Roamy roundup

It’s not all space today.

The Navy Times reports that a modification to the tailhook design is all that is needed for the F-35C.

Because the tail-hook has to fit within the outer mold line of the F-35, the device had to be fitted further forward on the jet’s ventral surface than on other naval aircraft, [F-35 program manager for Lockheed Martin, Tom] Burbage said. The result is that the hook behaves differently than on previous fighters like the F/A-18…Another factor that effects landing on a carrier is the sheer force of the impact from a carrier landing. Unlike conventional land-based aircraft, naval aircraft don’t flare on landing. While the landing is on a more precise spot, it causes the tail-hook to oscillate vertically- which increases the chances that it won’t catch a wire, Burbage said. The dampening of that motion has to be tweaked, he said.

The shape of the hook itself also has an effect on the probability of catching a wire, he added. All of these are being tweaked to increase the chances that the F-35C will catch a wire on a carrier’s deck.

Next, this Wired article is cool for several reasons. One, it mentions the Boeing A160 Hummingbird drone helicopter, its capabilities, including a long flight time of 18 to 20 hours, and its upcoming deployment in Afghanistan. The camera onboard the Hummingbird is the Autonomous Real-time Ground Ubiquitous Surveillance Imaging System, or ARGUS. (Argus in mythology had a hundred eyes and was all-seeing.) ARGUS can track multiple objects and gather six petabytes of video in a day. (A petabyte is 1000 terabytes.) Last, it mentions the Blue Devil 2 mega-blimp. Years ago, I worked on some polymer films for a military airship and am wondering if this is it and it’s finally going to fly.

Last but not least, the Wideband Global SATCOM 4 is set to launch from Cape Canaveral on a Delta IV today. Launch window opens at 7:38 pm Eastern time. This satellite will help communication in the field, especially with the bandwidth needed for telemetry from drones.

4 thoughts on “Roamy roundup”

  1. Naval AC do flare. You want the mains on first before the hook engages. There is too much of a tendency for an in-flight engagement otherwise.

    However, the mains go on hard, and the pilot goes to full power in case the hook doesn’t catch (called a bolter). Ideally, the nose comes down just after the hook catches. I get the impression that the 35’s hook has to be mounted much further forward than it has been on previous AC, and it is a bit too close to the main gear ad is creating problems. The gang over at Lex’s place has touched on it, but I haven’t seen much said as to what problem(s) this is causing.

    1. Actually, Naval aircraft don’t flare, in the traditional sense. They do want to land with a nose up attitude, and have the mains touch down first. But a Naval approach uses a constant positive angle of attack during the entire approach. The specific angle of attack varies from aircraft to aircraft, but the glideslope is typically a 3.5 degree glideslope from interception to touchdown. The perfect approach would have a steady, constant angle of attack, speed, and rate of descent from start to finish.

      Land based aircraft, on the other hand, arrest the majority of their rate of descent just before touchdown, that is, they flare.

    2. Flaring doesn’t necessarily arrest descent. But I see what you are talking about. I see flaring as primarily a nose up attitude with little consideration for arresting anything. If power is decreased at the same time, then you will get what you are calling a flare. I admit, that’s the usual usage of the word, however.

    3. Air Force and civilian aircraft flare to reduce the rate of descent. They just aren’t built to routinely withstand the 500fpm rate of descent at touchdown.

      IIRC, carrier jets are stressed to about twice that.

      as to “Flaring doesn’t necessarily arrest descent.”, well, it will, briefly. In the interaction between thurst, lift, drag and weight, increasing the angle of attack will briefly slow the rate of descent. But it will bleed airspeed to do so, and soon begin to descend (or more accurately, descend faster) again.

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