Sweepbacks nose high attitude on approach?

[ChristiaanJ]

Flying Spag Monster seems to be the only one who's got the point. It's the lift curve, i.e. CL versus alpha, that determines the alpha, hence body angle on approach (with such rare exceptions as the Crusader).

[flyburg]

Sjeezs,

I thought it had to do with flaps v slats (and other leading edge devices)together of course with angle of incidence.

Most straight wing A/C only have flaps, most swept wing have flaps and slats.

AOA is determined by the angle between chordline and relative wind, chordline is the line drawn between the extremities of leading edge and trailing edge.

For a a same relative wind, extending the flaps will increase angle of attack, extending leading edge devices will lower the angle of attack (all for the same relative wind).

Best example, sweptwing jets without leading edge devices (CRJ's, EMB's) ausually have a nose low attitude( depending also on angle of incidence) during approach. Swept wing jets with leading edge devices have a nose high attitude during approach.

Anyways, that's my understanding, I can always be corrected though.

[Lemurian]

These older aircraft did not have especially advanced airfoil sections, and....also did not have leading edge devices nor advanced trailing edge flap designs, so a lower body angle was absolutely needed.

That's patently wrong.
If we talk about western jet transports, bar a very few early designs (the Caravelle, the DC-9-10...) and some exceptions like the DC-8 and the Convair 880, they had all been provided with leading edge devices : the 707 was originally equipped with short Krüger flaps which got longer with heavier versions. The 747, IIRC was equipped with a mix of Krüger and slats (or at least variable camber Krüger flaps).
I remember that the best way to tell a DC-8 from a 707 at a distance was the low nose-attitude of the -8 on approach.

For a a same relative wind, extending the flaps will increase angle of attack

...
Yes, but the point is at reduced speeds.Lding edge devices, especially slotted slats allow higher AoAs by re-energising the airflow over the wing and giving more efficiency to the trailing edge devices...the Cl s augmented, allowing a lower approach speed for the same weight.

[411A]

the 707 was originally equipped with short Krüger flaps which got longer with heavier versions.

Yes, the original early models did indeed have that short LED section (between the inboard and outboard engines) and yes, full span LED's were fitted to later models, however as the weights increased on these later models (especially the -320B/C varients) the body angle on approach (and the approach speeds) remained about the same.
I should know, I flew these early models and well as the later ones, quite extensively.
By the way, the first B707 to have full span LED's was the -320 (straightpipe)
model, and it was delivered to South African Airways, for their LHR-JNB route, expressly built for SAA.