concorde?

[CupCrusher40]

too fast, safe expensive?

[SoCalFlyer97]

I have no knowledge of this retired aircraft. Thus, can't opine. However, Wikipedia has a section documenting why it was retired. According to the docs, this aircraft appeared to be an expensive, very noisy gas guzzler of a jet:

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

Concorde had considerable difficulties that led to its dismal sales performance. Costs had spiralled during development to more than six times the original projections, arriving at a unit cost of £23 million in 1977 (equivalent to £152.02 million in 2021).[38] Its sonic boom made travelling supersonically over land impossible without causing complaints from citizens.[39] World events had also dampened Concorde sales prospects; the 1973–74 stock market crash and the 1973 oil crisis had made many airlines cautious about aircraft with high fuel consumption rates, and new wide-body aircraft, such as the Boeing 747, had recently made subsonic aircraft significantly more efficient and presented a low-risk option for airlines.[40] While carrying a full load, Concorde achieved 15.8 passenger miles per gallon of fuel, while the Boeing 707 reached 33.3 pm/g, the Boeing 747 46.4 pm/g, and the McDonnell Douglas DC-10 53.6 pm/g.[41] An emerging trend in the industry in favour of cheaper airline tickets had also caused airlines such as Qantas to question Concorde's market suitability.

Wiki Source Ref
38. Marston, Paul (16 August 2000). "Is this the end of the Concorde dream?".

The Daily Telegraph.
39. "Concordes limited to 16". Virgin Islands Daily News.

5 June 1976.
40. The Concorde Compromise: The Politics of Decision-making.,

Ross 1978 pp. 47–49.

[dfwskier]

I'd suggest you ask the companies that flew it: Air France and British Airways.

[DancingDavidE]

The biggest value was in going supersonic, if there were enough people wanting to save a couple of hours that would pay extra for it, then it made sense.

Timing was probably an issue - right now many flights leave Chicago in the evening and arrive in Europe in the morning - there wouldn't be much benefit to going faster as you'd just be showing up in the wee early morning over there. I don't 

The sonic boom was a major downside and environmental regulations limited ability to fly that fast in the USA or over Europe and limited the time this was useful.

Friction goes up with the square of speed so going Mach 2 would be ~3 times as fast as air travel today but 9x the friction/drag. It was said that a Concorde carrying 100 people used as much fuel as a 747 carrying 4x as many passengers.

Due to the drag the Concorde also burned fuel that quickly, I don't think it had larger fuel tank to compensate so it was limited to fly from Europe to North and South America, or the Middle East, it couldn't do long-haul flights like the 747 going from Europe to the USA West Coast. 

I believe maintenance was a pain as well - in addition to the poor fuel economy due to friction going up as a square function of speed that speed/power also introduces stress and heat on all the components requiring more maintenance. 

There weren't enough airlines interested to fly it and charge enough to cover the costs, so the fleet of them was retired.

There is a story about a round the world trip in a day where the sun never sets on the Concorde as it went from Europe, through Mexico, to Hawaii, Guam, Middle East and back to Europe in 32 hours.

The trip from Paris or London would land in NYC "before it took off" in time for business meetings the same day.

[floridaguy]

Kinda like the Mercedes E63 AMG.  It is a lot of fun, but not that practical when you consider the cost and the basic maintenance.

Yes, I do own one and it is fun, but not cheap.

[CupCrusher40]

nasa has ideas for a 30 minute flight which usually takes 12 hours at 150,000 feet.

Fingers crossed