wilco737 From Greenland, joined Jun 2004, 8753 posts, RR: 77 Reply 2, posted (2 years 7 months 1 day 17 hours ago) and read 14922 times:
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The 744 has a design speed of Mach 0.85, the 748 0.855. So pretty close. I don't know about the Mmo of the 380, but I did 0.88 last week in the 744. Very shortly of course. Some wind change made the speed increase to almost Mmo 0.90...
Wingscrubber From UK - England, joined Sep 2001, 840 posts, RR: 0 Reply 15, posted (2 years 7 months 1 day 8 hours ago) and read 14410 times:
Quoting B777LRF (Reply 11): Nope, as previously mentioned it's the Space Ship Two. It's got wings and it will fly with fare paying passengers thus ticking all the boxes for "civil aircraft".
I think the words 'space ship' disqualify it as being 'an aircraft', as that is just one phase of its mission. Otherwise you would be justified in saying that the Sea Dart, or maybe an Apollo capsule, is the worlds fastest boat...
Gulfstream are going to claim the 'worlds fastest bizjet' title by certifying to mach 0.005 faster than the X, and they claim they hold a record for their Mach 0.995 dive test, but the Citation X supposedly hit mach 1.18 by accident, during its own dive testing, but I don't think it stands as a record as there was no independant adjudication when it happened, just some slightly astonished flight test engineers, I think.
Nonetheless, I think Cessna plans to retake the MMO record from the G650 with the 'Ten' eventually, as a difference of Mach 0.005 only equates to about 3 knots, so they can just bump up the MMO 6 knots to Mach 0.93.
RoseFlyer From United States of America, joined Feb 2004, 9134 posts, RR: 52 Reply 16, posted (2 years 7 months 1 day 7 hours ago) and read 14320 times:
While only still flying for the UK Air Force, in the subsonic Airliner world, I believe the VC10 was the fastest with a cruise speed of Mach 0.886. The speed was partially its downfall because of its fuel burn exceeded the 707-320s that it was competing against.
If you have never designed an airplane part before, let the real designers do the work!
Based on the various answers that have been given, it is obvious that the question does not have a definitite answer because of the various assumptions that can be made. For instance:
Do the airplanes have to be in current production only?
Or can they be previous production?
Do they have to be operating today? What if they no longer are flown?
Does the plane have to be certified to be considered? (The Gulfstream 650 isn't certified yet).
Is the fastest speed based on the design speed Mmo as found on the TCDS? Or is the fastest speed based on the Md speed required for certification?
Or is it the speed that it inadvertently went to during testing (beyond the requirements)?
Does civil include military models that are now operated under a civil registry?
imiakhtar From , joined Dec 1969, posts, RR: Reply 21, posted (2 years 7 months 1 day 1 hour ago) and read 13996 times:
Quoting RoseFlyer (Reply 16): While only still flying for the UK Air Force, in the subsonic Airliner world, I believe the VC10 was the fastest with a cruise speed of Mach 0.886. The speed was partially its downfall because of its fuel burn exceeded the 707-320s that it was competing against.
When my uncle flew them in the 70s, they typically operated them in the .84-88M range.
I recall him mentioning that they would regularly cruise at .93M during ferry/repositioning flights, though to do so they would have to pull a number of circuit breakers.
One of the few advantages the VC-10 had over the 707 was it's superb field performance. NBO-LHR on a hot summers day never an issue. The B707 and early 747 variants would struggle.
My uncle would often laugh at his ex PAF pals struggling out of the mid-east in their PK 707s.