Aircraft General Discussion

[David Standing 1Participant @davidstanding1]

Posted by Andrew Johnston on 21/08/2017 19:19:28:

Good grief; just heard a whump, whump indicating a low flying helicopter. Then a Chinook flew past a few hundred yards away. I could just see it over the bungalows behind me, so he was seriously low. Judging fuselage length versus height probably less than 150ft. Apparently military helicopters are cleared to gound level over most of the UK. Good job there aren't any high voltage transmission lines in the immediate vicinity.

Andrew

Wattisham's Apaches use our area regularly for ultra low flying exercises.

Unfortunately one of them got a bit too low last year

**LINK**

[EugeneParticipant @eugene]

Neil,

Cader is on "The Mach Loop" a designated low flying area. "Mach" isn't a reference to speed, just a shortened version of Machynlleth, the nearest town.

Enthusiasts park themselves on the mountain and make videos to post on Youtube as per ….  https://www.youtube.com/watch?v=rB4HVn6Rnmk I tried to embed it, but it didn't want to play ball.

Just to one side of the lake is the Tyn y Cornel hotel; many a time had a lunch there watching the show. About half an hour from home when we lived in Wales.

Eug

 

Edited By Eugene on 30/08/2017 10:37:36

[martin perman 1Participant @martinperman1]

After returning from our anniversary lunch friends and family sat around a table outside and watched the Lysander and what I think was the Gladiator circling around Old Warden, I think they had a show on as there also seemed to be a display team but we couldn't it.

Martin P

[Cornish JackParticipant @cornishjack]

"There, but for the Grace of God… Some years ago, my flying instructor suggested a cross-country flight to Sywell for that day's lesson. As we approached their airfield, I saw a smoke trail cork-screwing up into the air. Which was when I remembered the NOTAM that I had read that morning advising that they had an international aerobatics competition on that day. "Executing steep banked turn… "

Interesting!!

In the 60s with CFS(H) we did S&R standby for the Arrows at Little Rissington for an anniversary display with many 'bigwigs' present. The display finished with the usual coloured upwards bomb-burst and, seconds later. a Glos Air tourer came steadily putt,putt, puttering through the residual smoke!! "Gosh, look at that – coloured clouds!!"

rgds

Bill

[Mike PooleParticipant @mikepoole82104]

Posted by Andrew Johnston on 21/08/2017 19:19:28:

Good grief; just heard a whump, whump indicating a low flying helicopter. Then a Chinook flew past a few hundred yards away. I could just see it over the bungalows behind me, so he was seriously low. Judging fuselage length versus height probably less than 150ft. Apparently military helicopters are cleared to gound level over most of the UK. Good job there aren't any high voltage transmission lines in the immediate vicinity.

Andrew

Living under the approach for RAF Benson having the house shake when a Chinook goes over is a regular treat. Low flying around the village is common as Chalgrove airfield is used for exercises. They often bring a machine over for the village fete and land on the school playing field which is surrounded by trees, they have brought a Merlin in the past when they still had them but now it is a Puma. The Merlin certainly kicked up a draught and blew all sorts of bits of tree all over the place.

Mike

[Fowlers FuryParticipant @fowlersfury]

"Apparently military helicopters are cleared to gound level over most of the UK" and "The Merlin certainly kicked up a draught and blew all sorts of bits of tree all over the place."

Can confirm both of those statements as this Merlin just about took our TV aerial off !!!

[MikeParticipant @mike89748]

Being close to RAF Lossiemouth, we do get the occasional visiting Chinook – surely the noisiest-ever helicopter? By contrast, the Eurofighter Typhoon is much quieter than the Tornado. I wish one would give me a really low fly-by!

[Tim StevensParticipant @timstevens64731]

The Chinook is, of course, two helicopters joined like Siamese twins, so it can be expected to be noisier.

Come to mid Wales, we get Chinooks and Herculeses at eye level. All the sheep line up to stare. And other stuff which goes too quick to identify.

Cheers, Tim

[Ian AbbottParticipant @ianabbott31222]

When we were in England for a while a few years ago, we lived on a farm just south of Dartmoor, built on high ground where we could look out over the valleys onto the moor. We were apparently right underneath a regular training route. Just about everything went over, twin (rear) engine jets with munitions pods, Chinooks, Merlins, Hawks, Typhoons and especially low, the C130s (and maybe an A400, I think), which came over us at treetop height before going down and across the field into the valley. We looked down onto them until they dipped right below the horizon. After half a minute or so, they'd climb out, following the contours up on to the high moor. According to the ordnance survey there is a bombing range on the north side of the moor right in line with where we were. There were more, particularly prop driven stuff that I didn't recognise.

The most "fun" was when a dark grey helicopter, couldn't tell what it was, we were otherwise occupied. Literally. That hovered directly over the roof with black clad people hanging out of the doors with heavy artillery, while other black clad individuals with automatic weapons surrounded us. Apparently, someone had broken into a farm a couple of miles away and among the stolen items was a shotgun. Just a shotgun. They were very polite and after they'd ascertained that we were ordinary people who had just climbed out of bed and wearing very little, they apologised and buggered off. The wife was quite smitten by the "very handsome and cute young men", while my attention was more focused on whether the safety's on the automatics were on or off…..

[Danny M2ZParticipant @dannym2z]

It's actually fun (when young and carefree) to hang out of the side door of a Chinook cranking along below the tree line with only a harness and an M60 between you and the dirt.

The best part was that I got paid to do it. So thank you taxpayers as it was much more fun than sitting in an office.

* Danny M *

[Clive HartlandParticipant @clivehartland94829]

One of my functions as attached to the Royal artillery was to take recruitment photos. Exercise time was best as it was quite, 'Warry' and photo opportunities presented themselves all the time particularly when live firing.

The visiting inspecting officer turned to me and said, 'You can use my helicopter if you like', So off I went in a Bell heli. the one with the round plexi-glass cab.

Quite exhilerating, my main task was to take photos of the guns under camouflage and it was so easy as they left tracks. When we arrived back at base the pilot raised my heart rate a bit as he came in low and skidded along at about 50 knots on the grass. I was using a Rolleiflex 2.8 F for B&W photos and I still have that camera. I used a Rolleiflex T3.5 for colour work.

Clive

[martin perman 1Participant @martinperman1]

Many years ago I used to volunteer at IWM Duxford and I went with a friend who was an ex Guardsman who spent most of his time in Northern Ireland, we used to be offered air experienced flights and on one occasion we had the opportunity to fly in a Helicopter, my friend refused the offer saying he had spent many hours carrying Westland Scouts on his back and that was enough experience.

Martin P

[Neil WyattModerator @neilwyatt]

Posted by Andrew Johnston on 21/08/2017 19:19:28:

Good grief; just heard a whump, whump indicating a low flying helicopter. Then a Chinook flew past a few hundred yards away. I could just see it over the bungalows behind me, so he was seriously low. Judging fuselage length versus height probably less than 150ft. Apparently military helicopters are cleared to gound level over most of the UK. Good job there aren't any high voltage transmission lines in the immediate vicinity.

Andrew

On went over us yesterday. I didn't see it but when the whump whump is accompanied by a feeling the house is moving sideways you know it's a low flying chinook!

[Fowlers FuryParticipant @fowlersfury]

No doubt known to everyone, but I understand the "whump whump" as Andrew describes it, is because the tips of the rotor blades on most helicopters are travelling faster than the speed of sound i.e. mini sonic booms.

I later joked with the navy pilot of that Merlin pictured skimming our roof (previous post):-

He related – whether true or not – that the Merlin was introduced as a 'quiet, stealth' attack 'copter but when put into service it could be heard ages before it was 'in visual'. The spades on the ends of the blades were an unsuccessful attempt to quieten it.

Correction or elaboration welcomed !

[martin perman 1Participant @martinperman1]

If your refering to the Chinook I have always been led to believe its the aerodynamic collision between the fore and aft rotors.

 

Martin P

Edited By martin perman on 05/09/2017 21:25:25

[DrDaveParticipant @drdave]

Posted by Fowlers Fury on 05/09/2017 21:14:54:

No doubt known to everyone, but I understand the "whump whump" as Andrew describes it, is because the tips of the rotor blades on most helicopters are travelling faster than the speed of sound i.e. mini sonic booms.

The tips do not go supersonic on a helicopter, it is the interaction between main & tail (or both mains, as Martin said) that causes the characteristic noise. When a helicopter is flying at a high airspeed, the retreating blade tip is often going "backwards" through the air: I thought that the "spades" were an attempt to improve the chaotic aerodynamics this causes.

[Fowlers FuryParticipant @fowlersfury]

Thanks, a couple of minutes first on Google would have corrected my misunderstanding. Herewith a definitive sounding analysis:-

"The characteristic beat of a helicopter rotor is caused by the interaction between the rotor blade vortices, in particular between the main rotor and the tail rotor vortices. As the shockwaves of these impulses coincide, they create powerful (loud) harmonics. This effect can occur at rotor speeds well below supersonic. The vortex interaction can be reduced by surrounding (a smaller, multi-bladed) tail rotor – more like a fan – with a shroud. Such an installation is called a fenestron ("windowed", and actually a trademark belonging to Eurocopter), a ducted fan or fan-in-fin. This development was originally designed for improved safety and performance. Modifications to the main rotor to reduce the impulse from the vortex typically trade away power or economy. On the topic of supersonic speed, helicopters have a theoretical top speed of 417 kph in conventional flight mode because of the problem of the advancing blade reaching supersonic speed over too great an area and the retreating blade losing lift abruptly."

[DrDaveParticipant @drdave]

Thanks for the definitive explanation of the source of helicopter blade noise, FF. My helicopter knowledge was learnt 30 years ago when I worked on the Puma. And it was not a young aircraft then! The technology of rotor blades has moved on a bit.

I still remember being "self-loading ballast" for an envelope expansion flight in one of the test Pumas: a maximum rate turn at low airspeed sure shakes your teeth fillings. Strangly, I didn't take the offer of a second flight….

[Nick_GParticipant @nick_g]

.

Documentary about the P38 lightning (mostly interviews / stories with pilots) Quite long at 1 1/2 hours ish but well worth a watch.

Nick

[Fowlers FuryParticipant @fowlersfury]

Thanks for pointing out the P-38 vid; I've only watched about 10 minutes so far but the hyperbole didn't seem to tally with other assessments I'd read. There is a "History Net" article entitled "Why the P-38 Flunked in Europe".

http://www.historynet.com/p-38-flunked-europe.htm

It makes interesting reading IMHO……..especially that it was thought fitting it with Merlins would have transformed it's effectiveness in Europe. Undoubtedly it operated well enough in the Pacific theatre.

I'll watch the entire vid later and probably find it makes the same point !

[Anonymous]

Pretty awful weather today with heavy showers and rumbles of thunder. But at work this afternoon I heard something out of the ordinary. Rushed out to see the Flying Fortress go over, quite low, not much more than 1000 feet.

Andrew

[Fowlers FuryParticipant @fowlersfury]

Would have been en route to "The Victory Show" over this w/end:-

**LINK**b

"B-17 Flying Fortress – Sally B Flying Sunday 10th only

Europe's only Flying Fortress Sally B defies the odds and flies into her 42nd Season

One of aviation's most remarkable stories continues for an astonishing forty-second time this season as Sally B, the only airworthy Boeing B-17 Flying Fortress in Europe embarks on another Air Display season, a feat which has been described as 'impossible'. "

[Nick_GParticipant @nick_g]

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Somebody is a lucky boy.!

**LINK**

Nick

[Mike PooleParticipant @mikepoole82104]

Two unusual things this afternoon, me gardening and an Apache flies over on Benson approach.

Mike

[Neil WyattModerator @neilwyatt]

Posted by Nick_G on 12/09/2017 19:17:56:

.

Somebody is a lucky boy.!

**LINK**

Nick

That's the most impressive bit of parking I've ever seen.

Neil

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