Posts by user "tdracer" [Posts: 14 Total up-votes: 0 Page: 1 of 1]¶

Many years ago, I'd flown into Heathrow (after a horrible flight - a 6+ hour delay after pushback at JFK due to weather). I was in line to pick up my rental car when suddenly there was this horrendous noise - a "can't hear yourself think" noise. The strange part was no one else even seemed to notice . I turned and looked outside, and there was a Concord on it's takeoff run in full afterburner . It was the only time I was able to see a Concord moving under it's own power .

No idea what tail number it is, but there is a Concord at the Seattle Museum of Flight. First time I walked inside I was stunned at how small it was. The windows are tiny, and the seats would not appear out-of-place in economy on todays international flights. The cockpit is blocked off with clear Plexiglas, but looked decidedly primitive by todays (or even 1980's) standards. No doubt the cabin service was top notch, and there is definitely a luxury in making a six hour flight in two hours. But it's also not hard to understand why it wasn't a commercial success .

But I sure wish I'd had the opportunity to fly on one

Sorry, I blame spell check

BA was able to make money on Concorde as in positive cash flow. But they were basically given the airplanes. The commercial failure aspect comes from the simple fact that no one wanted them to build any more (what I've heard is that at least one production Concorde was built but never put into service - basically becoming a donor for spares - not sure if that's true). I also suspect it was too much of a point design - it didn't have the range to be useful in the Pacific.

If BA (and Air France) honestly thought Concorde was a profit center (rather than brand prestige), they would have wanted more .

BTW, my comments about the flight deck were not intended as criticism - no doubt it was state of the art when it was designed. I was just commenting on how much things have changed since then.

I don't mean to dispute that the Concorde was an incredible airplane and engineering achievement. Just saying that it never really had a chance to be successful. The same thing would have applied to the Boeing SST if it hadn't been cancelled (I knew a guy that worked on the Boeing SST inlet control system - talk about complex ). Cancelling the SST is probably the best thing that ever happened to Boeing - it likely would have bankrupted the company.

The Concorde and Boeing SST business cases were built on a couple flawed assumptions.

First, jet fuel would remain dirt cheap and the higher fuel burn of supersonic travel not contribute significantly to cost of operation - which was blown out of the water by the first Arab oil embargo.

Second, that the majority of demand for air travel would remain for the 'premium' product - basically that the majority of people would happily pay a premium to get there faster. This assumption applied to most people who flew on jets in the 1960's - either business travelers or well to do people that weren't that worried about what it cost.
Reality was it went the opposite direction - a shift that started with the 747 and other widebodies. The economies of the wide body aircraft lowered the cost of air travel to the 'everybody' level. Suddenly there was a whole new class of air traveler - people for whom an extra $100 airfare meant they just wouldn't go, never mind that they'd get there in half the time. In short, they didn't foresee air travel becoming just another commodity - the low cost trend that continues today.

The reality was, both the Concorde and the SST needed to sell hundreds of copies to even begin to justify the development costs. The evolution of air travel into a low cost commodity, combined with the rising costs of jet fuel, insured that would never happen.

Airbus/Boeing FBW systems use hardened versions of obsolete commodity hardware - the suppliers won't stop making them as long as there's a demand.

IC Part obsolescence is actually a big problem in aviation - our market is too small to justify keeping these components in production when they are decades obsolete in consumer products.
The best option is 'life time buys' - where the vendor stockpiles what they hope is a life time supply of the critical components (IC chips, ASICS, basically any logic devices). Of course, life time buys are not foolproof - not only is it dependent on accurate forecasts of need, but other things go wrong - crates go missing, warehouses burn down, bean counters dispose of what they think is excess inventory, etc.
The second option is to periodically certify hardware packages where they update components and re-certify. This is difficult and expensive - it takes extensive testing and analysis - even subtle changes in things like throughput timing can turn a digital system on it's ear. But it is done (in the last 10 years or so we've had FADEC parts obsolescence updates on both the PW4000/94" and CF6-80C2 FADEC controls - which date back to the mid 1980s).
The third option is just do a clean sheet of paper new device - really expensive and difficult, and often means having to update the associated s/w as well (this is what Pratt did with the PW2000 FADEC, coming out with completely new control - hardware and s/w - around 1995 to replace the original that dated back to about 1980).


But in the end the airplanes keep flying

If memory serves, the Concorde at the Seattle Museum of Flight has engines (or at least something that looks like engines).
It also has an interior and flight deck - visitors are allowed to walk through the passenger portion of the aircraft (can't comment on the completeness of the flight deck since there is a big chunk of Plexiglas preventing close inspection).

Decent article at Smithsonian.com with a brief history of Concorde and the crash that doomed it.
https://www.smithsonianmag.com/smith...M4MDQ0MDUyNwS2

Short answer is no. The advances in material technologies and manufacturing methods since the Concorde was designed would make a clean sheet design a much better and easier (read cheaper) to build aircraft.
Further, changes in the regulations/cert requirements would make it very difficult (if not impossible) to certify not just a Concorde clone but any future SST. I honestly don't know how any aircraft can meet the existing Part 25 depressurization requirements when operating at SST altitudes.

Pattern, I didn't bother to address the viability question, but unless there is a massive technological breakthrough we're not going to see another commercial SST. The costs and fuel burn of an SST compared to a conventional subsonic airliner make the potential number of paying passengers too small for it to be economically viable. There simply are not that many people who are willing and able to pay a massive price premium to save a couple hours of flight time. No matter how efficient the engines and the airframe, fuel burn is always going to be much higher going supersonic (as one of my college professors put it, 'it takes a lot of energy to break windows ten miles below'), and the stresses of supersonic flight mean high maintenance costs.
The one possibility for a future supersonic passenger aircraft is for a (relatively) small biz jet. Something targeted for the super rich who are willing and able to pay a huge premium to save a few hours (I'm talking about the sort of people who have a 747 as their private jet). The business case would have to assume a small production run (less than 100 aircraft) meaning the massive nonrecurring development and certification costs would need to be spread over a correspondingly small number of sales. On the plus side, the biz jet regulations are somewhat more forgiving than those for large commercial aircraft (i.e. Part 25).

Since we're on the subject of Concorde, I was watching an "Air Disasters' episode last weekend that touched on the Paris Concorde crash.

It got me thinking - what was the final straw that led to the crash? Was a very heavy Concorde unable to maintain altitude with two engines out? Or did the raging fire do critical flight control damage? Combination there of?

Perhaps I wasn't completely clear in my question - I'm not questioning the crew's actions in any way. They knew they were in deep trouble and were looking to set the aircraft down again at another airport but were unable to maintain sufficient altitude and crash.
My question is why couldn't they maintain altitude - not enough thrust or fire related flight control damage (or some combination thereof).

Stumbled on an interesting program on the TV last night - "Concorde - The Untold Story"
Two-part program (one hour each - closer to 45 minutes after commercials) but shown back-to-back. A good history of the three country 'race' to build a commercial SST, with what ultimately happened with the Boeing 2707 and Tupolev 144 (including how fitting the "Concordski" nickname was given the level of Soviet espionage that went on to steal Concorde technology so they could make the thing work).
A bit simplistic in some of the explanations of the technology and such, but understandable given that most people who watch won't have Aerospace Engineering degrees
Produced by MTV, at least on this side of the pond it's being shown on The Smithsonian Channel.
Hopefully it'll be made available on other sources for those who don't get Smithsonian.

A problem with Concorde was that its stall speed was quite high - well above 200 knots. An emergency landing in a field (gear down) is not apt to end well going that fast with a full load of fuel and an aircraft already on fire (granted, perhaps better than what ultimately happened, but a 'damned if you do - damned if you don't' choice at best). They reportedly tried to raise the gear (which would have helped reduce drag greatly) but the damage already done prevented that.
In 20-20 hindsight, I suspect they would have been better off to not shutdown the engine with the fire warning (#2?) and use whatever thrust they could still get from it to try to make another airfield, but something that would be next to impossible to realize real-time. The rapidly spready fire damage may well have made it a moot point anyway.

Concorde engine sells on ebay:
Concorde Engine Finally Sells On eBay, Afterburner Included (msn.com)

​​​​​​​