E3 Sentry Question
 

Heading back to work after lunch, I saw the distinctive large arc contrail remains of an E3 orbiting over the Borders, and sure enough, following the curve I saw it, just as it started to trail again. A couple of things I pondered over, that you guys may be able to answer. Is there an "orbit switch", that sets the aircraft up in a pre-planned orbit, or does it have to be flown manually? Everytime I have seen these over the Borders, apart from once, they are always in a right hand, (clockwise), turn. I always thought that the Captain of an aircraft, sat in the left hand seat and therefore it should be in a left hand turn/orbit, as the Captain is in charge and would need to see where the aircraft was heading. So why do the E3's, that I've seen anyway, go round in a right/clockwise turn?

Aircraft can orbit either left or right. Either pilot can be the handling pilot but captain is usually, but not always, in the left hand seat. Autopilot has a green rating so does most of the work. Orbits orientated to get the most out of the radar system, or to get the sun out of the captain's eyes.

Many tricky decisions to make on the E-3 flightdeck, but all the time in the world to make them.

..Tea or coffee?

..Sandwiches now?

..Sit down to pee....?

Thanks JTO. Heard what I thought were Typhoons, over the factory around the same time as the E3 was in the area, but they were gone by the time I got outside for a look.

If there is a one way airway nearby then some orbits are mandated to be cw/acw, as appropriate, so a/c are not going head to head.

The route to the orbit will have an effect. For example, ATC vectors or mandated routing prior to the join may lead to a smoother entry in one or the other direction.

Other than that? Sun position, toss of a coin, how the crew feels on the day. Does the nav prefer to sleep with head forward (lh orbit) or head back (rh orbit).

The rumour that half way through a sortie it needs to switch direction to 'unwind' is completely unfounded. Allegedly.

Of course, a clockwise orbit produces several extra radar scans an hour. ;)

Surely that's only in the Northern Hemisphere . . . :ok:

Had an AWACS trip to see how their side of the game worked. Orbit direction was preplanned (not sure why, think it was proximity to controlled airspace vs likely main threat direction). Orbits were free-flown every so often for pilot handling practice - they even let me do one. Lots of anticipation needed, like leading a formation really.

Perhaps it's all down to the Gyroscopic Torque Reaction of the radar scanner...............

HB

The right hand orbit is the is infact the orbit of choice for the nav. It allows him to slump back in the nav chair, thus getting a better qualtiy of sleep:zzz:! Until of course the question of tea or coffee and when to put the cumberland sausage breakfast in the oven.

F&^KIN& cut backs!!!

Thing is I preferred the slumped forward pose - cold wx jacket on desk as a pillow of course. If I lolled backwards I was always liable to snore, which would wake the poor engineer.

I always used to say certain members of the E-3 fleet couldn't take a dump without a plan.





(Apologies to Tom Clancy)

Well they were certainly covering some sky as the north end of the orbit was over Carrbridge!

UK9 perhaps.

Or a serious ****-up if they were meant to be in UK5

DG, don't listen to any of them. This is the wrong place for serious advice. Let me help you out. It is purely a comfort thing that comes down to being left or right handed. Most captains are right handers, hence most orbits to the right.

Serious advice already given. Time to lighten up afterwards.

Erm, I think I may have f***ed up here. I don't actually know the reason, I was hoping my answer would have been misleading, but believable. A real bu**er if I stumbled across one of the real reasons by mistake!

I'll get my coat...

Actually its all to do with the effect of changing groundpeed and angles of bank caused by the prevailing wind velocity at height with respect to the radar CFAR circuits and the orientation to the working areas.

Not that you would expect one of the pilots to understand that.... When this used to be taught to the new Sentry crews in the days of yore, the pilot instructor on Sentry Training Squadron refused to send his students because "we have already studied met at basic flying training". Sad but true!

That "groundpeed" sounds like a tricky concept to understand too....!




Or is it all to do with going to the toilet before you get airborne??? ;)