[Cyberpunk Engineering Challenge] #1 Hurricane Hopper

[Anthony]

Originally Posted by Ulzgoroth

So. You can't 'land' on a helipad, or any other reasonably constrained landing area, because the wind isn't going to let you be at rest either in the air or on the ground. Unreasonable solution: a deeply-seated mooring with very strong cables.

The easiest option might be a capture net. Solve the problem of being slammed into the ground by a gust by just making that survivable.

[Daigoro]

Hurricane Hunters do indeed fly into Cat-5 storms and cross the eye-wall. But how can they do it?
- Presumably, it's because their Hercules and Orions are just big dumb machines with enough oomph and structural integrity to power through the turbulence. They weigh 40-70 tons, so they don't get as thrown around as lighter aircraft. But they're also 1970's tech, so we should be able to improve on them even with today's aircraft, let alone mid-TL9.
- Do they have to fly into the prevailing wind, or can they fly across or downwind?
- Their mission doesn't require landing in that weather, so they can stay well above stall speed and they don't have to aim for a small ground target in it. They can ride the turbulence whereas ground-based structures get more battering under the same wind conditions.
- What other aircraft could replicate that? Chinooks? A-10 Warthogs? Sea Kings? (Rumours that Marine One is not rain-rated notwithstanding.)
- This implies that the hard segment of a Hurricane Hopper's flight plan is not the cruising at altitude, but flying near the air-ground interface and making a pinpoint landing.

I had two main ideas for achieving this.
1) Skyscrapers like Taipei-101 have a tuned mass damper, a large free floating ballast coupled to the structure by springs and motos, to absorb typhoon and earthquake vibrations. My original idea is to build the Hopper around a similar large ballast ball, so that the centre of mass continues on a smooth trajectory while the airshell vibrates around it. This might reduce turbulence shocks for passengers, but I'm not sure how much affect it would have on the craft's ability to fly.

2) Fight the turbulence with the aircraft's own tuned pocket of high-velocity wind. This is a form of vectored thrust, but being emitted in all directions simultaneously so that external wind can't impinge on the airshell. The thrust can be varied to compensate more on the windward side, and adjusted to rapidly change direction depending on wind vector changes.

Now, in itself, this is difficult to achieve, but there seems to be something called fluidic circulation control that uses fine jets of air to flow along flight surfaces allowing flight control in place of flaps and ailerons. If you couple this idea with fluidic thrust vectoring for highly responsive thrust changes, and control with high-resolution wind-speed radar, you could possibly start to approach the same effect.

Originally Posted by Anthony

Incidentally, even if you can handle the wind gusts, being hit by large chunks of debris is a real risk for low level flight in a strong hurricane.

Originally Posted by Ulzgoroth

You probably want as few exterior aerodynamic surfaces as possible, because those are going to be liabilities in the storm. A sturdy streamlined box (or disk as Fred Brackin suggested) with powerful vectored thrust jets would be my design concept, which is pretty common in cyberpunk and soft near-future SF anyway.

This sounds like getting toward a flying version of the CyberTruck, although that's not surprising. The cold rolled steel would be handy for those debris hits as well.

Originally Posted by Ulzgoroth

So. You can't 'land' on a helipad, or any other reasonably constrained landing area, because the wind isn't going to let you be at rest either in the air or on the ground. Unreasonable solution: a deeply-seated mooring with very strong cables.

The 'landing' device would probably resemble a ground-penetrating bomb, and be filled with mechanisms (behind the armored tip) to extend braces laterally through the ground from where it comes to rest to get it really set in there. Maybe don't drop this on a helipad!

It doesn't actually have to be a standard dumb helipad. It could be a landing pad designed for receiving Hoppers, so you arm them with the harpoon-anchor that they drop into a large receiver. The lead cable then draws down 3 or 4 anchor cables that are spread apart by the receiver to apply a stable pyramid of tension to the aircraft.

And actually, the idea of doing a controlled ditch into water for underwater docking is not irrelevant to the main purpose of why I'd need a hurricane taxi. The idea is that this would be used for accessing a floating hurricane abatement tower at sea, which would be tracking close to the eye-wall as it moves.

[Anthony]

Originally Posted by Daigoro

Hurricane Hunters do indeed fly into Cat-5 storms and cross the eye-wall. But how can they do it?

Planes at altitude don't care about their velocity relative to the ground, they care about their velocity relative to the air. Constant high winds just mean you go slower upwind, faster downwind, and as long as flight speed is higher than wind speed (most reasonable size aircraft have flight speeds exceeding the 157 mph of a category 5) they can still get to wherever they're going, and even if they hit turbulence, as long as it's not strong enough to cause the plane to completely break up, at reasonably high altitudes you can recover from whatever it causes. The other problem is that visibility is likely to be terrible, so you'd better be able to navigate by instrument.

Landing is an exciting problem because turbulence is likely to be greater near the ground, and turbulence that corresponds to a bumpy ride in midair is a crash when landing.

Originally Posted by Daigoro

And actually, the idea of doing a controlled ditch into water for underwater docking is not irrelevant to the main purpose of why I'd need a hurricane taxi. The idea is that this would be used for accessing a floating hurricane abatement tower at sea, which would be tracking close to the eye-wall as it moves.

The obvious question is why you're trying to access it in that way. Just use remote access, or if you really need physical access, use a ship. Or possibly a submersible (a sub will barely notice a hurricane, the only tricky part is docking with the tower, and all other options have the same issue).

[RogerBW]

Originally Posted by Daigoro

It doesn't actually have to be a standard dumb helipad. It could be a landing pad designed for receiving Hoppers, so you arm them with the harpoon-anchor that they drop into a large receiver. The lead cable then draws down 3 or 4 anchor cables that are spread apart by the receiver to apply a stable pyramid of tension to the aircraft.

This sort of situation (more specifically, landing helicopters on ships in high seas) is why the RCN developed Bear Trap:

https://en.wikipedia.org/wiki/Beartrap_(hauldown_device)

[Fred Brackin]

Originally Posted by Daigoro

It doesn't actually have to be a standard dumb helipad.

You'vre left out the part that gets the passengers out of the vehicle and into the "terminal". That has to be very different from a smal flight of movable stairs.

This is why i wanted to land the EWFO (Extreme Weather Flight Operations) vehicle in an underground bunker. If the passengers want to go anywhere other than the terminal the subway is the only mode of transport that might be unaffected by the Cat 5 (until the storm surge gets there and causes flooding).

People don't actually want to go _to_ locations that are experiencing Cat 5s. They want to leave such places and they do it before arrival time.

[johndallman]

Originally Posted by Daigoro

2) Fight the turbulence with the aircraft's own tuned pocket of high-velocity wind. This is a form of vectored thrust, but being emitted in all directions simultaneously so that external wind can't impinge on the airshell. The thrust can be varied to compensate more on the windward side, and adjusted to rapidly change direction depending on wind vector changes.

There are a couple of problems with this. First, if you're ejecting high-speed air in all directions, where are you getting all this air from? Also, what are you using for lift?

[Daigoro]

Originally Posted by johndallman

There are a couple of problems with this. First, if you're ejecting high-speed air in all directions, where are you getting all this air from?

I guess you'd have the intake at the front, although of course you would be faced with a volume problem.

I'm partly basing this on vague memories of a 1990's tech or conspiracy magazine article which described a possible propulsion system for the then-rumoured Aurora Project. It involved ejecting fuel through pores across the skin of the aircraft and igniting it on the exterior, forcing the aircraft to fly forward like squeezing a cherry pip. However, I can't find any mention of the article or that system now.

Also, what are you using for lift?

There'd be a differential between the outputs which can be tuned and directed to control the craft.

Originally Posted by Fred Brackin

You'vre left out the part that gets the passengers out of the vehicle and into the "terminal". That has to be very different from a smal flight of movable stairs.

I was considering an extending corridor that mates with the craft, much like modern airport aerobridge, maybe running on rails out to the craft. Another method is that the whole beartrap platform is drawn into a hangar along rails.

People don't actually want to go _to_ locations that are experiencing Cat 5s. They want to leave such places and they do it before arrival time.

Generally true. In this case it's mainly to get to the aforementioned hurricane abatement platform which tracks with the eye-wall for days or weeks. Realistically, boarding and disembarking would be limited to non-operational periods, but then how would a group of terrorists take it over in the middle of a hurricane?

However, we are seeing an increase in tropical storms and their intensities, so I would think the military would be interested in a vehicle that can still operate when everything else is grounded, for any number of reasons.

Anyway, as to a precognitively fast fly-by-wire system, there's this article and this video of the idea being tested. Basically, glide-hovering birds like the kestrel can feel wind drafts through their feathers and adjust quickly enough to compensate to a high degree. For the EOFWV, that could just be handled by the high precision 3D weather radar mentioned before. Otherwise, air pressure sensors on 2-metre long pylons extending from the nose, wingtips, dorsal and belly points, perhaps using short range laser turbulence mapping, might be a step more realistic.

[Anthony]

Originally Posted by Daigoro

I had two main ideas for achieving this.
1) Skyscrapers like Taipei-101 have a tuned mass damper, a large free floating ballast coupled to the structure by springs and motos, to absorb typhoon and earthquake vibrations. My original idea is to build the Hopper around a similar large ballast ball, so that the centre of mass continues on a smooth trajectory while the airshell vibrates around it. This might reduce turbulence shocks for passengers, but I'm not sure how much affect it would have on the craft's ability to fly.

You'd be better off just making the passenger cabin movable, and neither version will help the craft's ability to fly at all.

Originally Posted by Daigoro

2) Fight the turbulence with the aircraft's own tuned pocket of high-velocity wind.

Will probably make the situation worse, actually, because the storm will shove your entire pocket about, and it has more surface area relative to its mass than a plane does.

The basic problem for flying in a storm is that you can't just minimize interaction with the air, because you're relying on interaction with the air to actually fly. You can make the effect smaller by using smaller wings/rotors/fans, though doing so increases stall speed for fixed wing and increases power requirements for vectored thrust.

If you are willing to limit yourself to a sea landing and don't mind it being one-way (i.e. the people who are inserted will stay until the storm ends), just drop a pod capable of handing a splash landing from an airplane.

[Fred Brackin]

Originally Posted by Daigoro

In this case it's mainly to get to the aforementioned hurricane abatement platform which tracks with the eye-wall for days or weeks. Realistically, boarding and disembarking would be limited to non-operational periods, but then how would a group of terrorists take it over in the middle of a hurricane?

However, we are seeing an increase in tropical storms and their intensities, so I would think the military would be interested in a vehicle that can still operate when everything else is grounded, for any number of reasons.
.

Terrorists who operated in a Cat 5 Hurricane would find that nobody who wasn't in the same building would know they were doing so.

So rather than terroists seeking to publicize their cause you might be dealing with a secret black ops group who didn't want to get any publicity. You might still want fanatics who don't mind be trapped by the storm after then enter. Professionals might hope to make their escape in the post-storm confusion.

As to things being grounded by the storm the list starts with human beings and makes its' way up. I don't know if you could operate a 60 ton+ MBT is an cat 5 hurricane. Nobody has ever tried to my knowledge. Even if you could withstand the winds I don't think you could navigate very well.

[Anthony]

Originally Posted by Fred Brackin

I don't know if you could operate a 60 ton+ MBT is an cat 5 hurricane.

I'm sure it could move about okay, that's a lot of weight for its surface area, but be rather challenging navigating, as visibility is likely to be near zero.