Which side?

[keith smith]

In a two-pilot aircraft the commander is located on the left-hand side of the flight deck in the case of fixed wing and on the right for rotary wing. How did this come about, and are there any ergonomic benefits?. What happens in the case of tilt-rotor?

[airfoilmod]

Fixed, self explanatory. Helicopter? That was Igor's preference.

[Angels 60]

PIC in a helo can fly on either side, depending on the which way the rotor turns.
PIC in a plane doesn't have to be left seat, especialy as a flight instructor..

[gr8shandini]

The PIC* in a helo sits on the right because helos are inherently unstable. While you can put some friction on the collective and let go, letting go of the cyclic is a bad idea. So if you sit on the right, you can use your left hand to tune radios and the like. Since the controls aren't mirrored, sitting on the left would mean you would have to "hand off" control of the cyclic to yourself everytime you wanted to twiddle a knob on the IP or overhead panel.

Tiltrotors use the same approach for the same reason. So the real question is why do fixed wing drivers sit on the left? My guess is that it's due to most fields using left-hand traffic, which I believe came from the horrid gyro-coupling exhibited by airplanes in the early rotary engine days.

*obviously, you can be PIC from either seat, but I'll just use that term to describe the customary usage.

[Angels 60]

Look up where the PIC sits in a Robinson R44 vs a Eurocopter Astar. Get back to me and let me know if I am sitting on the wrong side.

[airfoilmod]

Sikorsky, S-61, as in Sikorsky, Igor. Igor Sikorsky, the father of the Helicopter. He preferred flying on the right side, I'm not kidding.(See Post #2, this thread)

Airfoil

[SNS3Guppy]

Look up where the PIC sits in a Robinson R44 vs a Eurocopter Astar. Get back to me and let me know if I am sitting on the wrong side.


You're flying a helicopter, now? You were a fixed wing captain with 10,000 hours and seven type ratings, flying a citation, and had just been rejected by Alaska airlines when you posted as ssg and then as Trickle451...both of your former identities which have recently been banned.

Now you're a helicopter pilot. Who'd have guessed?

[Pugilistic Animus]

In a chopper--I think I'll take the passenger side
if I had try to fly one--- I think I have less than 3 secs before a very, very loud noise:}

[airfoilmod]

And I don't, much, Gr8Shandini is on to it. Igor was building a completely new technology, and being right handed, liked having his best hand on Cyclic, His Call, not ridiculous at all. There may be more to it, if there is, I am unfamiliar and want change back from my two....

Airfoil pence.

[groundfloor]

I fly both, sitting on the right works for me especially now that I have a side stick in the fixed wing and "point" it where I want it to go.

Sitting in the left seat and trying to fly with the left hand is a little conversion in itself I am told :).

Why do Capt`s sit in the left on Fixed Wings? Maybe so the right hand was free to cuff the surly FO`s and or backhand the FE back in the 30`s. See - it all boils down to CRM :}.

So what was the first dual side by side and who sat where, Wright flyer?;)

[jb2_86_uk]

the wright flyer(s) were all single seaters... but the pilot wasnt sat, he was laid!

so what i guess i mean is, they were all single pilot aircraft! :ok: i got there in the end

[Groundloop]

Didn't this result from the mid-air collsion between two airliners over France in 1922?

They were flying in opposite directions in poor weather following the same railway line and collided head-on. After this the regulation was introduced that, if following a linear feature on the ground, you keep it on your left -hence opposite direction traffic would be on opposite sides of the feature.

When two pilot aircraft came along then the PIC sat on the left to keep visual with the feature.

[Angels 60]

Planes: Historicaly, most of the time, when choosing where to put flight instruments and controls, being a choice, left side, so that's where the pilot sits. He can reach and see what he needs.

Even in more modern aircraft, where there is much more redundancy in instruments and controls for the right seat pilot, most of the time, serious systems circut breakers are closest to the captain on the left side.

Helcopters. The advancing blade on the main rotor creates more lift then the retreating blade in forward flight. The pilot sits on the side of the advancing blade to counteract the roll tendancy at higher speeds.

In aircraft where there is no intention of a single pilot captain, then certainly systems, controls and the design of the aircraft are much more blended to accomodate comfortable flight control from either side.

Certainly exceptions do exist, and varies from manufacterer, make and model, as someone's idea of where to put CB panels, controls, and instruments vary.

I could make the joke, that because most of the world drives on the right side of the road(the way it should be) that is why the pilot sits on the left side...more akin to driving a car, visualy more similar and comfortable on taxi ways, up in the air ect.

[airfoilmod]

Your theory re: advancing Blade works only for Helicopters that have a counterclockwise Disc. Besides, the retreating Blade has more AOA, (Cyclic), so it balances the mass regardless of the Bum in the seat.

Igor was comfortable with his good hand on cyclic and the "redundant" appendage working the Collective. If on a coml. helicopter, you'll find the primary collective in the middle, meaning the left arm is "free" to tend to the myriad of demands of a vehicle trying to thrash itself to pieces and murder its occupants on a more or less continuous basis. On a Trainer, if the training pilot is the more experienced (one would hope), he is the more capable to manouver lefty OR righty. Since the command seat is on the right, the training vehicle mimics the layout of the ultimate mount of the trainee.

[Angels 60]

Airfoil...blades turn both ways on many helicopters, and as such, the tail rotors are installed accordingly.

In any event, I am comforatable now flying from either side...

[airfoilmod]

Thanks for the question, I think I'll move along.

Rgds, Airfoil

[gr8shandini]

Angels, you can sit on whatever side you like. In fact, I know a few folks that like to sit on the left when long-lining as it's more comfortable to lean over the collective to look down than to lean your body away from both controls. However, that doesn't change the fact that it's customary for the PIC to sit on the right in a helo. Any helo.

I'll direct your attention to the standard IP layout on page 22 of the AS350 tech specs:

http://www.eurocopterusa.com/Product/2007%20Tech%20Data/td_as350_b2.pdf

Please write to Eurocopter and inform them that they've been installing the primary flight instruments on the wrong side of the aircraft.

As for your dissymmetry of lift theory, a quick estimation of the W&B shows what little effect that has. Assuming a 200lb pilot sitting about 20" from the centerline and that the airplane is otherwise fairly well balanced laterally, the sum of the moments is 4000 in-lbs. Given a typical weight of about 4000 lbs, it looks like you changed your lateral CG by about an inch. I don't have an A-Star flight manual, but a typical lateral CG limit is about 4", so you're nowhere close to any sort of control limit.

[Angels 60]

Can you tell me where it says I have to sit in an Astar on the right?

If disymetry of lift wasn't an issue why do you have trim?

Certainly I didn't intend to imply flight instruments in all aircaft determine where the pilot sits..I hope you don't either... a helo is typicaly center panel configured anyway....If I am flying IFR EMS, all instruments packed on the right, sure I would fly right...long line with a bubble on the left...sit left..

The ops, equipment, and how the aircraft is configured, my comfort level, will coelesce to determine where I fly in any aircraft..

On a long x-country, going fast, not a bad thing to ease that cyclic force by sitting on the opposite side of the roll depending on the helo your flying.....

Another issue is that sitting left side, you can take out the center collective so some passenger doesn't bump it...many do...

[gr8shandini]

Well Angels, I was giving you the benefit of the doubt, but now I know you're full of it. The Astar IP is by no means the center stack variety:

http://www.flickr.com/photos/contrailsnw/160471777/

Back to the original topic, Keith, I did a little more searching of the ol' memory banks, and managed to dig out the connection between rotary engines and left hand traffic patterns. Specifically, it was the fact that for airplanes with a clockwise rotation of the prop (and hence engine), a right yaw would induce a downward pitching motion due to gyroscopic effects. So right turns, especially after takeoff, could get a new pilot into serious trouble if he wasn't prepared.

[gr8shandini]

I'm not backpedalling. You can sit on any side you like. Just don't fool yourself that there's an aerodynamic reason for it.

I may not fly helos for a living, but I do have an aeorspace engineering degree and 10 years experience as a Flight Test Engineer for various companies including 7 years with rotary wing outfits. I can guarantee you that there's no technical reason for pilots to choose one side over the other except for the human factors reasons I've stated above.

By the way, does your Astar not have a trim / mag release system? That'd be much more effective in countering any control forces than changing seats.

[parabellum]

Angels60 you are totally incorrect regarding FW LHS, Groundloop is on the money and it is all to do with following line features on the ground in poor weather and keeping them on the left hand side to avoid a head on, goes back a long, long way. Troll on. (I read somewhere that more road traffic in this World drives on the LEFT rather than the right).

gr8shandini - I used to fly the Bell47G, pilot flying sits on the left and am right handed so know what you mean about ease of controlling whilst changing frequencies etc.! But you do get used to it.

[Angels 60]

Say again Para...didn't catch it...

Ok...for those that don't fly helos in here, if you fly a helicopter fast enough, the retreating blade creates less lift then the advancing blade.. hence the roll effect tward the retreating blade.

Try to imagine the wing on the right side is creating more lift then on the left...hence the roll effect...the faster you go, the more roll tendency...

The faster you go in a helo, the more your rolling effect tward the side of the retreating blade...actual helo pilots help me out here. Trim counteracts this, along with the pilot sitting on the side of advancing blade, or even fuel tank position from what I hear...

Have you ever seen that little wing on the tail of a Jet Ranger for instance, and wondered why a Jet Ranger needs a little wing?

Since US helos typicaly have a counterclockwise main rotor path, as seen from above, the advancing blade is on the right...and viola...most helos have the pilot sitting on the right side, unless the blades turn the other way...

If you guys want I can go to book and grab some quotes and references...or start dragging some guys from the helo forum in here..

[gr8shandini]

I know all about dissymmetry of lift. Quote away. However, it doesn't change the fact that the moment produced by sitting on one side or the other is miniscule compared to that produced by the cyclic control.

And for the record, the stabilizer (or "little wing") on the back of the B206 and most other helos is there to reduce drag by keeping the fuselage more or less aligned with the airstream in cruise. If you look closely, they're heavily cambered and it's easy to tell that they're both providing a downward force to counter the forward pitching moment imparted by the rotor disc in forward flight. They're small because they're pretty far from the longitudinal CG. If they had to provide a lateral force, they'd have to be much bigger.

Well, it's pretty obvious that no one is changing Angels' mind so that's about all I have to say on this subject. I do have one parting question, though: So if you're carrying a passenger, do you make them sit behind you, or are they allowed to sit up front?

[Angels 60]

Great6Sandini

Page 65 / Chapter 9 Basic Helcopter Handbook : Hazards of Flight
AC-61-13B

.....The airflow over the retreating blade of the helicopter slows down as the forward airspeed of the helicopter increases: the airflow over the advancing blade spees up as forwards airspeed of the helicopter increases...

The major warnings of approaching retreating blade stall conditions in the order in while they will generaly be experienced are:

- Abnormal vibrations
- Pitch up of the nose ..............one reason why that little wing is there
- Tendency for the helicopter to ROLL

When one blade is losing lift, the other is gaining lift...that's called.....??

[Brian Abraham]

or start dragging some guys from the helo forum in here
I'm here. Well a crowd of one anyway.
Angels - that last post did it for me. The horizontal stabiliser on a helo has got absolutely nothing to do with controlling the pitch up tendency with retreating blade stall. Read up on Prouty if you want to argue the toss, or get Nick Lappos to put his twopenny worth in here.
the advancing blade is on the right...and viola...most helos have the pilot sitting on the right side
What a crock. Direction of rotor rotation has absolutely nothing to do with the side a pilot sits on. Helo convention does have the captain sitting on the right but there are exceptions, as mentioned, the Bell 47, also Enstrom and I think Hughes 500. In the S-76 normally the captain sits on the right, but in the SAR role the captain sits on the left. I qualify the last point by saying with one operator at least. In Vietnam on the Huey the US Army convention was for the captain to sit in the left seat. The reason given to me was that the visibily was much better because that seat had a smaller instrument panel obscuring the view. Personally when I made captain I stayed in the right seat because of the ease of access to radios etc as previously mentioned.

Why helo guys sit on the right has always been a subject of much discussion and there are many thoughts but little concrete. The best theory I have come across and think most likely is that the first helos had the one and only collective lever mounted between the two seats. That meant the left seat guy flew with left hand on the cyclic and right hand on the collective, the right seat guy of course it was the reverse, vis right hand cyclic, left hand collective. It was said that Igor preferred to sit in the left seat when training the new boys, and so the new pilots (in the right seat) grew accustomed and naturally preferred that position when they were let loose to the squadrons. Hey presto, a convention is born.

PS 20,000 hours helo and don't pretend to know everything, but do know a little bit.

[Brian Abraham]

Never argue with an idiot
Taking your advice Angel.

[Angels 60]

Yeah thanks for your imput Brian...and all the relevent info you brought to the forum...great help, really, really, thanks...

[Gordy]

Uh--Angel--I have in excess of 6,000 hours in the Astar--and many more in other helicopters. The position of the pilot has NOTHING to do with aerodynamics, but more of convenience. The Astar I flew had the PIC on the left because we flew clockwise around an island, and wanted to fit two passenger seats up front to view the island.

We bought our Astars new form the factory with the PIC on the right and then paid to have the aircraft modified for left hand PIC.

[Brian Abraham]

To those of you who may be wondering what the horizontal stabiliser on a helo does. The primary purpose of the horizontal stabiliser is to give the helicopter stability in pitch. Both the helicopter rotor and its fuselage have an inherent negative stability derivative in pitch and the stabiliser helps to give the helicopter better overall handling qualities. The large surface area of the fuselage ahead of the centre of gravity has a powerful negative stability influence.

The source material (an oustanding book) is "Principles of Helicopter Aerodynamics" by J. Gordon Leishman (Cambridge Aerospace Series) and a lengthy discussion can be found on page 311 at http://books.google.com.au/books?hl=en&id=nMV-TkaX-9cC&dq=helicopter+aerodynamics&printsec=frontcover&source=web&ots=Co8Ple2J8x&sig=gzBnt8k98gZz_Pn9Cgx1-_-QYYA#PPA311,M1

I would advise caution in the referenced materials use as Angel has not put his seal of approval on it. A poster on another thread put it rather well by saying "I have absolutely no sense of humor when it comes to those who disseminate erroneous information under the guise of being factual. These are understood characteristics in politics. They are dangerous characteristics in engineering." And I might add aviation. :ok:

[Oxidant]

Sorry to throw a little water on you Brian...
But, with the RAF SAR Wessex (now retired) & Sea King the Commander sits in the right seat. (Had a Nav. in the left seat of the Wessex)
One main reason was the hoist was on that side.

Regards.

O:)

[[email protected]]

Angels - your casual dismissal of other peoples' posts because they do not agree with you marks you out as either a wind-up merchant just causing trouble or someone who really doesn't know anything about helicopters other than what you have read from a book.

Brian is a well respected member of the rotorheads forum and his posts are always accurate and well informed.

With some ineveitable exceptions, pilots in helicopters fly in the right hand seat even at maximum speed in an ASTAR.

Compared to some I am still a newbie on helicopters but after 26 years and 7000 hours in helicopters (19 years as a QHI) I do have a vague idea of what happens in them.

Keep on fishing:)

[Heli-phile]

My Prefence in a fixed wing is the sitting on the LHS for the airmanship aspect (turn right so can see conflicting aircraft all the time as you pass each other etc), its also easier when reaching for your favourite item on the cheeseboard!!
My preference for sitting in a Helicopter is the LHS.
This has nothing to do with which way the main rotors happen to turn but simply the collective lever (up/down!) is always on the left. Apart from the hassle of having to lift ones leg over it when entering/exiting the aircraft it is far more comfortable to sit on the LHS. Unless you are tall or have arms like an orangutan sitting on the right side and watching an external load becomes very uncomfortable very quickly. When sitting on the left you can lean out over the collective and even reference power/pitch by feeling it against your thigh etc. over on the right you are streching your left arm way out to reach and hold the collective whilst straining your neck to the right look out and down at the load/obstacles below.:(:ouch:
(Also on the LHS having the Collective on the left guards it from accidental inputs from passengers feet/arms arse or handbag)etc.:eek:
Now just to prove the point about aerodynamics and retreating blade stall having no relevence to seating position:
Eurocopter 350 series BA,B2,B3, series pilot sits RHS
Eurocopter 350 B4 series Pilot sits on LHS.
Both machines have identical blades, rotorhead and transmission
both machine blades turn clockwise. not an issue!!
Also
military H500 pilot sits RHS
Civilian H500 pilot sits LHS otherwise identical machine (and rotors) QED:}

P.S.
Only reason the B4 pilot now sits on LHS is because that was what most pilots have asked for (as well as a twist throttle by the way):ok:
Only reason Military put pilot on RHS in H500 was so when they progressed to the huey they were used to sitting on the RHS.

[before landing check list]

Angels in response to your ”
.....now what happens when you sit on the right side of an Astar and go really fast..hmmmmm?” if you are talking about retreating blade stall you would eventually pitch up and roll right. If you sat in the left seat you would still roll right. It makes No difference where you fly from as far as aerodynamics are concerned. Long line pilots will routinely fly a B212 or a S61 from the left because the visibility during a hover is better. Now the MD530 is flown from the left….why is that?

[Brian Abraham]

I think Angels has a new identity aka Iflymach85

On a long x-country, going fast, not a bad thing to ease that cyclic force by sitting on the opposite side of the roll depending on the helo your flying

That has to be about the most laughable statement I've yet seen.

SNS3Guppy - You had him taped early. Walter Mitty reincarnated, or maybe his wingman.

You're flying a helicopter, now? You were a fixed wing captain with 10,000 hours and seven type ratings, flying a citation, and had just been rejected by Alaska airlines when you posted as ssg and then as Trickle451...both of your former identities which have recently been banned.

Now you're a helicopter pilot. Who'd have guessed?

[AndyJB32]

Angels 60, i think you're getting alittle bit confused. A rolling tendancy will occur due to retreating blade stall, which will be one of the criteria taken into consideration when determining a helicopters VNE. Retreating blade stall will occur as the speed of the helicopter increases to the point at which the flapping down of the retreating blade has increased the angle of attack of the retreating blade to it's stalling angle. As soon as any airflow occurs over the rotor disc there will be a difference in the airspeed between the advancing and retreating blades. This will lead to dissymetry of lift, which will be partially compensated for by blade flappping. This will allow safe flight within the flight manual speed parameters. The pilot may have to sit in a specified seat due to C of G considerations, but he certainly won't be required to compensate for a rolling tendancy due to aerodynamic instability in the cruise! If he has to do that, i suggest he find a different helicopter to fly - ie one that has been certified!!:eek:

[Brian Abraham]

Heeees back. Is that his shoe size or IQ.

[Brian Abraham]

But you told me not to talk to idiots!!!!! :=

[Sven Sixtoo]

I really wish I'd found this thread before my Cat renewal. It wouldn't have gone any better but at least the P of F would have got a laugh.

Sven.

[ShyTorque]

These theories probably come from a very good source.

Such as this one:

http://www.easyontheeye.net/ladybird/60s/606b/606b.htm

Or they might just be a collection of alternative answers given by the thickest student on the course (a role often played by a crafty CFS trapper).

[RAFEmployee]

Angels- With all due respect, do you actually know what you're talking about?

Forgive me, Tankdriver45 now I believe you are.

[Brian Abraham]

Getting back to the original question it is interesting that photos show the Sikorsky R-4 doing ship trials being flown solo from the left seat. Other photos show the helo with a hoist on the left side, which meant the helo had to be flown from the right seat for the hoistee occupied the left seat once up at the door (Lateral C of G considerations aside). So maybe Sikorsky either set a convention by deciding on what side to put the hoist, or the side to put the hoist was dictated by the preference of seating position by the majority of pilots. Who knows?

[enicalyth]

Quote: If Brian Abraham knew anything about helos.........

My place or yours Brian? Time for a Toohey's or two I think.

:D

[Coconutty]

From Post #25 :
the advancing blade is on the right...and viola...most helos have the pilot sitting on the right side

"Viola" eh ? -

Maybe TankDriver ( or whatever today's name is ) is on the fiddle ...

http://i34.photobucket.com/albums/d129/coconut11/viola1.jpg

... or maybe just a big pansy :rolleyes:

http://i34.photobucket.com/albums/d129/coconut11/viola2.jpg

( Both of the above are "violas" ;) )

http://i34.photobucket.com/albums/d129/coconut11/Coconutty.jpg

[Brian Abraham]

To wrap this thread up you will find the following comments re OnePercenter, tankdriver45, Angels 60 and his latest cattleflyer at http://www.pprune.org/forums/showthread.php?t=328287
I don't actually believe he's for real. Surely, no-one's that stupid.

Seldom have I heard anyone display the depths of their ignorance with such total conviction. The only downside is that there are others who might believe what he says through their own inexperience. The reasoning behind some of his statements would have made the Monty Python crowd very proud of him. He certainly sounds like he believes them himself and thats scary!
I have no comment.

[SNS3Guppy]

There goes cattleflyer, who is onepercenter (who has been banned, along with the rest of his names), agreeing with himself.

This is necessary, of course, because no one else will agree with him.

[Brian Abraham]

cattleflyer - of course you agree with Onepercenter, because thats you. Do you take us to be absolute idiots? When you start talking to yourself, do you have idea what that is a sign of?

[keith smith]

Two questions:1.Do all props/engines rotate clockwise?2.How big are groscopic moments in terms of the requred balancing elevator power?

[SNS3Guppy]

Keith,

Propellers rotate both directions, depending on the engine installation. This has no significant influence on elevator (pitch) operation with respect to the direction of operation, but it does have an impact on rudder requirements in single engine airplanes, and can affect the degree of assymetric thrust in multi engine airplanes.

With turbojet airplanes, the direction of rotation isn't of great significance.

With a propeller installation, gyroscopic forces aren't nearly as significant as a rotor on a helicopter or gyroplane. Gyroscopic forces are perceptible when performing an aerobatic maneuver or a rapid maneuver in an airplane, but the primary effect that gyroscopic precession has isn't on the pilot or aircraft, but stress placed on the crankshaft or prop extention (part of the reason that aerobatic aircraft tend to have significantly reduced TBO's on their engines).

[gr8shandini]

Keith,

When I mentioned gyroscopic forces, I was referring to the WWI era when the early rotary engines actually had the crankshaft bolted to fuselage and the whole engine rotated. Obviously, this means that the forces were much higher than the modern configuration.

[john_tullamarine]

These theories probably come from a very good source...

Thanks ever so much for that one ... I really was in need of a lift in this constant chasing down of multiple personality sufferers .... my day is now much brighter ..


I did read a long time back a tale which suggested that the early military aviation side of things had pilots (often with a cavalry background) "mounting" their avian steed from the left .. which led to the LH seat thing in fixed wing aircraft ... no idea whether this is kosher but it makes some sense, I guess ?

[Brian Abraham]

Just been looking at "Flying the Hump" by Don Bownie and he talks of flying the Hump in C-47's solo (a practice that was conducted in the early days of the war) and guess which seat? The right side (no I don't mean the left, the right right). Thats where all the controls were.

[ARINC]

I seem to remember an instructor telling me in the US that the PIC in a Heli sits on the right because he can follow the roads more easily...:E:E

This stemmed from the desire to prevent head on traffic conflicts when following topographical features. Ie always keep the road on the right.

This was of course right before he insisted on proving that I would not fall out with the doors off during tight banked turns....:{:{

[TheVelvetGlove]

I can't believe how many of you are taking the bait on this one... haha

Anyone who has flown a helicopter PIC from the left seat knows it's a real :mad: to manipulate the radios/nav. I never met anyone who preferred it that way.

A better question would be: Why would anyone design a helicopter with the PIC seated on the left? :ugh:

[helimech]

Kawasaki KH4 is flown from centre seat.
Perhaps japanese pilots are more well balanced?

[helimech]

Ever seen a sling load?
Twice when flying with John Twit.
Once as it passed the skids and the second time when it was jetissoned.