Jump to content

Virgin Atlantic 787 hits 800+ mph


Rimbo

Recommended Posts

7 minutes ago, hornimal said:

on an eastbound flight I hit 700+mph ground speed on a b737 catching a jetstream.  had it not been for the pilot making the announcement nobody would have had any idea.

Entering or exiting the core of a strong jet stream is usually pretty turbulent. 

700mph ground speed is really nothing special. In fact it’s pretty typical of West to East wintertime winds over the US. Given a TAS of 450 kts, or roughly .78M, and a 150 kt tailwind you’d be doing 700mph over the ground all day. 

However, exit a large area of fairly steady state winds and you’ll find rough air with the change in wind velocity and direction. Like leaving the jet stream. 

Edited by Bobby_Batronic
  • Like 1
Link to comment
Share on other sites

3 hours ago, RPM said:

What happens when they drop out of that tailwind? Is it a gentle reduction of wind or do you get slammed with a 200mph speed brake?

Generally when the speed drops of 30-50 knots over a short distance you get a rough ride, but the relative wind remains the same. Your ground speed just drops commiserate with the loss of tailwind. 

 

  • Like 1
Link to comment
Share on other sites

10 minutes ago, Bobby_Batronic said:

Entering or exiting the core of a strong jet stream is usually pretty turbulent. 

700mph ground speed is really nothing special. In fact it’s pretty typical of West to East wintertime winds over the US. Given a TAS of 450 kts, or roughly .78M, and a 150 kt tailwind you’d be doing 700mph over the ground all day. 

However, exit a large area of fairly steady state winds and you’ll find rough air with the change in wind velocity and direction. Like leaving the jet stream. 

Yeah right. Like anyone could actually know that. 

  • Like 2
Link to comment
Share on other sites

9 minutes ago, Bobby_Batronic said:

Entering or exiting the core of a strong jet stream is usually pretty turbulent. 

700mph ground speed is really nothing special. In fact it’s pretty typical of West to East wintertime winds over the US. Given a TAS of 450 kts, or roughly .78M, and a 150 kt tailwind you’d be doing 700mph over the ground all day. 

However, exit a large area of fairly steady state winds and you’ll find rough air with the change in wind velocity and direction. Like leaving the jet stream. 

I realized that while typing my reply I had deleted the note I made on my phone at the time with the exact speed, I was being conservative.  it must have been an impressive number, the crew mentioned they had never experienced that in all their years of experience.

Link to comment
Share on other sites

2 hours ago, Bobby_Batronic said:

My friend just posted a pic of his groundspeed on a flight from LA to Dulles in a 737. 623 knots of groundspeed while getting a TAS of  450 knots. 

So your saying its all relative. The plane didn't actually break the sound barrier? 

 

Link to comment
Share on other sites

It's not very efficient and it leaks fuel


It was pretty efficient given how fast it could roll, and it got better the higher Mach it was able to pull. Granted they did have to tanker right after takeoff (namely to give enough balanced field length and preserve the tires) and several times during the flight. What amazed me about it was how much propulsive work was pulled out of the careful management of the shock trap, bypass tubes, doors, nozzle, etc that effectively made it a ramjet at high speed.

Now Concordski couldn’t figure it out and I don’t think it had the legs to even do x-Atlantic, which I always found comical. Probably as they didn’t have the ability to get the inlet and nozzles figured out well like Concorde/SR-71...I think it could only stay supersonic wet.





/nerd post
Link to comment
Share on other sites

The unusual case of the plane being limited by aerodynamics/thermodynamics and not its motor. Concorde had the same issue to a degree.   

I always wondered how fast they actually managed to go in one. 

Concorde was also one of the saner flight deck layouts the Brits produced. They had some very interesting ideas about ergonomics  in everything from their fighters to their bombers and airliners. Maybe the frogs reeled them in a bit. 

Link to comment
Share on other sites

31 minutes ago, Parliament said:

Like what?

Oh, the general scattershotting of everything which wasn’t that uncommon back in the day. The VC10 looked like it had two extra sets of thrust levers next to the actual thrust levers. They were trim controls. The VC10 and Concorde had very large piano key styled autopilot controls. The entire center pedestal of the Vulcan was hinged at the top and lifted so that the crew could take their seats before putting the panel back in place. There’s tons more. I’ve been watching flightdeck tours of the Concorde, VC10, Vulcan, Buccaneer, Jaguar and others lately. Just very interesting ideas with regard to instrumentality and control placement. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×
×
  • Create New...