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AerBabe
18th Aug 2003, 00:20
Just returned from a great display at Redhill of the P51 Big Beautiful Doll (amongst other things). I keep meaning to ask, and keep forgetting to, what is responsible producing the high-pitched whine that makes your hair stand on end (those of us have have got some)? Airspeed seemed to be a factor, but then it did it again during a low pass.

Thanks, AB

Lowtimer
18th Aug 2003, 03:18
Wotcha, AB.

I've been told it's a peculiarity of the airflow across the open gun ports on the P-51D. Can't prove it one way or the other, but it's what I've heard. My observation is that it seems to come out strongly when pulling G, whereas there is no such effect in high speed level flight, makes this sound plausible to me, as only in high G manoeuvres will you get the stagnation point shifting down the leading edge in combination with high energy air flow, making an effect like blowing across the top of a beer bottle. I'll demonstrate with a beer-bottle when I see you, if you buy teh beer..

It sounds from your post as if the low pass to which you refer must have been at low speed, in which case the AoA would again have been high, perhaps creating teh effect even at 1g

Another bit of circumstantial evidence is that I don't remember hearing it at Reno when I attended some years ago, even though I was out at the pylons where they came round at very high speeds and quite a few G. All those Mustangs had the gun ports removed, or at the very least faired off to reduce drag.

AerBabe
18th Aug 2003, 04:01
Yo Lowtimer,

Yes, it did seem to coincide with G...

No need to demonstrate with the beer bottle - I play flute, remember? ;) However, if you could do it with a pint glass I'd buy you all the beer you could drink.

If your theory is correct, I presume one could alter the pitch of the sound generated, thus being able to play tunes by flying differently tuned aircraft past. Nice. :ok:

BEagle
18th Aug 2003, 04:32
The 'beer bottle effect' was used by a chum of my late father to interesting effect in WW2. This chap used to fly Stringbags and Albacores with the Fleet Air Arm; when bored over North Africa they'd look for an Arab campsite at night, climb up a bit and then throttle back before throwing out a beer bottle or two. Allegedly it sounded like a bombing attack and the poor old Arab's animal herds would leg it to all points of the compass, hotly pursued by cursing herdsmen!

Rotten $od!

LowNSlow
18th Aug 2003, 12:57
Didn't the Javelin have the "blue note" whistle across it's gun ports as well or was that the Hunter?

treadigraph
18th Aug 2003, 15:34
Usually hear it as the aircraft is pulling out of a dive or into a hardish turn, so the G factor sounds authentic. Sometimes they make little "peeps" of the noise as well... Perhaps Lomcevak could comment, he flies the things!

I always understood that it was the airflow through the radiator scoop, but I can't offer any scientific evidence for its defence! No matter, it sounds great: get yourself up to Flying Legends next year, Aer Babe, you should hear six or seven Mustangs in line astern making it! Makes the old hairs on the back of me neck stand to attention!

AerBabe
18th Aug 2003, 19:24
....found somewhere in Florida that's advertising $500/h... :ok:

BIG MISTER
19th Aug 2003, 00:30
$500 an hour........where ?.....do tell flower......I'm over there next month !

AerBabe
19th Aug 2003, 01:43
Sorry... I was having a bad brain day...
There is a place in Florida with a P51, but they don't advertise their prices, and haven't answered my email.
The place that's $500/hr is in California. :O
(And shall we have a bet as to where the hidden charges will be?)

BIG MISTER
19th Aug 2003, 04:14
Extra's........mmmm.......I dont know what you mean ! ! ! !

:}

So did you see much of the P51 from the beer tent then ?

:D :D :D

StbdD
19th Aug 2003, 05:29
http://www.stallion51.com/home.cfm

Kissimmee Gateway Airport (Orlando Area)

$2,750.00 per one hour fam ride. :ooh:

The rest of the info is on the website.

(I'm not connected with them in any way, just helping with the info as I can telephone them less expensively than others.) ;)

AerBabe
19th Aug 2003, 06:07
And $3,500 if you want training, ie. if you're planning on buying your own.

I must get a good job...
I must get a good job...
I must get a good job...
I must get a good job...
I must get a good job...

Airbedane
19th Aug 2003, 14:02
I always thought it was the raidator, too, but the gun ports do sound the obvious answer.

The Hunter and Meteor produce a fantastic noise through their respective gun holes. I've no 'hands on' experience of the latter, but the former could be sensed as a vibration in the cockpit at around 400kts, if I remember right, or was it 500 - it was a long time ago. However, I do remember that too fast or slow and the noise would go away - happy days.

No need to get a good job, AB, all you need is to be in the right place at the right time with the right experience and recognise the opertunity as it goes past. Certainly, Gary Newman and others like him have done it by getting a job with money, but there are far more pilots on the warbird scene who've got there by the method described above than otherwise.

Good Luck,
A

BIG MISTER
19th Aug 2003, 14:10
Thats quite a few beer tokens.......but I could do with trimming down ! ! !

Think I'll have to make do with something a little cheaper for a while yet till my 6 numbers come up !

Whats the going rate on a Chippy these days ?

:}

Maybe worth a look...........

www.spitfiresquadron.com


:} :} :}

andyb79
19th Aug 2003, 16:02
would be nice but 250hp and vne of 250 mph doesnt sound to original to me

BIG MISTER
19th Aug 2003, 16:10
No its not.....sadly.....but they say that its a 1-1 scale replica. theirs is currently being built in Oz.

There is a Merlin engine option....but if youve got the money for a 1500hp engine and servicing then I suggest your going to try and buy the real McCoy ?

:D

DragonRapide
21st Aug 2003, 01:23
Meteor "blue note" - I had a conversation a couple of years ago with Rod Dean who had been displaying the (Kennett?) Meteor F8 that has now gone overseas.

His enthusiastic (too enthusiastic, according to his engineer, apparently) routine produced a wonderful noise - I think I remember Rod saying that he thought it was produced by the cannon-shell ejection chutes that project from the underside of the Meteor's nose.

Really good routine, that - anybody else remember it?

LowNSlow
21st Aug 2003, 13:54
BIG MISTER I'll think you'll find it's not a 1:1 copy but an 80% scale replica made in OZ by Supermarine Aircraft and designed to take the new Jabiru flat 8 cylinder engine. This is what gives it the cowling like the Griffon engined Spits. I doubt VERY much there is a Merlin option on this........

250 mph Vne and 250 hp sounds reasonably affordable to me. OK it's not the real thing but it's damn close.

Looking at the War-Bird Squadron website. they seem to have an 80% scale Mustang as well. Anybody know where that comes from? Not wishing to denigrate their efforts but claiming that their "Spitfire" is a "rare, specially designed trainer / two seater" is stretching the point a bit as I think all these kit Spits are two seaters. The statement " A Group of Spitfire Enthusiasts have gained ex MOD Base to reform a Spitfire Sortie base" seems a bit of a fantasy as well. They could have used a cameraman with a steadier hand for the videos too.

Having just re-read the above, it sounds a bit whingey but you know what I mean ;)

Unwell_Raptor
21st Aug 2003, 16:24
Interesting. I had always understood that the Mustang howl came from the supercharger.

BIG MISTER
21st Aug 2003, 19:36
Low and Slow

I take your points re the 80% scale and the engine options and that was excatly what I said to them myself......having seen the same adverts for the 80% scale jobby in the magazines.

I can only report back what they said....its not 80% its 100% and the Merlin is on the options list too. Seems this is another animal.

proplover
21st Aug 2003, 20:14
Believe the U_R is correct about the distintive Mustang whine comming from the supercharger.

BeauMan
21st Aug 2003, 20:56
Low'n'Slow / BIG MISTER - I seem to recall reading about this in Pilot / Flyer / Today's Pilot (one of them, but can't remember which) about 18 months ago. The company that makes them are calling them Spitfire Mk25's (single seaters) and Mk26's (two seat), following on from the last original Spitfire mark. I think the kits were being marketed for about 45k USD, works out about 30k sterling. Certainly had me frantically trying to work out how much equity I'd got in the house and whether I could fit the kit into the garage. Probably one of the reasons why Mrs BeauMan soon became ex-Mrs BeauMan... :E

Re the Mustang blue note, I've always been under the impression that it's the airflow over the gunports. There are one or two 'stangs over here in the UK that don't have either open gunports or the slightly protruding stubs (ie, a clean leading edge) and they don't seem to whistle like the others do.

DragonRapide - I remember the Kennet Meteor (VZ467 G-METE, now flying at Temora in Oz) at one of the Duxford shows a couple of years ago, the only time I ever saw, or should that be HEARD, it fly. Absolutely amazing sound, utterly captivating. :ok:

LowNSlow
21st Aug 2003, 20:57
BIG MISTER they're talking Horlicks methinks. The picture of the cockpit in the gallery shows an original Spitfire cockpit with the articulated control column. The picture in the main blurb shows the 80% scale version with a solid column. Also the specs given for the Spit match the 80% version perfectly........a bit of a giveaway there I think. No Merlin going in that little baby.

Also the picture of the Mustang flying is a real Mustang, the one on the ground is a scale replica. The Me-109 is definitely a replica, check out the engine cowling.

I wish War-Bird Squadron luck but I was not impressed by their website generally due to the grammer, spelling, general layout and the seeming desire to create a bit of a false impression.

Finally, they also seem to be unable to produce the photos the right way around. Check out the reversed registrations.

It makes me wonder what colour the sky is over the War-Bird's base????

Beauman I'd forgotten that there was a single seater as well.

BIG MISTER
21st Aug 2003, 21:02
Theres no pulling the wool over your eyes is there !

:p

AerBabe
21st Aug 2003, 21:24
LowNSlow I was not impressed by their website generally due to the grammer :E

I am going to assume that was deliberate...


Airbedane - Instead of getting a good job, I shall spend all day hanging around Duxford instead.


BIGMISTER - You asked about Chippy rates... £140 ish an hour I believe. But if you want it cheaper, and can get to the Midlands, PM me.

LowNSlow
21st Aug 2003, 21:31
Ov korse it wuz AerBabe :rolleyes: :rolleyes:

Unfortunately at around 50,000 GBP plus sales tax and shipping the Spitfire Mk26 will remain a dream for me I'm afraid. Rats

Dr Illitout
22nd Aug 2003, 04:23
I always thought the whine was from the supercharger impeller, might be wrong though!!!.

proplover
28th Aug 2003, 01:22
Definatly the supercharger whinning, its geared from the crank and is proberble a 2 stage (for different heights) 2 speed blower. At low altitude for dispays I believe (I'm struggling to remember here) the supercharger is running at some 12500rpm.
Will find out from Mustang owner if its a critical 'must know' answer:ok:

146fixer
28th Aug 2003, 21:09
I think it could be super charger wine as well, they can make a bit of a noise.But I could be wrong.It could be a combination of serveral things you heard.:D

DamienB
28th Aug 2003, 22:39
LowNSlow -
Also the picture of the Mustang flying is a real Mustang, the one on the ground is a scale replica.

Unless they've changed the site since you looked, the flying shot is of the same aircraft as the static shot, and is definitely not a real Mustang - spinner is elongated and canopy out of scale (doesn't help that the picture is stretched to fit the wrong-sized space - not great web design).

BEagle
29th Aug 2003, 00:45
The Mustang sound isn't the same as the Meatbox 'blue note'. I remember 'Wingnut' turning up in VZ 467 'Winston' at Honington in 1976 and cracking the most superlative howl across the aerodrome!

Single seat Hunter blue note was best made at about 450 KIAS, idle thrust on a cold day. I know - 'cos I did that rejoining at Brawdy rather quicker (and a bit lower) than the FOB allowed which silenced the ground school lecture going on at the time. Someone then reminded me what the rules were......but agreed that it was indeed a wonderful noise!

Reichman
29th Aug 2003, 06:58
The high pitched howl from the Mustang is not from the supercharger, it is indeed from the gun ports. If you care to watch it carefully throughoput the display the note is affected by the angle of attack of the wing. ie it stops briefly during different manoeuvres.

The Daimler Benz powered Me 109 had a very distinctive howl which sounded completely different to a Merlin, and this was caused by the "blower".

LowNSlow
29th Aug 2003, 18:37
DamienB you're right. The stretching of the pic confused my befuddled bonce :ooh:

All criticism of the site aside, the baby Mustang does look interesting, wonder if there's a kit (LowNSlow slips dreming hat on :hmm: )? Ditto for the "109".

Reichman also agree with the howl from the DB powered 109. Fond memories of a visit to Duxford with my dad (ex-WW2 RAF on Halifaxes) being crowned by Black 6 putting on a mini-display. Dad's comment: "Last time I saw one of those little b*ggers it was spitting cannon shells at me".

proplover
29th Aug 2003, 20:11
Humble Pie time!!:{
Just checked with Mustang owner and .....it is the gun ports!!!:O
In straight and level flight there is no noise but as the aircraft turns the airflow over the gun ports changes. The example used was 'like blowing air over the open end of a bottle'. Mustangs with no gun ports do not emitt the whine. The note will change if the aircraft is pulled tighter ie the angle of attack changes.
So there we are! Should have checked first!!:uhoh:
Must get some sugar for this pie now.:ugh:

Synthetic
1st Sep 2003, 06:57
Not so fast with that pie C2, I also know someone with a substantial share in a P51 and he voted for the radiator.:confused:

When I saw the title of this thread, I thought someone had merged the Miles and Auster threads!!

fruitloop
1st Sep 2003, 15:59
Synthetic. I always thought it came from the rear of them (moderated radiator outlet)and it sounded more like a whistle then a whine.
Cheers

LowNSlow
1st Sep 2003, 18:52
Here's a solution:
1. Find a tame Mustang owner
2. Cover the gun ports with tape
3. Go for a whizz about and see if the "Blue Note" is apparent.
4. Repeat steps 1 -3 with open gun ports.

It makes more sense than trying to get a Mustang to fly with the radiator scoop balnked off :uhoh:

Good excuse for blagging a back seat ride I think :ok: :ok:

proplover
1st Sep 2003, 20:10
What my man said was that Mustang aircraft with no gun ports in the wings do not emite the whine - not sure if he would go for the ' I need to sit in the back of your Mustang whilst experimenting with your gun port appatures' line :hmm:

AerBabe
1st Sep 2003, 21:43
As a hopefully-soon-to-be-qualified researcher, I could bring myself to volunteer for the job of making sure all the angles had been covered. Negative controls, positive controls, repeated experimentation with various protocols, etc etc. It would be a tough job, but I don't mind doing it in the name of aviation...

DamienB
1st Sep 2003, 22:20
To throw a further suggestion in, asked a tame mate-of-a-P51-owner yesterday after he'd got out of the P51 he was flying in, and he reckoned it was the gun cartridge ejection slots making the noise... not the guns or the radiator or the supercharger.

Now can we broaden the discussion to figure out what it is on a CAP 232 that makes the same noise when it's in a high speed dive? Cos I don't think it's got guns... :D

treadigraph
1st Sep 2003, 23:12
It's probably the pilot in a CAP 232 :)

Can't say I'd ever noticed that one, but then every CAP 232 I've seen has been flying everywhichway but straight, usually with maximum deflection of the control surfaces.

AerBabe, in the interests of research do you plan to be strapped to the external parts of the Mustang so that you can place your shell-like close to the various appertures and hear which is indeed the guilty party? Now THAT would make the Utterly-Nutterlys look a bit tame!

Treadders

Synthetic
2nd Sep 2003, 07:08
I suspect that if I was flying in a CAP 232 - I would be whining!

AB - a question which has been at the back of my mind for a while - as someone who knows a little about fish and a little more about aerodynamics, is your personal title a tennable position?:ouch: