Eyelets on upper wing of Airbus
 

Well, at least I think it was an airbus. :)

I was on a flight the other day with our CEO, who loves aviation. I could answer most of his questions, but got stuck when he pointed out the yellow painted eyelets on the upper wing. Didn't look quite big enough to be hoisting points.

Anyway, I need to correct my otherwised unblemished perceived aviation-knowledge with an answer, sad as it may be. :rolleyes:

So if it was the upper wing you were obviously in a biplane - else they were the hoisting points on the upper wing surface ( of a monoplane) used for hanging the aircraft from the hangar roof during maintenance - else they are anchor points for slide rafts should such things ever be needed during evacuation.
see previous threads and Take your pick[B][COLOR=red]

yeah yeah - i was using the term 'upper wing' for brevity, so these eyelets were on the (sorry to have to clarify) monoplane airbus variants :rolleyes:

Also a safty harness point for maintenance Lads/Ladies

Having just read the interesting thread about the increased TOW available with a more rearward C of G on the 73, I expect that the ever-practical Airbus people have fitted these eyelets for the extra lift available with said rear C of G!

I work on the 733 and the eyelets are on the wings of my aircraft too.

A cord with a hook can be found within the frame of the overwing exits. When attached to the wing they can be used as a guide to hold onto during a evacuation after a ditching.

However, there is nothing in our ditching drill about using them. It is just one of those little extra things if time/cercumstances permit them to be used.

I heard these were clever recessed vortex generators - IE AIRBUS loves to crow about their clean wing designs as opposed to Boeing's love affair with dispatch critical VGs on wing, nacelles & empennages ..

I find it hard to believe that a stew is going to take the time to hook ropes into these things following an unscheduled incident ....

I think you will find that these hard points are for use if the slide deploys but then deflates.

In these circumstances there is an attachment hook on the slide that can be attached to this hardpoint and allow someone to tension the slide from the ground, thereby allowing it's continued use.:ok:

No slides on a 73 or A320 over the wing, they are to hook in a "help" rope. Maybe you big guys in HongKong have slides over wing, but not us!!

I thought they were crane attachment points. They're the only way you'll get a decent rate of climb out of an A320 or A340!!:E

I used to design A319/20/21 wings in a previous life...they are indeed life rope attachment points (or drowning rope when the aircraft sinks).

Next pub quiz question what are the large sticky out bits at the 2 O'clock ish position on A320 engines for?

Clue ..it relates to high AOA flight.

I know ! I Know !! Ooo! Ooo! I Know ! I Know !


Im not sure what you mean by Sticky out bits - but,

You must be referring to the protrusions on the engine nacelles - IE Strakes or Chines in US vernacular.

These have been used for several reasons - Douglas used two of them per nacelle on the DC-10 to increase lift ( Kerker was the Douglas Engineer that did the development ) - Im not sure of the aerodynamic theory as to how they work - because of the engine nacelle coupling - IE the DC-10 engines hang really low ( A300 has literally DC-10 engines, nacelles & struts ) - and therefore the nacellel vortexs do not interfer with the flow over the wings & spoil lift. Boeing & AIRBUS use the nacelle chines for a different purpose - to improve low speed stall characteristics- they physically improve the strength of the nacelle vortex so that it will not burst as it passes through the leading edge pressure gradient - these are vortex shed amplifiers - otherwise the characteristically week vortex would "burst" as it passes though the pressure differential when going from underside to topside of the wing. A bursting vortex will hose the flow over the top side of the inboard wing causing it to want to stall before the outside wing. Because of the fact that modern jets use a swept wing - this stalling unloads the inboard wing first - while the outbord reagion is still flying. This can cause a stall pitch down moment - that will limit your slowest approach speed - IE airplane will keep pitching over following stall & brealk - not allowing you to continue slowing down with AOA. If you make the damn thing too effective ( IE the size of the chine ) you will make the inboard wing hang on too long- IE NOT want to stall at all - making the aircraft divergent in pitch - IE Airplane wants to stay pitched up regardless of what the pilot wants - SSSoooooo - as St Augistine said - prudence is in the middle - IE there is a sweet spot in between too small & too Large. AIRBUS copied this use from Boeing - who did it on the 737, 767 & 777. The A320-100 delivered with out these & put them on later after they considered the cost & expense of trailing edge improvements. Now everybody uses them Embraer ERJ170 included. THe big question is WHY AIRBUS uses two of them instead of Boeing's use of one - & that is because they do not want to spare a left & right handed nacelle - IE they have a universal part. I believe Embraer is subscribing to that line of thinking ..


Correct ?

... to do with larger engines and reduced nacelle-wing clearance on later aircraft causing nacelle vortex flow to go over, rather than under, the wing. The chine (big VG) makes the flow a little better behaved at high alpha.

There is a good article in the Tech Log URL sticky which gives an overview of what is going on....

As memory serves, the chines are only on the CFM's, not on the V2500 on a 320. Tere again, how much notice do I pay on a walkround, I'm too busy dodging people who want to fine me for not wearing a vest ;)

Anyone know for sure why AIRBUS uses 2 of these on A319 & A318 ??

And on the IAE 321 actually. Don't know about the CFM.

" but got stuck when he pointed out the yellow painted eyelets on the upper wing."
For the A320, these are anchor points for a rope stowed in the narrow doored over head stowage, around the o/wing area, have noticed that the ropes are not on all operaters aircraft.
I'll follow up later.
And yes the B737 Classic has the rope in the top corner of the cut out for the O/wing hatch.