Vertol vs Helicopter

[thrash]

Best I can tell from a description, the V-22 takes advantage of its fly-by-wire system to make it handle like a helicopter at a hover and like an airplane in forward flight. In GURPS terms, the pilot should really be qualified for both, although you might let the character get away with Pilot (Heavy Airplane) and a perk (V-22 Qualified).

Similarly for quadcopter RPVs: the aerodynamics are rotary-wing, not vertol, so that's the skill I would require. The throttle vs. collective (which usually includes an automatic throttle control) difference isn't that significant. You can fly a helicopter with just the throttle and cyclic, though it's a pain in the ass and only used for certain emergencies (stuck right pedal).

Real vertols (AV-8 Harrier, for instance) are very different animals with their own aerodynamics and quirks. From what I understand, flying one in hover mode is more like piloting the Apollo Lunar Module than a helicopter. Just one example to illustrate: helicopters hang from their rotor systems; vertols stand on top of their thrust.

At some point, higher technology and fly-by-wire will flatten out a lot of the differences. I always imagine that spacecraft, etc., capable of hovering handle like helicopters (cyclic, collective, and pedals), but only because that's what I know. There was a station in the SIMNET combined flight simulator at Fort Rucker in the late 1990s that was primarily intended for observers (i.e., it didn't simulate a real aircraft). The "flight" control was a ball on a fixed stick: twist for roll, pitch, and yaw; push for lateral movement.

Edit to add: The FAA has an airplane category for pilot licensing called "powered lift":

Originally Posted by 14 CFR 1.1

Powered-lift means a heavier-than-air aircraft capable of vertical takeoff, vertical landing, and low speed flight that depends principally on engine-driven lift devices or engine thrust for lift during these flight regimes and on nonrotating airfoil(s) for lift during horizontal flight.

So there's some justification in creating a new category and using it for Harriers as well (but not Cyberpunk's AV-4, which doesn't have wings).

[Tinman]

From talking to a few Osprey pilots I would say it's Helicopter & Heavy Airplane.

[RogerBW]

Originally Posted by thrash

So there's some justification in creating a new category and using it for Harriers as well (but not Cyberpunk's AV-4, which doesn't have wings).

Except that a Harrier when it's not hovering flies just like any other fixed-wing single-engine subsonic jet fighter - the only difference is that you have VIFFing available, and that's surely a familiarity, not a whole separate skill.

In the Travelleresque space trader game I ran under hybrid 3/4e (pre Ultra-Tech, never mind Spaceships, with full Vehicles writeups for the spacecraft), I - incorrectly per RAW - required multiple pilot skills for different modes of flight on the same vehicle: High-Performance Spacecraft for manoeuvres in orbit, Aerospace for re-entry, Vertol for vertical landing/takeoff. I still think there's something to be said for that as a design philosophy.

[Cthugha]

Originally Posted by RogerBW

In the Travelleresque space trader game I ran under hybrid 3/4e (pre Ultra-Tech, never mind Spaceships, with full Vehicles writeups for the spacecraft), I - incorrectly per RAW - required multiple pilot skills for different modes of flight on the same vehicle: High-Performance Spacecraft for manoeuvres in orbit, Aerospace for re-entry, Vertol for vertical landing/takeoff. I still think there's something to be said for that as a design philosophy.

I am not sure about Vertol, but Aerospace for atmosphere and High-Performance Spacecraft for space is very RAW - at least in Spaceships.

[Phantasm]

Originally Posted by Cthugha

I am not sure about Vertol, but Aerospace for atmosphere and High-Performance Spacecraft for space is very RAW - at least in Spaceships.

Yeah, though sometimes I think the aircraft modes should really be High-Performance Airplane or Heavy Airplane rather than Aerospace; I tend to reserve Aerospace for making the actual transition, craft like dropships and shuttles, and for orbiters. This gives stuff like aerospace fighters three "modes" or skills: High-Performance Airplane for fighting in atmo, High-Performance Spacecraft for fighting in a vacuum, and Aerospace for making the transition between vacuum and atmo.

[thrash]

Originally Posted by RogerBW

Except that a Harrier when it's not hovering flies just like any other fixed-wing single-engine subsonic jet fighter - the only difference is that you have VIFFing available, and that's surely a familiarity, not a whole separate skill.

But the Harrier pilot does have to know how to hover to be proficient. A regular fixed wing pilot could manage the straight line flight modes just fine, but would crash and burn attempting to go vertical. It's a different skill set.

The FAA rating implies that the pilot of a powered-lift aircraft has to be equally skilled at all modes of flight, since proficiency will be evaluated in all of them.

My impression is that GURPS flight skills are specific to the vehicle, not the mode of flight. There's no requirement for High Performance Spacecraft pilots to have (or roll against) Low Performance Spacecraft skill to perform low energy docking maneuvers, for example. Infrequently used modes of flight are captured in lower defaults to other specialties.

[The Colonel]

Originally Posted by thrash

But the Harrier pilot does have to know how to hover to be proficient. A regular fixed wing pilot could manage the straight line flight modes just fine, but would crash and burn attempting to go vertical. It's a different skill set.

However, you could, as I understand it, drive a Harrier perfectly well without knowing how to hover as long as you didn't try any vertical manoeuvres and treated it as an STOL aircraft ... I get the impression that the same cannot be said of tilt-rotor machines (so far limited to the Osprey AFAIK) and helicopters.

Actually, speaking of helicopters, quadcopters and similar things, is driving a twin rotor (like a Chinook) a different skill from a single rotor? How about Kamov style stack rotors? Based on my (limited) understanding of how these things fly, they should behave very differently...

[RogerBW]

I think one big question at this point is:

"Should a single aircraft only ever require a single GURPS skill to fly it in all its modes?"

And I think the answer must be "no", because we have things like Ospreys and Harriers and stoppable-rotor helicopters that have multiple distinct – let's call them "flight modes", one helicopter- or vertol-style for hovering and low-speed flight and one airplane-style for faster flight.

Mind you, I'm working right now on an adventure set during the Falklands War, and one of the stock PCs is a Harrier pilot who's been shot down. I'm not going to insist that he have Vertol as well as High-Performance Airplane even if that's what he should have, because his piloting skill in this adventure is only going to be useful for knowing things about aviation, not for flying.

[johndallman]

Originally Posted by The Colonel

However, you could, as I understand it, drive a Harrier perfectly well without knowing how to hover as long as you didn't try any vertical manoeuvres and treated it as an STOL aircraft ...

It's not actually STOL if the thrust is not vectored. Its wing is fairly small, and it needs a fair run to take off or land in this mode.

[thrash]

Originally Posted by The Colonel

However, you could, as I understand it, drive a Harrier perfectly well without knowing how to hover as long as you didn't try any vertical manoeuvres and treated it as an STOL aircraft

I suggest that this is the realm of skill defaults, with no (or extremely poor) defaults allowed for completely novel flight modes.

I get the impression that the same cannot be said of tilt-rotor machines (so far limited to the Osprey AFAIK) and helicopters.

Osprey can take off and land like conventional airplanes. There's a bit of jiggery required because the prop/rotors are wider than the ground clearance, but that should be in the checklist.

Helicopters, not so much.

Actually, speaking of helicopters, quadcopters and similar things, is driving a twin rotor (like a Chinook) a different skill from a single rotor? How about Kamov style stack rotors? Based on my (limited) understanding of how these things fly, they should behave very differently...

More of a familiarity penalty than a different skill altogether. The aerodynamics are fundamentally the same -- it's the applications that vary.

Features that can produce different handling characteristics even in a single main rotor helicopter include clockwise vs. counter-clockwise rotation, fixed vs. semi-rigid vs. fully articulated rotor system, high vs. low inertia rotors, conventional tail rotor vs. ducted fan vs. NOTAR, nose-high vs. skids-level hover attitude, and degree of automation and hydraulic assist in the flight controls.

I was surprised and pleased as a senior aviator to sit down in my first unfamiliar helicopter type in almost ten years (fifth overall) and pick it up to a hover with nary a bobble. Learning all the systems and how to respond to specific emergencies took considerably longer -- but that's what familiarity penalties represent.