minimum altitude is for dumping fuel
 

Just curious what your minimum altitude is for dumping fuel?

http://www.aeroinside.com/item/3202/...down-in-flight

A Korean Airlines Boeing 777-200, registration HL7531 performing flight KE-32 from Dallas Ft. Worth, TX (USA) to Seoul (South Korea), was in the initial climb out of DFW's runway 35L when the left hand engine (PW4090) emitted a loud bang and streaks of flame prompting the crew to declare Mayday and shut the engine down. The aircraft stopped the climb at 3000 feet, worked the checklists, then decided to dump fuel and climbed the aircraft to 5000 feet commencing fuel dump. After about 40 minutes of fuel dump the aircraft returned to DFW for a safe landing on runway 36L about one hour after departure.

Boeing FCTM says 4000'
Ops Manual says 5000'
Then you have to consider the state variations ie Min Altitude for fuel jettison in Australia is 6000' :ok:

In europe also mostly 6000 ft

Back in the 1980's, there was a 747 taking off from London (Heathrow I think - it's been quite a while). Anyway, they over rotated quite badly and both outboard engines surged and did not recover. They managed to circle around and land on two engines, dumping fuel the entire time :uhoh:.

A guy that used to drive KC135s told me that the original turbojet powered airplane (prior to the engine retrofit) takeoff performance was so marginal that if they lost an engine after V1, there was a handle the flight engineer could pull to start dumping fuel out the refueling drogue at whatever the max fuel transfer rate was. :eek:

I'm sure the original question was about the 'legal' fuel dump altitude - just pointing out that sometimes you need to do what you need to do :rolleyes:

Its my understanding that fuel being dumped vaporizes in 3,000'. ATC seems to like 6,000' as a safety measure.

Given my thought that it is better to dump fuel on the population than an entire aircraft containing fuel, it has been part of my takeoff briefing to initiate fuel dump immediately under certain circumstances.

Used to do two engine ferrys in 727s. Part of the training in the sim was having a second engine failure at V1. A good FE would be dumping before Vr.

Regarding ATC guidance CAP493 says the following:

Fuel Jettisoning
1.77
Pilots of aircraft in flight are permitted to jettison fuel in an emergency.
The decision to jettison rests solely with the pilot but he may request
guidance from ATC.
1.78
When an aircraft in controlled airspace needs to dump fuel, ATC should
co-ordinate with the flight crew:
1.
the route to be flown which, if possible, should be clear of cities
and towns, preferably over water and away from areas where
thunderstorms have been reported or are expected;
2.
the level to be used;
3.
the estimated duration of the fuel dumping; and
4.
the frequency to be monitored whilst the aircraft is dumping fuel.
1.79
Controllers are to recommend to flight crew that jettisoning of fuel
should be carried out above 10,000 feet agl. Exceptionally, if fuel
dumping at this level, or over water, is operationally impracticable or
inconsistent with safety, fuel may be jettisoned above 7000 feet agl
in winter and above 4000 feet agl in summer. For fuel to be jettisoned
below these levels the situation must be unavoidable.
1.80
A vertical separation of at least 1000 feet between aircraft should be
maintained.
1.81
Adjacent ATC units and control sectors should be informed of the
fuel dumping taking place, including co-ordination with units providing
services outside controlled airspace where the aircraft’s track is near to
the boundary of controlled airspace (both laterally and vertically)


http://www.caa.co.uk/docs/33/CAP%204...dition%205.pdf

Considering 14 CFR Part 25.1001 states that an airplane may need to jettison fuel just to meet Part 25.119 and 25.121 climb requirements, I certainly hope there is no minimum altitude.

Landing climb and approach climb!

You will have already met take off climb requirements or you wouldn't be taking off:ugh:

I don't believe I mentioned takeoff, but neither do I see why you're banging your head. It's not like "approach climb and landing climb" start at 10,000MSL or anything.

tdracer,

You might be thinking of the Contintal 747 at London Gatwick 1st Feb 1988.
You could see the dead grass across the road at the end of the runway, where the fuel had been dumped straight after lift off.
AAIB report here:
http://www.aaib.gov.uk/cms_resources...9%20N605PE.pdf

Tdracer. If a Kc135 guy told you anything about a flight engineer he didn't know what he was talking about. I am an old Kc135 guy and we didn't have one. The copilot could dump fuel very quickly though. The check list was: Open the line valve to the boom, close another valve I don't remember the name of, open the dump switch and turn on the refueling pumps. Takes ten times longer to type it than do it. We could and did dump at 6000 lbs a minute. I had an engine blow up at rotation one time and we were dumping by the time the gear was up and locked.

If you're thinking of a Continental 747 @ LGW, there is quite a bit wrong with the quoted scenario

I don't think the COA B742 incident at Gatwick is the one being described. That only lost one engine (no 4), not two, during a normal rotation (though it continued to pitch up, to a maximum of 22°, after the engine surge). The aircraft was then airborne for nearly an hour before landing back at LGW.

It did, however, start to dump fuel immediately (even before no 4 was shut down) and continued to do so in the climb to 4000'.

There is no requirement to dump fuel and land within a certain time limit and therefore no altitude requirement. As such you would climb to a suitable altitude.

All other scenarios are outside of certification requirements so all bets are off.

It could well be the Continental event that I was thinking of (although I was thinking it was early 1980s, not late 1980s) - basically going off 25 year old (or maybe older) memory of a second hand account.:uhoh: I wasn't involved in that investigation - just remember hearing the story. I do remember being told that the surge was caused by over-rotation, however the JT9D was notorious for that so it may have been embellishment by the teller....

Rick777 - what I recall KC135 driver telling me was that "they" had a handle to start jettison - I just assumed it was the flight engineer (I am rather surprised to hear the KC135 didn't have one - they must have kept you guys driving busy). As for the 'handle' part - again it may have been embellishment by the teller. A "handle' does make for a better story than a "procedure" ;)

Again, I was just trying to make the point that fuel jettison can happen well below the altitude where the authorities would like it to take place.:ok:

I agree. Therefore, there is no minimum altitude either, correct?

6,000ft. ..........

Flyboyike

What does your company Ops Manual say?

BBK

We don't have any aircraft with fuel-dumping capability, so our manuals are mute on this subject.