I live somewhat near a military base and a few times per week what I believe is a C-5 Galaxy passes over my house just a few hundred feet above the ground.

First time I experienced it I thought for sure a plane was about to crash into my house. Occasional I still get that feeling. It's loud as **** and even causes the trees to sway slightly.

Tho it is fun to watch the reaction of friends and family when they experience it for the first time.

W0X0F doesn't live to far from me and can probably correct me if I have the plane wrong. If it isn't a C-5, its ****ing big.

There are three variables in fuel consumption: drag, weight, and engine efficiency.

Drag is a characteristic of the airplane design, so the airline doesn't have a lot of control over that. The same applies to engine efficiency.

Weight can be managed somewhat with efficient fuel planning, i.e. not carrying more than is necessary (i.e. tankering fuel). It's cost fuel to carry fuel, so we have certain exemptions, based on forecast weather, that allow us to carry less fuel than would be required under a strict interpretation of the FARs.

Another procedure used, especially on flights across the ocean, is to have a re-dispatch point along the route. So, for example, if the destination is Moscow, we might actually have a different destination on the flight plan. At some point, maybe 20 West longitude, we get a message from our dispatcher to make sure we have some minimum amount of fuel on board. If we do have at least that amount of fuel, we change our destination to Moscow and continue on our way. In this way, we are able to take less fuel than would be required, with weather reserves, to make it to Moscow without this procedure. (That's probably not all that clear and I'm sure my explanation is not exactly how a dispatcher would put it, but it's all about carrying less fuel and therefore less weight.)

You wouldn't see it doing 500+ mph that low. The red line on the MD-88 is around 350 kts. We never see 500 indicated on the airspeed indicator. When we are at altitude doing, say, 450 kts, the airspeed indicator is showing something around 260 kts. That's because the airspeed indicator is really registering ram air pressure.

Still, doing 350 kts down low would be impressive. I'd like to try it sometime, but it would be my last flight.

American Airlines had bare metal planes for years, but they've recently changed their livery, which includes full airframe paint like most other airlines. It would be interesting to know what difference this has made for them.

Winglets do improve efficiency, but they are also extra weight. On the 767, the winglets are about 13 feet high (iirc) and I'm sure they weigh several hundred pounds. There's a breakeven point on the flight where the fuel efficiency exceeds the fuel penalty of carrying that weight.

There are different kinds of winglets and Southwest is now getting a "split scimitar" winglet on their 737's. Here's an interesting link about winglets.

The C-5 is a big one (still the biggest plane the U.S. military flies, I think). But the only base for that anywhere in the area is Dover AFB and I can't imagine you live close to that, so I really can't imagine what you've been seeing.

So wait, that means at least some of the time you don't reach Moscow and need to land elsewhere? How do you sell that to the passengers?

This is really interesting and you explained it perfectly imo. I had no prior knowledge if this. Just another example if why this thread is so great.
I know you would never actually fly cruising speeds that low. I was more hoping somebody has seen a video of some sort that has been edited or animated to demonstrate what that speed looks like when not 35k feet up. The conversation went "it's cool how it looks like that plane is barely moving, I wonder how fast it is going" - "pretty damn fast. If you could see it at street level you would miss it if you blinked."

I guess the closest example we have video of is the bullet trains going 300mph.

Coasterbrad, is something like this what you're looking for?

If you type in 'high speed low pass' on youtube you can easily waste a few hours of your life. Watching jets break the sound barrier at low altitude never gets old.



The one at 1:44... WTF!

Awesome videos. They both help get the point across and that second one has some incredible footage. Thanks for finding them.

I've never heard of it happening, though I guess it must have sometime. I was seeing this practice more and more in my last couple of years flying international and we were never even close to the minimum fuel required when we reached the redispatch point. This is just a dispatch procedure which allows us to legally takeoff with less fuel than the strict interpretation of the regulations would require. The only way a divert would happen is if the winds aloft were much, much worse than forecast.

Seriously. Lunatic.

Wouldn't power setting also be one?

Go to an air show with the Thunderbirds or Blue Angels. They usually do a maneuver at around 500 mph at fairly low altitude..

Yes it would be. I guess I was thinking of the things which affect fuel efficiency with operation at "normal" power settings. We don't actually look for a specific power setting in cruise flight (though we definitely do for takeoff); it follows as a result of the target cruise airspeed the dispatcher had planned.

In the MD-88, we usually plan for around .76 mach. This would be on the slow side for the 757, which is usually flight planned for .77 to .79 mach. The 747 flies even faster on typical flights. For each type, there is a speed that gives the best fuel efficiency and in most cases that's the speed that is used. On rare occasions, shaving some time is deemed worth the extra fuel that is used to achieve it.

Delta just took delivery of two B739s with split scimitars, presumably more on the way. United and Alaska also have some (though I think they have them on -800s). SWA has them on both -700 and -800 iirc.

Does the mile high club really exist? If yes, what kind of extravagant behavior have you witnessed?

Fit to fly?

Look at the first few pages where the subject was covered and put to rest.

Just came across this NTSB report, thought I'd share...

http://www.ntsb.gov/_layouts/ntsb.av...12X18632&key=1

Are you allowed to choose your flight level? My understanding is the most efficient setup is to have control surfaces "flat" and determine altitude with your speed.

Needless to say I was a little surprised to look over and see this right around takeoff on my flight today:



Apparently it's an emotional support animal. A friend of mine who's an airline stewardess said she's seen pigs and mini-horses. Have you been seeing a lot of this?

I went the Australian F1 Grand Prix last month and Qantas did a display with a 747. I was surprised how manuverable that thing was. Pilot did some amazing turns. Lasted 10 minutes or so.

Best part was when I was lining up for a beer and a FA18 did a fast low pass that made me nearly poo my pants! Pilot did the most awesome display, going low and fast then pulling up to a vertical climb almost instantly and almost stalling at the top followed by a dive, absolutely amazing, then he did rolls and turns for about 10 minutes and as suddenly as he appeared he was gone. Makes you realise what a powerful weapon those planes are.

Thanks for sharing that!

The flight plan generated by our dispatcher has planned cruise altitudes on it. These altitudes, as well as the route of flight, will be chosen based on the winds and weather. I use the plural (altitudes) because our flight plan often has step climbs along the route. As we burn fuel, we are capable of higher altitudes. Occasionally, the flight plan will have planned descents on it. This is usually to avoid a rough ride because of forecasted turbulence.

Pilots will fly the planned altitudes if it makes sense, but we have the authority to deviate from the plan. Earlier today, for example, on a flight from Milwaukee to Minneapolis, I chose to stop at FL280 rather than climbing to the planned altitude of FL350. This decision was based solely on the ride; ATC reported that the rides were better below 30,000 feet. If our altitude varies from the flight plan by 4000' or more, we notify our dispatcher via ACARS just to keep him in the loop. At the lower altitude, our fuel burn is higher but passenger comfort is high on the list of priorities.

Don't me started on this crap. It's the latest big scam and sickens me. I had a guy get on the plane in Miami a few weeks ago with two dog on leashes, walking down the jetway. I asked him, "support animals?" and he said yes and I left it at that. I asked the chief pilot about it later and, though he rolled his eyes about it, he didn't seem that concerned. I just wonder, how many support animals is one person allowed? To me, it's just a symptom of our narcissistic society. What if the person sitting next to them gets anxiety from dogs? Doesn't matter, I guess.

I haven't seen a cat yet, but I know that a famous tennis player was not allowed to bring a support squirrel on board last summer. The line was drawn at rodents.