RAF P-8 breaks the sound barrier

[B Fraser]

Airflow at high subsonic speeds can become supersonic at various points around an airframe. I have seen standing shockwaves above the wing of several commercial airliners and there are a few online videos that demonstrate this. When the entire aircraft goes supersonic, is that the point at which the shockwave moves rearward to the trailing edge ?

[teeonefixer]

Originally Posted by Timelord

Lomcevak, R. .k P. . . ..ps insisted he took me supersonic (indicated) ( medium level shallow dive) on a Buccaneer trip at the end of my tour despite my reluctance. What really surprised me was that he asked Scottish for clearance!

I'm quite surprised by the high speeds quoted for Buccaneer in this thread - but I'm not an aerodynamicist. A group from the DO visited the Buccaneers detached to Waddington in the mid 80's and a query was raised about clearances at higher speeds (M0.9 ish springs to mind). The reply from one learned chap was that the fin/tailplane bullet fairing was a limiting factor and could easily be addressed, but there was no MoD request to do so.

[falcon900]

On the basis there was an RAF aircraft involved, and it was flying, and it was pointed away from Scotland, that would make it one of the more accurate and fact based stories in the Daily Record.......

[OJ 72]

LOMCEVAK, Timelord...the self-same pilot also took me supersonic in a Bucc at the end of an airtest.

When I pointed out that this would be contrary to the FRC/Aircrew Manual limitations, the suave, rather louche reply from the front cockpit was...'James, my dear chap. We did this all the time in the Navy'!!!

So that's all right then!!!

[LOMCEVAK]

Originally Posted by OJ 72

LOMCEVAK, Timelord...the self-same pilot also took me supersonic in a Bucc at the end of an airtest.

When I pointed out that this would be contrary to the FRC/Aircrew Manual limitations, the suave, rather louche reply from the front cockpit was...'James, my dear chap. We did this all the time in the Navy'!!!

So that's all right then!!!

I haven't seen RP for a while but this will be an interesting chat over a beer! The clean aircraft limit was 0.95M but directional stability was rather weak by then to say the least! I have no doubt that you could get to 1.0M indicated, and perhaps that was actually 1.0M true, but what interests me is the recovery from the dive. I suspect that there was a deceleration with idle thrust and/or airbrake before the pull out because the tailplane would have been not very powerful.

Airflow at high subsonic speeds can become supersonic at various points around an airframe. I have seen standing shockwaves above the wing of several commercial airliners and there are a few online videos that demonstrate this. When the entire aircraft goes supersonic, is that the point at which the shockwave moves rearward to the trailing edge?

The definition of 'transonic' is the speed range from when a point of local airflow first goes supersonic until all of the airflow over the wing is supersonic, and there will be a shock wave at the trailing edge at that point. Therefore, what you have described is the transonic region.

[Alex Whittingham]

0.95 was MMO in the Victor K2, often and easily achieved. Dont't think it makes much difference whether your machmeter is indicating M0.95 or M1.05, there's going to be local supersonic flow.