Fast Flying
 

My Mother just left for Denver after a 27 hour delay due to maintenance issues on an A319. I just looked up the flight in FlightAware and the pilot is Hauling Ass into Denver at almost 600mph.. Airframe max speed for an a319 is .82 mach, they are at .92.. I'll be interested to talk with her when she lands..

http://forums.pelicanparts.com/uploa...1415813138.jpg

He has a big tailwind, thus a big groundspeed. He is not exceeding the airplane's max Mach number but he's probably up close to it. He too had an unplanned overnight because of the mechanical issue and he wants to get home.

Full disclosure: 737 airline copilot 16+ years, ten before that in the KC-135R and others.

Is that ground speed or TAS?

Nevermind.

Says GS in MPH.

hit 609 groundspeed

That's one hell of a SE Tailwind..

http://forums.pelicanparts.com/uploa...1415813960.jpg

Yep, Winds aloft over 80 kts along the flight path

http://forums.pelicanparts.com/uploa...1415814155.jpg

It's that time of year. I was 35" early into DFW from SEA yesterday. Over 500 GS most of the way, ECON cruise in the box (FMC) which, with that wind at 35,000 and 37,000 meant a Mach number in the .75 region. Longer drive home though.

African or European Airbus?
(reference to a monty python joke)

Is she flying West, then the time zone gives change gives him an extra hour or two, which makes the speeds look crazy !......................... just kidding

Slightly off topic - I fly a lot (for me) these days, and recently a USAir pilot stated that due to the delay at the gate he had requested more fuel and would still probably get us to our gate on time, which in fact he did.

Is that common? And why not do so all the time - wouldn't it allow greater utilization of the aircraft?

I'm sure they wouldn't purchase anymore fuel then necessary. If they can save money somewhere they will.

No I get that they don't want to waste fuel, but if they can get their faster than the next guy, or can get an extra flight per day from the aircraft, wouldn't they be saving $$?

In the airline business the best bean-counters are expert at making one penny stretch into 50 feet of copper wire.

Your USAir pilot added fuel for his own reasons, perhaps possible ATC delay at the destination or weather considerations. Maybe even for added speed but that would be hard to justify with the dispatcher unless the dispatcher was okay with it.

Several variables here, in my experience. It's hard to make up that much time--enough to utilize the airplane again in a day. It really does boil down to cost. Whatever the cost advantage is usually controls the decision. If adding fuel (more weight/more cost) results in more pad for ATC or weather delays (flow control) then that is an acceptable cost. Getting ahead of other aircraft can be done but ATC, in my experience, is usually hip to that and will slow you down so as to keep the flow into the destination steady and manageable. If the destination is a low traffic airport then they might let you go fast. Bottom line is cost. COST, COST, COST. If the final cost outcome, the best one, means add fuel and fly faster then that's what we'll do. If it means fly normally even though you're late then you fly slowly. "Slowly" being an average Econ mode in the FMC. They crunch the cost and then decide which method is most advantageous overall and pass it along to the captain. He can still fly a little faster if he wants to, 'captain's authority' to some extent, but he might have to defend that later on.

Cost control explains much of our daily lives. In the airline business it explains absolutely everything down to the last cent. Distill a situation long enough and cost control is the final result.

Thanks for the info - much appreciated!

I saw that right after I posted. Left it in anyway.

There is more to consider than fuel cost as well, increase your speeds in flight works your engines harder, which makes for much more expensive maintenance costs

By the way, 80 knot winds at altitude this time of year are normal. It's not uncommon at all to have a 160 knot jetstream wind in the fall and winter months, with occasional numbers near 180 knots. I've seen groundspeeds in the 650 knot range on a few occasions, while cruising at a normal speed of around 480 knots True Airspeed. That's about 750 statute mph groundspeed.

Not quite. IAS (Indicated airspeed) is probably normal or slightly lower actually. IAS works off of ram air or what the airplanes 'feels' as it going through the air and if you have a huge tailwind, IAS will usually read lower than normal because there is less air pressure in front of the airplane if that makes sense. GS (Ground Speed) is of course much higher and TAS (True Air Speed) is "normalized' for different factors. So while they are doing 600 mph in GS they are probably only indicating .76/.77 or so. It will never read faster than the airplane can go in smooth air. My record GS is 752 in a Citation X, which normally goes .92.

With what Air Refueling Wing did you fly?
I was with the 93rd Bomb Wing at Castle AFB, CA - mid 60's.
.
BTW, ever wish that KC-135 tanker had parachutes & ejection seats?