Cost of overweight landing inspection vs dumping/burning off fuel

[Sidestick_n_Rudder]

Hi,

The other day I started thinking on the following scenario.

Let's say you are departing a wide body on a long haul flight and develop a tech problem requiring a turn back. Some relatively minor stuff, e.g. pressurization problem, forgotten gear pins :E, i.e. a non-emergency situation, but still requiring a turn back.

In that case you'd have to either land overweight, or dump/burn anything upwards of 30-40 Tons of fuel.

Are there any rules restricting overweight landing to emergency cases only? Airbus FCTM mentiones "exceptional conditions (air turnback or diversion)", which can be interpreted in various ways.

What would be the cost of overweight landing inspection vs the cost burned/dumped fuel?

Do your airlines provide any guidance for such cases?

[DaveReidUK]

Good discussion of overweight landing vs fuel dump considerations here:

OVERWEIGHT LANDING? FUEL JETTISON? WHAT TO CONSIDER (http://www.boeing.com/commercial/aeromagazine/articles/qtr_3_07/article_03_1.html)

[B2N2]

Interesting link but it wasn't an answer to the question

What would be the cost of overweight landing inspection vs the cost burned/dumped fuel?

For the sake of the discussion let's say we need to dump 30 tonnes or 10k gallons which is anywhere from $15k-$20k depending on price of contract fuel.
That's about 5-6 tires for a 747 let alone brake replacement or fuse plugs melting. I don't know if after a controlled deflation the rim needs to be replaced.
Brake lines may have heat damage and it progressively gets more expensive from there.

Uncontained engine fire or catastrophic structural failure necessitates an overweight landing without the airplane crumpling into a pile as per certification requirements.
Anything else, just dump the fuel as you can't garantee a pretty landing and you don't want to end up spending a dollar trying to save a nickel.

https://s3.amazonaws.com/files.digication.com/M3a393cbf62f74d3dd421214e8e3905fd.jpg
https://k60.kn3.net/taringa/8/C/1/D/6/7/MRangoni/1E7.jpg

[rigpiggy]

Don't forget swissair 111. 7 minutes made a bit of a difference

[PEI_3721]

“…but it wasn't an answer to the question”
Wrong question? A pilot should not have to consider cost in such situations; either in flight or on the ground.
If advice were to be provided, then it should be to choose the safest option for the situation.

As a hypothetical question, then how do you know if the situation has been correctly identified, so that a meaningful choice can be made.
How can you forecast that the pilots activity will be satisfactory during an overweight landing. Presumably this type of landing landing would not have been experienced before. Although this should be within ‘normal capabilities’, the risk might be low, but there is still increased risk above normal operations.
How can the outcome be forecast. Judged on the outcome of some normal landing incidents, perhaps not very well.

A more valuable question is to first ask ‘why am I asking this question’, change the start point for your thinking.
So why ask?

[B737900er]

I understand your thinking side stick. Here was A scenario I heard in a CRM discussion
that is a true story. A B737 Departed from Airport A and got a Leading Edge Transit light after departure. The aircraft took the hold and ran the appropriate QRH NNC. The aircraft landed over weight back at airport A.

I queried this scenario and said it was not a emergency so why did the skipper overweight land?

The answer that was given was on the lines of, "An overweight landing is not a big deal and only requires a visual inspection. It also mitigates any time delay and commercial impact".

[B2N2]

In an non-emergency non-normal like the leading edge example company would be involved in the decision making and cost analysis process.
I've had that exact same thing happen in a 737 am company made the decision to return to departure airport. In our case we departed below max landing weight so overweight landing was no issue.
73 can't dump anyway.

I think that in a non-emergency the economic impact to company and customers should definitely be included in the decision making process of the PIC.

[DaveReidUK]

Interesting link but it wasn't an answer to the question

The OP asked several questions. :O

The link answers the one re the regulatory aspects, including examples of what the FAA considers as an emergency that would permit an overweight landing.

[B2N2]

True and I apologize for being quick on the trigger there.
Last week flew with a Captain who at one point in his career was 1/3 way across the Pacific when they blew an engine.
After return to the West Coast all the FAA inspector wanted to know was if he declared an emergency. He said yes. Had he said no he would have been written up for 27 ( give or take) violations.
Rule of the game; always declare an emergency. Even when life's not in imminent danger.
So I would suggest to declare for an overweight landing and have equipment standing by.

[PEI_3721]

B737, the answer to your question assumed an outcome; 'an overweight landing is not a big deal', thus there would be little to inspect. However, where the choice to land overweight remains the same, a different outcome due to unforeseen circumstances could result in completely different view.
The Captain holds the responsibility for both the choice of action and achieving the best outcome whatever the circumstances.

Those who argue commercial aspects might only have to face an irate passenger, but one who is knowledgable of aviation risks and decides to seek compensation for the added risk in landing overweight - because there was a choice, make the landing near normal as possible or expose passenger to ‘the extra 10t of fuel’, etc, which may dazzle the legal system.

If a Captain chooses a course of action based on what s/he knows at the time, then whatever the outcome there is a basis for defence. I hate legal arguments in aviation, safety and only safety first, but unfortunately times change.

DR, exactly; what is an emergency…. Judgement, at the time, by those who are there, and have to assess the situation according to what is perceived; everything else is hindsight. Unfortunately the industry now suffers over regulation and SOPs (which are often amended with hindsight.)

[DaveReidUK]

DR, exactly; what is an emergency….

Well the link that I posted previously contains some examples:

"In June 1972, the FAA issued Air Carrier Operations Bulletin No. 72-11 giving three examples of situations the FAA considered typical of those under which pilots may be expected to use their emergency authority in electing to land overweight:

Any malfunction that would render the airplane unairworthy.
Any condition or combination, thereof, mechanical or otherwise, in which an expeditious landing would reduce the exposure to the potential of additional problems which would result in a derogation or compromise of safety.
Serious illness of crew or passengers which would require immediate medical attention."

I don't think many would argue with those.

[PEI_3721]

Dave, I was fishing for a more philosophical view. :ok:
In pedant mode, would pilots have the same understanding of airworthy as the FAA; would it be a common understanding world wide? Would the QF32 crew been ticketed by the FAA?
Who judges medical urgency?

The second option is closer to the issue, that of identifying and judging risk - the process of risk management. Also I wonder if the ideas behind this Ops Bulletin are still applicable some 45 years later.

I have no argument with what is presented; but question if such advise helps crews to manage events which nowadays are usually unknown; unforeseeable.