Training student pilots at a tower-controlled airport, I have received numerous position-and-hold clearances over the years. When the student pilot can explain why we received "position and hold" instructions, or - even better - can anticipate them, I view it as evidence the trainee is developing a satisfactory level of situational awareness. Nor do we just sheepishly follow the controller's instructions. Rather, we use our eyes to verify that the situation is as advertised. Only then do we venture out onto the runway. We watch what is going on ahead of us so that we can be ready for the takeoff clearance when it comes. But we also look and listen carefully to what is going on behind us. If arrivals are inbound, we know that our takeoff clearance will have to come very soon.
Twice in those years of flying and instructing from our large, tower-controlled home airport, where the tower is easily a mile from the departure end of either runway, I have been cleared to taxi into position and hold - and then been forgotten. In neither instance was there a shred of danger, since other traffic was not a factor. But in both instances it took a query from our cockpit to get things going again. The transaction was handled with good humor on both ends. I have been up in that tower, and I know how tiny a single-engine trainer looks from such a distance. But it goes to show.
Perhaps it also illustrates that not all the causes of incursions highlighted in the FAA's ongoing push to attack the problem through education can be addressed via better pilot knowledge of airport diagrams, taxiway markings, and so on. Just as distractions cause accidents in cockpits, distractions or divisions of attention in control towers can be hazardous as well. Then the pilot has to be experienced enough to sense the developing problem and act to avoid it. Should there be a standard interval of radio silence after which a pilot sitting on a runway should speak up? Should the tower tell pilots how long they should expect to wait for takeoff clearance whenever "position and hold" instructions are given?
The Pilot/Controller Glossary in the Aeronautical Information Manual offers this description of the position and hold clearance: "Used by ATC to inform a pilot to taxi onto the departure runway in takeoff position and hold. It is not authorization for takeoff. It is used when takeoff clearance cannot immediately be issued because of traffic or other reasons." Instructors should not only ensure that student pilots understand this, but they also should point out how this clearance has the potential for creating those sudden, temporary invasions that everyone in aviation wishes fervently to avoid.
On October 12, 2001, a student pilot in a Piper Cherokee (PA-28-140) was preparing to depart from an intersection on Runway 16R at the Van Nuys, California, airport on a local training flight. A Piper Malibu (PA-46-310P) was on approach to the same runway. They collided at the intersection, on the ground, damaging both aircraft but without injury to the pilots. According to the preliminary National Transportation Safety Board report, "the PA-46-310P was cleared to land on runway 16R at 1824:11 by the Van Nuys Air Traffic Control Tower, and the pilot was advised 'traffic will depart prior to your arrival.' The tower then cleared the PA-28-140 to taxi into position and hold on Runway 16R at intersection 13F at 1824:47 and advised that pilot 'traffic a Malibu three and one-half mile base to final Runway 16 Right.' At 1826:01, the PA-46-310 transmitted 'Four-Bravo-Papa on final,' and the tower replied 'Malibu Four-Bravo-Papa Runway 16 Right cleared to land wind calm.' The collision occurred about 1827:55, on Runway 16R at intersection 13F." Three minutes and eight seconds had elapsed between the time the position-and-hold clearance was given to the Cherokee and the collision with the Malibu. Sunset had occurred about four minutes earlier.
The FAA's recently released Advisory Circular 91-73, designed to create procedures for safe ground operations at airports, discusses the many factors associated with incursions (against a backdrop of the increasing complexity of airports and surface operations). Suggested remedies include such procedures as using written taxi instructions, minimizing other workload items during taxi, giving comprehensive readbacks of taxi instructions, using aircraft lights, and planning ground operations with the same care as a pilot would use in planning the flight itself.
The 11-page advisory circular (which also included two appendices and a pilot guide to airport markings) pointed out the need for pilots to maintain situational awareness "by monitoring ATC instructions/clearances issued to other aircraft." For a student pilot about to embark on a solo training flight, the ability to keep track of radio chatter while visualizing what is going on around him or her is a developing skill at best. The wariness referred to earlier about "position and hold" instructions is also only acquired by experience.
Meanwhile, student pilots and their flight instructors should sit down together and read aloud the following passage from the situational awareness section of the AC: "You should be especially vigilant when instructed to taxi into position and hold... Do not remain in position and hold on the departure runway for an extended period without direct communication from ATC. If you are uncertain about your status, or if you are uncertain about any ATC instruction or clearance, contact ATC immediately." Such contact could be as simple as, "Tower, Cessna One-Two-Three-Four-X-ray is still in position and holding on Runway 16R." The response will either be a reaffirmation of your holding instructions, or a takeoff clearance. As a student pilot, it is also entirely acceptable to simply decline a position-and-hold clearance until you feel more comfortable complying with one. This may delay your takeoff a bit, or cause others in a departure line to grouse, but that's a small price to pay for not feeling hurried or pressured.
Another NTSB report reminds that the urgency of vacating a runway after a flight (also emphasized in the AC) is likewise a time to let wariness and situational awareness guide your actions. On October 20, 2001, in Kissimmee, Florida, a Cessna 172 on a training flight had landed on Runway 6 and cleared at Taxiway Delta. An SNJ-6 warbird (a large taildragger with limited forward visibility on the ground) also on a training flight landed behind the Cessna and cleared at the same taxiway. Quoting the NTSB document, "The pilots contacted ground control and were advised to hold position. The flight instructor in the Cessna reported that another Cessna airplane was on the taxiway in front of their position taxiing from right to left. While waiting for further clearance, the flight instructor and private pilot in the Cessna began completing their after-landing checks. While doing so, their airplane was struck from behind by the SNJ-6." The report states that after the SNJ pilot turned onto the taxiway centerline, he lost sight of the Cessna. The collision of his propeller and the Cessna's empennage occurred at about the time he was contacting ground control.
But this scenario, too, is in the spirit of AC 91-73, which advises pilots, "Unless otherwise instructed by ATC, taxi clear of the landing runway even if that requires you to cross or enter a taxiway/ramp area." What all pilots should remember in each surface operation they face is that those sudden, temporary invasions don't just happen when a befuddled pilot strays from a cleared route into harm's way. They can also occur when everyone is trying to do the right thing, but someone lets their guard down for an instant.
Dan Namowitz is an aviation writer and flight instructor. A pilot for 18 years and an instructor for 12, he enjoys learning to fly "anything new and different."
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