WHEN WORKING on my instrument rating in 1956, I had to execute instrument approaches using four-course, lowfrequency ranges.
Although they served their purpose, I am thankful that these sadistic procedures and radio aids have been
superseded by modern technology. The good news, though, was that only a low-frequency receiver was required. It was no more complex than a conventional AM receiver. The bad news was the punishment administered incessantly through the headphones while struggling to interpret the aural signals against a background of static and hash. Orientation often was confusing, frustrating, and created mental
anguish.
I also learned to execute the much easier ground-controlled approach or GCA. Later called PAR (precision approach radar), these involved simply following a controller’s heading and descent instructions to decision height. Although PARs are relics, they are still in use at many military bases. In some
cases, a civilian pilot can obtain permission to make a PAR approach — especially when controllers need practice to maintain proficiency — but be prepared to go-around at minimums.
Landing at a military base anywhere in the world without permission usually results in inhospitable treatment.
When I joined TWA in 1964, I thought I had seen the last of the ground-controlled approach. Not so. While heading toward Fiumicino Airport near the end of a redeye passenger flight from New York to Rome in a Boeing 707, we were advised that the ILS was “oscar sierra” (out of service), and that we were to expect a
“radar-guided” (PAR) approach.
The “Fiume” weather was reported as the equivalent of a 200-foot overcast and
a half-mile visibility. I was a new first officer, and neither I nor the captain had executed a radar approach for years. We agreed, though, that this was no big deal. All we had to do was follow the controller’s instructions.
The approach controller vectored us to final approach and then handed us over to the final controller, who would provide lateral and vertical guidance to decision height where we would hopefully see
enough of the runway to make a safe landing.
In preparation for final approach, the radar controller issued the standard admonition, “TWA Eight Four Zero, if no transmissions are received for a period of 10 seconds, execute a missed approach.” Instructions for the “miss” were then provided.
The reason for such a missed approach was obvious. A lengthy pause in communications could signify radio
failure, and it would be dangerous to continue descending at such a time. (In the United States, a 15-second period of silence is the maximum allowable.)
The final controller began his litany, “TWA Eight Four Zero, turn left heading
340. Glide path intercept in two miles. Do not acknowledge further transmissions. <pause> Turn further left 338. Prepare to begin descent in one mile.”
We lowered the landing gear, extended the flaps to 50 degrees, turned on the rudder pump and reduced airspeed to VREF plus 5 knots.
“TWA 840, turn back right heading 340. Begin normal descent. Correcting nicely.”
A normal descent consists of the sink rate needed to descend along a threedegree glide slope. This can be
determined from an ILS approach chart by referring to the “sink rate vs. groundspeed table.” Or you can use the rule of thumb: add a zero to groundspeed and halve the result. A three-degree descent profile and a groundspeed of 120 knots, therefore, require a sink rate of about 600 fpm.
Our wings sliced into the undercast and our world changed from brilliant, eyeballbleaching
sunshine to milky gray. The final controller continued, “TWA
840, turn left heading 340. Going slightly low on the glide slope, decrease sink rate.
On course; turn right 342. On glide slope; resume normal descent. Tower clears you to land Runway 34 Right.” Some pilots are nervous about descending to low minimums without otherwise verifying their position relative to an electronic localiser and glide slope.
Not to worry. PAR controllers are so reliable and skilful that they can almost talk a pilot to touchdown. At 500 feet agl and still descending, the radio got quiet for too long. No instructions, no nothing. The captain, I
knew, was mentally preparing for the possibility of a miss. At 400 feet. Still nothing. We were only 200 feet above minimums and sinking. I grabbed the mike and asked anxiously,
“Fiume Radar, TWA 840. Are you there?
Are we okay?”
“TWA 840, you’re doing just-a fine. Don’ta touch-a nothing.”
Such was the nonchalance of Rome Radar.
Italian controllers were a breed of their own. A year or so later we found ourselves at the end of a long line of departing aircraft. Departure radar, we were advised, was “oscar sierra” (something was always
“oscar sierra” in Italy in those days) and aircraft were allowed to depart in only five-minute intervals.
Pilots were becoming impatient at the snail-like progress of the departure queue. A few aircraft had been waiting so long that they had to return to their gates for refuelling.
Finally, one pilot, an American (in the Pan Am 707 immediately ahead of us, we suspected) transmitted, “C’mon Fiume. How about moving this parade a little faster?”
The Italian controller responded, “All aircraft on-a da ground at Fiumicino, ground control going closed.
Subsequent calls to Ground were unanswered and surface traffic came to an immediate halt. Thirty minutes later, the controller came back on the air and said, “All right, you guys. Now tell-a me. Who’s-a da boss?”
