Runaway plane

December 2022

Q: Your roommate, an English major, is drafting an unsolicited screenplay for “Unstoppable II.” Instead of a train accelerating out of control, it’s about an airliner with some 200 souls aboard. Being an aeronautics major, you ask if you can take a look. The first scene is labeled, “I. Cockpit of a conventional airliner at cruising speed and altitude.” The captain and first officer are engaged in small talk about the perks of perhaps retiring early. Suddenly, the radio crackles: “Flight 124, due to the jet stream, you can expect a strong tailwind a few miles ahead.” The captain says to the first officer, “Uh-oh, that tailwind is going to make us go so fast we’ll cause a sonic boom!” You snicker, and your roommate asks what’s so funny. What do you say?

AIAA Fellow Jim Kuchar of MIT’s Lincoln Laboratory provided the idea for this question and helped refine it. He will review your responses.

Send a response of up to 250 words that someone in any field could understand to aeropuzzler@aerospaceamerica.org by noon Eastern Dec. 14 for a chance to have it published in the next issue.

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From the November issue: A CHRISTMAS SURPRISE:

We asked you if the Grinch’s U.K. cousin was right in thinking his “Ultra …” engine was loud and dirty. Four of you responded correctly.

WINNER: The world’s largest aircraft engine is Rolls-Royce’s UltraFan engine. However, unlike what Mr. Grinch may hope, it is designed to have much lower emissions than regular aircraft engines.
George Kyriakou, AIAA Young Professional Member | New York, New York

WINNER: The U.K.-based Grinch (a Brinch?) has brought home a Rolls-Royce UltraFan. And while its lighter weight will make it easier to carry, the 15 decibel reduction in overhead sound — a 65% lower ground level noise — clearly will keep the Brinch unhappy for some time. Better that he had found a Pegasus or Olympus engine. Now those would make his missing ears perk up!
David Newill, AIAA Associate Fellow | Zionsville, Indiana

WINNER: Unfortunately, it seems the Grinch has had a stroke of environmental genius rather than evil genius. The engine he has found belongs to Rolls-Royce and is a prototype of the next-generation UltraFan series of engines. Coincidentally, this engine is big. What it is not is loud and dirty (comparatively).
Adrian Nomi, AIAA student member | Tsukuba, Japan

WINNER: I suspect Mr. Grinch has stumbled upon the Ultra …. Fan. A clean, quiet, efficient turbofan demonstrator from Rolls-Royce and the opposite of dirty and loud as intended by Mr. Grinch. Ultra does mean big, a turbofan with a diameter of 140 inches — almost 12 feet. Ultra indeed.
Rich Wahls, AIAA Fellow | Williamsburg, Virginia