Relating Automobiles with Airplanes

[BoeingGuy 0]

It's winter, and I know that many cars will need ABS, Traction Control, Stability Control, etc.Do plane's have any of these types of systems? I know some airliners have an Anti-Skid switch, does this do anything?I'm just curious to know. :( Thanks!

[Geofa 108]

It's winter, and I know that many cars will need ABS, Traction Control, Stability Control, etc.Do plane's have any of these types of systems? I know some airliners have an Anti-Skid switch, does this do anything?I'm just curious to know. :( Thanks!

How about the hourly cost for cars vs. airplanes.I just did the math for my interest-and the cars lose out big time compared to the aircraft-of course most tend to look at cars like a right to life and aircraft like a luxury-however the numbers show else wise....

[michal 44]

It's winter, and I know that many cars will need ABS, Do plane's have any of these types of systems?

Sure many have ABS, I don't think the rest is relevant for airplanes, you don't take a 747 for some off road fun.But to get an ABS on an aircraft you are probably talking $5 mln+ price range, there is a LOT of other expensive stuff a pilot would rather have than an ABS.

[onurksn 1]

I suppose anti-skid is used in wet runway conditions or according to the breaking action (not sure about that though).Aircraft however that operate in hot and humid environments have more powerful engines compared to ones operating in say... central Europe.Operating cost is very a interesting subject. Not airliners but GA aircraft of course!

[Guest Boeing Skunk Works]

ABS is the equivalent of the anti-skid system found on most transport aircraft.

Aircraft however that operate in hot and humid environments have more powerful engines compared to ones operating in say... central Europe.

?????

[onurksn 1]

Yeah, sorry for not being clear. What I meant actually was that companies choose to use different engine variants according to their operating environments. Apart from that, as an option 737NG's have the Short Field Performance variant. Commonly used by GOL. This version, although not different in engine power, has a few modifications for STOL capability.Oh, there is also the high gross weight variant of the 738, which has slightly more powerful powerplants.

[KevinAu 441]

It's winter, and I know that many cars will need ABS, Traction Control, Stability Control, etc.Do plane's have any of these types of systems? I know some airliners have an Anti-Skid switch, does this do anything?I'm just curious to know. :( Thanks!

Aircraft do not need traction power from wheel contact with the ground in order to obtain motion on the ground. Unlike cars, aircraft move because thrust from its engines push backwards against the body of the aircraft. While cars depend on the wheels gripping the ground in order to propel them. Aircaft can move around on the ground without any wheels whatsoever. The only car technology that is useful with aircraft are anti-lock brakes, since skidding is a phenomena that affects any sort of wheel that is attempting to decelerate. Disabling antiskid can be useful in case of system malfunction or to make very tight turns when a locked wheel is desired.

[Cessnaflyer 56]

How about the hourly cost for cars vs. airplanes.I just did the math for my interest-and the cars lose out big time compared to the aircraft-of course most tend to look at cars like a right to life and aircraft like a luxury-however the numbers show else wise....

How do you calculate the cost per hour for your airplane?

[Chock 17,769]

Aircraft do indeed have many similar systems. The one most people will have direct familiarity with is the Antilock Braking System (ABS), which works the same as an aircraft's antiskid system. In fact this and many other technologies have showed up on cars because such technology has filtered down from the aerospace industry.ABS for either a car or an aeroplane usually works by means of transducers detecting the rotation of all the wheels on a vehicle and comparing their rotation, thus it can detect a change (either a speeding up or slowing down from the average) at a particular wheel and determine whether it can increase or needs to reduce the braking pressure at that wheel.To some extent aircraft are not as reliant on this as cars, because they can use reverse thrust as a means to reduce their speed and this is often recommended on very slippery runway surfaces, although most turboprops can in fact brake quite well simply by reducing the throttles to idle and flattening the pitch of their props to rely on the aerodynamic drag this creates. Many modern turboprops can in fact shift their props into negative pitch to provide genuine reverse thrust, which is generally, although not completely accurately, known as 'beta mode'. Of course with jets it's easy to reroute the air thrust from modern high-bypass turbofans to provide reverse thrust, simply by sliding open the engine cowlings, because more air actually passes around a modern turbofan's engine than actually goes through it to the rear than is the case with older turbojets, hence the name 'high-bypass'.Another aircraft system which is beginning to show up on cars is of course the Head Up Display, first it was only to be found on expensive fighter aircraft, then it showed up on civilian aircraft and airliners, now you can find it on quite a lot of cars. Similarly, satellite navigation used to be the preserve of expensive avionics, but nowadays you can buy a sat nav for your car from a supermarket.You could regard some fly by wire systems as being partially analogous to stability augmentation often found on cars, in that both systems direct their efforts to keeping things under control, although its hard to compare them directly in terms of their workings.Although most things tend to flow down from the aerospace industry to the car industry, it's not always the case. An example of this is airbags, several aircraft manufacturers have flirted with the idea of putting airbag systems on their aircraft, and that's not a silly as it sounds; studies have shown that many fatalities in aircraft accidents are not as a result of the impact of the crash itself, but because the survivors cannot evacuate the aircraft before succumbing to the effects of smoke and fire because of broken limbs, caused by them hitting the seat in front. It's probably pricing, weight reduction and maintenance costs that have prevented this becoming widespread in airliners however.For years the automotive industry has cosseted potential customers with flashy showrooms intended to show off features of cars to best advantage, but it is only in recent years that the aviation industry has done this sort of thing. Car manufacturers have had a bit of a jumpstart on aircraft makers as far as ergonomics go (usually more trendily known as haptic design these days). Not that long ago, you were lucky to find an overhead light, air vent and somewhere to plug in some headphones surrounding your airliner seat. But these days airliner manufacturers are aware that's not enough to please the airlines and they have started getting into that kind of thing more and more, although to some extent the pendulum has swung back, with many MPVs emulating the airlines recent love affair with TV monitors in seat backs.Airliner makers have in recent years copied the flashier car dealerships as far as sales go. For example, Boeing now have a massive facility at Renton which deals solely with this aspect of airliner sales - The Boeing Customer Experience Center - which looks like a very posh interior design store inside. It has mock ups of all current Boeing airliner cabins and a vast array of cabin furnishings on display. To woo airlines into buying, the BCEC has facilities including the ability to create a virtual reality representation of a potential customer's cabin fitting choices, which the client can walk through, and which is not dissimilar to what the posher car manufacturers have been doing for quite a while with regard to option selections. Much of this has contributed to the massive initial orders Boeing received for the 787 Dreamliner, although now of course they are having a lot of those orders cancelled because of the huge delays in the 787 production programme. Which, ironically, is something the car industry has also suffered from time to time.Al

[Geofa 108]

How do you calculate the cost per hour for your airplane?

We take all costs-hangar,insurance,average maintenance,gps database updates, xm weather,charts, etc. and comes up with an hourly fee which is has minor adjustments every year-but has been pretty much the same over the five years I have been in this aircraft.

[RatRace 4]

Aircaft can move around on the ground without any wheels whatsoever.

they certainly help in reducing the friction tho :(

[michal 44]

they certainly help in reducing the friction tho :(

What he probably meant that wheels can often be replaced with skis or floats, etc. So wheels are simply accidental to aircraft.

[RatRace 4]

What he probably meant that wheels can often be replaced with skis or floats, etc. So wheels are simply accidental to aircraft.

Yes, what he says - in a rather complicated way - is that cars are wheel-propelled vehicles, whereas aircraft wheels are unpowered. The engine(s) of the aircraft act(s) on the air, not on the ground. The aircraft wheels are not powered and thus don't push against the runway to accelerate the airplane. All I'm saying is that freely turning wheels, rather than the belly of the aircraft, are desirable in this instance. Unless of course the pilot sets the brakes.

[n4gix 4,947]

IIRC, auto ABS were developed from* aircraft ABS......which is but one example of the aerospace industry contributing to automotive safety... :(Apparently, ABS first appeared aroung 1929, but limited customer product use in autos didn't occur until around 1950.* http://en.wikipedia.org/wiki/Anti-lock_braking_system

[BoeingGuy 0]

Wow, thanks for the replies guys!One more question:Most cars have Electronic Stability Control/Program. What this does is detect understeer/oversteer and brake individual wheels, and, in some cases, reroute power to bring the car under control. I know rerouting power isn't possible in airplanes since the wheels are unpowered.For example, if you want to turn left yet the car keeps sliding straight, the car can brake the inside---in this case, the left---wheels to force the car to turn.It's a little silly, but can airplanes make use of this? Let's say the same situation above happened to an airplane, could the left main gear be braked to bring the plane under control?Thanks again!