RAF P-8 breaks the sound barrier

[ORAC]

Hmmm - one of those secret supersonic P-8s again….

https://twitter.com/thesun/status/1493574083619004419?s=21

[KonfusedofKinloss]

A bit more research needed at the Daily Record I believe....

Scots anti-submarine plane takes off causing ‘sonic boom’ felt across UK - Daily Record (https://www.dailyrecord.co.uk/news/uk-world-news/scots-anti-submarine-plane-takes-26235830?fbclid=IwAR3b3w4ptkkiCzwtFBMyTw8D_MNv0AG2PS1UbO5pZH aZmRqvzNjdGU88LkE)

[Toadstool]

A bit more research needed at the Daily Record I believe....

Scots anti-submarine plane takes off causing ‘sonic boom’ felt across UK - Daily Record (https://www.dailyrecord.co.uk/news/uk-world-news/scots-anti-submarine-plane-takes-26235830?fbclid=IwAR3b3w4ptkkiCzwtFBMyTw8D_MNv0AG2PS1UbO5pZH aZmRqvzNjdGU88LkE)

Funnily enough, the report has been taken down. So many errors in the headline, never mind the article.

[NutLoose]

According to Daily Record :}

https://ukdefencejournal.org.uk/newspaper-inexplicably-claims-p-8-poseidon-behind-sonic-boom/


https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1200x785/nonsense1_2708f038ddf0a64276e905d62fe5ec77ae904bc3.jpg

[charliegolf]

Did I dream up the story/legend/myth that a VC10 crew left the climb setting on a bit long and, er, got a bit speedy?

I do dream up such scenarios... Age.

CG

[sealo0]

According to Daily Record :}

https://ukdefencejournal.org.uk/newspaper-inexplicably-claims-p-8-poseidon-behind-sonic-boom/


https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1200x785/nonsense1_2708f038ddf0a64276e905d62fe5ec77ae904bc3.jpg
bit early for the 1st of April

[BEagle]

Did I dream up the story/legend/myth that a VC10 crew left the climb setting on a bit long and, er, got a bit speedy?

If you did, 'twas utter bolleaux!

[Top West 50]

I think I came close in a Victor B1. On high speed shallow dive without mach strut, instructor said, "look out!" Did we used to go as fast as .98? Someone will remember. Anyway, straight from training I looked out - of the window and lost track of the mach meter momentarily. Whatever the speed it recovered beautifully.

[charliegolf]

If you did, 'twas utter bolleaux!

Bit sharp! Piles at you again?

CG

[Bksmithca]

bit early for the 1st of April
I would have to agree, hard to believe a 737-800 would be capable of breaking the sound barrier

[meleagertoo]

I would have to agree, hard to believe a 737-800 would be capable of breaking the sound barrier

Particularly during take-off!

[Consol]

I was talking to a retired Bucaneer crew member once and I asked could go supersonic. He said it wasn't meant to but he had been supersonic in one....

[JEM60]

A D.C.8 Airliner went supersonic many years ago. Hard to believe, but it WAS true!.

[chevvron]

A D.C.8 Airliner went supersonic many years ago. Hard to believe, but it WAS true!.
I thought it was a Convair CV990; the one with 'speed pods' like the Victor had.

[Commander Taco]

I thought it was a Convair CV990; the one with 'speed pods' like the Victor had.

Nope. It was a DC8 that was later delivered to Canadian Pacific Airlines.

[tdracer]

Nope. It was a DC8 that was later delivered to Canadian Pacific Airlines.
It was done during the DC-8 flight test program - intentionally. Reportedly a bit of a 'one-up' jab at the 707, since even if Boeing had duplicated it, they'd still be second...

I looked at a whole lot of 747-8 flight test data showing Mach numbers above 0.99 during flutter testing (granted, not sure how accurate the instrumentation was at that speed). Never saw anything over 1.00, but surely it wouldn't have taken much to do it.

[chevvron]

But the Victor did go supersonic a few times (once with 4 Lightnings in tow) ; there was a thread on here about a year ago.

[VictorGolf]

Myth or not I heard the VC-10 supersonic story from an East African pilot. Apparently it was on an acceptance flight and the crew agreed to see "What will she do".True or not I still loved being SLF in their VC-10s.

[LOMCEVAK]

One consideration here, which has been mentioned briefly above, is true M versus indicated M. Static source errors and pitot errors are often very large in the transonic region so true M could be significantly greater or less than what is indicated. I know of one Tornado ADV trial during which the crew thought that they had remained subsonic but booms had been dropped over the Somerset levels and surrounding area!

I have seen about 0.97M in a Buccaneer (c. ISA -35C at low level) but would like to hear about someone going supersonic because tailplane power was very low at high M, hence why complete loops were not cleared in case you went too high M on the down vertical!

[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!

[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]

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]

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.