Vertol vs Helicopter

[RogerBW]

Originally Posted by p. B214

Helicopter: Any aircraft that uses rotors for both lift and thrust.
…
Vertol: Any aircraft that flies by brute-force application of thrust rather than by using rotors or wings.

Clearly if you saw the wings off a Harrier (or you have something like the old Cyberpunk 2020 AV-4, a box bolted onto a VTOL engine) it'll come under Vertol.

What about a modern quadrotor RPV? Is it closer in skill terms to a helicopter or to that hovering Harrier? Or should it be considered its own thing with a new Piloting specialisation?

What about an Osprey or other tiltfan?

I have flown helicopters and Harriers in simulations, and quadrotors in real life, and I think the quadrotor is closer to Vertol: you have an actual throttle, not a collective.

As for the Osprey I really want to say it needs Helicopter and Heavy Airplane; from what I've heard, that's pretty much how the flight controls are set up, with two different modes so that existing helo pilots could learn easily.

But I'd like to hear other people's opinions.

[Fred Brackin]

Originally Posted by RogerBW

What about an Osprey or other tiltfan?

I have flown helicopters and Harriers in simulations, and quadrotors in real life, and I think the quadrotor is closer to Vertol: you have an actual throttle, not a collective.

As for the Osprey I really want to say it needs Helicopter and Heavy Airplane; from what I've heard, that's pretty much how the flight controls are set up, with two different modes so that existing helo pilots could learn easily.

But I'd like to hear other people's opinions.

The Osprey apparently isn't really that much like a helicopter and it may have killed a few pilots who didn't understand the ways in which it was different. It certainly re-directs its' lift/thrust much more dramatically. I'd go with Vertol.

I haven't seen Thrash post much in this forum but he'd be the most knowledgeable person I can think of. You might be able to get his e-mail off a post from the Traveller forum.

[phayman53]

I don't have a source for this, but I seem to recall that the accident rate in the V-22 was helped when they switched from putting transport-only pilots in it to pilots with helicopter training. This, to me, means that helo training is at least helpful to understanding how to fly the V-22. But, all things considered, I think vetol is the way to go as it combines both winged and power-lifted flight.

[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...