Term for the height of a craft from wheelbase to top of rudder

[HarvesteR]

Hi,

So, this struck me as a peculiar thing. I've been searching here for a term by which to call the size of a craft along its yaw axis, that is, the 'runway height' of a craft, or the 'cross section height' of a rocket sitting at the pad, and I thought it was very strange that I could find no specific term for that dimension.

This seems particularly odd in a field like aerospace, where each and every possible measurement seems to have a particular name (like dihedral, chord, wingspan, and so on), that such a basic dimension of an aircraft must be referred to by the ambiguous word 'height', or by a long name like 'cross section height' or something like that.

So, looking for the largest aggregation of savvy minds in this field brought me here.

Does anyone know if there is a specific name for this measurement?

Thanks in advance for any input.

Cheers

[sal_vager]

We really need someone from the aviation industry to comment I think, but all the references to aircraft height I was able to find just called it "height", all but one...

The Federal Aviation Administration call this measurement the "Tail height" of the aircraft, which makes sense as in nearly all cases the tail is the highest point of an aircraft on the ground.

[B787_300]

In all my AE books it is referenced as the Height, any variations on height is reserved for other dimensions like wheel height, Rudder Height, Fuselage height (normally a diameter)

[WestAir]

Depends on the manufacturer. Boeing likes to list their ground to tail measurement as tail height. Others just use the term height, and there are even other manufacturers (usually defunct ones like Douglas) that don't use a term at all, and just have a graph with numbers.

I imagine this is another one of those "fulcrum" and "datum/moment" cases where we depend on the manufacturer to decide.

As an aside, I've never seen anyone list the height of a retractable gear aircraft with the gear stowed (clean). I'm not sure if it's because it's too difficult to get accurate measurements or if it's because wings tend to deform during flight so the height of the aircraft changes depending on wing load.

Edited November 23, 2014 by WestAir

[technicalfool]

Decided to ask a guy from Boeing about it.

He knew of no such term.

I guess "tail height" for aircraft and "cross section" for rockets will do?

[HarvesteR]

I'm using tail height here ('T-Hgt' actually) for the time being, for want of a better term, and to fit in the UI space available for it...

I'm surprised that there is no actual term for it though, 'height' I always assume to mean flight height above ground (as opposed to altitude), so calling the tail height of an aircraft 'height' as well is oddly ambiguous for a field so particularly specific as aeronautical engineering.

Oh well. I suppose 'height' at SPH or X-section at the VAB will do then.

Cheers

[sal_vager]

Well, we could make a new term, and other words exist.

I quite like "Elevation" for the highest point of a plane or a rocket

Or maybe an acronym, LHO, Lowest Hangar Opening

[magnemoe]

Well, we could make a new term, and other words exist.

I quite like "Elevation" for the highest point of a plane or a rocket

Or maybe an acronym, LHO, Lowest Hangar Opening

Some hangars has an small door over main door in the center for the tail. But yes its still lowest hangar opening.

[Rakaydos]

LHO works, as long as the acronym is explained somewhere. If it's being used as a limit on Spaceplane Hanger tiers, it even make sence- you're limited on how big a craft you can get out the door.

[Vanamonde]

"Tail height" assumes the tail is the highest part. How about "vertical clearance"?

[Kulebron]

'height' I always assume to mean flight height above ground (as opposed to altitude), so calling the tail height of an aircraft 'height' as well is oddly ambiguous for a field so particularly specific as aeronautical engineering.

I don't think so.

I used aeronavigational charts a lot, and never saw "height" for any sort of altitude. It's always altitude ASL (above sea level) and altitue AGL (above ground level), the latter shown in parethesis (or vice-versa if I'm confused, but the distinction is like this).

Height ALWAYS applies to obstacles height, and always shown unambigously, either ASL or AGL in parens.

Ground always has elevation to it.

That's how terms are used.

(I think it should be the same in Portuguese, no? altura vs altutude)

Edited November 23, 2014 by Kulebron

[HarvesteR]

I don't think so.

I used aeronavigational charts a lot, and never saw "height" for any sort of altitude. It's always altitude ASL (above sea level) and altitue AGL (above ground level), the latter shown in parethesis (or vice-versa if I'm confused, but the distinction is like this).

Height ALWAYS applies to obstacles height, and always shown unambigously, either ASL or AGL in parens.

Ground always has elevation to it.

That's how terms are used.

(I think it should be the same in Portuguese, no? altura vs altutude)

Yes, what I meant was, I assume height to mean the distance from the base (ground) to the topmost point of whatever you are measuring, as opposed to altitude which (unless specified otherwise) is the distance of this topmost point to sea level.

It is ambiguous when the tail height of an aircraft must be factored in with another height, like flight height though, but more importantly, when the yaw axis of the craft doesn't point 'up', as is the case of a rocket at the pad.. hence my search for a better term.

In any case, the point is now moot. The craft size uses AABBs (axis-aligned bounding boxes) so the Y axis is always going to be 'height' in this context. Be it tail height sitting at the runway, or stack height at the launch pad. The Z axis I renamed to Length, so that's that I guess.

Thanks for the help everyone!

Cheers

[zxczxczbfg]

I rather like "vertical clearance", though I suppose that could be misconstrued as ground clearance (i.e. the distance from the belly of the plane to the hard, unforgiving tarmac). I think rockets could just use "length" since they're usually measured that way in real life.

EDIT: Ninja'd. By HarvesteR, no less.

[Red Iron Crown]

I would suggest "Minimum Overhead Clearance".

[Deadpangod3]

we could measure them with the orange rockomax tanks, eg "my rocket is 3.5 oranges tall."

[EdFred]

The only height term I am aware off the top of my head that has to do with height above the ground is TCH - Threshold crossing height. That's the altitude you cross the threshold at if flying an ILS, and that's usually listed in feet AGL.

Everything else is altitude and elevation. MSL and AGL on all the charts. To answer the question, the technical term is "height." Although on my plane that can vary depending how much air I have in the front strut.

[KerbMav]

http://www.airliners.net/aircraft-data/stats.main?id=20

http://www.aircraftbluebook.com/Tools/ABB/ShowSpecifications.do

Lists height as a dimension - no mention of with or without extended landing gear.

http://upload.wikimedia.org/wikipedia/commons/0/0e/B727FAMILYv1.0.png

But this picture suggests that it is simply always with landing gear.

Edited November 24, 2014 by KerbMav
Google can still not outrun actual knowledge - nod to @EdFred

[Pecan]

Don't know about aerospace but the marine industry has a term for this:

"Draft" is the depth to which a vessel extends below the water-line (surface).

"Air Draft" is the height above the surface to which it extends.

A typical small sailing yacht might be 14m "tall", of which 2m could be "draft" (hull and keel sitting below the waterline) and 12m "air draft" (hull, superstruture, mast, radio antennae above it).

(Draft is important so you don't run aground, air draft so you know when you can safely fit under bridges, etc.)

[HafCoJoe]

Mixing terms previously mentioned, you could use Vertical Height or "V-Hgt". If you're also adding in measurements for Width and depth though, I suggest you go with the GUI labeled "Door/Hangar dimensions" and having boxes comparing the "clearance vs. build height" and "width vs. max width" (Or whatever term for max width you want).

Edited November 24, 2014 by Avera9eJoe

[Fuzzy Dunlop]

I acctually wouldn't expect the "tail height" to have a special name because it dosen't seem that important. Really its only purpose would be to avoid collisions while moving the aircraft into hangers, and how often does that kind of accident happen?

Wingspan and Length are more important when you consider how often aircraft smash into each other while taxiing (much more than you would expect).

[justidutch]

The only height term I am aware off the top of my head that has to do with ...

Why don't we call it: "top-of-head height"???

[EdFred]

Why don't we call it: "top-of-head height"???

Maybe I do.

[cantab]

As an aside, I've never seen anyone list the height of a retractable gear aircraft with the gear stowed (clean). I'm not sure if it's because it's too difficult to get accurate measurements or if it's because wings tend to deform during flight so the height of the aircraft changes depending on wing load.

Well when would you need it? It's not going to be relevant when taxiing on the wheels, and other planes certainly shouldn't be flying so close in the air that it matters there. If the plane is being transported, eg by truck, then it's probably being partly dismantled anyway.