Saturday, April 14, 2007

Your route V. Reality

Sorry guys, my bad, i should have made this clear earlier. I did not WRITE this post. This was sent into me by a reader as was the art one and part two from "The Crew of JetBlue Hostage." I am know nothing about aeronautics but I leave both sides of the argument up on here and the comments.

Airbus A-320 Range Directly From Jet Blue Airways Site (2700nm...it says "miles", but in aviation that is not a unit of measurement because of the curvature of the earth):
http://www.jetblue.com/about/whyyoulllike/about_whyairbusstats.html

Jet Blue route map:
http://www.jetblue.com/wherewefly/

Great Circle Mapper (keep in mind these don't factor in taxi fuel, atc delay, weather rerouting's, most efficient TOC---top of climb...and a bunch of other variables)

http://gc.kls2.com/

JFK-OAK = 2576
JFK-SFO = 2586
BOS-SFO = 2704 (A clear demonstration of being "over" the 2700 threshold)
BOS-OAK = 2693 (7 miles below the 2700 threshold)--this isn't a car, fuel is precision and fuel is the 2nd most costly economic staple of flying an airplane)

7 comments:

17 more years said...

OK- understood- so does that explain why, on a flight from Ft Lauderdale to JFK (on the A 320), we had to make a refueling stop after being in a 35 minute holding pattern over Virginia? Oh yeah- did I mention that we stopped in ATLANTIC CITY (a big 15 minutes from JFK)?

Scott said...

Wow not a lot of research going on here if you are going to lie about stuff you might want to check your facts first:

A-320 range is 2600 NAUTICAL miles (per airbus' website: http://www.airbus.com/en/aircraftfamilies/a320/a320/specifications.html) or 2615 NAUTICAL miles (per airliners.net http://www.airliners.net/info/stats.main?id=23)

To convert Nautical Miles to actual miles you multiply Nautical Miles * 1.1516 (See http://www.answers.com/topic/nautical-mile or you can see http://en.wikipedia.org/wiki/Nautical_mile).

Which means the actual range of an A320 is either 2994.16 miles or 3011.434 miles.

The distance to SFO is 2,580 miles (per http://www.webflyer.com/travel/milemarker/) or 2,586 per your choice of webpages http://gc.kls2.com/.

Now if you take into account the engines (which you ignore) the fact that JetBlue uses a IAE V2527-A5 instead of a V2500 in the above specs the engine increases the range to approximately 3,047 miles (or 2,646 nm).

Obviously this site is to incite people with lies and unresearched thoughts. I wasn't going to post but this was so blatantly false that I couldn't resist.

Please have some responsibility and check your "facts" before actually posting something.

Dizel8 said...

Obviously you are lacking in the fact area, which, considering you are "advising" people is unfortunate.

Where to start: There are plenty of great circle route mappers availbale on the net, here is one:http://gc.kls2.com/cgi-bin/gc?PATH=bos-oak&RANGE=&PATH-COLOR=&PATH-UNITS=nm&SPEED-GROUND=&SPEED-UNITS=kts&RANGE-STYLE=best&RANGE-COLOR=&MAP-STYLE=,
in this case BOS-OAK. As you can clearly see, the mileage will be listed, in this case it is in Nautical Miles, not statute miles, now to you that may not mean much, but there is a difference.

If you do not know what the fuel reserves are, then how can you say, that jetblue does not carry enough fuel. However, to enlighten your readers, the computation for fuel reserves are such, that an airplane must be able to fly to it's destination and then for an additional 45 minutes. If the weather is bad, a secondary airport must also be listed, if that is the case, the airplane must have fuel to fly to the first airport, the second airport and then again have fuel for another 45 minutes.

You say jetBlue files to an intermediate airport and then makes a decision to continue based on fuel. This is not correct, the practice you refer to is called re-release and jetBlue is not authorized by the FAA to use said procedure. Besides, that procedure is mostly used for long range international flights.

To the gent that said he stopped in Atlantic City, this does happen and to all airlines I might add. The more weight is on an aircraft, the more fuel it burns, hence adding fuel increases fuel burn, so all airlines try to plan correct amount of fuel. Roughly any tankering, ie extra fuel above that require, will cost 1/3 of the tankered fuel. Tankered 3000 gallons, 6-900 gallons is used to haul it.So obviously, it is not like your car, where you just fill it up anytime you go.

Certainly you add fuel for expected or anticipated delays, but sometimes they end up being longer than estimated and hence you may have to divert. It may add to the travel time, but remember, the overriding emphasis will always be safety.

Hope this cleared up a few issues.

Kind regards

17 more years said...

My experience on the FLL to JFK route is clearly not unique. Out of curiosity, I tracked the same flight yesterday afternoon. The weather was clear up and down the Eastern seaboard, so that was not the issue. The same flight was once again put into a holding pattern over Norfolk, VA, and then diverted to Atlantic Ciy, where it was held for whatever reason for approximately 30 minutes. Who's to blame? Jet Blue, for not having an adequate fuel reserve? Or JFK for their nightmarish amount of ground traffic?

Dizel8 said...

17 years more:

Actually a large part of the blame should rest with Air Traffic Control and their flow management system, or rather lack therof.

If they announce the delays, the anticipated delays etc. then the airlines can plan for it. Yesterday I flew in from the west coast, beatiful day in NY, no delays announced and yet, we ended up holding for a bit 500 miles from JFK.

Pilots and their dispatchers wil evaluate the conditions on every flight, weather, winds, loads, delays etc, and plan fuel accordingly.Companies will track flight times and fuel for every flight, thereby trying to make a plan that work consistently.

As mentioned previously, it cost fuel to carry extra fuel and hence money, so all airlines try to cary the appropiate amount. Further, there is the issue of max landing weight, meaning taking off full of fuel out of FLL wouldn't work, since wih that amount of fuel, not enough would have been used for the airplane to land within limits. Yes, you wouldn't have to stop, but you would have to circle for a few hours to burn of the excess fuel.

You can rest assured, that stopping in Atlantic City, or any other city for that matter, that is not the intended destination is not something the company wants to do, nor the crew and of course, much less you. It delays later flights, cost money and is generally a pain in the......

Dizel8 said...

I should ask though, what kind of fuel reserve doyou think would be appropiate. An extra 45 minutes, an hour, two?

The flight would have been planned for: taxitime + computed flight time + 45 minute reserve +5% percent route reserve + dispatch additional.

"Dispatch additional" would probably be 30 to 45 minutes extra fuel. I you sat in a holding pattern for 35 minutes, that would burn the added fuel, while still leaving the aircraft with adequate reserves. Pilots are very conservative and normally will paln for worst case scenarios, as they well should and which you should want, hence, if 35 minutes passes by and there isn't a definite timeframe, then yes, a divert is the best choice.

John David said...

Hello, please don't think of this as hate mail, I was just trying to understand what the point of this math lesson is. I don't know much about aircraft and fuel and so forth, but...

Jetblue's aircraft is incapable of flying the route? How is it, then, that they successfully (barring cancellations) fly this route every day? Maybe you're saying they intentionally divert every flight because they can't fly it?

If that is true (pretty sure it's not), I think that merits a full investigation of why the FAA would let them do this every day.

This is like arguing the color of the sky, I don't understand the point of it.