Diverting vs a go-around

[ukpilotinca]

My wife flew to Sacremento yesterday and said that they did a go-around and landed second time around. She said it was because fog had blown over the runway, though I'm not sure if that was an official announcement or she was just looking out of the window.

A friend of hers arriving on a different flight near the same time diverted to Oakland. However, there was an announcement saying that they didn't have enough fuel for a go-around and were going to divert instead and pick up fuel, and come back.

Her question to me was: if they didn't have enough fuel for a go-around, how did they have enough fuel to divert?

My thinking was that they perhaps didn't have enough fuel to do the approach, go missed, hold and come back with the appropriate reserves. But they did have enough to go to the alternate.

Am I on the right track, or is there some other reason?

Paul
ps when my wife says a go-around I wonder if she is meaning a missed approach...

[Reds Blues Greens]

Paul,

Interesting question.

Firstly as I understand a Go-Around and a Missed Approach are the same thing. Although there may be some variation in the definitions that I am unaware of. As you are probably aware, the call from pilots to initiate a missed approach/go-around is always "go-around".

From what you have described it sounds like the flight crew decided that an approach into the airfield with the bad weather would have been a waste of fuel due to the current weather and perhaps in combination with a deteriorating trend.

Fuel on flight plans almost certainly would have allowed for an approach, go-around, diversion to be safely made. It seems it just may have been more commercially viable and comfortable for the passengers to divert to the alternate as a first action.

I would be interested to hear what anyone else thinks.

Cheers,

RBG.

[Paracab]

First of all I have to say that there are many prooners that have a lot more knowledge on this type of thing (and I know they will correct me if I am wrong :O ) however my understanding is as follows...

Go around - Initiated for a reason such as an obstructed runway.

Missed Approach - An approach is attempted but the runway cannot be seen at the minium legal distance/height (due to fog, for example) therefore the approach is aborted.

This is just something I read recently, I could be wide of the mark.

Try a search for an explanation on holding fuel and diversions, there has been plenty of discussion on here in the past.

Also, you may have more luck if this is posted in the 'Questions' forum.

Regards,

Pc

[Gonzo]

A 'go around' is when the aircraft puts power back on and climbs away from the runway.

This will lead into a 'missed approach procedure' which is laid down in aeronautical charts, for example: Climb straight ahead to 3000 feet. At 1500 feet turn left to track 150 degrees.

So airliners will usually perform a 'go around' which then is followed by a 'missed approach'.

Depnding on what avionics equipment is installed, and what experience and qualifications each member of the flight crew has, there will be apporach minima, expressed in metres (visibility). If the visibility goes below the a/c minima, than it won't land, and some days that change will occur pretty late on the approach.

The fuel situation is copmplicated. Don't take the figures as accurate, this is just an example. Basically, each fuel load is calculated like this: 'Flying A-B' fuel (x hours and y minutes), 'anything the crew want to put in at their discretion' fuel, plus 20 minutes holding at destination, plus 10 minutes to fly an approach, plus 10 minutes for a missed approach, plus 30 minutes flying to diversion, plus 20 minutes holding at diversion, plus 10 minutes to fly an approach at diversion, plus 20 mins emergency reserve.

At each stage of the flight, the fuel remaining will be checked against what one should have, and then actions will be taken. For example, if it's calculated that you have less than an hour plus emergency reserves, you will be looking to divert. However, at some airports with more than one independent runway, the diversion fuel can be used to continue holding (in effect you're 'diverting to the other runway')

NB I'm not an airline pilot, and this was rather rushed!

[flapsforty]

(JAR-OPS 1.375(b), App 1 to 1.375(a)(ii)&(iii), App 1 to 1.045A O 8.3.7).
An aircraft at a holding beacon must divert when the fuel reaches Reserve plus Diversion fuel. However it can continue to hold without an alternate being available so long as an EAT or maximum delay is known, a minimum of Reserve fuel will be on board on landing, and the landing could be completed in the event of any forecast deterioration in the weather and plausible single failures of ground and airborne facilities. Although these are the legal requirements, the crew would also take into accont the number of runways available at the destination and alternate. If at any stage a situation developed where the aircraft was going to land with less than Reserve fuel, then a Mayday would be declared.
The Diversion fuel is calculated for a go-around from DH, so a diversion from the hold would generally use less fuel.

also.......

Your reserve fuel is made up of Alternate fuel + Final Reserve Fuel

Alternate Fuel:
Missed approach at destination + Cruise to + Approach and landing at alternate

Final Reserve Fuel:
Hold at 1500ft at alternate for 30mins

and..... ;)
As soon as you reach a fuel quantity that equals your diversion fuel+final reserve fuel then by law you MUST divert.

As a humble trolley dollie I of course have no real knowledge of these things, but years of pruning has at least given me a basic understanding of these matters and the ability to use the search button. :)

[Torque2]

Practically, if you are approaching an airport which has weather sufficiently bad that aircraft are making go-arounds or missed approaches (same thing), you could well be expected to enter the holding pattern and await your turn for attempting a landing.
At this stage you may be given an expected holding estimate or an expected approach time, ie the time that you would leave the hold and commence the approach to the airport.

As is described by the previous correspondents you are legally required to have the required fuel for the approach, missed approach and diversion plus reserves. It may be however that the holding pattern has so many aircraft that your expected approach time eats into your reserve fuel and it would be more prudent to go straight to the diversion airfield and re-assess the situation. Hope this helps
;)

[zehutiman]

Missed approach and go-around are technically, not the same.

As has been pointed out already, a missed approach is executed from an instrument approach, whereas, a go-around is executed anywhere when the aircraft is in a position to land. Moreover, a pilot cannot execute a missed approach just anywhere he pleases. He may want to execute a missed approach 3 miles from the runway (for whatever reason), but the instrument approach procedure might require him to continue straight ahead for a certain distance or time.

When I fly, and it's the other pilot's leg, I often hear him correctly brief a visual approach to the runway, and then in the same breath, incorrectly brief the missed approach procedure for, let's say, the Instrument Landing System (ILS) to that runway. We're performing the visual approach, not an instrument approach, therefore, there is no missed approach procedure. The proper briefing would say that in the event of a go-around, we'll follow tower instructions...(and whatever else might be pertinent to the field or flight, etc.). Additionally, if a crew was cleared for the visual approach and on short-final they decided they needed to go-around, the tower would probably be very upset if they performed some (ILS,VOR,RNav,GPS) missed approach procedure automatically w/o input from the tower.