[RVD]

Originally Posted by Jeroen

I don't know about such extreme, but I have seen them very stable flying over Cities, park, canals etc.

You are suggesting that when one would use DA over DH that would also be used to perform the auto land? I'm not so sure about that, as far as I know, on Boeings at least it will always use RA. The DH/DA is purely the read out on the PFD.

Jeroen

I am not suggesting that at all. Note that autoload is independent of DA and DH. If you give the AFDS the inputs required for an auto land, the aircraft will perform an auto land irrespective of what minima is set. Mimina is for the flight crew to decide whether or not to continue an approach. Auto land can be performed in fair weather conditions as shown in the pictures above and in all probability, you would have seen the runway environment much ahead of you DA/H. The question of DA/H comes during marginal weather conditions and in such case one always uses DA as one is guaranteed of a smooth surface extending from the runway and there is no abrupt changes in RA. Remember, one can do an auto land even in a place like Mangalore as the flare mode is engaged at 50FT RA which is over the threshold and hence the terrain before does not play too much of a role but usually such airports are not certified for CAT 2/3 Approaches due to rapid changes in RA during the approach which could be quite confusing to a flight crew during actual low visibility conditions. What I was suggesting in my previous post is that I was surprised at the minima of 200Ft, which is CAT 1 minima was set on Radio and not Baro which is what is followed by most operators. Only a minima below CAT 1 is usually set with reference to Radio Altimeter.

[RVD]

Jeroen, do see the link and notice the RA fluctuation at the bottom of the PFD during an auto land.

https://youtu.be/r4WKikGDLqk

[Jeroen]

Originally Posted by RVD

Jeroen, do see the link and notice the RA fluctuation at the bottom of the PFD during an auto land.

https://Youtu.be/r4WKikGDLqk

Thanks.
Im checked a few Boeing video's too and saw the same behavior. I do wonder how they keep a smooth descent rate with such a jumpy reading?

As far as I know/remember the autoland system always uses the RAs, correct? I don't think you can switch to use barometric pressure? Switching from DA to DH only affects the readings on the PFD or does it do anthing else?
Jeroen

[RVD]

Originally Posted by Jeroen

Thanks.
Im checked a few Boeing video's too and saw the same behavior. I do wonder how they keep a smooth descent rate with such a jumpy reading?

As far as I know/remember the autoland system always uses the RAs, correct? I don't think you can switch to use barometric pressure? Switching from DA to DH only affects the readings on the PFD or does it do anthing else?
Jeroen

I think you may have the concept a little wrong. The descent rate is smooth because the the autopilot system is flying the glide slope all the way. It's as simple as that. The RA is only taken by the system for the FLARE mode which happens at 50Ft and Auto throttle RETARD mode which happens around 30Ft. As long as the surface is flat approaching 50Ft, the auto land system will land the plane just fine. Do read up on Turkish airways crash that happened a couple of years back where the RA was faulty and the system went into FLARE/ RETARD mode while being a fair distance off the runway.

[Jeroen]

Originally Posted by RVD

I think you may have the concept a little wrong. The descent rate is smooth because the the autopilot system is flying the glide slope all the way. It's as simple as that. The RA is only taken by the system for the FLARE mode which happens at 50Ft and Auto throttle RETARD mode which happens around 30Ft. As long as the surface is flat approaching 50Ft, the auto land system will land the plane just fine. Do read up on Turkish airways crash that happened a couple of years back where the RA was faulty and the system went into FLARE/ RETARD mode while being a fair distance off the runway.

Thanks that makes sense. I remember now, its been a while since I last looked into these systems, or flew with them.

No autoland on the Cirrus and Diamond I used to fly.

For those interest in this particular incident, in my home country

http://www.onderzoeksraad.nl/en/onde...airlines#fasen

[coolboy007]

What a brilliant thread this is, currently in Madrid doing my A320 type rating and the entire thread is so exciting to read and there is so much to learn about other aircraft. Am still going through my vpt sessions and really waiting for the FFS to start soon, tons of systems to study and so much hard work to put in right now but i completely love it.

[Hells Bells]

I am so glad I just need to buckle up and allow the pilot to do dew As much as I loved browsing the conversation, I just could not bring myself to actually read the whole technical details!

But awesome thread nevertheless. Goes to show people who love their set of wheels do not differentiate amongst them and are all on t-bhp

[maddy42]

I just booked a 1 hour intro flying experience out here in Phoenix. Excited to do it but the schedule is for a month away!

Have a couple of questions:
1 how much fuel a flight consumes in probably a 1 hour flight. I know it depends on the flight but just give us some examples.
2 on a pvt jet do you have a separate terminal which saves you time getting to the airline? Also is there abundant parking area when you fly to a new airport? Is there parking fees etc and do you get a vehicle till your flight the way they show in movies?
3 how much time in advance do the pilots get notified on their next flight or are they on standby like a doctor?
4 where is the fuel on a aircraft stored? Always confused due to the shape of the aircraft.
5 this is my favorite one... Has anybody travelled on a Concorde? If so how was it?

I have more queries but will save them for later.

Maddy

[RVD]

Originally Posted by maddy42

I just booked a 1 hour intro flying experience out here in Phoenix. Excited to do it but the schedule is for a month away!

Have a couple of questions:
1 how much fuel a flight consumes in probably a 1 hour flight. I know it depends on the flight but just give us some examples.
2 on a pvt jet do you have a separate terminal which saves you time getting to the airline? Also is there abundant parking area when you fly to a new airport? Is there parking fees etc and do you get a vehicle till your flight the way they show in movies?
3 how much time in advance do the pilots get notified on their next flight or are they on standby like a doctor?
4 where is the fuel on a aircraft stored? Always confused due to the shape of the aircraft.
5 this is my favorite one... Has anybody travelled on a Concorde? If so how was it?

I have more queries but will save them for later.

Maddy

Congratulations!!! You will enjoy your introduction to flying. Regarding your questions, perhaps a charter pilot can answer better but here goes :
1) Depends on the aircraft and the altitude. A very rough ball park for a narrow body jet airliner is about 2100- 2500 Kg/H.
2) All these depends on the airport. Some do and some don't. Parking slot and fee is arranged by prior communication with the aerodrome operator.
3) Depends on where and what you fly. Typically commercial airlines operate on a fixed schedules and so it is easier for them to assign flights to their Crew who usually get their roster for the next month during the end of the previous month. Charter pilots do not have that luxury.
4)IT is always stored in the wings. Additionally, there could be other tanks depending on the manufacturer and the range requirement of the operator.
5) Nope.

[Jeroen]

You are likely to fly a Cessna or such and they have a fuel consumption somewhere in the range of 6-10 gallons per hour. For jets fuel consumption is also heavily influenced by what altitude you get assigned by ATC.

Especially in the USA a lot of the so called FBO (fixed base operator) provide excellent service to private pilots and their planes. The FBOs are they guys that operate the hangars, provide fuel, repair and maintain your plane etc.

Especially, if you allow them to fill your plane the rest of their services are often free. They might wave your landing and or ramp fees, if any. And they usually have a few crew cars that you can borrow for free. You are expected to fill up used petrol which is only fair.

Fuel is typically stored in the wings and or central fuselage tanks. Planes like the747 have stabiliser tanks as well (out on the tail!).

In the early mid eighties I had the pleasure of flying Concorde once. BA had a special promotion. You basically took of and flew for 20 minutes or so. So we never went supersonic. Included was also a BA helicopter ride from Heathrow to Gatwick or vice versa, can't remember. We lived in Brighton, UK at the time and I think I drive to Gatwick, took the helicopter to Heathrow, boarded Concorde etc.

It was a very special day. These days you can only visit static Concords in various places around the world

Jeroen

[searchingheaven]

Originally Posted by maddy42

How much fuel a flight consumes in probably a 1 hour flight. I know it depends on the flight but just give us some examples.

This is a very vague question, since it depends on a LOT of parameters. But since you want some ballpark figures, here we go. All values in kgs.

A320/B738/Any typical narrow body airliner

• Assuming sea level, ISA conditions, idle fuel burn is around 540 kg/hr.
• Cruise fuel burn depends on so much, environmental conditions, cruise speed, altitude, weight, etc... but ballpark with a decent passenger load (total burn rates) for a B738 - 2,700kg/hr early in the flight (heavy) to 2400 kg/hr in cruise and reducing to 2,300kg/hr before descent.

Learjet 60XR

• Assuming sea level, ISA conditions, idle fuel burn is around 320 kg/hr.
• Taxi: 350 kg/hr
• Cruise fuel burn 700 kg/hr

Boeing 777-300 ER - The big baby

• Taxi Fuel Burn - GE Engines 2,000 kgs/Hour
• APU Fuel Burn - Ground consumption 240 kgs/hour - In-flight consumption 140-270 kgs/hour dependant on Altitude and Weight
• Cruise fuel consumption 8550 kg/hr during initial climb. Then it hovers around 8100 kg/hr for cruise phase. Descent rates are around 7750 kg/hr.
  
• The variation in fuel burn rates of the 777-300ER is high due to the fact that we have around 100,000 kgs of fuel on 10 hr+ routes.

Figure 1: This is the fuel plan for a B777-300ER from EGLL-KLAX. Notice the release fuel? Its around 95,000 kgs. By the time of landing, we will burn about 80,000 kgs(i.e around 12, 000 kg REMAINING at KLAX).

Originally Posted by maddy42

Where is the fuel on a aircraft stored? Always confused due to the shape of the aircraft.

Depends on the aircraft and its configuration. For eg. a 777-200LR with 3 Aux tanks has different fuel storage option compared to the normal config. Anyways, Fuel is usually stored in 3 tanks, the center(fuselage) and 2 wing tanks. The locations are shown below for a private jet(LR60) and a B777-300ER.

Figure 2: Fuel Tank locations B777-300ER

Figure 3: Fuel Tank locations Learjet 60XR



Figure 4: This image is from the MFD(multi function display) of the 777-300ER. It shows the total amount of fuel as 102,000 kgs. Green rectangles are the fuel pumps, total of 6. Normally, the center tanks are emptied first and then wing tanks are used. Also, notice the cross feed valves. Generally, the Left fuel pumps supply fuel to left engine & vice versa. The crossfeed valve is used to temporarily connect the two sides of the system. This system allows the shortest route for the fuel and keeps the systems separate, so a leak on one side cannot drain the entire system. The crossfeed valve is generally kept shut for this reason. A || double line indicates a closed valve while a single line indicates a open valve.

.

Originally Posted by maddy42

On a pvt jet do you have a separate terminal which saves you time getting to the airline? Also is there abundant parking area when you fly to a new airport? Is there parking fees etc and do you get a vehicle till your flight the way they show in movies?
Maddy

Yes, most airports have a private terminal which allows us to skip long queues. For example Washington has the Signature terminal. Typically, you arrive at the 'FBO' (fixed base operator... essentially the private terminal) 20 mins before departure. They will take you to your plane in a golf cart (along with your luggage), or let you walk out (depends on the airport). I have very rarely used cars to out to the waiting jet. Total time from arriving at FBO to airborne? 5 to 10 minutes. Also, private jets can land at small airports closer to where you intend to travel. There are many more minor airports than major ones, so you often don't have to travel as far to get to one. And they're less congested, making the experience more pleasant.

Just FYI, I was informed by a friend of mine that GVK has stopped allowing private cars to ferry passengers up to their jets at CSIA, Mumbai. They have started their own service(i.e a Merc/Camry), which picks up passengers from Gate no 8 at CSIA and drops them near the jet. Its costs Rs. 10000 for a 2 minute, 200m trip .. Even the Learjet cannot match upto their service's operating cost.

Originally Posted by maddy42

How much time in advance do the pilots get notified on their next flight or are they on standby like a doctor?

Pilots are people, not machines. They cannot fly 24x7. They need rest, time off for training, time off for family. I know people who call their pilots 2 hrs before leaving. I find that to be a be a very insensitive thing to do. At my organization, we usually have a policy of calling them 8 hrs to 10 hrs before leaving, so that they can rest, if they haven't already done so.

Originally Posted by maddy42

5 this is my favorite one... Has anybody travelled on a Concorde? If so how was it?

Nopes, not lucky enough to get that opportunity.

[maddy42]

Originally Posted by searchingheaven

Just FYI, I was informed by a friend of mine that GVK has stopped allowing private cars to ferry passengers up to their jets at CSIA, Mumbai. They have started their own service(i.e a Merc/Camry), which picks up passengers from Gate no 8 at CSIA and drops them near the jet. Its costs Rs. 10000 for a 2 minute, 200m trip .. Even the Learjet cannot match upto their service's operating cost.

Haha wow that is one pricey charge. It would ensure a lot of folks skip the main airport entirely and move to Juhu maybe.

Thanks for all that info.

Maddy

[sagarpadaki]

I have a doubt. When there are two runways parallel to each other and an aircraft intercepts the glide-scope in an ILS how does the ILS system resolve the runway to be chosen to land? Since the resolution between a Left and Right runway will be blurred when the glidescope is intercepted a few miles away and will only become clearer when the aircraft is closer to the runways

[Jeroen]

Originally Posted by sagarpadaki

I have a doubt. When there are two runways parallel to each other and an aircraft intercepts the glide-scope in an ILS how does the ILS system resolve the runway to be chosen to land? Since the resolution between a Left and Right runway will be blurred when the glidescope is intercepted a few miles away and will only become clearer when the aircraft is closer to the runways

They operate on different radio frequencies. So you do need to make sure you select the correct frequency for the correct runway obviously. On the jet airliner you would choose the appropriate runway on the flight management system. Once you select it, it would automatically set the correct ILS frequency.
Even so, this always get verified as part of the pre landing checks.
The ILS also sends out a morse code and you can listen into it to verify you got it right.

Also, most pilots will call out the runway number once they can read it of the runway.

Still planes occasionally land on the wrong runway, sometimes the taxiway amor even the complete wrong airport.

But if you ensure you got the correct ILSAe frequency set you should be ok. But check and double check!

[Jeroen]

Maybe just to add for further clarification to my previous post. In such a scenario each runway would have a dedicated ILS system with dedicated specific respective frequencies.

Check this link which will illustrate. See the bottom part with the different runways, each with a specific frequency and ident. The ident is the morse code I mentioned before

http://ivao.co.uk/atc/egll/