How much Airplane DV do I need?

[Sentmassen]

I want to send an expedition to the arctic using plains/jets but I have no idea how much range (DeltaV) I need to get there and back. So assume I use the basic jet engine and try to keep it around peak efficiency, how much DV would i need to get to the poles and back?

Also, is it better to fly low with hi ISP but slower, or fly high with crappy isp but high speed?

[Motokid600]

Honestly... Ive never once looked at the Dv my planes have when I build them. I design my aircraft for whatever purposes I need then I fuel it in way that's favorable for its flight performance. Then its whatever Dv I have in the end.

As far as fuel efficiency goes the best thing you can do is cruise at the highest altitude with minimal throttle. As far as telling wether or not your craft will make it too and from your destination is just a guess really. It's so easy however to build a plane with enough fuel that can circumnavigate Kerbin that I just don't worry about it.

The one time I built a plane that needed extra range I used drop tanks. Worked really well.

[Alshain]

I want to send an expedition to the arctic using plains/jets but I have no idea how much range (DeltaV) I need to get there and back. So assume I use the basic jet engine and try to keep it around peak efficiency, how much DV would i need to get to the poles and back?

Also, is it better to fly low with hi ISP but slower, or fly high with crappy isp but high speed?

It's not that easy to predict dV for planes. It depends on a number of factors, especially altitude. It may take some trial and error. As for what altitude, that is entirely up to you. Kerbin is a big planet though, and I prefer not to be flying in a straight line for quite literally hours (can't imagine using RSS to do that) so I fly a high as I can. If you are using FAR, you can climb high and glide for quite a distance too, I'm not sure how well gliding works in stock, it takes a little longer but not as long as a low altitude flight.

[Motokid600]

It's not that easy to predict dV for planes. It depends on a number of factors, especially altitude. It may take some trial and error. As for what altitude, that is entirely up to you. Kerbin is a big planet though, and I prefer not to be flying in a straight line for quite literally hours (can't imagine using RSS to do that) so I fly a high as I can. If you are using FAR, you can climb high and glide for quite a distance too, I'm not sure how well gliding works in stock, it takes a little longer but not as long as a low altitude flight.

You can go alot higher and faster in stock. Mainly because Ferram incorporated AJE into FAR which got rid of the over powered turbo jet. Stock Kerbin could easily be circumnavigated in a few hours without timewarp. With warp it can be done in around a half hour I wager. You can cruise at a 1kms in the upper atmosphere with that OP engine.

FAR takes much more power to achieve the same speeds now due to the nerfed engine, but I still think it can be done in a decent time.

As Alshain said OP it's trial and error. If you build a decently sized plane I bet It'd be more then enough.

[Taki117]

Another option is to go sub-orbital. Build your aircraft as a space plane, but don't worry about making orbit.

[capi3101]

I've been to both poles of Kerbin, and have returned the craft to KSC both times. I use stock aerodynamics. I can tell you this - you want to be using Turbojets (you can travel faster the higher up in the atmosphere you go, and the Turbojet is definitely a high-altitude engine), and you won't need much more than a single Mk2 Liquid Fuel tank for the round trip. Maybe the extra few units you'd get from a pair of Nacelles, and that's only if you don't feel like draining out the things. Seriously, go with the Turbojets; you can make either pole inside of 15 minutes if you do.

[Crzyrndm]

You can go alot higher and faster in stock. Mainly because Ferram incorporated AJE into FAR which got rid of the over powered turbo jet.

AJE is entirely different from from the changes ferram makes. Turbojet just gets its max thrust and velocity curve cut down a bit so you can't go orbital on only the turbojet (0 thrust stock is 2400m/s surface speed, 0 thrust in FAR is 1800m/s IIRC).

FAR takes much more power to achieve the same speeds now due to the nerfed engine, but I still think it can be done in a decent time.

You're looking at just over a half hour flying (before warp) in stock (approx. low orbit period), FAR is probably more like 45 minutes since surface velocity is only going to be ~1300 m/s.

Another option is to go sub-orbital. Build your aircraft as a space plane, but don't worry about making orbit.

^^ Most fuel efficient option. Sub-orbital hops can cover enourmous distances for very little fuel. The higher your surface velocity, the better (orbital velocity is obviously the extreme here at 0 fuel per km covered). No need to build it as a spaceplane either, just nose up and go fast.

Edited February 19, 2015 by Crzyrndm

[MarvinKitFox]

With turbojets, the most fuel-efficient is a suborbital hop.

With only basic jet engine, the most fuel-efficient is at something like 11.5k alt, and as low throttle as you can while maintaining that alt. Boring, though.

flying at 16k alt at full throttle is only about 20% less efficient, and you get there four times as quickly.