On Jun. 12, U.S. aviation regulators ordered immediate inspections of Eclipse 500 small private jets because of an engine thrust problem that surfaced during a harrowing landing in Chicago this month.

The Federal Aviation Administration (FAA) directive followed a recommendation earlier in the day by aviation safety investigators who analyzed the Jun. 5 incident at Midway airport and concluded emergency measures were necessary.

This is thought to be the first notable safety problem with the new class of aircraft that some industry experts believe could revolutionize private air travel. Most small planes are propeller-driven.

Some industry insiders have predicted thousands of the lightest jets on the market would fill the skies in coming years, with several manufacturers, including auto companies, seeking government certification to build them. Output and projections have slowed due to the softening economy.

The FAA ordered immediate inspections of throttle systems on the Eclipse 500s, equipped with engines made by Pratt & Whitney Canada, a unit of United Technologies Corp. So far, 200 planes have been delivered to customers. Any planes that fail inspection must be fixed before further flight.

Alana McCarraher, spokeswoman for privately held Eclipse, had no comment except to say the New Mexico company was cooperating with the government.

In Chicago this month, an Eclipse 500 had to abort a landing attempt when it could not slow the plane to a safe speed on the runway. It landed on the second try with one engine shut completely and another at idle and not responding appropriately to pilot throttle commands.

There were no injuries to the crew or two passengers.

The Eclipse 500 does not have mechanical links or cables between the throttle controls and the engines. Throttle levers are connected to devices that create electric signals, which regulate fuel flow to the engines.

The NTSB investigation concluded a failure in the plane's throttle system likely occurred when the pilot in control of the plane sought more power just before the failed landing when the aircraft encountered "windshear" -- a sudden downward draft of air -- and began to lose altitude at a dangerous rate.

The FAA has also issued guidance to pilots on throttle control to avoid problems in certain situations.