Free Tom Swift in the Caves of Nuclear Fire by Victor Appleton II

engines!" Tom said, and worked the throttles frantically.
    Approaching the copilot instrument panel, Bud noticed that the fuel-pump RPM indicator showed an alarming decrease.
    Tom commanded, "Cut in the fuel-pump boosters, Bud!"
    His friend threw the switch. No change!
    Tom scanned the instruments again. "Altitude’s going—fast!" he declared. "If we don’t get power back in a couple of minutes, we’ll have to ditch!"
    "Y-you mean in the ocean?" cried Ry Cully fearfully. The slender, gray-haired geophysicist was the eldest member of the crew. Despite his enthusiasm for the overall project, he had confessed a manageable fear of flying.
    Hank Sterling made some suggestions as to what might be going wrong. Tom tried various adjustments to the controls, but nothing worked.
    "The aeolivanes are still operating, thank goodness," Tom muttered. "But without jet lifters or the forward jets, we’re just a great big glider. We won’t be able to stay aloft."
    "And—we don’t have either of those little planes on the hangar deck, either," said Craig.
    "We’ll have to ride her down for a water landing," Bud said.
    Arvid Hanson had entered the control cabin behind them. He quickly grasped the situation. "Tom, should you radio our position—while the radio still works?"
    Tom stared at him grimly. The Flying Lab was beginning to shudder—a sign of insufficient airspeed.
    Frantically, the young inventor scrutinized his instruments for some sign of the cause of the mechanical failure. Nothing new showed up. The Sky Queen continued to sink seaward like a wounded gull.
    "We’re down to fifteen thousand feet!" Bud called out, trying to keep his voice steady. "Tom?"
    Tom did not reply. He worked the throttles again, but the rate of forward thrust was decreasing more and more rapidly. Suddenly Bud, glancing out the forward viewpane, cried out:
    "Tom, look up there! It looks as if we’ve picked up ice in our engine air inlets!"
    The pilot peered at the gaping orifices above and ahead of the control cabin, clustered beneath the craft’s snub-nosed prow. "You’re right!" Tom exclaimed. "Ice is choking off the air to our engines! The pumps slow automatically without a sufficient airflow." The Queen ’s futuristic engines made use of a special hydrogen-based fuel which required a constant influx of atmospheric oxygen to maintain combustion.
    "Ice!" Craig repeated in surprise. "The sky is clear! Where did all that moisture come from?"
    Tom clapped a hand to his forehead. "I must have been daydreaming!" he said. "A little while ago I pulled the Sky Queen up through a layer of cirro-stratus clouds. But the thought of moisture freezing on the inlets never entered my mind!"
    "I’ll switch on the inlet de-icers!" Bud offered. He dashed to the flight engineer’s control panel, situated just to the rear of Craig’s seat, and threw a series of switches. Nothing happened!
    "Jetz! The ice is so thick," Bud yelled, "it won’t break off!"
    "We’re down to ten thousand feet!" declared Craig, as he caught a glimpse of the altimeter.
    Setting his jaw, Tom cut off the sputtering jet lifters completely and shoved the control wheel forward. The Sky Queen pitched into a steep dive. His companions stared out the front viewpane as the deck tilted sharply and they approached the ocean at an alarming rate.
    "Good gravy!" Ry Cully gasped. "Are you planning to drown us?"
    "Tom knows what he’s doing!" retorted Bud.
    Tom held the craft in its diving position. Then, when a crash seemed inevitable, he hauled back carefully on the control wheel, pulling the nose of the plane up. The fast recovery from the dive caused the occupants to feel as if they weighed tons. A veil of gray gauze seemed to drop over their eyes.
    Can’t black out now! Tom told himself. A slight forward motion on the wheel decreased the angle of ascent and relieved the threat of unconsciousness.
    Craig, gripping his seat, was amazed to discover that they were flying only a few feet above the