Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The de Havilland Comet

greatdisasters.co.uk

Post reply on HN
Print view View original

11–20 of 54 posts

Re: The de Havilland Comet

#11

Post by pjc50 »

arethuza wrote: post #7
NeedMoreTea wrote: post #6

I still think the Comet manages to look more futuristic than other civil planes. Something about the look of those engines in the wing roots with not a nacelle in sight. Such a shame it turned out to be doomed due to being first and the now well known metal fatigue story. The article, as with everything Comet related, ends with noting that lesson is why airliners now have very rounded windows. Yet none ever wonder or…

The Comet did go on in a military role as the Nimrod - I once saw an AEW Nimrod parked at the edge of RAF Kinloss - a staggeringly ugly beast: https://en.wikipedia.org/wiki/Hawker_Siddeley_Nimrod

They were an amazing example of a legacy system being maintained far beyond any reasonable expectation of life at gradually increasing cost, to a great extent because nobody could agree on a replacement and the one-off cost of a replacement was always a bit more than the endless "maintenance" and "refurbishment".

If I remember rightly the refurbishment project hit the problem that, because the original planes were hand-built to 1950s tolerances, building new parts off the original plans simply wouldn't fit. The only viable approach was measure the specific plane you wanted to fit, and build a custom part for it.

Eventually one simply caught fire in the air: https://www.telegraph.co.uk/news/1528109/Fire-was-reported-o...

The destruction of the airframes was controversial: https://www.bbc.co.uk/news/uk-england-12292390 but I see it as a symbolic driving of a stake through the heart of a project that should have been honorably retired a couple of decades previously but instead took on a vampiric, undead, and ultimately fatal life.

Re: The de Havilland Comet

#12

Post by na85 »

NeedMoreTea wrote: post #6

I still think the Comet manages to look more futuristic than other civil planes. Something about the look of those engines in the wing roots with not a nacelle in sight. Such a shame it turned out to be doomed due to being first and the now well known metal fatigue story. The article, as with everything Comet related, ends with noting that lesson is why airliners now have very rounded windows. Yet none ever wonder or…

>Yet none ever wonder or look at why cockpit windows remain decidedly rectangular. :)

Aerospace engineer here. It's not the shape of the window but the radius of the corner. A circle is just a square with large-radius corners, really, and it's the sharp corner that causes stress concentrations.

If you look closely at modern jet liner cockpit windows you'll see they are in fact still rounded at the corners.

Re: The de Havilland Comet

#13

Post by enriquto »

arethuza wrote: post #5
garethrees wrote: post #4

Earlier quoted context omitted.

The film was based on the novel "No Highway" (1948) by Nevil Shute, who had worked as an aeronautical engineer at De Havilland.

It's good that not all of Nevil Shute's predictions were so accurate: https://en.wikipedia.org/wiki/On_the_Beach_(novel)

How do you know? As far as it goes, this novel might be actually an accurate prediction (except for the year).

Re: The de Havilland Comet

#14

Post by dsfyu404ed »

The foreshadowing was obvious when they called out the square windows in the first few paragraphs. Everyone who's ever slept through an engineering class knows corners cause stress risers.

Re: The de Havilland Comet

#15

Post by detritus »

arethuza wrote: post #9
NeedMoreTea wrote: post #8

Earlier quoted context omitted.

Yeah but Nimrod was bloated, and positively covered with warts and radomes. I'd claim they spoilt the lines a tad. :)

The normal Nimrod's were quite handsome beasts - used to see them a lot when I was a kid as I grew up near Kinloss.

My school was right next to a runway (as in a couple of hundred metres at most) — whenever a Nimrod was taking off, class had to stop and wait for it to do its thing as there was simply no competing with it on volume. Loud buggers!

As with a lot of British war jets from the post War decades, there was something quite beautiful — almost organic — in their lines.

Re: The de Havilland Comet

#16

Post by TheOtherHobbes »

detritus wrote: post #15
arethuza wrote: post #9

Earlier quoted context omitted.

The normal Nimrod's were quite handsome beasts - used to see them a lot when I was a kid as I grew up near Kinloss.

My school was right next to a runway (as in a couple of hundred metres at most) — whenever a Nimrod was taking off, class had to stop and wait for it to do its thing as there was simply no competing with it on volume. Loud buggers! As with a lot of British war jets from the post War decades, there was something quite beautiful — almost organic — in their lines.

Concorde is still the most beautiful aircraft ever, IMO.

Re: The de Havilland Comet

#18

Post by arethuza »

detritus wrote: post #15
arethuza wrote: post #9

Earlier quoted context omitted.

The normal Nimrod's were quite handsome beasts - used to see them a lot when I was a kid as I grew up near Kinloss.

My school was right next to a runway (as in a couple of hundred metres at most) — whenever a Nimrod was taking off, class had to stop and wait for it to do its thing as there was simply no competing with it on volume. Loud buggers! As with a lot of British war jets from the post War decades, there was something quite beautiful — almost organic — in their lines.

I remember seeing a Vulcan bomber doing aerobatics over our wee Scottish village - quite a site and the noise was incredible.

Re: The de Havilland Comet

#19

Post by KineticLensman »

pjc50 wrote: post #11
arethuza wrote: post #7

Earlier quoted context omitted.

The Comet did go on in a military role as the Nimrod - I once saw an AEW Nimrod parked at the edge of RAF Kinloss - a staggeringly ugly beast: https://en.wikipedia.org/wiki/Hawker_Siddeley_Nimrod

They were an amazing example of a legacy system being maintained far beyond any reasonable expectation of life at gradually increasing cost, to a great extent because nobody could agree on a replacement and the one-off cost of a replacement was always a bit more than the endless "maintenance" and "refurbishment". If I remember rightly the refurbishment project hit the problem that, because the original planes were ha…

> Eventually one simply caught fire in the air

Full details in the Haddon Cave report [0], the official investigation into the crash of Nimrod MR2 aircraft XV230 in Afghanistan in 2006. The 'simply' here (as in 'simply' caught fire) was in fact a catalogue of known problems and missed opportunities. The Nimrod variant involved was originally intended to perform long-duration maritime surveillance and was designed to allow the crew to intentionally switch off one of the engines when the plane arrived on station (to save fuel while loitering for hours). To restart the engine there was a pipe routed through the fuselage that carried hot gases from the running engine to kick start the cold one.

A separate modification of the complicated tanks and plumbing that supported in-air refuelling led to a (leaky) fuel pipe that was routed right past the (very hot) engine cross-coupling pipe. Very minor leaks somewhere in the system were routine.

In this case there was a fuel leak near the engine cross-coupling pipe. The unfortunate crew of 14 had six minutes from initial fire warning to the eventual and unavoidable explosion that killed them all.

[0] https://www.gov.uk/government/publications/the-nimrod-review

Re: The de Havilland Comet

#20

Post by m-i-l »

detritus wrote: post #15
arethuza wrote: post #9

Earlier quoted context omitted.

The normal Nimrod's were quite handsome beasts - used to see them a lot when I was a kid as I grew up near Kinloss.

My school was right next to a runway (as in a couple of hundred metres at most) — whenever a Nimrod was taking off, class had to stop and wait for it to do its thing as there was simply no competing with it on volume. Loud buggers! As with a lot of British war jets from the post War decades, there was something quite beautiful — almost organic — in their lines.

They used to do low level flying training in my parts. On at least on occasion I was walking in the hills and got to look down on a stream of jet planes tearing through the valley below, which was quite something to behold (especially as a youngster). Seems like they publish the timetables now[0], so it may be possible to plan a walk to co-incide.

[0] https://www.gov.uk/government/publications/operational-low-f...

Post reply on HN