Editor’s Note: While datalink weather is all the rage these days, some 60 years ago, Captain Robert N. Buck thought another hot weather technology, onboard radar, was ready to change the world. Radar technology has improved dramatically since then, but the predicted “end of the thunderstorm hazard” hasn’t quite come about yet. This article originally appeared in the November, 1956 edition of Air Facts, and it’s still a fascinating look at how pilots interact with new technology.
An Eye to See With
Here comes the end of the thunderstorm hazard
About the beginning of September thunderstorms look tough again. The earliest suggestions of winter are cold fronts that come from the north with more definition and authority. The cooler air begins to break through and shove the warm languid air out of town. There is an argument and nasty thunderstorms are the outcome.
With little thoughts about these things I looked at the weather map for a trip to London. A cold front was pushing down from the northwest and would parallel our course to Newfoundland. The cold front should, according to the forecaster, stay to the northwest of our route, but if it moved faster it might get on course―and that would be interesting because the front had quite a line of thunderstorms. Normally, with a situation like that you brood about the thunderstorms and quietly hope they’ll stay where they ought to and leave you in peace and serenity. But a new factor makes them less frightening―RADAR!
When we received our Gee Constellations we also acquired radar, AVRQ-10 RCA, 5 centimeter, to be exact, which, if you’re like I am, is a lot of numbers technical people flip around in their conversation when actually what we want to know is “Where do you turn it on and how does it work?”
It’s pretty simple and if you are good tuning the TV set you’ve got radar in the bag. The important knobs are two, one marked Gain and the other Intensity. If you turn the Gain knob too high the scope gets all snowy and streaked. If you turn the Intensity too much the scope gets smeared with a yellowish light and you can’t see anything at all. The way to do it is get them both backed off pretty far, as far as possible and still get good contrast. But I could sit here all day writing how to do it and it still wouldn’t be as good as ten minutes of fooling with it.
The scope, picture tube, or whatever you want to call it, is 5 inches in diameter. When it’s fired up and going you see, of course, the sweep going around and around. The center of the scope, actually a little back of center, is you. Lines radiate, like ripples, from your center position and these are range marks that allow you to measure distance. There is an azimuth ring around the edge of the scope for taking bearings and you can rotate this by hand if you want.
The radar has different ranges―ours are 20, 50 and 150 miles. By flipping a switch you change the scope picture’s area of coverage―simply, it’s like looking at different scale maps when you change the range of the radar.
How It Works
We all know that radar works by something being shot out, hitting something, bouncing back and then electronically placed on a scope where you can “see” what was hit. The signal that goes out, in this case, does so in a beam, just like a searchlight beam, and this one is 7° wide and 4° high. It sweeps around and around. If it pointed straight ahead the narrow beam would just cut a little hunk through the sky and you wouldn’t know what was going on below or above that area―so the set has a tilt knob and you can tilt this beam 10° up or 15° down, which seems to be adequate. If you tilt it up and the sky is clear you don’t see anything. If you tilt it down you get return from the earth’s surface and that is mapping. How you want to tilt it depends on what you’re interested in at the moment and what range you are using. This too takes a little experimentation. Mapping, I find I like the 50 mile range with 5° tilt down―that is if I’m flying level. If I’m climbing the nose of the airplane is up so I tilt down a few more degrees; vice versa during descent.
There’s another switch marked Stabilization. When you flip that it gyro stabilizes the rig so that turns, bumps and so on don’t tilt the picture and confuse you. This does not affect the up and down tilt.
There’s one more switch called Contour and that helps in rain and thunderstorms. What radar sees in a storm is the rain; it bounces off the rain. Now if it bounced off the front of the rain area all rain areas would look the same, the same strength, when actually one area might be a light shower and another might be one of those man-look-out kinds. This contour circuit fixes things so that the gradient of the rain―its density, so to speak―is measured and the real no-foolin’-this-is-for-keeps kind of rain shows up as a dark area with a light colored periphery, like little irregular doughnuts on the scope. These show the business end of thunderstorms; these are the things to circumnavigate, to stay away from, not to fly through. You flip this switch to get this effect.
What will all this do? Well, it maps pretty well, but the 5 centimeter is best for looking at weather, the thing it is particularly made for. Mapping is secondary, but it does a good mapping job if the contrasts are good―coast lines, high mountains and all that. On our overseas routes this is good. I can see a coast 150 miles before getting there; you can get a ground speed check by timing a coast line as it crosses the range marks. You can see ships at sea and one night when talking to weather ship Juliett I asked him for a radar fix. In this routine he gets me on his scope and tells me how far away I am and on what bearing. Well, this night he said he couldn’t pick me up. All the time we had him on our scope so we told him we’d give him a fix! You find there are a lot of ships on the North Atlantic you never knew about. Most of the ocean flying is on top and you see the surface less than 10% of the time, so you don’t know what’s down there. Radar gives you a look and it’s interesting. There’s a lot of traffic on the ocean too!
For seeing other airplanes it’s just about useless. The beam has to hit them square. If the other airplane is below you he gets lost in the ground picture and you can’t see him. One night, for example, I was going from Frankfurt to London; a BEA Viscount was traffic. London ground radar told me the Viscount was 10 miles ahead so we knew where he was very closely, yet it took about 10 minutes of fiddling with the tilt and range before we finally found him and then he was difficult to see. Of course the set isn’t made for that. Ones that are, I hear, do a pretty good job seeing other airplanes, but I’ve never seen them.
But the big deal is weather. The day we were talking about with the cold front turned out rather well and actually the front did stay off to the northwest, our left, but I could see not too far away the towering cumulus. It was almost dusk and enough light had gone from the day so we could see lightning flashes. The scope showed the storms. According to the range marks they were 40 miles away. This is one of the many interesting by-products of having radar. You’ve looked at thunderstorms and wondered how far off they really were. Well, now we measure the distance and get an idea―offhand I’d say they are further away than they look. So if you have experience with radar it may help when you are flying without it, to some extent.
Along similar lines, it’s interesting to watch a line of storms and, without consulting radar, try to figure where the best place would be to go through; then look at the scope and see how right or wrong you were. It’s strictly a gamble.
On this same trip we had a front at sea with a possibility of some thunderstorm activity in it. As my bunk time was arranged so that I’d be awake for the front I went to bed early. When I got up I struggled into the cockpit, got settled and looked ahead expecting to see the beginning high clouds of the front, but the sky was clear. “Where’s the front?” I asked the copilot.
“They missed its location. We passed it an hour ago.”
“Nothing in it, eh?” I asked, because if there had been a bump I would have awakened, and I hadn’t.
“Yes there was, quite a little activity, but we just slid through watching the scope and never hit a ripple!” So along with other things I may get more sleep!
Theory and Reality
With the coming of fall things also get a little unsettled around the British Isles and Ireland. As we approached this area the sky was dotted by big CB’s that built to great heights; the anvil and scarf clouds of a thunderstorm marked most of them. We were on top of a solid deck and these CB’s stuck up through it. The radar showed these storms plainly and the little doughnut pattern was strongly evident on the scope as we slid by the storms. But it was interesting to see that some of these clouds didn’t have the doughnut―in other words, they were not supposed to be tough and bouncy. Logically this could be. We know that a thunderstorm cell isn’t static; it is either being born, growing or dying, and the dying ones don’t have the wallop left in them, even though they still look nasty. There is a visual hint; when a storm cell is on the way out the anvil, scarf or what you may visualize as the high clouds, take on a diffused, fuzzy look; when the cells are new, growing and nasty they look firm, well defined―but this is one of those ideas you don’t feel good enough to count on 100%. If a cloud looks like a thunderstorm it looks like a thunderstorm and you and your Adam’s apple don’t like to poke into it!
But I do notice that on the scope this theory seems to be true and flying toward London some of the clouds would show activity and some not, but being able to duck around I didn’t have to go through any of them.
All good things end and they did near London. The big CU’s lined up, the lower deck became thicker, other layers appeared and, of course, it was time to descend! Now we would be in the stuff and see nothing. Without radar you fasten the seat belts, slow down and hope for the best, and you still do that with radar, but you feel much, much better. We descended into the mess―only slight bumps, but the scope showed numerous little doughnuts and we wandered around them, not turning very far, 10 or 15 degrees either side of track for a bit, and no big bumps came. Without radar the little bumps would make you nervous. You’d think they were the sign of big things coming, and sometimes the big turbulence would come and sometimes it would not. Now, looking at the storms with radar, you see the cells of tough turbulence are scattered and being in there without radar makes missing them just luck. Actually there are fewer cells than our wildly pessimistic emotions think there are, but without radar this information is of little help because it would be a problem if there was only one little tiny one in there.
Descending we waltzed around and didn’t hit a thing. You find you don’t have to wander very far.
I’ve talked to pilots on the domestic routes, where they really get a lot of thunderstorms―especially in the midwest, and they say they can duck around and hardly ever get off the airway. At first, when radar came along, I think we visualized using it to see storms a long way off and then avoid the entire area, but in practice you can get right in close and do broken field running instead of long end runs. Of course there’s nothing against an end run if it’s practical!
Coming down into London we began to see the ground from about 4000 feet, just rain washed hunks of it down through canyons and corridors of huge CU and various layers. London Radar was in the act and took us over on his scope to steer us into the runway. One airplane was ahead and we were Number 2. They gave us headings to swing our track a little wide so we would not be too close to Number 1. We kept looking at our scope too and could see various showers and finally there was a doughnut on the scope right ahead. I called London Radar.
“There’s a heavy shower on my scope, about 3 1/2 miles ahead. Have you another heading so I can stay out of it?”
“Right,” he said, “I see it also.” Then he gave me a heading that brushed us by the shower. In a few moments we were below all clouds and there was that big long runway and we were on the ground, no fuss, no bumps.
This new addition is a big help for aviation. It needs some work. The scope should be more brilliant for reading in daylight―as it is now one crew member has to bury his head in a black shield to see it. We will hope for better and better quality.
Radar will be one of those things you’ll wonder how long you got along without. I wonder now! It’s changing our thinking and peace of mind too. It all summed up the other day; I was driving to the airport and as we all do I looked up at the weather noting what the sky held, what it would mean to the departure. The sky was hazy and big cumulus built up, the air was heavy, and my mind thought of thunderstorms, how near developed would they be by takeoff time, was a front coming, and all those little thoughts. But suddenly I remembered I would have radar, and in that instant the thunderstorm lost its awesomeness. It wasn’t important any more, it fell back into place with all the other weather problems we’ve watched slip into the past.