Quote:
Originally Posted by Artemis
Incident shortly after take-off, no fuel jettison (fuel dump) capability and no time to hold pattern to burn fuel to achieve maximum landing weight at touchdown. So if max fueled, pilots had to inevitably handle an overweight landing (exceeding the MLW) attempting to avoid a runway excursion. |
1. You're hardly ever "max fuel" in a 737. More fuel equals less payload (i.e. paying cargo or passengers), so you only take what you need. The amount is calculated by the airline Dispatcher with the concurrence of the Captain. You need the fuel to get where you're going, fuel for an Alternate (if required), and FAA/FAR Reserve- plus a bit for APU usage and taxiing to the runway. The only time I've ever taken maximum fuel on a 737 was going from Newark to San Diego in the winter and into the wind-- I had about three minutes of extra fuel (according to the flight plan), and that was with tanks filled to the brim. Luckily, I was able to taxi out quickly (which saved gas) and got some Direct clearances that saved me a little more-- my other option if I burned more than planed was to drop into Denver for a fuel stop.
Bonus Trivia: The shortest distance between two points (e.g. Newark to San Diego) is NOT a straight line. You have to consider Great Circle (distance measured on a sphere) as well as winds and weather. Winds in the US usually blow generally W to E-- so even though you might spend more time flying a longer distance out of the wind, you'll save gas rather than going directly into the wind-- it's sort of counter-intuitive, but that's how it works. That's why on a winter East to West coast flight, you might find yourself over the Dakota's instead of down near Colorado.
2. Pretty much the only jets that have dump capability are the big ones-- 747, 777, 787, etc. The smaller 737 & 320 types don't have the capability, as you noted.
3. Maximum landing weight is what Boeing has called a "Bought Weight"; i.e. you can buy the data for a higher landing gross weight-- it only costs money. Realistically, if you can take off, you can land (assuming available runway). You have an overweight checklist, but it pretty much says to just watch your sink rate and to write it up for maintenance. The maintenance guys will take about 1-1.5 hours to do a check of the aircraft-- it's honestly not a big event.
3a. FAR's (which govern pretty much everything in aviation) require that the aircraft can safely land at 10 feet per second (Ow!) at max landing weight and 6 feet per second at max takeoff weight. A normal landing is around 1-2 feet per second. So, as long as you keep your sink rate AT TOUCHDOWN less than 3-400 feet per minute, it's a non-event as far as the aircraft is concerned.
4b. Runway available on an emergency return is usually not a problem for the Guppy; in the 737 world, there really aren't that many runways that are short and sketchy-- as in a handful. And most of them are fairly close to great big ones-- an example is John Wayne/Santa Ana. It's got a 5700' runway. Would I emergency return there above max landing weight? No-- not unless I was on fire, I couldn't put it out, and I had no other options. Instead, there's about 12,000' of runway 36 miles away that I'd aim for (I'm looking at you, LAX).
4. I this situation, I wouldn't dump (even if I could) or Hold (delay) to get down to maximum landing weight-- for all I know up in the cockpit, the tail may be about to fall off. As well, I have a bunch of very scared, very cold and very windblown passengers back there-- get the jet on the ground as soon as you safely can, but don't be stupid-- in other words, take the time to run your checklists, make sure everything you can do has been done, and be ready to successfully fly the approach and landing.
R.