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Overweight Landing and Field Length

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Overweight Landing and Field Length

Old 10th Nov 2009, 18:46
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Overweight Landing, Field Length & 1.67 Safety Factor

Hello. I am looking for some feedback on the following scenario:

1) B737-300 Take off at 59000 Kg.

2) Flight has to be discontinued and a land back is required at the departure aerodrome. Reason for land back is Depressurization. However no emergency situation requiring to land ASAP. Everything (including passengers) under control.

3) Max landing weight is 52000 Kg.

4) Unfactored landing distance (for 59000 Kg) is around 5700 feet.

5) Factored (1.67) landing distance is 9500 feet.

6) Landing runway is 9000 feet.

7) Runway condition is Dry. Night time and a non-precission (VOR) approach is in progress. Weather and visibility is not an issue.

8) No contact with the company for any assistance regarding making a heavy or a normal landing.

9) Burning 7000 Kg of fuel to bring the landing weight to normal limit requires 2 hours holding as fuel jettison is not possible.

10) No overweight landing procedure in the checklist.

Considering the above mentioned scenario, what will you do? Choose one of the following options:

A) Make a heavy weight (7 tons above limit) landing, based on unfactored landing distance of 5700 feet. Considering that runway is 9000 feet and safety factor of 1.67 is only for dispatch (pre-flight planning) purpose. Intention is to save fuel and 2 hours holding time.

B) Hold for 2 hours and reduce the A/C weight to avoid complications of a heavy weight landing in addition to bringing the factored landing distance of 9500 feet (at heavyweight) to less than 9000 feet (at normal landing weigth) to cater for the field length of 9000 feet. This would be based on the fact that the A/C is not in a state of emergency and safety factor of 1.67 can still be applied to avoid unnecessary complications in order to save fuel cost and holding time. Intention is to enhance safety.

C) Some other better course of action - please mention.

Looking forward to atleast 5 or more opinions on this issue. Thankyou.

Last edited by Haroon; 14th Nov 2009 at 05:20.
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Old 10th Nov 2009, 18:59
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Boeing guide on overweight landings (I know you didn't mention type, but we are talking general principles here) basically says that anything technical enough to require a return will probably require more engineering time than the overweight landing inspection. The aircraft is designed to land at MTOW without a problem, and I am confident enough in my skills to land. Night and VOR approach doesn't affect anything.

I would land - 7000kg of fuel and 2 hours flying time is a lot of money.
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Old 10th Nov 2009, 19:27
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Thankyou Checkboard. Would you like to comment on using the safety factor of 1.67 i.e. it is required for a normal landing in routine but why not when you are making a heavy landing when it is needed more as compared to a normal landing.
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Old 10th Nov 2009, 19:30
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First of all it would be the unfactored ALD that you would apply since you're in flight. The 1.67 only applies to the planning-stage, as you pointed out.

The answer to your scenario is:
'It depends..........'

Why do you have to discontinue your flight to destination? Are you landing performance limited at current weight?
When on fire I would definitely land ASAP applying the overweight landing c/l or not (time permitting).
With just a relatively small failure it would perhaps be more sensible to burn off the fuel in the hold in a high drag config.
Inter-polate between the two examples above and you will have your answer.
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Old 10th Nov 2009, 21:44
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I once took off from Perth (Western Australia) in a BAe 146, and had a cabin fan failure. This means absolutely nothing in terms of the QRH, or continuing the flight - however it does mean that, should a cabin smoke event occur, you couldn't clear the cabin of smoke.

Continued flight was fine, however the MEL wouldn't allow you to take off with the problem, and we were planned to a no-engineer port (as were most of our ports in Australia). So a "perfectly fine" aircraft (short of a cabin fire), but the company wanted us to return to Perth were we had engineering, and we were a couple of tons overweight.

The decision was made eventually to hold over the water (out of the way of arrivals) for 40 minutes with the gear down and airbrake open in order to burn off the fuel. Well the passengers became increasingly nervous about the vibration, despite several PA's from the Captain (I was an FO), including one in the cabin, and we nearly ended up with a riot - the passengers convinced themselves we couldn't land, and the vibration was the "real problem" - in effect, they thought we were lying to them!

So that is a consideration as well!

Would you like to comment on using the safety factor of 1.67 i.e. it is required for a normal landing in routine but why not when you are making a heavy landing when it is needed more as compared to a normal landing.
The extra weight is taken into consideration in the landing calculations, the 1.67 factor is to allow for either floating (less likely when you are nervous about landing overweight) or "skidding", so the only time I would think it is "needed more" is with a slippery runway. The weight isn't a problem.
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Old 11th Nov 2009, 00:16
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Haroon one of the ‘five or more opinions’ on how to judge the landing distance required is to consider the factors in the certification and assumptions in preparing the normal, factored landing distance – knowledge and then application.

The 1.67 factor (1.92 if wet) provides a margin of safety to reduce the probability of an overrun by allowing for variability in normal landings.
The airspeed and altitude accuracy expected at the threshold are critical factors. In an emergency, a pilot might claim to fly with greater accuracy, and achieve the expected touchdown position. However, assuming that you are not well experienced in overweight landings, and with the stress of the unusual situation, then some allowance should be made for possible unfamiliarity with the aircraft at that weight. Possibly a slower pitch/power response or operating nearer the wing lift curve limits – wings bend more at high weight.
These points would suggest considering the touchdown at approx 1200ft beyond the threshold as a minimum (probably 500ft above the unfactored distance) and a further 500ft for not deploying spoilers / reverse, and not braking as quickly as the test landings demonstrated in obtaining the data. Then add another 500ft for possible +10ft, +5kts at the threshold (AC91-71), or should this be +10kts – does everyone land fast at night. Do not unduly pressure yourself, stay as close as you can to normal operations.

You did not specify if the unfactored distance was wet or dry, or included the airborne distance (Boeing data usually doesn’t include the 1000ft+ from threshold to touchdown) – know before you go.
So including air distance, you need 7200ft (5700+500+500+500), but without air distance at least 8200ft – check wet/dry. Then ask yourself why the dry (1.67) factored distance is 9500ft, and how many overruns have there been this year.

Consider the brakes; any factor less than 1.67 probably requires max brakes until you are absolutely sure of stopping; is there likely to be a brake energy limit. Also consider the runway surface, wet/dry, grooved or smooth, and how much overrun is there. Check runway slope and wind values if not in already the book factor – double check the wind, make allowance for any reporting errors.
You may not wish to, or have the capability for a go around (obstacles), thus plan a more conservative approach and provide additional margins.

After considering all of the above, consider again what the landing distance factor is for – a margin of safety; what further addition would you add for safety.

You state that there is an option to burn off fuel. Safety must always come first; take option (B), as any non-normal (overweight) landing will involve some risk. Even with a much longer runway why take the risk on commercial grounds – you still have to answer for the consequences if anything goes wrong.

If you have to land immediately then accept reduced margins of safety – greater risk, but always consider the operational consequences; consider what mitigating actions can you take. By doing this, you pre-prepare your answers; lawyers usually state “always do what is right – do what you can justify”.
Beware advice from other people, they may not understand the situation from your point of view, or the safety of the operation; don’t assume that others have the same understanding. Yes, consider all advice (use all resources), but you have to decide on the safest course of action.
Fuel cost and time do not always equate to safety, the pilots first priority is safety. If you think that an overweight landing has the same level of safety as a normal landing then be prepared to prove it.

Re the ‘factors only apply at dispatch’; many regulatory airworthiness authorities imply that the factor should still be used at destination after checking the actual conditions. Remember that in the event of an accident, the regulators may have to defend their position; if a factor is required at dispatch to reduce the probability of an overrun, then what has changed at the destination – are they going to accept a higher probability of an overrun. Whichever way the regulators call the game, the pilot holds the final accountability in the decision to land.

Landing performance of large transport aeroplanes.

AC 91-71 Runway Overrun Prevention.

Managing Threats and Errors during Approach and Landing.
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Old 11th Nov 2009, 01:29
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You have to answer a few questions in your own mind in real time:

Is the situation critical -- does it endanger the airplane or those aboard?

Are the conditions such that you can make a successful landing, rollout, and stop?

Is the current inflight situation more dangerous than the IMMEDIATE risks of overweight landing?

Any 2 YES answers likely dictate an overweight landing. You will then have to evaluate whether the risk of the X hours burning fuel is less than the risk of the overweight landing.

Most of these will be subjective, except landing distance on a dry runway...
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Old 12th Nov 2009, 15:53
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Before continuing further I would like to present the summary of documents which Safetypee has provided, in reference to using the safety factor for landing performance.

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FAA Advisory Circular (AC No: 91-79 ) on Runway Overrun Protection.
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- The unfactored landing distances in the manufacturer-supplied AFM reflect performance in a flight test environment that is not representative of normal flight operations. The operating regulations require the AFM landing distances to be factored when showing compliance with the predeparture landing distance requirements. These factors are intended to account for pilot technique, atmospheric
and runway conditions and other items to ensure that the filight is not dispatched where it will be unable to land.

- As part of the operator’s Safety Management System (SMS) and SOP, the FAA recommends using either factored landing distances or adding a safety margin to the unfactored landing distances when assessing the required landing distance at the time of arrival. This landing safety margin should not be confused with the regulatory predeparture runway requirements.

- Operators should use the appendices, which contain detailed information about all of these hazards, to develop their SOPs. The 15 percent safety margin additive recommended by the FAA is intended only to account for slight variations in achieved performance.

- The unfactored certified landing distance may be different fom the actual landing distance because not all factors affecting landing distance are required to be accounted for by certification regulations.

- A survey of numerous operators’ Flight Operations or General Operating Manuals by the FAA’s Landing Performance Team indicated that approximately 50 percent of the operators surveyed did not have adequate policies in place for assessing whether sufficient landing distance exists at the time of arrival at the destination airport. Not all operators performed landing distance assessments at the time of arrival nor did all of the operators who performed assessments account for contaminated runway surface conditions or reduced braking action reports, nor did they apply a consistent safety margin to the expected actual landing distance. Operator specific SOPs should be developed for the assessment of landing performance, including the application of a safety margin, to ensure a consistent evaluation of airport conditions at the time of arrival.

- Unfactored landing distances determined in compliance with certification regulations and published in the FAA-approved AFM do not reflect operational landing distances. Landing distances determined during certification tests are aimed at demonstrating the shortest landing distances for a given airplane weight with a test pilot at the controls and are established with full awareness that operational rules for normal operations require the addition of factors to determine minimum operational field lengths.

- Flight test and data analysis techniques for determining landing distances can result in the use of high touchdown sink rates (as high as 8 feet per second) and approach angles of 3.5 degrees to minimize the airborne portion of the landing distance. Maximum manual braking, initiated as soon as possible after landing, is used in order to minimize the braking portion of the landing distance. Therefore, the landing distances determined under §§ 23.75 and 25.125 are much shorter than the landing distances achieved in normal operations.

- Aircraft Landing Weight. Calculate the anticipated landing weight by starting with the aircraft gross takeoff weight at departure and subtracting the anticipated normal consumption of fuel and oil required to arrive at the destination airport. If en-route fuel burn is less than planned, then the aircraft will arrive at the destination at a weight heavier than planned. Therefore, a recalculation of the aircraft’s landing performance must be done prior to attempting a landing maneuver. The pilot may control the landing weight by adjusting fuel burn en route or decreasing fuel load or payload prior to departure.

- Touchdown Point. Extended flare and runway slope are two factors which affect pilot control of the touchdown point. Turbine airplanes should be flown onto the runway being held off the surface as speed dissipates. A firm landing is both normal and desirable. An approach flown using a 3.5 degree glidepath with a touchdown at 8 feet/sec. rate of descent witouchdown down at the target touchdown point, which for certification purposes is approximately 1,000 feet beyond the runway threshold. The typical operational touchdown point
in the first third of the runway, and it may be farther down the runway than the 1,`000 fpoint. This additional distance should be accounted for in the landing distance assessment at the Air Safety Foundation Approach-and-Landing Accident Reduction (ALAR) Briefing Note 8.3, each 1 percent of runway down slope increases the landing distance by 10 percent.

- SOPs should clearly outline procedures to accommodate changes from the original plan. Preplan contingencies. Include the safety margin (factor) required by company SOPs or the appropriate regulation in all landing distance calculations. SOPs should address a process for conducting a landing distance assessment

- Develop procedures to ensure that a full stop landing, with a reasonable safety margin beyond the actual landing distance, can be made on the runway to be used.

- In the absence of other specific guidance, and to ensure that an acceptable landing distance safety margin exists at the time of arrival, the FAA recommends, as a best operating practice, that a 15 percent safety margin be applied to the actual airplane landing distance at the time of arrival. The 15 percent safety margin accounts for actual performance considering the meteorological and runway surface conditions, airplane configuration and weight, and the utilization of ground deceleration devices.


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U.K. Aeronautical Information Circular AIC 14/2006 (Pink 91) on Landing Performance of Large Transport Airplanes
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4.3.1 Another common factor in landing overrun incidents is a deep touchdown, which is most usually caused by excessive height at
the threshold. An additional 200 ft of runway is needed for every 10 ft of excess height at the threshold.

4.3.2 An extended flare, concluding an otherwise accurate approach, might result in a smoother touchdown, but will use up valuable
runway in the process. Aeroplanes can decelerate far more quickly on the ground than by floating along just above it. This merely
reduces the available runway length in which the stopping procedures can have effect.

4.3.3 An additional factor to consider is that for a given threshold height and glideslope angle, a downhill runway will tend to yield an
increased distance from threshold to touchdown compared with a level runway, if allowance is not made in the flare manoeuvre.
Runways with a significant amount of downslope at the beginning of the landing run are most likely to cause problems in this area, and
those in the UK are now highlighted in the AIP.

4.3.4 The conditions that create optical illusions which give misleading indications of height relative to the glidepath, created by, for
example, sloped runways or by particularly narrow or wide runways are well known and should be anticipated when such
characteristics are encountered. To help compensate in conditions where the visual perception of the flight path during a visual
approach may be affected, all available runway approach aids should be utilised.


Inflight re-check of Landing Performance

As stated earlier, an aeroplane's suitability to land at the intended destination is predicted upon forecasts at the time of despatch.
order to ensure that the assumptions made at despatch remain valid, JAR-OPS 1.400 prescribes an inflight re-check requirement,
requires the commander to satisfy himself prior to commencing an approach to land, that a safe approach and landing can be
made, taking into account the actual state of the aerodrome. This re-check is particularly important given that JAR-OPS 1 permits
despatch on the basis of dry landing distances if the landing runway is forecast to be dry at the estimated time of landing.


Any significant departure from the flight plan, such as an unscheduled diversion, would clearly justify a review of the landing
performance. If such a diversion was as a result of an emergency aeroplane condition which necessitated a prompt landing, then
clearly this would be justification for contemplating a landing on a runway which, although nearby, could not fully accommodate the
increase in the factored LDR due to the failure condition. Such a decision requires a sound knowledge of the principles involved to
make an assessment of the conflicting considerations.
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Old 12th Nov 2009, 16:06
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Message To Everyone:
----------------------------

I have updated my first post and have added the following details as many of you wanted to know for a proper answer.

A/C type: B737-300

Reason for land back: Depressurization. However no emergency situation requiring to land ASAP. Everything (including Passengers) under control.

Runway condition: Dry

----------------------------------------------------------------------------------------------------

To OPEN DES
----------------------

Thanx for your response. I have updated the scenario to be more precise. Now what do you say.

To CheckBoard
--------------------
Thanks again for your response. Your incident is really interesting and i can imagine what passengers, at times, can turn to!

Considering the summary of what Safetypee suggested, do you still think that saving fuel and time is a better option as compared to using the factored landing distance.

I agree that extra weight has been catered for in the performance but if safety margin is required at normal weights then why not otherwise, especially if the situation is not Land ASAP. Is there anything that stops from using the safety factor once airborne?

Quoting Safetypee:
"if a factor is required at dispatch to reduce the probability of an overrun, then what has changed at the destination – are they going to accept a higher probability of an overrun"


To Safetypee
----------------

Thanks for the useful Links. I have updated the scenario to be more precise. Do you still have the same answer.

Quoting Checkboard:
" The extra weight is taken into consideration in the landing calculations, the 1.67 factor is to allow for either floating (less likely when you are nervous about landing overweight) or "skidding", so the only time I would think it is "needed more" is with a slippery runway. The weight isn't a problem.

So if the runway is dry, is it still worth it to waste 7000 Kg of fuel and 2 hours operational cost? I mean anyone would like to go for safety but considering a huge cost isn't 67% safety factor a bit too much. According to the AC 91-79 even FAA suggests 15% safety which is different from dispatch safety factor.


To Intruder:
---------------
Thanx for your post. I have updated the scenario to be more precise. Now what do you say.
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Old 12th Nov 2009, 16:47
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Thanks for the extra info Haroon.
I would definitely burn-off the fuel to be below MLW (either structural or performance limited) in this scenario. Best to do this in a high drag situation (low and dirty).

I would not deliberately do an 'overweight landing' (not knowing how critical this is in your type and/or if there is a procedure available).
In my a/c type (A320) an overweight landing is an abnormal procedure; in my view only an emergency situation would warrant deliberately doing an 'abnormal' landing when a normal landing (albeit delayed) is available.
Time permitting you could perhaps liaise with the company/maintenance through ACARS/company VHF to let them consider the implications (cost) of an overweight landing.

I remember once we were overfuelled (over MLW) and there was no defuelling available. We had 2 options:
-increase fuelburn (high speed, lower level, early config)
-doing an overweight landing hereby voluntarily making an 'abnormal situation' out of something nominally 'normal'
We chose the 1st option for obvious reasons.

Hope this helps
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Old 12th Nov 2009, 16:51
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Hi Haroon. If there was no technical reason to Land ASAP, then you can't land over maximum certified weight (52 Tons?) for commercial reasons.

I would have held until I'd burned the excess weight off.
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Old 12th Nov 2009, 17:42
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To Intruder:
---------------
Thanx for your post. I have updated the scenario to be more precise. Now what do you say.
Saving time & fuel is a noble quest. However, are you sure the departure airport is your only option? If not, consider another suitable alternative within your 2-hour hold time.

At what weight will your "factored" landing distance equal the runway length? Why is a 1.67 factor used in the first place? Is it used simply for additional margin for a rejected T/O, or is there some kind of landing consideration? Does it include use of reversers? Autobrakes? Full braking? Normal braking?

If your 5700' figure includes air distance from threshhold to touchdown point, and normal braking, I see no reason to wait for landing due to the runway length. If the crew is reasonably proficient, even the lack of ILS should not be a problem, especially if VASI or PAPI is available..
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Old 12th Nov 2009, 20:10
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Always consider whether a lawyer could make mince meat of you if an incident were to happen on that landing.
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Old 12th Nov 2009, 20:18
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Haroon, in virtually all situations, particularly the one which you describe, then the safest option should be taken, I remain with option (B). If you judge that you can do otherwise then you have to be prepared to justify your decision – possibly in the worst of circumstances, an accident which was not foreseeable or necessarily of your making. You would still have to justify why you were flying the chosen option where the safer alternative may not have resulted in the accident factors coming together. Consider a hindsight view and turn it into foresight.

Re your quote from Checkboard; I don’t believe that this view necessarily agrees with the assumptions held by the certification agencies.
Currently I am unable to locate any regulatory material to support this. However, the following is taken from a 2002 certification conference:
There is no readily identifiable underlying technical explanation of the operational landing distance factors, which have existed for some time” and “The factors have now become ‘accepted’ as providing a satisfactory safety record. However, subsequent research into the industry’s concerns about overruns reported:-
For dry runway the current operational factor of 1.67 for both Destination and Alternate airports appears to be reasonable
For wet runways, without reverse thrust:
1.92 for Destination airport appears to be low
1.67 for Alternate airport appears to be really low
For wet runways, with reverse thrust:
1.92 for Destination airport appears to be marginal
1.67 for Alternate airport appears to be low
Flight Working Paper 730 and Transport Canada Aircraft Certification Flight Test Division Discussion Paper No. 22
From the Loughborough University Report “A New Aircraft Overrun Database 1980-1998 based on data from “English-speaking world”:
A high proportion of overruns involve near or over maximum weights
Three times as many overruns in landings than aborted takeoffs
Wet runways, contaminated runways and tailwinds are factors in many overruns, particularly landing long and fast.
The overrun accident rate in recent years might suggest that the industry is operating too close to limiting conditions, particularly with respect to human judgment; thus this links with Intruder’s comments (#14).
Once we entertain the thought that we might be able to land overweight, then we suffer bias – a tendency to find supporting information. The example questions given seek to justify the factor; none of which individually or collectively are sufficient or correct.
The factor (in UK CAA terms) is a landing distance safety-factor. It identifies with that undefined margin that we should seek to provide in all of our flying.
Instead of thinking ‘can we land’, we must question our assumptions and consider ‘should we be landing’ in these conditions.
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Old 13th Nov 2009, 01:03
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A few thoughts ..

Flight has to be discontinued and a land back is required at the departure aerodrome. Reason for land back is Depressurization. However no emergency

Then one would suggest that the land back is desired, rather than required, and one would be looking to observe all regulatory requirements as part of one’s decision process. One needs to keep in mind that the MLW is a Type Certificate limitation and, as such, is an underpinning factor in the aircraft’s design airworthiness.

Landing over gross for convenience would be a bit like trying to explain to the nice policeman that you were doing 110km/hr just before he pulled you up ... because the speed limit changed in the next few km, anyway, and you were saving the company some travelling time .... I have discovered, in my occasional discussions with the good constabulary folk, that that sort of argument has never worked really well ...

A) Make a heavy weight ... landing.. Intention is to save fuel and 2 hours holding time.

Hard to argue when the Regulator seeks to revoke your licence ?

B) Hold for 2 hours and reduce the A/C weight .. Intention is to enhance safety.

A good call, I suggest.

C) Some other better course of action

B) is a conservative strategy and you could quite easily plan with a bit more finesse to land pretty well right on MLW.

The aircraft is designed to land at MTOW

Irrelevant if the AFM limit is MLW and MLW is less than MTOW

I would land - 7000kg of fuel and 2 hours flying time is a lot of money.

Fine, but would you not then chose to engineer an emergency situation for the record ?

The 1.67 only applies to the planning-stage

I suggest not, unless you have an emergency and chose to invoke the emergency powers of the commander .. and, even then, you may need a good story for the investigation ...

The answer to your scenario is: 'It depends..........'

exactly

Inter-polate between the two examples above and you will have your answer.

Distances will be related to a quadratic sort of relationship rather than linear so a simple interpolation needs to be approached with some care.

So a "perfectly fine" aircraft (short of a cabin fire), but the company wanted us to return to Perth were we had engineering ... hold over the water

The commander gets paid to think on his/her feet. Some discussion with ops/eng and a sensible decision is the result.

the passengers became increasingly nervous about the vibration ... and we nearly ended up with a riot

Sandgropers .. what did you expect ?

The extra weight is taken into consideration in the landing calculations

Run that one past us again ? The landing calcs are for the declared weight .. if there is some “extra” weight involved, then the calcs change accordingly.

the 1.67 factor is to allow for ..

The raw FT data should be viewed as being unachievable. Even the TP couldn’t do it every time. What may end up as the base, unfactored, data in the AFM may have a little bit of negotiated fat but still represents a routinely unachievable brick wall.

Whatever regulatory factor (generally 1.67) is applied covers all those other reasonably expected things which might cause a problem and seeks to achieve the relevant failure rate which is built into the certification process.

Boeing data usually doesn’t include the 1000ft+ from threshold to touchdown

Can you cite any objective evidence to support this claim ?

So if the runway is dry, is it still worth it to waste 7000 Kg of fuel and 2 hours operational cost?

You don’t have the option. If the situation is not an emergency then the normal operational/certification standards must apply.

let them consider the implications (cost) of an overweight landing

And what are your considerations regarding the implications of the regulator’s seeking to revoke your licence ?

Why is a 1.67 factor used in the first place?

Unfortunately I don’t have sufficient information to comment with any authority on the specific factor.

However, in the olden days, the early regulators had to come up with a range of arbitrary “seems a good idea” figures to start the process going. These were then varied, as necessary, on the basis of historical accident data.

So, for instance, the 70 mph single stall speed was a FITWWAG which still is enshrined in FARs as 61 kts ... the 50 ft approach height clearance likewise came from the trees around a military parade ground ...

One would need to dig into the ancient archives to follow the history through to determine the origin and sequence for the present factor presuming that were possible .. but, I suggest, it will have followed the basic philosophy described above.

Always consider whether a lawyer could make mince meat of you if an incident were to happen on that landing.

Whatever story you come up with after the event, the legal system is going to endeavour to hang you out to dry and go for both the jugular and the deepest pockets.

Every time you take it upon yourself to be innovative, you stick your neck on the figurative chopping block ... I am convinced that all pilots, maintainers and engineers should review, if not be involved in, significant legal actions following serious or fatal accidents ... very sobering. So far I have thwarted attempts to sue proceeding beyond lodging a defence .. all due to a conservative approach to the way I do business.

Although not of direct relevance to this thread and I have no knowledge of the specifics, the following thread and a related one hark back to a recent Australian damages case which, I suggest, is of relevance to this thread ..

Consider a hindsight view and turn it into foresight.

Succinct.
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Old 13th Nov 2009, 01:34
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Be a Captain! Assume the authority and accept the responsibility! Judgement is what we get paid for, because we can teach monkeys to flick or depress a switch.

As for the A320 overweight landing procedure being an abnormal, of course it is, but it amounts to a landing vertical speed of no more than 360fpm (if memory serves me), which is no big deal. No special maintenance action needed thereafter. As for the landing distance, not sure what the 737 manual says anymore, but ALL performance factors are based on a set of circumstances, which, in the case of a depressurization, would tend to suggest you have considerably greater landing capability than the conditions listed for the landing calculation.

For those who seem to think landing over MLW is a huge deal, it is done with some frequency in regular line operations all over the world. However, as has been said over and over, with the authority comes the responsibility, so one has to ensure that landing margins and conditions merit not waiting for a lower landing weight. Also, in the example, it appears that one does not NEED to burn all 7,000kgs of fuel, as one is only trying to get down to the "factored" landing weight that creates a legally suitable hard surface. Again, I emphasize that I do not remember the normal landing conditions (braking, reversers, spoilers, anti-skid, etc..), but usually you have one or two of these systems in your back pocket to reduce (sometimes vastly) landing distance. One last thing, if the 737 is like the 320, then MANUAL braking considerably reduces required landing distance over auto brakes, so I would be standing 'em up, if needed!
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Old 13th Nov 2009, 02:11
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For those who seem to think landing over MLW is a huge deal, it is done with some frequency in regular line operations all over the world.

If the latter part of the statement be true, then I can only admit to being utterly astounded ...
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Old 13th Nov 2009, 09:03
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Hi John, I'm speechless that MLW is allegedly being exceeded on a regular basis for commercial reasons.
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Old 13th Nov 2009, 09:41
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For those who seem to think landing over MLW is a huge deal, it is done with some frequency in regular line operations all over the world.
I want to see some statistic to back up this rubbish please.

VERY VERY BAD STATEMENT!!
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Old 13th Nov 2009, 09:51
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Did he say it was for 'commercial reasons'?

He said it happens regularly and I believe that is true.

I would probably land overweight in the above scenario.

Performance wise it is comfortable and legal.
We are not able to continue the flight due to a technical problem .
We are not landing for 'commercial reasons'.
We would have consulted the QRH.
If the a/c actually depressurised at height you would be on a Mayday or at least a Pan call.

In reality the above landing should be a non-event. Don't thump it in.

As usual expect to have to defend yourself if anything goes amiss!
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