pilot in WW2. As I had never heard about St Elmos before or "nimcum" effect. (I cant quite rember the exact abbreviation he stated)I am learning something new everyday!


Kind Regards

_RAAF_Schuftie

RAAF website -http://members.optusnet.com.au/raafgames/crest.jpg (http://www.raafsquad.cjb.net)

effte
01-29-2004, 03:55 AM
S:t Elmos fire is caused by an electrical charge uncharging through pointed tips and edges on the airframe. As a metal object, such as an aircraft, goes throught the air or even better, electrically charged clouds, static electricity builds in the airframe. This causes S:t Elmos fire, typically seen on window frames and windshield wipers. It is strongly detrimental to radio reception. The short carbon wicks on the trailing edge of the wings are to dissipate this static charge. During WWII, aircraft reported being followed by "foo fighters", which were nothing more than stronger versions of S:t Elmo's fire on these aircraft without static discharge wicks.

If you look at car cellphone antennas, the ball on the tip is to avoid having a sharp tip where such discharges would form and ruin the reception.

You have the clouds somewhat mixed up. They're called cumulonimbus clouds, or usually "CBs" and are indeed something to be very vary of. They form in unstable atmospheric conditions and can contain very strong down- and updraughts. Even airliners steer clear - that's one of the main purposes for fitting them with weather radar. CBs will show up as large red blobs.

CBs typically form along cold fronts.

They can and have been used by gliders to really gain altitude fast. You better know what you are doing though, and you have to know when to get out. When the CBs form into thunderheads (yes, thunderheads are large CBs), you don't want to be there even in these aircraft built for it. I've seen Foka gliders with an additional vario, measuring 30 m/s positive and negative, to be used in cloud flying...

They also form massive draughts beneath the clouds. One type of these are known as microburst, which are real killers. I flew under a mini-CB, hidden in an overcast layer once. It was a very weak one, but still not an enjoyable experience. Vario swinging wildly between approx -5 m/s and +3 m/s climb, ASI going up and down by 30 km/h. That's noticeable, with a normal approach speed of about 110 km/h!

As a microburst passes, the wind can change 180 degrees within no time at all. That's storm winds! You really do not want to be flying there.

What CBs will not do is suck up water, not to mention fish and other objects. That's tornadoes, something forming when to air masses collide in the right conditions.

An aircraft won't break the funnel though - we're not nearly significant enough in the big scheme of meteorological conditions, unfortunately.

Cheers,
Fred

RAAFVirt75th
01-29-2004, 04:30 AM
Fred,

Thanks for the explanation. I knew I probably had stuffed up on the term he explained.

But he did mention about planes going down when going into the "funnel?" as the result of water coming back down and taking the aircraft with it.

Even though the bloke is 92 years of age - his mind is still sharp as a tack. What would explain this type of incident? Please advise.


Many thanks

Kind Regards

_RAAF_Schuftie

RAAF website -http://members.optusnet.com.au/raafgames/crest.jpg (http://www.raafsquad.cjb.net)

effte
01-29-2004, 06:01 AM
It could be that he is not all that meteorologically schooled or is mixing things up. The heavy rainfall often associated with CBs certainly could give that impression. I had waves form on top of the canopy in the aforementioned incident... you can come down fast in a microburst, no surface water required to cause that.

Cheers,
Fred

micada23
01-29-2004, 10:46 AM
Hello :-)
And that's how Cumulonimbus with anvil looks like (taken on EPNT, cloud formed over Tatry mountains)
http://www.icsr.agh.edu.pl/~adamczak/p/puchacz.jpg

By the way, effte, gliders are made (at least here in Poland) with second vario for cloud flying, thats right, but not for cumulonimbus flights. They're mainly used in cumulus mediocris or similar clouds (in summer) and in cumulus lenticularis when wave flying...as you have said, good pilot could probably benefit from being close to mighty Cumulonimbus but not in it!
Michal

effte
01-29-2004, 12:07 PM
Look at historical competition flying... the entire field would head for the closest CB! As I was saying, not the largest ones as that would be suicidal, but CBs it was.

It cost a few lives though. In one of the first attempts to fly in CBs, three wooden aircraft went in. One came out, badly torn and battered but able to land. Two came out in pieces, one followed by the pilot in his chute. The third pilot pulled his chute too early, was swept up hanging from the chute and either froze to death or succumbed to hypoxia. http://ubbxforums.ubi.com/infopop/emoticons/icon_frown.gif

Also check the plaques in those aircraft. One I saw had a particulary interesting one, regarding cloud flying. It seemed to state that, with the right equipment installed, flying in clouds with one ligtning bolt was OK but not flying in clouds with two lightning bolts. We were unable to grasp exactly what the plaque was trying to communicate, but found it rather extraordinary!

Flying into lenticularis clouds? Hmm... good indicators of mountain wave activity but less useful for flying in, I'd say.

Heh, nice to find other glider pilots (I assume?) here!

Cheers,
Fred

micada23
01-29-2004, 01:10 PM
Hmm, okay, probably you're right about competition flying using CBs, perhaps small ones. When it comes to flying in serious CBs...I know similar story.
Here in Poland we had (early after WWII) IS-4 "Jastrzab" ("Hawk") wooden aerobatic glider (quite similar to German Lo 100 or Czech Lunak). It was said to have L/D ratio same as axe ;-), but was "practically indestructable".
One of Polish gliding champions took Jastrzab into really serious CB. Well, he came out without the glider, saving his life on parachute...

Flying in Ac len, well, from what I've been told, on EPNT they often lay in such places that you cannot return to airfield without flying in them. And people without good knowledge of flying in clouds are simply not allowed to fly wave here.

And yes, I'm glider pilot (beginner with some 60 hours, but anyway). Hmm, do you think we should try to talk Oleg into putting thermal model into FB? If he do so, I promise to buy 3DS and make some glider models :-D

Regards
Michal

SeaFireLIV
01-29-2004, 02:06 PM
Well, one thing I`ve learned above all others.

You can`t know everything. Even in a lifetime. Thanks for that interesting topic guys. http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

SeaFireLIV...

http://img12.photobucket.com/albums/v31/SeaFireLIV/greypilots.jpg

VW-IceFire
01-29-2004, 02:08 PM
Excellent picture of a classic anvil shaped cloud. Those are the precursors to your classic thundercell. I've got some decent shots on film of such clouds with lightning inside the cloud. Fantastic to see!

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!

effte
01-30-2004, 01:14 AM
How about a J3 Cub? It'd be more in place than some other additions, and I've heard of people thermalling with them... http://ubbxforums.ubi.com/infopop/emoticons/icon_wink.gif

In fact, word has it they flew them on delivery flights here and saved landing to fuel up through cutting the engine and gaining altitude in thermals. Amazing, but not entirely unbelievable... provided the thermals are strong!

Cheers,
Fred

swingman
01-31-2004, 04:23 AM
I think having different characteristics for different kinds of clouds would make the sim more interesting. It would make one have an extra look at a cloud before deciding whether to hide in it or not. I found this pic of what may happen if you venture into a CB well grown enough to contain hail:

http://www.jetphotos.net/viewphoto.php?id=137003

Of course, the fighers, especially the late-war ones, are more rugged and not as likely to suffer structural failure, but it would certainly be a very bumpy ride. I'd hate to go there with an I-153!
_
/Bjorn.

E_Temperament
01-31-2004, 07:13 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by effte:


What CBs will not do is suck up water, not to mention fish and other objects. That's tornadoes, something forming when to air masses collide in the right conditions.

An aircraft won't break the funnel though - we're not nearly significant enough in the big scheme of meteorological conditions, unfortunately.

Cheers,
Fred<HR></BLOCKQUOTE>

I have seen many small tornados forming off the coast of North Queensland. During one episode 5 tornaods were forming from the same cloud base. They drop out of the bottom of the cloud and slowly meander to the ocean surface, staying there for 30 to 40 minutes at a time. The locals called them water spouts, I suppose because they seem so gentle and slow when observed from the shoreline, I wouldn't like to be out there in a dinghy while there forming, I always thought they were very savage little suckers. Anyway my interest is that some of these small twisters ie no larger than 3 or 4 meters in diameter and others that appear to be maybe 20 or 30 meters across, that it maybe quite feasible that a large slow flying seaplane would interfer with the uplift in a small 3 meter water-spout/twister and possibly cause it to come crashing down on the plane. A 3 meter spout probably would weigh a few hundred tonnes at least.

guderian_ente
01-31-2004, 10:54 AM
http://iml.jou.ufl.edu/Newszine/staff/Homepages/Summer00/Nichols/stelmocast.jpg

RAAFVirt75th
01-31-2004, 11:15 PM
Thanks E-Temprament for your comments. I knew I had probably stuffed up on what the common name of this was e.g. "waterspout". It was the term used. And indeed this person used to fly missions from North Queensland region e.g Cairns area etc. So that makes sense to me now.

Anyway I appreciate everyones posts as have learned far more about the weather and it's affect on flying conditions. I am totally amazed and even more fascinated by it all.

Some of the glider photos and stories are pretty cool. Talk about extreme sports! Also saw what the rain/hail did to the nose of that - crikes.

Cheers
RAAF Schuftie

_RAAF_Schuftie

RAAF website -http://members.optusnet.com.au/raafgames/crest.jpg (http://www.raafsquad.cjb.net)

JG77Hawk_9
02-01-2004, 01:45 AM
Guderian_ente, thanks for the informative pic of St Elmos Fire. Really looks dangerous doesn't it. I for one would hate to be flying around with that type of atmospheric condition happening (-:

Nazi_Boy_USA
02-01-2004, 07:40 PM
Sounds like good additions. Want it to happen. Perhaps a little St. Dimphne's Fire as well.

God Bless German weather

PE_Tigar
02-02-2004, 10:32 AM
Just one note regarding Cumulus lenticularis--it usually appears on the side of the hill or mountain facing from the wind direction, and marks area where "rotors" (horizontally turbulent airflow) is present. Therefore, flying close above the hilltop an airplane may end up in a rotor which will pull him down. Not nice.

IV_JG51_Razor
02-02-2004, 11:51 AM
Getting back to the original request.....

I think that the biggest problem with including more realistic weather effects in any flight sim is purely a hardware issue. It could be done, but without a Cray in your garage, you might be looking at a slide show!

It would be nice though, to have solid overcasts with variable thicknesses and/or cloud base elevations and tops as seen in LockOn.

Razor
IV/JG51 Intelligence Officer

"Good judgement comes from experience, and experience comes from poor judgement"