The 727 was designed to cruise at Mach .92, but then the 70s gas crunch hit and everybody throttled them back. Nobody throttled them back up after the crunch was over (Should have been a hint to Boeing regarding the Sonic Loser.......people do not want to pay more money to save a little time). I have flight test video of the 727 at mach .97. Somebody around here posted a pic of their 747 at mach .91 and it was shaking pretty badly.
Yes Moggie, will admit that that the VC10 is a fast aircraft...and indeed still in service with the RAF. Having said this, the TriStar was designed to cruise at M.865, and indeed did so for a very long time at the ME airline that I used to work for...rushing to the cheap fuel (then 18 US cents/gallon, at that time). Come to think of it, the TriStar is still used by a few pax aircarriers....something the VC10 can only dream about.
Having said this...the VC10, HS121 Trident (first autoland aircraft, least anyone forget), CV990...and the TriStar were designed when fuel prices were cheap(er)...and it was great to cruise faster.
Sorry a little long but probably worth to read !!!! Summary from an article on A/C performance
Now that Concorde has been retired, what is the fastest passenger aircraft in current service?
In a previous question about the fastest commercial airliners, it was pointed out that the supersonic Tu-144 and Concorde were the two fastest passenger aircraft flown to date. Now that both of those planes have been removed from service, there is no obvious record holder for fastest plane in commercial service. All current passenger aircraft cruise between Mach 0.8 and 0.85 with a maximum speed typically between Mach 0.85 and Mach 0.9. Nevertheless, I suspect that the current record holder, even if by the slimmest of margins, is probably the Boeing 747. We have previously discussed an aerodynamic principle called the area rule that describes how to minimize drag on an aircraft flying above Mach 0.8. In simple terms, the area rule states that the shape of the fuselage should be changed from the traditional tubular shape to more of an hourglass shape when the aircraft cruises in the vicinity of Mach 1. When both the fuselage and wing are added together, this layout creates a smooth distribution of the aircraft's cross-sectional area from the nose to the tail.
Effect of the area rule on overall vehicle shape This smooth distribution of area minimizes the likelihood of forming shock waves over the surface of the vehicle, which minimizes drag. Now take a look at the layout of the 747 and note the large bulbous region located atop the fuselage forward of the wing. This bulge contains the cockpit and upper passenger deck.
Boeing 747 This distinctive "hump" has the effect of giving the 747 fuselage a shape closer to the hourglass contour described earlier. As a result, the 747 experiences lower drag than a comparable airliner that lacks the bulged fuselage. The aircraft can therefore travel slightly faster than its competitors for the same amount of fuel. If we compare the maximum speeds of airliners, we find that the 747 is quoted as being capable of Mach 0.885 whereas most other airliners can go no faster than Mach 0.87. While the advantage is a small one, it does appear to give the Boeing 747 the distinction of being the fastest commercial airliner in service today.
I flew for an airline that had been of the main operators of the CV990, altho' it had been retired about 8 yrs when I joined. I knew many who had flown it, and it was cruised at 0.92, with Mmo 0.96. Obviously, fuel cost tuppence h'apenny a barrel pre-1973!
As per original design specs in good old mph terms:
Long Haul: CV 990 . High speed cruise worked out at 610 mph at 20,000ft , - Economical cruise 556 mph at 35,000 ft. (880 didnt have the streamlined wing fences and was about 10 mph slower). ATC folk will well remember some of the sporty performances of the 990 around Europe when operating for Spantax
Short Haul: Trident 1 high speed cruise at 27,000 ft was 605 mph and economical 596 at 30,000. I seem to remember though BEA early on advertising it as a 610 mph aircraft, presumably rounded out upwards to the nearest 10mph.