STT runway?

[sherban]

http://en.wikipedia.org/wiki/American_A ... Flight_625

word

[JC]

We flew home yesterday on Delta (STT/ATL/MSP). Our flight was delayed getting off the ground by 25(ish) minutes (for whatever reason). We were re-routed through San Juan for fuel which added another hour plus. We literally sprinted through ATL to make our connection (after waiting for the tram that never showed up) that (thankfully) left about 15 minutes late! We arrived in MSP no more than an hour late.

Welcome to flying.

Anything to get to Love City. Anything to get home.

A nice hot shower and my own pillows...ahhhhhhhh...it is good to be home!

344 & Counting...

[PSUWethr]

We flew out yesterday on USAirways. They were working on the taxiways. We were on a 757 and the only thing that was different is that we had to taxi to the end of the runway on the runway. Then we did a 180 to turn around. (That was definitely different and doesn't sound too good). Oter than that we didn't have any problems.

The only problems we had were the stop light on North Shore Road where they were working.....Not all the locals know to stop on red and we almost hit someone head on

[sailvi767]

We flew out on Saturday. Delta flights were delayed. The JFK flight by about 3 hours and the 2:30 flight to Atlanta by about 2. They closed the last 1000 feet of runway, so the large planes could not make it with a full fuel tank. We were on the 4:30 to Atlanta and had to stop in San Juan to refuel. We missed a connection had to overnight in Atlanta. The flights on Sunday had stand by lists of over 70 people. Crazy!

Really? Delta flies 757's in and out of STT. I'd think they could make it even loaded with fuel. It's not like they're bringing in any big wide bodies. That's amazing that they can't take off in 6000 feet and have enough fuel to get up to NYC or to ATL.

I pray this crap is fixed by July. Our home-bound connections don't allow for w 3+ hour delay.

I have posted online before about what goes into the weight limits and max takeoff weights airlines have to live with under part 121 regulations. Its far more complex them most people understand.
To clear up a couple of things. Delta flies both 757's and 737's into STT. The 737's have been fuel stopping more the last week with the closure of 1000 feet of runway.
As far as runway length anything under 8000 feet is short for a jet airliner. There are in the US several airports that operate with 7000 feet such as Washington National, Laguardia, Midway. Orange County Airport operates with 5700 feet. The length of the runway is however only one consideration in the max takeoff weight and often not the limiting one.
There are about 8 different considerations depending on the airport and the route flown. Several are route specific such as max enroute driftdown weight. ETops diverson weights ect.. They don't apply to STT flights.
When a airline is getting close to departure from STT the process is started to generate a weight and balance and determine a legal takeoff weight. Some but not all of the requirements are listed below.
1. Aircraft must be able to accelerate to a speed where the TO can be continued with a engine failure and have the aircraft be at a height of 35 feet over the end of the runway with the most critical engine inop or stop in the runway remaining without the use of reverse thrust.
2. Aircraft must be able to clear all obstacles after TO by specific amounts with the most critical engine inop.
3. Max TO weight must not project the aircraft to exceed max landing weight.
4. Aircraft max structural weight must not be exceeded.
To generate a weight and balance they start with number 4. You can't exceed that number ever. Then they look at the planned fuel burn and the max landing weight to comply with number 3.
Figuring out number 1 and 2 gets a lot more complicated. Most airlines refer to item 1 as the runway weight limit and item two as the climb weight limit.
Runway limit is normally determined by the length, Temperture, headwind/tailwind and obstacles in the depature path and flap settings.
Climb limit is a function of temperture and flap settings.
STT airport is unique in that it combines many things that limit takeoff weight. It has a short runway, rising terrain (obstacles) in the departure path, normally higher temps (jet engines hate warm air) or a tailwind if you choose to takeoff over the water. When load planning airlines have to decide if they want a downwind TO without obstacles or TO into the wind but also into rising terrain. Which is correct depends on the aircraft type, temp, engines in use, winds and total aircraft weight. The pilot can elect to takeoff with more flap as this will increase his runway allowable weight but will decrease the climb limit weight. Less flap decreases the runway allowable weight but increases the climb limit. In general at STT if you are going downwind over the water you use a lot of flap for takeoff since climb limits are not that important and if going into the wind and the terrain you use less flap to increase the climb limit.
This is getting lengthy and is far more info then most want to know so I will cut it short. The load planner will look at all the above factors. He will figure out the aircraft zero fuel weight.(airframe, cargo and passengers). He will then decide the best takeoff options as far as runway and flap settings. In the case of a 757 lets say the maximum takeoff weight is runway limited at 210,000 lbs. The operating empty weight is 168,000 bls. He can carry 42,000 lbs of fuel for the flight. That is plenty of fuel to get to Atlanta or New York City however you have to carry a reserve and then you have to look at the weather at the destination. Depending on the number of runways and number of instrument approaches at the arrival airport combined with the weather forcast at arrival time you may need to carry additional fuel to allow the aircraft to fly to a alternate airport plus reserves. If you have to fly to NYC and must have a alternate then 42,000 lbs may not be enough to make the flight without a fuel stop even though you can easily get to NYC with that amount of fuel.
I hope this gives a bit of understanding to the issues at STT with 1000 feet of the runway closed. Its far more complicated then most realize and each flight is unique. Different airlines also take more or less conservative positions in load planning. Some like Delta always build in a additional safety number while others go with the minimum.

George

[pipanale]

Thanks for the clarification. I knew a lot went into determining all that and that STT is an odd airport (Length + obstacles). What I hadn't realized is that Delta brings 737's down there. But, I believe Continental does. So, it surprised me that a flight from STT-JFK would need fuel (regardless of hardware) and a flight from STT to EWR would not.

But...could be airline-specific or the need for more reserve into JFK over EWR...or something.

Still...at an airport with so little wiggle room, work like this is gonna screw things up no matter how hard they try to do work overnight.

[lprof]

sailvi767... thank you for that detailed explanation; my already high respect for aircraft, pilots, and flight crews has been bumped a notch higher. We all want to get there and back safely and with minimum bother... I am sure that you want it that way too.

[x2bate]

Sailvi767. Thanks for the info. From someone that always wanted to get into the cockpit instead of my seat, thats gotta be one of the best post I've read in a long time! Way cool

[DuxDweller]

Sailvi767 - I flew in on a 767 last month (US Air out of CLT). The plane had just come back from a transatlantic - HUGE.

We had a full plane. Quite an interesting landing in STT. Seemed to me that the pilot overshot the approach a bit and didn't get the wheels down until he'd eaten a football field. Once the wheels were down he had full reverse thrust. We didn't stop until we were VERY close to the end of the runway. Passengers all applauded when it finally did stop! I am wondering how often the BIG planes are landing there??

[jimg20]

You practically have to be a rocket scientist to figure this out..........Oh wait, they are rocket scientists!

Thanks for that explanation....and welcome to the Forum.

[sailvi767]

Sailvi767 - I flew in on a 767 last month (US Air out of CLT). The plane had just come back from a transatlantic - HUGE.

We had a full plane. Quite an interesting landing in STT. Seemed to me that the pilot overshot the approach a bit and didn't get the wheels down until he'd eaten a football field. Once the wheels were down he had full reverse thrust. We didn't stop until we were VERY close to the end of the runway. Passengers all applauded when it finally did stop! I am wondering how often the BIG planes are landing there??

He may have had to land past the damaged portion of the runway. Here is a link with the first real explanation of what is going on. Sounds like the problem should be over as I type this.

http://www.virginislandsdailynews.com/i ... d=17644937

[Steve Palm]

This web page looks like the be all end all on Boeing 757 model airplanes.

http://www.boeing.com/commercial/757fam ... 0back.html

Steve