The meaning of "Contingency".
Thread Starter
Join Date: Dec 2009
Location: Brazil and Italy
Age: 50
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
The meaning of "Contingency".
Hello all, I would like to ask you about this topic, please. I know it refers to an abnormal situation.
What could you add to this subject, please?
Thank you in advance.
What could you add to this subject, please?
Thank you in advance.
Join Date: May 2014
Location: In thin air
Posts: 186
Likes: 0
Received 0 Likes
on
0 Posts
Google is your friend:
contingency
noun possibility, happening, chance, event, incident, accident, emergency, uncertainty, eventuality, juncture I need to provide for all possible contingencies.
Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002
contingency
noun possibility, happening, chance, event, incident, accident, emergency, uncertainty, eventuality, juncture I need to provide for all possible contingencies.
Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002
It can be thought of as "What if...?"
What if the headwinds are stronger than expected?
What if an engine fails after V1?
What if the destination airport is closed for some reason?
Each of those is a "contingency" - a possibility that will require a "Plan B" - a change in operation from the original plan, to accomodate the changed situation.
"Concorde could fly non-stop Caracas - Paris, contingent upon the winds and weight." Meaning that normally it could not, but if the winds and weight - the contingencies - were abnormally favorable, it could.
What if the headwinds are stronger than expected?
What if an engine fails after V1?
What if the destination airport is closed for some reason?
Each of those is a "contingency" - a possibility that will require a "Plan B" - a change in operation from the original plan, to accomodate the changed situation.
"Concorde could fly non-stop Caracas - Paris, contingent upon the winds and weight." Meaning that normally it could not, but if the winds and weight - the contingencies - were abnormally favorable, it could.
Join Date: Jul 1999
Location: England
Age: 61
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
EASA guidance material:
GM1 CAT.OP.MPA.150(c)(3)(i) fFUEL POLICY Factors that may influence fuel required on a particular flight in an unpredictable way include deviations of an individual aeroplane from the expected fuel consumption data, deviations from forecast meteorological condi- tions and deviations from planned routings and/or cruising levels/altitudes.
GM1 CAT.OP.MPA.150(c)(3)(i) fFUEL POLICY Factors that may influence fuel required on a particular flight in an unpredictable way include deviations of an individual aeroplane from the expected fuel consumption data, deviations from forecast meteorological condi- tions and deviations from planned routings and/or cruising levels/altitudes.
Join Date: Jun 2000
Location: last time I looked I was still here.
Posts: 4,507
Likes: 0
Received 0 Likes
on
0 Posts
M/S're. First a curious pseudonym for such a question. Hm?? Contingency is a buffer a margin to allow for error, unexpected events, change of plan etc. If you are designing something you always build in an extra factor for 'allowances'. It needs 3g for everyday use so you add 25% for exceedance margins. No-one likes to be operating on the edge all the time, so a little extra legal full is always welcome.
Prof. Airport Engineer
Join Date: Oct 2000
Location: Australia (mostly)
Posts: 726
Likes: 0
Received 0 Likes
on
0 Posts
Contingency coffee is a spare sleeve of Nespresso capsules in the suitcase, in case the hotel / site office runs out.
Thank you m.s - let me go and pack one right now.
Thank you m.s - let me go and pack one right now.
Moderator
.. or, according to my poodles .. all of whom adore real coffee ... Nescafe is somewhere between definitely unacceptable and only just barely a contingency in extremis ...
Join Date: Nov 2002
Location: Europe
Age: 61
Posts: 69
Likes: 0
Received 0 Likes
on
0 Posts
Instant coffee is not a contingency, it's a measure of absolute last resort.
Moderator
.. I suspect, though, that most folk would seriously be looking at getting a top up before launching. Philosophically a bit like MELs and QRHs, methinks ?
Join Date: Dec 2006
Location: Casablanca
Age: 53
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
ICAO recently modified it's definition of Contingency fuel to take into account extended taxi time.
Contingency fuel, which shall be the amount of fuel required to compensate for unforeseen factors.
It shall be 5 per cent of the planned trip fuel or of the fuel required from the point of in flight re-planning based on the consumption rate used to plan the trip fuel but in any case shall not be lower than the amount required to fly for five minutes at holding speed at 450 m (1 500 ft) above the destination aerodrome in standard conditions;
Note.— Unforeseen factors are those which could have an influence on the fuel consumption to the destination aerodrome, such as deviations of an individual aeroplane from the expected fuel consumption data, deviations from forecast meteorological conditions, extended taxi times before take-off, and deviations from planned routings and/or cruising levels/altitudes.
Contingency fuel, which shall be the amount of fuel required to compensate for unforeseen factors.
It shall be 5 per cent of the planned trip fuel or of the fuel required from the point of in flight re-planning based on the consumption rate used to plan the trip fuel but in any case shall not be lower than the amount required to fly for five minutes at holding speed at 450 m (1 500 ft) above the destination aerodrome in standard conditions;
Note.— Unforeseen factors are those which could have an influence on the fuel consumption to the destination aerodrome, such as deviations of an individual aeroplane from the expected fuel consumption data, deviations from forecast meteorological conditions, extended taxi times before take-off, and deviations from planned routings and/or cruising levels/altitudes.
Exactly John!
To set the scene on this *hypothetical* (!) flight, imagine it was a long-haul ETOPS flight from JFK-LHR with reduced contingency fuel as per the Flight Plan.
There has been extra fuel to allow for a 45 minute taxi out at JFK, but taxi time ends up being more like 1h45. Therefore all the contingency fuel is burnt before we are anywhere near the runway.
Now I know that JFK is a nightmare for getting back onto stand (the last time I had to go back to stand it took 3 hours...that was in the snow though) and max FDP is relatively tight on this particular flight, but my view is that burning all the contingency fuel (and some of the ALT 2 fuel!) before you even get airborne is a tad dodgy. Ok, you could argue that it's 'only a planning thing' and statistically how likely are we to need it anyway?!
What would the view of the regulators be if you had an emergency situation that then led to a fuel emergency as well? Which is not beyond the bounds of possibility in the above scenario - maybe a flap or gear issue on final approach into LHR after holding requiring a missed approach, or a diversion due to LHR closing (as has happened to me in the past)!
I'm not so much interested in the decision making process as to what anyone would do, but more interested in terms of the regulatory requirements, and the view that the subsequent enquiry board would take!
To set the scene on this *hypothetical* (!) flight, imagine it was a long-haul ETOPS flight from JFK-LHR with reduced contingency fuel as per the Flight Plan.
There has been extra fuel to allow for a 45 minute taxi out at JFK, but taxi time ends up being more like 1h45. Therefore all the contingency fuel is burnt before we are anywhere near the runway.
Now I know that JFK is a nightmare for getting back onto stand (the last time I had to go back to stand it took 3 hours...that was in the snow though) and max FDP is relatively tight on this particular flight, but my view is that burning all the contingency fuel (and some of the ALT 2 fuel!) before you even get airborne is a tad dodgy. Ok, you could argue that it's 'only a planning thing' and statistically how likely are we to need it anyway?!
What would the view of the regulators be if you had an emergency situation that then led to a fuel emergency as well? Which is not beyond the bounds of possibility in the above scenario - maybe a flap or gear issue on final approach into LHR after holding requiring a missed approach, or a diversion due to LHR closing (as has happened to me in the past)!
I'm not so much interested in the decision making process as to what anyone would do, but more interested in terms of the regulatory requirements, and the view that the subsequent enquiry board would take!
Join Date: Dec 2006
Location: Casablanca
Age: 53
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
