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An Israeli F-15 landed without a wing (2020)

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Re: An Israeli F-15 landed without a wing (2020)

#41

Post by MerelyMortal »

JoeAltmaier wrote: post #12

Better title: Ziv Nedivi landed an F-15 without a wing Plane didn't land itself.

In English, the title is perfectly fine. It just says the plane landed, not how it was landed.

The title is correct, and while the pilot does deserve recognition for the impressive feat, the article is primarily about the plane, not the pilot, so changing the focus of the title from the plane to the pilot is not appropriate in this instance.

The subtitle is terrible though: it mentions "he" (the pilot), but doesn't say who "he" is. So for the subtitle to make sense, the pilot's name should be in the title. Perhaps it was originally written with the pilot's name, but was changed by an editor for the reason listed above.

Re: An Israeli F-15 landed without a wing (2020)

#42

Post by intrasight »

When I was a senior at CMU in '88, a group of us went on a plant trip to the McDonnell Douglas factory in St. Louis where they built the F-15. I've previously posted on HN about how cool are plant trips and that engineers should take every advantage. Well, this factory visit was as cool as they get. Some highlights that I remember that related to the article about the Israeli incident.

1. This plane was machined out of blocks of titanium. 80% of the material is machined away. I asked the guide if it's collected and reused. He said "no". Their optimization for performance didn't really have to consider cost.

2. Seeing the "testing" was a mind-blow that I can still see in my mind 35 years later. They had an aircraft in a test harness and grabbed the tips of both wings in massive hydraulic presses, and bent that wing up and down by a couple meters. My brain was like “that’s impossible – they should snap off”.

3. “Avoid FOD” signs everywhere - "Foreign Object Damage". I learned many new acronyms that day.

Re: An Israeli F-15 landed without a wing (2020)

#43

Post by js2 »

jlkuester7 wrote: post #35
dogma1138 wrote: post #30

Earlier quoted context omitted.

Yes, aircraft are designed to be transportable and repairable so the wings and other control surfaces are easily removable. The wings on an F-16 for example are secured by two bolts all you need is to disconnect the avionics remove the bolts and the wing comes off. You can replace a wing on an F-16 within under half an hour without skipping any steps it is like changing tires on a car.

I hope that the techs give an extra tug on the wrench "just to be sure" when they are tightening those two bolts back on like I do when putting the lug nuts back on my car wheel...

They are undoubtedly using a torque wrench, and so should you. Opinions differ one whether to use anti-seize compound:

https://www.rtsauto.com/should-you-put-anti-seize-on-your-lu...

Re: An Israeli F-15 landed without a wing (2020)

#44

Post by eesmith »

jlkuester7 wrote: post #34
stavros wrote: post #17

Earlier quoted context omitted.

Rockets are a testament to the truth of that :P

Apparently no one told that to Elon.... It may have been German mad-scientists who pioneered sending rockets to space, but I think you actually have to be more crazy to think you can bring them back down again and land them in one piece! (Not that it has stopped Musk from doing just that...)

https://curious-droid.com/1107/vertical-landing-rockets-befo...

> You may well be forgiven for thinking that rockets which take off vertically and then land again vertically were a recent development by the likes of Blue Origin and SpaceX but a quick look back the history of rocketry and you’ll see that this technique is far from new and was first used nearly 60 years ago ...

> The image of rockets landing vertically on their tail fins has been popularised in Science fiction since buck Rodgers in the early 1930’s, though it took nearly 30 years to bring the technology to a point where it could be used practically ...

> The first instance of a rocket-powered vertical take off and vertical landing was shown in 1961 with the Bell Rocket belt. ...

> But within a few years there would be a rocket-powered vertical take off and vertical landing vehicle that would be a total success and be seen by hundreds of millions of people around the world.

> That vehicle was the Apollo lunar lander, a design that was used in the most inhospitable place man had even been to and worked without fail on six separate missions. ...

> It wasn’t until the mid 1990’s that the first true vertical take-off and vertical landing rocket was seen in the form of the McDonnell Douglas Delta Clipper Experimental or DC-X.

Video of the DC-X from 1995, launching and landing, https://www.youtube.com/watch?v=wv9n9Casp1o .

Re: An Israeli F-15 landed without a wing (2020)

#45

Post by dogma1138 »

jlkuester7 wrote: post #35
dogma1138 wrote: post #30

Earlier quoted context omitted.

Yes, aircraft are designed to be transportable and repairable so the wings and other control surfaces are easily removable. The wings on an F-16 for example are secured by two bolts all you need is to disconnect the avionics remove the bolts and the wing comes off. You can replace a wing on an F-16 within under half an hour without skipping any steps it is like changing tires on a car.

I hope that the techs give an extra tug on the wrench "just to be sure" when they are tightening those two bolts back on like I do when putting the lug nuts back on my car wheel...

I was a bit incorrect on the total number of bolts it’s two bolts per strut and there are 8 struts in total.

https://media.defense.gov/2013/Nov/27/2000892775/-1/-1/0/131...

“…each wing possesses 16 wing attach bolts.”

Re: An Israeli F-15 landed without a wing (2020)

#46

Post by dogma1138 »

js2 wrote: post #43
jlkuester7 wrote: post #35

Earlier quoted context omitted.

I hope that the techs give an extra tug on the wrench "just to be sure" when they are tightening those two bolts back on like I do when putting the lug nuts back on my car wheel...

They are undoubtedly using a torque wrench, and so should you. Opinions differ one whether to use anti-seize compound: https://www.rtsauto.com/should-you-put-anti-seize-on-your-lu...

They have a hydraulic jig that does everything the bolts need to be torqued to 600 foot-pounds you aren’t getting that done with hand tools.

Re: An Israeli F-15 landed without a wing (2020)

#47

Post by tonyarkles »

_0ffh wrote: post #16
stavros wrote: post #14

Earlier quoted context omitted.

Isn't that what these planes basically are? They aren't very aerodynamic so they can maneuver quickly, so they need tons of thrust to stay aloft. I heard one described as "a brick with a jet engine strapped to it".

I think in the RC flying community there's a saying like "Anything can fly, with enough thrust". Safely landing, otoh, now that's a feat!

“If lift plus thrust is greater than load plus drag, anything will fly!”

When I was a kid, my father attributed the phrase to a short-lived TV show: https://en.wikipedia.org/wiki/The_Flying_Nun

Re: An Israeli F-15 landed without a wing (2020)

#48

Post by CobaltFire »

jlkuester7 wrote: post #35
dogma1138 wrote: post #30

Earlier quoted context omitted.

Yes, aircraft are designed to be transportable and repairable so the wings and other control surfaces are easily removable. The wings on an F-16 for example are secured by two bolts all you need is to disconnect the avionics remove the bolts and the wing comes off. You can replace a wing on an F-16 within under half an hour without skipping any steps it is like changing tires on a car.

I hope that the techs give an extra tug on the wrench "just to be sure" when they are tightening those two bolts back on like I do when putting the lug nuts back on my car wheel...

This is a common misconception. Once you hit the rated torque you NEVER do an "extra click" or anything else. That increases the applied torque beyond rated, and can (has) had disastrous consequences by weakening the bolts and/or the material the bolts are seated against.

Source: career Naval Aviation Maintainer, QA on F/A-18's and H-60's, etc.

Re: An Israeli F-15 landed without a wing (2020)

#49

Post by CobaltFire »

dogma1138 wrote: post #46
js2 wrote: post #43

Earlier quoted context omitted.

They are undoubtedly using a torque wrench, and so should you. Opinions differ one whether to use anti-seize compound: https://www.rtsauto.com/should-you-put-anti-seize-on-your-lu...

They have a hydraulic jig that does everything the bolts need to be torqued to 600 foot-pounds you aren’t getting that done with hand tools.

We do 600+ foot-pounds by hand on H-60's. It's not fun but it doesn't require a hydraulic jig. It requires a specific (long) wrench and a guy who can brace. If you can deadlift 200lbs you could do it.

The jig is likely to speed up the process and prevent fatigue; doing that torque 16 times per wing would get exhausting.

Re: An Israeli F-15 landed without a wing (2020)

#50

Post by sabjut »

_jack_cox wrote: post #28
amelius wrote: post #22

So the pilot seriously risked their life to save the government a few million $.

Ejecting is very risky for the pilot. Many pilots are seriously injured in the process (1 in 3 chance of spinal injury https://www.smh.com.au/education/how-dangerous-is-it-to-ejec... ). Ejection is the option of last resort; I'm guessing the pilot felt that he wasn't quite that desperate yet.

Operators of vehicles like boats or airplanes are much more likely to try and save the vehicle with all means necessary. This is probably due to a number of reasons but there is a somewhat increased attachment.

Car people love their cars yes, but boat people and pilots treat their vehicle like a child. No idea why.

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