Plane / Planes / Aircraft / Aeroplane / Airplane appreciation

Pretty sure it is - origin of the Lincolnshire Poacher signal?

I helped at a careers event last year and was next to the RAF recruitment stand. Noticed the pilot was wearing an 84 Squadron t under his flying suit, so had a chat about Akrotiri. I got round to asking if there was still funny black gliders about the place, and although he didn't confirm (or deny), I was amazed to find out later it's still very much in service.

Went to Duxford a few years back to see the SR71 and the U2-C, really stunning to see close up. Much smaller than I was expecting!

I already have a copy, but if you're a certain kind of nerd - and, let's be honest, if you're on this thread you probably are - it's one of the best books on the Spit's technical development. Not much by way of narrative, just loads of crunchy data and tech info.

Er. Was there too for Flying Legends...

Looks pretty big to me. B^P

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Oh yeah - the section of that Iraqi super gun in the background was great to see (and unexpected!). Another nutty project going on in plain sight.

Space X.
An incredible thing, landings especially. But where does the sonic boom come form?
compressed air from engine thrust?
https://www.youtube.com/watch?v=kFfJrvOGojs&ab_channel=KyleGilson

But where does the sonic boom come form?

The vehicle is travelling at supersonic speed until the engine fires and decelerates it. Any object going through any fluid at a speed greater than the speed of sound in that fluid will generate one or more shock waves.

It also occurs a considerable length of time before it reaches the spectators. About 5 seconds per mile.

aagh So it's not anywhere near ground level, it is way above. Makes more sense

Looks like ~4.5 miles horizontally (educated guess at where it was shot from, could be even further away), so take into account the slant range and the sonic boom might be from about 25 seconds prior to hearing it, close to the start of the video.

Kinda weird to think sound travels that 'slow'.

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Still Thunderbirds cool. 😎

Interesting update from the place I had planned to get my licence a few years back (then work got busy)

After reading all available information that has been released from the UK CAA and EASA in the last couple of days, it transpires that if you want to hold an EASA Licence commencing January 1st 2021, then you will have to apply to convert your licence to another competent authority (country) before December 31st 2021. There will be no EASA recognition of any UK licences after December 31st 2020.

Yup, Britain quits EASA on that date. The CAA will have to take over everything. EASA is probably the best aviation authority in the world as regards safety and legislation, and we’re leaving it. Utter fucking madness.

Only really a problem if you regularly fly non UK registered EASA aircraft.

Not sure I am confident in the CAA's general ability to keep on top of things post brexit though...

Seen this: https://boomsupersonic.com/

First supersonic commercial plane in 50 years or something

https://en.wikipedia.org/wiki/Boom_Technology

Had a couple of these whizzing around today, some sort of exercise just offshore with a navy boat.

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Ryanair to buy 75 Boeing 737 max. Wonder what discount he is getting on that order?
Could be using some of the interest he made on the £1k that he held for me from March until August in refunds :)

SpaceX Starship SN8 test was very cool.

It's not flying, it's falling with style.

Wow! Seriously thunderbirds until t+6.42

Scott Manley described the green flame on landing as an "engine-rich burn". Ouch.

Lean burn vs rich burn are two different types of fule/oxygen mix scenarios for engines...maybe a reference to that? Rich burn is when just enough oxygen is provided for 100% fuel burn. Lean burn is when an excess amount of oxygen is provided.

https://www.gallois.be/ggmagazine_2013/gg_04_07_2013_148.pdf

"While lean‐burn gas engines are usually more
economical and powerful and operate at higher
loads, rich‐burn engines can achieve lower
emission levels with a single after treatment
and show a higher flexibility regarding transient
loads and ambient conditions"

Can highly recommend this book if you can find a copy. Its a bit chemistry nerd but funny too. Foreward by Issac Asimov.

https://www.amazon.co.uk/Ignition-Informal-Propellants-University-Classics/dp/0813595835

EDIT: Stand down, just saw that Elon Musk also recommended it.

Seem to recall the opening page is a photo of the rubble and remains of a fuel testing lab!

maybe a reference to that?

It's obviously a reference to lean/rich, but (and I haven't watched Scott yet) I imagine if he said "engine rich" he was trolling SpaceX by suggesting that it was burning more than a stoichiometric amount of engine 🙂

Yup, that was my point, which i obviosuly didnt make very well.

pdf of Ignition! hosted here, with the opening before/after photos;
http://www.sciencemadness.org/library/books/ignition.pdf