F-35B carrier ops video

I'm surprised it can actually accelerate and move forward with that lift fan cover open!!

reply to post by Aloysius the Gaul


What was even more impressive was the amount of water being thrown up when hovering, and when taking off, and the amount of flex in the nose strut when he touched down. I've never seen a strut flex that much to the side like that.

reply to post by Aloysius the Gaul


no plane expert perhaps zaphoid(sp?) will be in here to explain it better but i think the plane can move with the lift fan open because it has the rear engine that seems to be able to rotate to either slow decent or take off depending on if its landing or taking off

to have that make a bit more sense i think the fan provides uplift while the rear engine provides thrust if that makes sense

reply to post by RalagaNarHallas


That's exactly how it works. The lift fan door does cause a lot of drag, but it's only used at take off, and landing/hover. So you're getting lots of drag, for a really short time. Once they have a positive rate of climb, they close it up, and your drag goes away. They'll probably have to refuel not long after take off, but they have a really nice fuel fraction, so maybe not.

reply to post by Zaphod58


figured if any one on ats would know it would be you good sir thanks for the info

reply to post by Zaphod58


The gear on the Harrier took a lot of abuse too.

Enjoyed the rolling STO. It does look a bit ungainly with all the barn doors open.

Such a huge difference between this and China's new carrier flight ops... Looks pretty solid despite all the haters.

Also, I've never seen anything like the object under the nose before. Is this some kind of new optics or something?

reply to post by Aloysius the Gaul


I want one.



Just beautiful actually.

reply to post by Clisen33


It's the Electro Optical Targeting System. It's similar to a SNIPER pod, but without having to carry a pod and be more visible.

Super nice. American ingenuity...

...UNMATCHED.

...2nd to NONE.

reply to post by Aloysius the Gaul


I would like to see LockMart's tests of the failsafe mechanisms on the lift fan doors and the rotation mechanism for the rear nozzle. I'm curious to see what they have done to make sure failed doors don't get ingested into the lift fan and cause Fun. I also noticed that on rotation during takeoff the rear nozzle actively tilts downard, and I'm curious to know what happens if there is a problem with that system. I'm sure there is some design aspect preventing the pilot from going into the drink but I'd be interested to know what it is.

that design aspect would be called an ejector seat and he's still getting wet


all joking aside

if there's one thing you can call that, it's certainly not an elegant solution, but still, if it gets the job done, hey ho

Originally posted by RalagaNarHallas
reply to post by Aloysius the Gaul

 

no plane expert perhaps zaphoid(sp?) will be in here to explain it better but i think the plane can move with the lift fan open because it has the rear engine that seems to be able to rotate to either slow decent or take off depending on if its landing or taking off

to have that make a bit more sense i think the fan provides uplift while the rear engine provides thrust if that makes sense

Yes that is how it works - but the lift fan cover is such a massive airbrake/drag inducer that it defies conventional aerodynamics - I'm an aircraft mechanic - small-medium airliners - and typical airbrakes on those have nothing on that cover!!

AFAIK naval a/c undercarriages are beefed up quiet a lot as they have to take loads that conventional a/c do not - eg side loads from teh ship rolling and pitching while the a/c is parked.

there's a LOT of air comes out the bottom of a VTOL a/c - anyone who has seen a Harrier land in wet conditions will be familiar with the mist/rainbow (or is it a new method of dispersing chemtrails??!! ) - but I wonder if the carrier in use here is a Helicopter Carrier, so quiet a bit smaller and lower than the mega-carriers, so the exhaust is also closer to the ocean??

You can see a similar effect in videos of Harriers landing - but they are a bit smaller with less thrust & it is coming from 4 nozzles instead of 2 so is probably more dispersed.

Drag is a function of the square of velocity. At the very low speeds the lift-fan is employed in, it probably doesn't matter too much. It certainly "looks" wrong on takeoff, though.

It looks like they are on the USS Wasp (LHD-1) which is a bit smaller than Nimitz class carriers. Only STOVL and helos can use it.

en.wikipedia.org...

reply to post by jrod


It was the Wasp. She did the sea trials for the F-35.

Originally posted by _Del_
Drag is a function of the square of velocity. At the very low speeds the lift-fan is employed in, it probably doesn't matter too much. It certainly "looks" wrong on takeoff, though.

Yeah I know.....but it just....... looks.....so.......wrong!!

I'd suspect the lift fan is drawing one heck of a volume of air in on the forward side of that cover. So up to a certain forward speed, I'd say that cover is more likely to get sucked down than blown back. (Just like a how a wing works, but the faster air is moving down into that fan.) Maybe they designed it so by the time it reaches that amount of forward speed where pressure evens out, it's due to close anyways since it would be at transition speed. (Engineers are a clever bunch that way.)

Other than that, it's probably fastened on there in a way that's just as strong if not stronger than most of the control surfaces.

As for getting sucked through the fan? Probably wont happen. Likely designed with overlap so that cover wont fit though, and unlike positive pressure, a vacuum has a limit. (Sort of the reason why a vacuum cleaner speeds up when you cover the nozzle, since it's no longer under load. Probably not the best example, but gives an idea.) That hatch may see more pressure differential from the aircraft doing hard manuevers than what that fan would pull on it at full power while shut.

What impressed me is these things seemed pretty steady control wise. Harriers always seem to have a bit of drift or wobble, but I figure these F-35s have computers doing all the small adjustments so they almost seem locked into a straight path. I'm curious to how well it will work once aircraft are actually loaded out with ordinance and extra fuel.