Joint Strike Fighter test force overcomes hurdles linked to night flying

Published Feb. 21, 2012
By Kate Blais
95th Air Base Wing Public Affairs

EDWARDS AIR FORCE BASE, Calif. -- Flying off into the sunset has new meaning for the 461st Flight Test Squadron. Reaching another milestone in the test program, the Joint Strike Fighter Integrated Test Force completed the first F-35A Lightning II night flight Jan. 18, 2012.

Taking off just before sunset, the aircraft flew test points in both twilight and darkness.

"We did a sequence of approaches to the runway, including touch-and-go approaches, to make sure everything was safe to use at night," said Lt. Col. Pete Vitt, 461 FLTS director of operations. "We were doing an evaluation to check and make sure that the interior cockpit lighting, the exterior lighting and the landing and taxi lights were adequate and safe for the F-35 at night."

Little difference exists between preparation for day flights and night flights, however, lighting conditions at night are closely considered, as well as sunset timing, moonrise and phase, and variables such as amount of cloud cover.

Although the actual sortie took place in January, initial testing to get the plane in the air at night began long before that.

"We did an internal cockpit lighting evaluation in spring 2010," said Rachel McKinnon, 773rd Test Squadron human factors engineer. "This examined the aircraft for any internal glares, reflections, anything that would be a distracting lighting source for the pilot."

This testing discovered that the software on the aircraft did not allow for console dimming, which is vital to for optimum lighting configurations during night flight, added McKinnon. To achieve optimal cockpit lighting at night means to eliminate distracting glares and any light sources that could lead to visual illusions for the pilot.

"We found a lighting problem with our taxi landing light and a software problem," said Capt. Jeff Newcamp, 461 FLTS flight test engineer. "Before we could fly at full capability at night, we had to write an amendment to a test plan in order to allocate some build-up test points to fly at night in the build-up fashion."

Once a 461 FLTS pilot noticed that the taxi landing light was not sufficient for taxi during a pre-dawn flight, that light source was evaluated and deemed insufficient.

"We noticed that light wasn't providing enough visibility; neither the forward coverage nor side coverage that we'd anticipated," said McKinnon. "When you have one light that performs two things, you have to find a compromise."

McKinnon explained that the compromise came in the form of altered refractory geometry in the light source, which optimized the optics inside the light. This change provided pilots with sufficient side-to-side and forward visibility to both taxi and land safely at night.

"Some of the feedback we've received from the pilots is that this is some of the best internal cockpit lighting they've flown," said McKinnon. "Everything [in the cockpit] dims down really nicely, lighting is optimized and the landing taxi light is really bright. I think that's incredible for having an unsuitable solution just a couple months ago."

This round of testing expands the F-35's combat capability and provides the Integrated Test Center at Eglin Air Force Base, Fla., with a training platform that is representative of what will be flown in the field.

"Part of the procedure here [at Edwards] is to release capabilities to the warfighter," said Newcamp. "We fight wars under all conditions and we need to deliver those capabilities to the warfighter."

Future night testing includes aerial refueling evaluations to ensure that the F-35's lighting characteristics are compatible with various tankers.

"We have aerial refueling night evaluations with both the KC-10 and KC-135," said Vitt. "There are also some test points that are specifically designed to be done at night with various mission systems on the aircraft."

The JSF ITF overcame these unique technical challenges by taking the time to adjust testing in order to deliver an optimal product.

"We had night flying in our test plans but, but not necessarily in this fashion, this was kind of our version of slowing down and looking at this [the lighting issue] a little closer prior to jumping into night flying," said McKinnon.

"We have over 800 people in the ITF and this night flight project really touched most of those folks," said Newcamp. "Each group came together, did their own piece, and enabled us to fly two night sorties in January. Once we conquered the technical hurdles and got the jet in the right configuration to fly at night, two sorties went off, and both were remarkable successes."