Military

Boeing shuts down and restarts T-7A trainer engine in flight

Boeing shuts down and restarts...
The US Air Force has ordered 351 Red Hawk T-7As
The US Air Force has ordered 351 Red Hawk T-7As
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The US Air Force has ordered 351 Red Hawk T-7As
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The US Air Force has ordered 351 Red Hawk T-7As

In a graphic display of self-confidence, Boeing deliberately shut down and restarted the engine on one of its T-7A Red Hawk trainer jets as part of a major safety test. At an altitude of 20,000 ft (6,096 m) over a test area in Illinois, T-7A Chief Pilot Steve Schmidt and Boeing Pilot William Berryman switched off the aircraft's GE F404 engine for 48 seconds before restarting it and returning to Boeing's St. Louis facility.

If you want to find something that a jet fighter pilot really doesn't want to experience, having the engine shut down is probably pretty high on the list. It is possible to restart an engine in flight, assuming that there isn't a mechanical fault, but even then it isn't easy.

A flameout under the wrong conditions can result in the pilot learning very quickly what happens after pulling the lever on the ejector seat. Therefore, it's a small wonder that Boeing regards the recent test as a critical development milestone.

Overall, Boeing says the T-7A has clocked up 175 hours of flying time on over 160 test flights. It's slated to be delivered to the US Air Force in 2023, the T-7A Red Hawk is being developed by Boeing and Saab under a US$9.2 billion dollar contract for an initial order of 351 aircraft and 46 simulators, plus ground equipment, to replace the Air Force's aging fleet of five-decades old T-38 trainers.

The T-7A has twin tails for greater maneuverability and a high angle of attack, stadium seating, and an advanced cockpit with embedded training systems. It can also blend with state-of-the-art ground-based training and boasts a number of features for fast and easy maintenance.

"Engine air start testing requires a large amount of preparation, planning, and teamwork," says Schmidt. "It’s a test of all the subsystems built for backup in the event a pilot would have to shut the engine down in an emergency and power it back up again."

Source: Boeing

3 comments
paul314
It's good that they have gotten to this point, but inflight restarts are also a standard part of flight testing. Because there are all kind of non-catastrophic reasons an airplane engine might shut down in flight, and it's really expensive to have to eject every time that happens. (You also don't want a non-test pilot to be the first person confronted with the problem.)
Kpar
The GE404 was first developed for the F/A-18 Hornet. It was described as a "leaky turbo-jet" because it is a low-bypass turbofan. It does have an afterburner, so I suspect this trainer is supersonic capable, like the T-38 that it is meant to replace.
kwalispecial
Google and Wikipedia show both jets as the same weight. They show the T-38 with engines, each with a max thrust of 2900 lbf for a total of 5800 lbf. They show the T-7a with a single engine with a max thrust of 17000 lbf. But they show the T-38 with a top speed of 858, and the T-7a with a top speed of 808. I know there is more to speed than thrust, but how can 2 jets have the same weight, and one has almost 3X the thrust, and that one is slower? I would think the T-7a would have to be a 7000 lb cube to require 3X the power to reach the same speed... Is the info on the internets just wrong?