A cell phone usually communicates through the nearest cell site. The farther the signal travels, the weaker it becomes; its energy spreads out and is attenuated by terrain and obstacles, such as buildings, and is blocked by the curvature of the earth. As a result, the signal is normally too weak to cause interference at other, more distant cell sites, and the same frequency may be used by those other cell sites to carry other calls. But in a cell call made from an airborne aircraft, the signal could be strong enough to cause interference at multiple cell sites. Even though the airborne signal becomes weaker as its energy spreads out, it isn’t attenuated by terrain and obstacles or blocked by the curvature of the earth.
According to FCC spokesman Matt Nodine, however, the FCC isn’t aware of any enforcement action having been taken against pilots using cell phones in emergency situations during the past 30 years.
But you don’t want to leave your cell phone on as a matter of routine. In 2002, a TBM 700 pilot reported that the aircraft’s localizer and glideslope were unusable during an approach, although other pilots hadn’t reported a problem to the tower. After the Socata made a safe landing, it was discovered that both pilot and passenger cell phones were on. When the same ILS approach was tried by the same pilot later, with the cell phones off, there wasn’t a problem.
Help In The Air
It is good...to remind people that when a signal is too weak for voice communication, you may still be able to communicate by text.
A pilot who encountered an emergency situation in February 2003 described his use of a cell phone as “lifesaving.” While flying on an IFR flight plan in a Cessna 182, the pilot noticed the ammeter discharging. At the time, he was in cruise flight at 6,000 feet, in and out of cloud tops. The pilot couldn’t reestablish proper operation of the alternator, so he declared an emergency and was given vectors to an airport in Cleveland, Miss., and cleared to descend to 2,100 feet for a GPS instrument approach.
When the pilot’s windshield began to ice up at the lower altitude, he abandoned the approach and climbed back to 6,000 feet. He requested an approach into Little Rock and informed Memphis Center he would turn off all electrical equipment en route to conserve battery power. He used his cell phone to call the FSS 60 miles out, and the FSS gave him the direct number for Little Rock Approach Control. The controller informed the pilot he was 20 miles east of Pine Bluff and suggested he try an ILS approach there. While the controller was giving vectors over the phone, the pilot tried to turn the radio on and discovered he now had a complete electrical failure. The controller told him Pine Bluff was reporting 1,800-foot overcast and cleared him to descend to 1,800 feet. The pilot broke into the clear and was able to land safely after receiving a vector from the controller.
Page 2 of 3