On a dark and stormy night in late December 1955 I was on duty at a US air defense radar base in north-eastern Italy near the town of Campoformido.
Just north of us were the Dolomite Mountains, also known as the Italian Alps. The cloud cover (ceiling) was at best 200 feet. With the technology of the day, this was not the kind of night you wanted to be flying. Suddenly, we got a call from a USAF pilot who told us he was in a storm, not sure of where he was, low on fuel and needed help. We were not really in position to give it to him. We didn’t even have a paved landing strip. There was C-47 on our base so that fliers could log in time and earn their flight pay, but they took off and landed on a grass field – only in the day time because there were no landing lights.
We did have a search radar for detection of aircraft (see photo) . It rotated steadily, sweeping the airspace with a narrow beam. When the beam strikes a flying object, a blip appears on a circular radar scope. And there was a height radar that didn’t rotate but did bob up and down in the direction it was pointed and gave the altitude of the flying object at which it was pointed. In 1955, technology was extremely crude. A blip on our radar screen was, in actual size, more than a mile in diameter. So we didn’t have as good an idea of his position as we would have liked. So, we were faced with a serious problem.
My goals were to
1. get the plane to travel in the right direction,
2. get some lighting on our field,
3. get better accuracy on the position of the aircraft, and
4. feed the pilot information about rate of decent by telling him at what altitude he should be at different distances from us as he approached the landing.
Since the grass landing strip was right next to the radar, direction was not a problem – just aim the plane at the center of the radar scope.
For lighting I asked a sergeant to get all the trucks and cars he could find, line them up on both sides of the “runway” and turn their lights on.
For better accuracy, we pointed the height radar at the aircraft. While we didn’t need the altitude information because we could get that from the pilot, it would give us better resolution than the search radar.
Goal number 4 was harder. But I came up with a crazy idea. A year earlier I had earned a degree in mathematics, and I remembered some things from trigonometry that might help. The reader might know that trigonometry was about such things as sines, cosigns, tangents, etc. But it was also about triangles, particularly about right triangles (ones that have a 90 degree angle). I remembered that ratios of the sides of a 30-60-90 degree triangle were as follows: if the short leg (opposite the 30 deg. Angle) is of length X, the diagonal (hypotenuse) is of length 2 times X and the long leg (opposite the 60 deg. Angle) is X times the square root of 3 – in symbols √3
What I needed to do was, for different ground distances from the landing point, calculate the altitude, x, in feet at which the plane should be on its decent and feed that info to the pilot so he could adjust his altitude accordingly. For example, at 10 miles from the base I had to solve for x in the equation:
10 (miles) = x (miles) × √3
or x = 10 miles ÷ √3
or x = 10 miles÷ 1.732 = 5.7735 miles
To get the altitude in feet, you multiply x by 5,280 – the number of feet in a mile. Hence the altitude should be 30, 485 feet at 10 miles from touchdown, if he is descending at a 30 degree angle. At 5 miles from touchdown the altitude should be 15,242 feet. And so on.
This is simple arithmetic today – my hand calculator gives me the square root of a number with one click. But one must remember that in 1955 we had no calculators. To get the square root of 3, we started with a guess, multiplied the number by itself, looked at the result adjusted the guess up or down and did it again. After doing this multiple times we set the square root of 3 at 1.7320508.
The result of all of this was what I thought was a miracle – the plane burst through the cloud cover in line with the lights provided by the cars and trucks. Everybody was delighted especially the pilot and his passengers that included a USO troupe of musicians and dancers. Lucky us. We all went to a large villa that I rented with 3 other officers and had a grand party.
About a year later I was dining in the Officers’ Club at a base outside of Casablanca and the pilot of that flight saw me from across the room and brought a group of people over and related the story to them.
In World War II, our site was an Italian air base. The place we used for the Officers’ Club was the basement of a building that was bombed in December 1945. It turns out that one of my golfing buddies may have been the one that dropped the bombs. On the record of his missions was a note that, on Christmas Day 1945, while returning from escorting bombers to and from the Ploesti oil fields in Romania in his P-38 fighter, he dropped some bombs on the Campoformido air base.