The great big "ask an airline pilot" thread!

AnRothar

Bleak wrote: »

Great thanks. Makes sense. Last question (I think ��). Where would this information have come from? Is say information ‘Mike’ coming from flight computer or say from flight plan at start?

ATIS (Automatic Terminal Information System).
Ground based transmitter at the airport.
Computer or person it depends.
Modern systems usually are electronic but someone will still cross check the info to ensure its correct before validating it for transmission.

Bleak

Thanks. Could I ask a question as well on RULAV. Is it in Irish controlled airspace? It doesn’t show on the published Dublin charts as termination waypoints such as NEVRI and PESIT do so I assume it’s in UK airspace? Clearance is always given on say LIFFY 6A departures direct to RULAV and never LIFFY. Excuse my ignorance and any info appreciated.

AnRothar

RULAV is on the far side of LIFFY, On the Q36 airway.

breadmond

Bleak wrote: »

Thanks. Could I ask a question as well on RULAV. Is it in Irish controlled airspace? It doesn’t show on the published Dublin charts as termination waypoints such as NEVRI and PESIT do so I assume it’s in UK airspace? Clearance is always given on say LIFFY 6A departures direct to RULAV and never LIFFY. Excuse my ignorance and any info appreciated.

If you're talking about aircraft already airborne being cleared dct RULAV rather than LIFFY that's because in being cleared for the LIFFY6A SID they are already cleared to the end of that SID i.e. LIFFY so it would be redundant to clear them there again. Aircraft are instead cleared to a point on their route beyond the SID so RULAV in this case. If the airspace is not busy this clearance may be given before the aircraft has flown the full departure also which will allow them to make a more direct route to their airway routing and so save time and fuel

PinOnTheRight

Bleak wrote: »

Thanks. Could I ask a question as well on RULAV. Is it in Irish controlled airspace? It doesn’t show on the published Dublin charts as termination waypoints such as NEVRI and PESIT do so I assume it’s in UK airspace? Clearance is always given on say LIFFY 6A departures direct to RULAV and never LIFFY. Excuse my ignorance and any info appreciated.

https://skyvector.com/ is a useful website that you will show you the airways and waypoints. If you can't find it on the map, type it into the flight plan window and it'll help you find it.

goingnowhere

RULAV is the next point after LIFFY, it is off the Isle of Anglesey in Wales.

Its a small shortcut to skip having to fly over LIFFY can go direct to RULAV, in the old days it was direct ROLEX which is off Llandudno

Do the airlines play around with MTOW to minimise charges at Dublin Airport?

smurfjed

It’s a common practice, so the answer is most likely yes. Will also apply to overflight charges.

basill

Deleted User wrote: »

Do the airlines play around with MTOW to minimise charges at Dublin Airport?

Not in mine.

billie1b

[Deleted User] wrote: »

Do the airlines play around with MTOW to minimise charges at Dublin Airport?

Yes, most operators have different MTOW’s of their aircraft, usually 3, my operator has up to 5 on some aircraft, when flight plans are completed the line maintenance engineer with get a copy of what weight the specific aircraft needs and change it to match the flight plan, over the course of a year it can save thousands of euros in charges.

OK. Thanks.
Following on from the MTOW question can an officially de-rated 777 200 ER take off from Dublin and make it to East Coast North America.

smurfjed

What do you mean by officially derated?

Boeing 777’s have two type of derated thrust, fixed derate usually (10-25%) and these are selected by selecting TO-1 or TO-2nin the FMC. On top of this, they have another method called “assumed temperature method”, this basically tells the engine that the outside air temperature is hotter than it actually is and the engine therefore delivers less power. The 2 ratings can be combined so that the engine is operating at around 55% of the installed thrust.

The last time I checked the numbers for Dublin, aircraft could easily get to the west coast.

"777-200ER
Aircraft landing approach. Side view of a twin-engine jet in flight with flaps and landing gear extended.
A 777-200ER of British Airways, its launch operator
The B-market 777-200ER ("ER" for Extended Range), originally known as the 777-200IGW (increased gross weight), has additional fuel capacity and an increased MTOW enabling transoceanic routes.[80] With a 658,000 lb (298 t) MTOW and 93,700 lbf (417 kN) engines, it has a 7,065 nmi (13,084 km) range.[177] It was delivered first to British Airways on February 6, 1997.[81] Thirty-three customers received 422 deliveries, with no unfilled orders as of April 2019.[2]

As of July 2018, 338 examples of the -200ER are in airline service.[10] It competed with the A340-300.[178] Boeing proposes the 787-10 to replace it.[179] The value of a new -200ER rose from US$110 million at service entry to US$130 million in 2007; a 2007 model 777 was selling for US$30 million ten years later, while the oldest ones had a value around US$5–6 million, depending on the remaining engine time.[180]

The engine can be delivered de-rated with reduced engine thrust for shorter routes to lower the MTOW, reduce purchase price and landing fees (as 777-200 specifications) but can be re-rated to full standard.[181] Singapore Airlines ordered over half of its -200ERs de-rated"

smurfjed

Pretty much all airliner engines come “derated”. The only smaller engines that I remember for the B777-200 were for the early versions, I think that the engine thrust was 76,000 lbs. these were the first aircraft that BA retired from service.

goingnowhere

The poster asking the question seems to be the hunt to find out if a 'US' carrier running DUB-US with a 777 has been playing around with the MTOW for ATC fees.

1. The 777-200 ER has ~50 MTOW more than the plain -200, so you could register at a significantly lower MTOW as you won't need that extra 50 tons out of Dublin to East Coast US

2. If you are running a 777-200ER at -200 weights then you clearly could do a derate (Boeing)/flex (Airbus) take off within the operational limits set down by the operator and manufacturer. If you are talking about actually going into the engine FEDEC and swapping some jumpers and making max trust lower so 100% is not 100%. The 737NG has this where the engines are plugged to a certain level but if you firewall the thrust levers it will give you max design thrust


Airbus tried to offer a regional A350, lower thrust, lower MTOW. You could then pay for some nice person in Airbus to visit, give them another briefcase of cash and they would tinker with the systems and enable insane mode to get you a full A350.

goingnowhere

goingnowhere wrote: »

The poster asking the question seems to be the hunt to find out if a 'US' carrier running DUB-US with a 777 has been playing around with the MTOW for ATC fees.

1. The 777-200 ER has ~50 MTOW more than the plain -200, so you could register at a significantly lower MTOW as you won't need that extra 50 tons out of Dublin to East Coast US

2. If you are running a 777-200ER at -200 weights then you clearly could do a derate (Boeing)/flex (Airbus) take off within the operational limits set down by the operator and manufacturer. If you are talking about actually going into the engine FEDEC and swapping some jumpers and making max trust lower so 100% is not 100%. The 737NG has this where the engines are plugged to a certain level but if you firewall the thrust levers it will give you max design thrust


Airbus tried to offer a regional A350, lower thrust, lower MTOW. You could then pay for some nice person in Airbus to visit, give them another briefcase of cash and they would tinker with the systems and enable insane mode to get you a full A350.

I'm just asking because the 777-200er is really cheap now and for specific missions might where not reaching the limits of its range be better than a 787 or 330 or 789. Obviously anyone who can legally reduce charges they should.

TP_CM

I have a general flying question.. When an aircraft is coming in to land during bad weather and, at the last minute, is struggling to get the wheels on the ground maybe due to air speed or a sudden gust of wind, instead of a go-around, why aren't the engines thrown into reverse thrust? It seems like that reverse thrust is only employed when the wheels are on the ground only. If you're a few feet from the ground, is it not tempting to turn on the reverse thrust? Is the reason due to safety? Or because it would not be effective?

basill

Use of reverse thrust in the air in the situation you describe would likely lead to at best a hard landing and at worst a crash and collapse of the landing gear and other related structures.

Airborne use of reverse thrust generally only features on military aircraft and typically is used to increase rates of descent into war zones to avoid ground to air threats whilst simulatenaously deploying chaff.

Modern commercial jet transports reverse thrust is engaged by a combination of weight on wheels and spoiler activation to avoid inadvertent airborne deployment.

Fritzbox

TP_CM wrote: »

I have a general flying question.. When an aircraft is coming in to land during bad weather and, at the last minute, is struggling to get the wheels on the ground maybe due to air speed or a sudden gust of wind, instead of a go-around, why aren't the engines thrown into reverse thrust? It seems like that reverse thrust is only employed when the wheels are on the ground only. If you're a few feet from the ground, is it not tempting to turn on the reverse thrust? Is the reason due to safety? Or because it would not be effective?

well, Russians (or former Soviets at least) like to do it that way...

goingnowhere

Concorde and the Trident were certified for reverse trust in flight, DC8 inner engines could be reversed in flight. You get a fairly insane decent rate...

737 can select reverse below 10 feet radar alt

Once selected in the flare you better be sure to land...

de biz

I remember Flight Safety telling us about a GIV Captain deploying the buckets on finals to Palma!VERY lucky to recover....

smurfjed

remember Flight Safety telling us about a GIV Captain deploying the buckets on finals to Palma!VERY lucky to recover..

it isn’t designed from work in the air and is governed by a weight on wheels system called a nutcracker.

bkehoe

TP_CM wrote: »

If you're a few feet from the ground, is it not tempting to turn on the reverse thrust? Is the reason due to safety? Or because it would not be effective?

Presuming use of reverse in flight was permitted on an aircraft, generally once you select reverse thrust you've committed to the landing. Up until selection of reverse, a go around is still an option. And if you've 'floated' past the touchdown zone the last thing you want to be doing is committing to a landing from which you potentially cannot stop before the end of the runway as the calculations the crew will have performed will usually have been on the basis of wheels touching tarmac about 300m from the start of the runway. If you ever watch a commercial aircraft training with touch and goes (landing and shortly taking off again) you'll see the reversers are never deployed for the same reason - no guarantee of ability to quickly provide forward thrust once the actuators start to deploy the reversers (it takes several seconds).

A comment here suggests it's possible on the 737. This is correct but only due to systems redundancy - it's impossible to deploy the reversers as long as the aircraft is in 'flight' for safety and use of reversers in flight is prohibited (even below 10ft). In case the normal weight on wheels sensors for the air/ground logic do not function as normal the system is designed to also use the radio altitude.

goingnowhere

Fairly sure it is possible on all first generation jets though not in the book as authorised, the unfortunate Lauda 767 incident refocused the industry.

Several US airlines for a while permitted/allowed push back using reverse trust on the 727/DC9/MD80 families

Markus Antonius

I'd like to know when pilots are going to pull together and discuss the obvious

1123heavy

Markus Antonius wrote: »

I'd like to know when pilots are going to pull together and discuss the obvious

??

Tenger

Markus Antonius wrote: »

I'd like to know when pilots are going to pull together and discuss the obvious

If this is any of the utter tripe I have seen on twitter over the last week there will be a forum ban involved

EchoIndia

goingnowhere wrote: »

Fairly sure it is possible on all first generation jets though not in the book as authorised, the unfortunate Lauda 767 incident refocused the industry.

Several US airlines for a while permitted/allowed push back using reverse trust on the 727/DC9/MD80 families

Types on which reverse in flight was possible and permissible were the Douglas DC-8 and HS.121 Trident. There was a discussion of this on the Pprune forum recently. https://www.pprune.org/aviation-history-nostalgia/640540-raf-vc-10-flight-reverse-thrust-use.html

1123heavy

Tenger wrote: »

If this is any of the utter tripe I have seen on twitter over the last week there will be a forum ban involved

I genuinely have no idea what is being discussed here but this now has increased the curiosity

A quick explanation or even a PM if acceptable would be much appreciated!

Edit: disregard, a quick google of "twitter pilot" seems to have revealed it

Markus Antonius

Tenger wrote: »

If this is any of the utter tripe I have seen on twitter over the last week there will be a forum ban involved

Don't know what that story is about. I'm talking about an apparent "gag order" on pilots discussing certain things or speaking with the media at all under threat of termination of contract or even worse.

I'm sure reasons are for "security" purposes but I want to know the extent of this order and what exactly they are not allowed discuss...