Weather Radar Techniques

Re: Weather WX Techniques

It's never cut and dry....realistically I try to stay out of any return, wether it be a level 1 or level 5; however, this is not always possible. There are times when in even the mid 30's the entire gulf coast is socked in, and you just have to pick out the "least worst" way to go.

Not surprisingly, there are people at the airlines who don't know how to use the radar very well all.

A few years back I was flying with a guy who insisted that I get vectors around the city of St. Louis in good weather (he was using negative tilt on the radar, painted St. Louis and thought it was a storm). ATC of course responded "we don't see anything, but proceed as requested", and I, not being one to question the captain unless I feel safety is at stake, didn't second guess. I don't mention this to belittle anyone, but merely to illustrate that radar use is sometimes tricky even for relatively experienced pilots. Most captains I fly with seem to just leave the radar tilted between 1 and 4 degrees up regardless of altitude. This is effective at keeping ground clutter to a minimum, but I feel it is often misleading about the potential intesity of returns.

IMHO, learning to use negative tilt and recognizing radar shadows is critical if you expect to identify storms at high altitude in IMC. However, if you plan to do this, knowing the geography of the area you're flying in is critical....for instance, cleveland or new orleans can look like a big storm casting a "shadow" (intense returns from the city followed by darkness from the lake) if you don't know what you're looking at.




I *believe* this would be what is known as "Threat Identification
Procedure", or "TIP", basically where the lower beam is parallel to the
ground. Or, in simpler terms, it will be where if you are painting
anything, it will be at or above your altitude (although irrelevent
IMO). Zero tilt, also known as "calibrated zero", is actually when the
center of the beam is parallel with the ground. Most modern day
aircraft, like the RJ's, are pretty well calibrated for zero tilt
right out of the box at zerp degress of tilt, or so I am told.

If I'm not mistaken, zero degrees of tilt (at least in the EMB) means the center of the beam is paralell to the ground.....so with an 8 degree beam width and zero degrees tilt selected, the bottom 4 degrees would still be showing returns below the aircraft's altitude. So like you said, Selecting 4 degrees tilt up would have the lower beam paralell to the ground. I have no idea what common beam widths are in other aircraft, as this is the only radar equipped airplane I have flown.
 
Re: Weather WX Techniques

Then why the 'it's alright for freighters to plug through level 3 cells at 250 but you'd be stupid to do it otherwise' comment?
You misunderstood what he wrote. He said if it shows level 3 or 4 at FL250 probably = bad news. If it shows level 3 or 4 but you don't check what altitude that strong a return is at, you might or might not have a problem. A low level rainshower with heavy precip but no vertical development may well show a level 4 return on radar yet have a smooth ride, albeit noisy from the rain.
 
Re: Weather WX Techniques

Then why the 'it's alright for freighters to plug through level 3 cells at 250 but you'd be stupid to do it otherwise' comment?

Tell ya what. Since you seem to like to comb through the things I say for anti-freight comments - and then try to call me out, I'm gonna ask you to go ahead and put me on your ignore list, mmmm, K? I'll do the same.
 
Re: Weather WX Techniques

Bro my mistake, I was reading through your reply and saw what I thought was the incinuation that it was alright for freighters to plug through cells that would otherwise be suicide to plug through. If that was not the implication of your statement then it was my mistake and I apologize. This is a subject that I read through, seeing that I'm gonna have to be using this stuff in about a year from now when I make my transition.
 
Re: Weather WX Techniques

Keep in mind that you freight boys don't have to worry about grandman in 15C spilling her drink and complaining......
 
Re: Weather WX Techniques

Granny paid for an airplane ride... Give her one! :)
 
Re: Weather WX Techniques

True, but you know how much of a panzy I am when it comes to thunderstorms, Steve. Remember that flight back from Memphis?

"But....the tops are like at 8,000...you think it's safe to punch through that???"
 
Re: Weather WX Techniques

True, but you know how much of a panzy I am when it comes to thunderstorms, Steve. Remember that flight back from Memphis?

"But....the tops are like at 8,000...you think it's safe to punch through that???"

"Don't be a p****. You got that instrument rating for a reason, right?"


:)
 
Re: Weather WX Techniques

Those Archie Trammel tapes are like Chinese water torture... sooooo boring. And not even that good, in my opinion. I hear Dave Gwinn is a lot better, but I haven't seen his... has anyone here?

Somehow never saw this thread, but the difference between Trammel and Gwinn is that Gwinn actually knows what he's talking about AND is more entertaining. I have a very low opinion of Trammel.
 
Re: Weather WX Techniques

Somehow never saw this thread, but the difference between Trammel and Gwinn is that Gwinn actually knows what he's talking about AND is more entertaining. I have a very low opinion of Trammel.

They used to threaten us with that in college. We watched it once and if we complained about something in class, they'd threaten to pull Archie out.
 
Re: Weather WX Techniques

Somehow never saw this thread, but the difference between Trammel and Gwinn is that Gwinn actually knows what he's talking about AND is more entertaining. I have a very low opinion of Trammel.

Trammel's a pimp....and don't ever forget it.......:bandit:
 
Re: Weather WX Techniques

Somehow never saw this thread, but the difference between Trammel and Gwinn is that Gwinn actually knows what he's talking about AND is more entertaining. I have a very low opinion of Trammel.

Can you expand on this? Why do you feel AT's work is incorrect?

I don't have access to Gwinn's book at the current time, but I'd like to see some differing opinions.

AT has long been known (from my research at least) as the leader in RADAR techniques. Not saying that makes him right, though.

EDITed to add: I just read thru a 5 page article by Gwinn. He apparently works for Honeywell now, and has the same recommendations that Archie has regarding tilting technique (which is mostly what I am posting about). He disagrees with Archie in regards to using the RADAR as a tool to navigate or map terrain, but that doesn't have anything to do with operating the RADAR as a weather RADAR.

The most significant difference I saw was that he recommends a spread of 18,000 - 25,000 as the "meat of the storm" (probably why the Honeywell information I had recommended that) while Archie uses a flat base line of 25,000.

kellwolf said:
Gwinn's radar bookley and CD from Sporty's just went on my Xmas list.....
Same here :D!
 
Re: Weather WX Techniques

Can you expand on this? Why do you feel AT's work is incorrect?

I don't have access to Gwinn's book at the current time, but I'd like to see some differing opinions.

AT has long been known (from my research at least) as the leader in RADAR techniques. Not saying that makes him right, though.

EDITed to add: I just read thru a 5 page article by Gwinn. He apparently works for Honeywell now, and has the same recommendations that Archie has regarding tilting technique (which is mostly what I am posting about). He disagrees with Archie in regards to using the RADAR as a tool to navigate or map terrain, but that doesn't have anything to do with operating the RADAR as a weather RADAR.

The most significant difference I saw was that he recommends a spread of 18,000 - 25,000 as the "meat of the storm" (probably why the Honeywell information I had recommended that) while Archie uses a flat base line of 25,000.


Same here :D!

OK, you already pointed out a couple of Trammel's idiotic ideas. Basic tilting technique is (or should be) widely known, so you shouldn't expect too much variation.

The major difference comes on how the practical use of the radar and how to best actually avoid storms. You are comparing someone that never flew anything bigger than maybe a Beech Baron to someone that spent his entire career, flying DC-9s and similar in the mid-west. One has never used a 30 inch radar dish, the other spent years actually using them and avoiding the real thing. One is reciting book knowledge (and making some odd extrapolations at that), the other HAS the knowledge. One has literally been removed from being able to testify as an expert witness for accidents, the other is sought after to be an expert witness. One is a self promoting low experience pilot, the other is someone that was recognized first by his peers, made committee chair at an ALPA committee and became well known because of what he knew, not how he promoted himself.

Gwinn only recently joined Honeywell. Before that he was TWA, originally Ozark. Additionally, he is a great story teller, knows how to put things in a useable format (divide altitude by four and other trammelisms that are not realistic in a real world environment, will not be found) and puts on a very entertaining presentation that is not hard to remember. There is more, but this might give you a place to start.
 
Re: Weather WX Techniques

OK, you already pointed out a couple of Trammel's idiotic ideas. Basic tilting technique is (or should be) widely known, so you shouldn't expect too much variation.

That's just it, I don't think it really is. Even after flying thru the summer, I hadn't encountered one captain that used the techniques Archie/David decribed. Not one. I have even been called "anal" when I tried to figure out what Archie-the-engineer was talking about using my little handbook enroute. Kinda frustrating.

After flying with this CA, I looked thru my new hire books and low and behold there some info. Not even touched on in college, indoc, or recurrent. I just can't believe I've gone this long without actually hearing it somewhere. That's why I was wondering if it waswas touched on at other companies.
 
Re: Weather WX Techniques

That's just it, I don't think it really is. Even after flying thru the summer, I hadn't encountered one captain that used the techniques Archie/David decribed. Not one. I have even been called "anal" when I tried to figure out what Archie-the-engineer was talking about using my little handbook enroute. Kinda frustrating.

After flying with this CA, I looked thru my new hire books and low and behold there some info. Not even touched on in college, indoc, or recurrent. I just can't believe I've gone this long without actually hearing it somewhere. That's why I was wondering if it waswas touched on at other companies.

We teach it.
 
Re: Weather WX Techniques

That's just it, I don't think it really is. Even after flying thru the summer, I hadn't encountered one captain that used the techniques Archie/David decribed. Not one. I have even been called "anal" when I tried to figure out what Archie-the-engineer was talking about using my little handbook enroute. Kinda frustrating.

After flying with this CA, I looked thru my new hire books and low and behold there some info. Not even touched on in college, indoc, or recurrent. I just can't believe I've gone this long without actually hearing it somewhere. That's why I was wondering if it waswas touched on at other companies.

We watched Gwinn's Honeywell tape in INDOC...

J.
 
Greetings, Fellow Aviators:
I happened by accident upon this site, enjoyed reading this thread, and thanks to those who complimented me. It took hundreds of hours, discussing-with, arguing-with, engineers and creating a pilot vocabulary for radar. Who cares whether it is dBz or % of power if we have a conceptual grasp and mastery of the subject?

Radar has been on board for 50+ years and STILL the available training is "Lousy". In Zurich, a Swiss Air pilot told me: "I feel like a puppy dog watching Television. I SEE it, but I sure don't know WHAT it means." (You too can be an authority: (1) You must have a PowerPoint Presentation, (2) You must be from out of town, (3) You talk fast and get gone. In addition, add gray hair to look experienced, glasses to look sophisticated, a paunch to look properous, and if you have a hernia, ya' always look sincere.)

Tilt control is simple, your effective range depends upon your antenna (approx the two-troposphere point in your beam as range), and you are calibrated to STRATUS rainfall rates, ie, 1/2"-hr is RED. Magenta is 2" per hour and no Stratus cloud can produce that, so you are seeing a storm. See the comparative radar chart and print it out on my web site: www.davegwinn.com

Quickly, you should be tilted UP 15-degrees for takeoff, and 15-up within 15-NM of the airport on approach to land. You're severely tilt limited/viewing altitude limits when at low altitudes; you're seeing low level returns. You really need to understand the ASR-9 and ASR-11 capabilities of Terminal Radar for the best assistance.

I'm talking now to two tele-conferencing companies about visual presentation on your computer, and teleconferencing over a speaker phone, for corp. operations and 'Radar Training'.

Dave Gwinn
 
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