I made an air raft

[whulorigan]

Which brings up an idea I have been kicking around. Using the airboat model instead of the flying car model.

I think that was more along the lines of the original idea as adapted from the Dumarest "Raft". The Air/Raft should be thought of just as the name implies: a (relatively) slow floating craft designed for local transportation and moving things from point-to-point, like an inflatable raft w/ outboard motor on water or like a station-wagon / estate-car / light pick-up truck on land. More of a floating utility craft.

The Air/Car or Grav/Car (G/Car ?) concept should be thought of and conceptualized differently.

Note that the Air/Raft has always carried the alternate names "Floater" and "Flyer" in Traveller descriptive texts. I consider the Air/Raft proper to be the Floater and the Flyer to be the Air/Car. In T5 terms that would mean that the Air/Raft "Floater" has Lifters only, whereas the Air/Car "Flyer" likely has an additional motive thrust agency.

 

[Condottiere]

While I wouldn't take it into orbit, but if you had barebones kit with just the power unit, gravitational motor, and controls, and the rest inflatable.

 

[Spinward Flow]

The Air/Car or Grav/Car (G/Car ?) concept should be thought of and conceptualized differently.

LBB2.81, p23 and LBB3.81, p23 and TTB, p59, 111, 114.

Speeder (8) Cr1,000,000, 6 tons. A streamlined grav-powered craft intended for high speed transport between points on a world surface. Similar in principle to the air/raft and the GCarrier, the speeder is streamlined and concentrates on speed. It is capable of 1000 kph cruise speed (maximum speed is 1200 kph), and has a virtually unlimited range. Refueling is required every ten weeks from a ship's power plant. The speeder carries a driver (who operates the craft at air/raft skill minus 1), a single passenger, and 100 kg of cargo. The speeder is capable of reaching orbit within an hour.

It's called a Speeder.
Basically a GRoadster (minus the "need for roads" of course).

 

[infojunky]

Note that the Air/Raft has always carried the alternate names "Floater" and "Flyer" in Traveller descriptive texts. I consider the Air/Raft proper to be the Floater and the Flyer to be the Air/Car. In T5 terms that would mean that the Air/Raft "Floater" has Lifters only, whereas the Air/Car "Flyer" likely has an additional motive thrust agency.

You know I am in that camp too.

 

[Kakistocrat]

Shut up! It’s Space Pleather™!!

As developed at the Research Plab on Pluto!

Make it watertight, and then it can float.

Tom Swift’s triphibian.

Hence the need for tail fins. (And lots of chrome.)

It’s called a Speeder.
Basically a GRoadster (minus the "need for roads" of course).

GRoadster − Roads = Gter. “That there’s one of them new jeeters.”

 

[Grav_Moped]

I think that was more along the lines of the original idea as adapted from the Dumarest "Raft". The Air/Raft should be thought of just as the name implies: a (relatively) slow floating craft designed for local transportation and moving things from point-to-point, like an inflatable raft w/ outboard motor on water or like a station-wagon / estate-car / light pick-up truck on land. More of a floating utility craft.

The Air/Car or Grav/Car (G/Car ?) concept should be thought of and conceptualized differently.

Note that the Air/Raft has always carried the alternate names "Floater" and "Flyer" in Traveller descriptive texts. I consider the Air/Raft proper to be the Floater and the Flyer to be the Air/Car. In T5 terms that would mean that the Air/Raft "Floater" has Lifters only, whereas the Air/Car "Flyer" likely has an additional motive thrust agency.

It looks to me like the functional equivalent of a "deuce-and-a-half" (2 1/2T payload mil truck) except that it can fly.

 

[whulorigan]

LBB2.81, p23 and LBB3.81, p23 and TTB, p59, 111, 114.

It's called a Speeder.

No, the Air/Car or G/Car (Flyer) concept falls between the Air/Raft (Floater) and the Speeder in performance. I do not imagine an Air/G/Car (Flyer) getting anywhere near 600-800 mph. It is a Flyer (perhaps 150-350 mph on average, depending on model); a Speeder is a much faster transport.

The Flyer (G/Car) is something more akin to the old Paranoia Press Civilian Flyer in Merchants & Merchandise, or the Grav Car in T4.

 

[whulorigan]

It looks to me like the functional equivalent of a "deuce-and-a-half" (2 1/2T payload mil truck) except that it can fly.

Perhaps for the larger capacity/payload models, yes.

 

[spank]

Perhaps for the larger capacity/paylo

500 mile an hour open top vehicles?
why not?

 

[Timerover51]

I spent a few weeks of my allowance on getting that book. It has vanished over the years. I know a bookstore that probably has a copy.

 

[whartung]

That's interesting, so I guess there's an engineering advantage to hang the engines from the wing, rather than to mount them on top. I wonder if it's weight or what.

 

[Spinward Flow]

I guess there's an engineering advantage to hang the engines from the wing, rather than to mount them on top. I wonder if it's weight or what.

Often times, it's simply a matter of ease of access for ground crews. By hanging the engine nacelles under the wing, it makes it easy for ground crews to reach and work around them while standing on tarmac/concrete, rather than needing ladder/stair trucks to get up onto the wings. That then turns into a differential advantage in maintenance and overhead costs that shows up in balance sheet bottom lines that the accounting department gets cranky about.

When the name of the game is shaving micrograms of copper plating off every penny ... those kinds of "unnecessary expenses" can add up across a fleet of hundreds of aircraft flying daily.

 

[infojunky]

It looks to me like the functional equivalent of a "deuce-and-a-half" (2 1/2T payload mil truck) except that it can fly.

Note a deuce-and-a-half has a 5 ton payload on road....

 

[PVernon]

But what is it's dton capacity?

 

[spank]

But what is it's dton capacity?

270 cubit feet, a little over 1/2 dTon.

There is also a longbed version that has a capacity of a little over 3/4 dTon.

 

[Grav_Moped]

500 mile an hour open top vehicles?
why not?

View attachment 4379

Center-of-mass issues?

 

[spank]

Center-of-mass issues?

I'd worry more about center of pressure,
but Lockheed seems to think it wouldn't be a issue.
Or atleast thought they could manage any issues.
But honestly, something more like the Fairchild pack-plane would probably be more friendly from a freight handling perspective.

 

[whartung]

Wouldn't there be an issue with crosswinds? As I understand it, the wind is quite strong at higher altitudes, and even if you're going 500MPH, a 100MPH cross wind is a 100MPH crosswind.

 

[Grav_Moped]

Wouldn't there be an issue with crosswinds? As I understand it, the wind is quite strong at higher altitudes, and even if you're going 500MPH, a 100MPH cross wind is a 100MPH crosswind.

That crosswind is like having (yikes, trig time!) a 520mph airspeed* while flying at an 11^o yaw.**

In practice, the aircraft centerline will be aligned with the net airflow direction because it has vertical stabilizers. That yaw calculation would only apply to lateral gusts or while penetrating the boundaries of transverse air flows.

The real issue is the parasitic drag of the exposed payload (goes up as the square of airspeed). You do not want to do this with the depicted turbofans -- this thing needs to go slow enough that turboprops are more suitable. And that drag proportional to airspeed² is going to manifest as force on the exposed cargo.

-------
* not really, airspeed would probably remain constant but I'm just approximating here.
"" I was supposed to use inverse arcsine there, right?

 

[Ekofisk]

You do not want to do this with the depicted turbofans

This was tragically demonstrated by Aloha Air Flight 243