[V.Narayan]

Rated a well deserved 5 stars. Truly the best of Team BHP. Thank you for the lucid write up and answering the many questions painstakingly. here's wishing many happy & safe hours of flying for you.

[apachelongbow]

Originally Posted by honeybee

So I searched on YouTube for the Birmingham airport and watched a clip with several planes trying to land in crosswinds.

A couple of questions: I see a couple of planes very close to landing, but still deciding to go around, one even had its main wheels on the tarmac before it lifts off again and goes around. What gives? I can understand a few feet above the ground it's all shaky, but once on terra firma or within inches of touching it, should one go around?

I read in one of the posts above that while landing in a crosswind situation the nose of the aircraft may be pointing somewhere else, but the undercarriage is aligned with the runway - How do you do that? The only analogy I have is of beat-up and chassis-damaged vehicles with their body/nose pointing a few degrees right or left compared to the wheels. How do you do that in a modern airplane?

Sorry, a third question - On touchdown, do you guys just kill the power/throttle, like go from 40% power to zero or something? Would that help in reducing the speed (and in turn the lift) and help keep the aircraft 'down' on the tarmac?

Part of the third question above, really - with flaps out during the landing approach, you get more lift at reduced speeds. Also at touchdown, there are 'brakes'? or some flaps which are raised 'above' the wings to brake the speed. At this point, would it help to retract the flaps back in to prevent generation of lift, which would lift the aircraft again in air? Or do you NOT do it just to allow you to go around even after a touchdown?

One can elect to go around anytime as long as reversers are not selected. Classic example is the Air India Mangalore crash: The pilot/s decided to abort landing and go around post selecting reversers. The result was tragic and avoidable accident

Aligning with runway is possible when you follow the localizer or track. The aircraft is naturally crabbing with nose into the wind. She will also touchdown that way,and the pilot has to only use rudder to decrab, that is move the nose to align with the runway, a few feet before touch down. One can also decide and touch down with the crab, but it puts enormous pressure on the main gear, due pivotal action, hence is best avoided.

One never ever lands a jet with power, unlike a turbo prop, the general power used to maintain approach speed is about 45-55% of N1, however one needs to cut power before touchdown, to ensure touchdown in the landing zone and no possibility of ballooning up during flare.

[Gansan]

Are you automatically eligible to fly a turboprop, being a jet pilot? And can a turbo prop pilot fly jets? If one is qualified to fly both, does he need to put in a specified number of hours in both every year to retain the eligibility?

[apachelongbow]

Originally Posted by Gansan

Are you automatically eligible to fly a turboprop, being a jet pilot? And can a turbo prop pilot fly jets? If one is qualified to fly both, does he need to put in a specified number of hours in both every year to retain the eligibility?

Nope. A pilot needs to be rated on each and every aircraft type/variant he/she has to fly. He/she can hold multiple ratings but has to be current on type that is: on a span of say 6 months he/she needs to have done 3 takeoff landings on each of aircraft type he/she has on his/her license. The time period can vary among licensing agencies, generally its 6 months based on ICAO norms.
Type rating is the certificate on your license to fly that particular type of aircraft only. If we explain using automobiles than you need a endorsement on your driving license to drive say Tata Safari Storme 400, one more endorsement to drive Safari 3.0 liter (reason different engine technology, gearbox), a new endorsement to drive a Fortuner (different manufacturer) and so on. You may not drive a Earth mover and a Nano on the same license, likewise you can't generally operate a turbo prop and a jet aircraft on one license, but again subject to operator and licensing agency norms.

[Jeroen]

Originally Posted by Gansan

Are you automatically eligible to fly a turboprop, being a jet pilot? And can a turbo prop pilot fly jets? If one is qualified to fly both, does he need to put in a specified number of hours in both every year to retain the eligibility?

To add what Apachelongbow already stated

Here is a good overview of the various licenses under FAA. Might be somewhat different in different countries but not by much.

https://en.m.wikipedia.org/wiki/Pilo..._United_States

Most pilots will start with a PPL. Private Pilot License. That will allow you to fly single engine (not jets) planes up to 5700kg. Actually, you are allowed to fly any plane. So you could fly a Cessna 150, 172, Mooeny etc. without type rating. Everybody would agree you should never get into a plane younare not familiar with, but legally you can.

PPL allows you to fly under Visual Flight Rules. Most pilots with a PPL will quickly get a few endorsements such as complex plane (e.g. Retractable gear, variable pitch propellor), high altitude, high power (more than 200 BHP).

Endorsements can be given by a CFI, Certified Flight Instructor, so you don't need to take an official FAA exam. It gets signed off in your log book.

Next for most it will be about getting an instrument rating, IFR. Next would be twin engine rating and then the various commercial licenses and a so called ATP before you go on to the various type ratings.

Before you pass your so called check ride for you PPL, you are known as a student pilot. At some point in time during your PPL training there will be that moment that you will take of solo for the very first time! Every pilot will remember that flight, one of the most exciting moments in my life! Typically your instructor will tell you I think you are ready to go solo, do you think so to. Upon the next landing he/she will get out and you will be asked to do take off, fly the circuit and do a few touch and goes and land again. Unbelievable experience. I was so exited afterwards I called just about everybody that was listed in my phone to tell them about it!

I went solo at my 12th flying hour. Passed my check ride and got my PPL after 42 hours, and a lot more hours to my IFR.

As student pilot, as part of your training, before you can go for your check ride, you have to conduct several mandatory cross country flights as well. So even before you are officially a pilot you will be out there, all by yourself, up in the air!

Jeroen

[honeybee]

Another stupid question. While returning from Mumbai tonight, I could watch from the EEH two planes approach the airport for landing. I have once been able to see a plane barely a few feet above the airport boundary wall near Kurla, me sitting in a taxi and the plane approaching overhead.

Also during my train travel days I could see at least two to three planes each night on their approach to the airport.

All these night time sightings are amazing for one big reason: the lights.

So my normal question: what are the different types of lights on the exterior of the aircraft? Strobes, beacons, floods? What are they used for?

And the stupid question. I guess there is a massive floodlight on the nose gear and it's switched on as soon as the gear is in landing position in the night. While the plane is still in the air and a few kms away from the airport, does that light show up anything in the air or on the ground? Or is it more to tell others that you are approaching?

Also I remember reading somewhere that there is a set of lights at the beginning of the runway which tell you if you are on the right approach. If you are too low or too high, the lights will be of a different colour. Could you please be able to throw some light on this? (Pun intended)

[searchingheaven]

Originally Posted by V.Narayan

Rated a well deserved 5 stars. Truly the best of Team BHP. Thank you for the lucid write up and answering the many questions painstakingly. here's wishing many happy & safe hours of flying for you.

Thank you so much for your encouraging words and for being a good reader. It really means a lot to us.

Originally Posted by honeybee

So my normal question: what are the different types of lights on the exterior of the aircraft? Strobes, beacons, floods? What are they used for?

I guess there is a massive floodlight on the nose gear and it's switched on as soon as the gear is in landing position in the night. While the plane is still in the air and a few kms away from the airport, does that light show up anything in the air or on the ground? Or is it more to tell others that you are approaching?

Also I remember reading somewhere that there is a set of lights at the beginning of the runway which tell you if you are on the right approach. Could you please be able to throw some light on this? (Pun intended)

Exterior lighting consists of these lights:

• Landing Lights
  The landing lights consist of the left, right, and nose gear landing lights. The left and right landing lights are located in the left and right wing root. These lights are adjusted for flare and ground roll. The two nose gear–located landing lights are adjusted to provide the best illumination for approach. Landing lights are kept ON below 10000 feet, performing the function of recognition lights. When landing, they start lighting up the ground about 200 feet or so above the runway. Landing and taxi lights are awfully bright. We have to be cautious with them when ground personnel are nearby as they can cause serious retinal damage. We also use landing lights to illuminate the sky outside when we are in turbulent/cloudy weather. And NO, landing lights are not used to scare flocks of birds, that is a myth.
  
  
• Runway Turnoff Lights
  Runway turnoff lights are installed in the left and right wing roots. They are also called 45-degree lighting. Turnoff lights usually point out to the side of the aircraft and illuminate an area 45-degree from the center line. Its function is to illuminate the area the Aircraft would turn to, so that while taxiing we can visually see an illuminated area prior to turning. However, these are also used as recognition lights along with the landing light. Recognition lights are used to increase your visibility to other aircraft. Our operator has a strict rule of RWY turn-off lights ON below 18000 feet. Runway turnoff lights are similar to the static bending lamps found in new cars these days, which illuminate an area before the car turns.
  
  
• Taxi Lights
  Taxi lights are installed on the non–steerable portion of the nose gear. They are simply used to illuminate the taxiway ahead of us. They are located below the nose gear landing lights. Consider this one synonymous to your car’s headlights.
  
  
• Strobe Lights
  The strobe lights are white anti-collision strobe lights located on each forward wing tip and on the tail cone. These lights flash about once per second. These are usually turned on ONLY when near a runway since these are mounted on the wing and can be a distraction for the other pilots.
  
  
• Beacon Lights
  The beacon lights are red anti-collision strobe lights located on the top and bottom of the fuselage. It flashes slowly. The beacon has to be switched ON before any of the engines are started. When ground personnel see those red lights flashing, they know the engines are running and the area is unsafe.
  
  
• Navigation Lights
  The navigation lights are the standard red (left forward wingtip), green (right forward wingtip), and white (aft tip of both wings and tail cone) position lights. Nav lights were used in ships and are now used in aircrafts as well. At night, nav lights can tell us whether an aircraft is coming towards us or going away.
  
  
• Logo Lights
  Logo lights are located on the stabilizer to illuminate the airline logo on the vertical tail surface. Us pilots like to call it the PR(Public Relation) lights. They really look very majestic when switched on at the gates and while taxiing.
  
  
• Wing Lights
  Wing lights are installed on the fuselage and illuminate the leading edge of the wing. These wing inspection lights are used for engine checks and also while passengers board the aircraft for better visibility of the ground near the aircraft.

Standard Operating Procedure

The SOP for using these lights varies by the operator and pilot. As for me, I have ONE rule: Christmas tree below 10000 feet. It doesn't cost me anything and it provides better visibility.

1. Once we are inside the aircraft, we turn on the navigation lights to show than an aircraft is powered; either by external power or APU.
2. Before engine start, beacons are turned ON.
3. When taxi clearance is received, we turn ON all lights except landing and strobe(since these two lights are extremely bright).
4. As soon as we turn onto the runway, the strobe and landing lights are also switched ON.
5. After taking off, wing and taxi lights are turned off at 2500 feet AGL.
6. Landing lights off at 10000 feet MSL.
7. Runway turn-off lights off at 18000 feet MSL.(Lot of VFR traffic in US below 18000 feet.)
8. The above order is reversed while landing.

PAPI(Precision Approach Path Indicators)

The PAPI light is a light array located just beside the runway. It normally consists of four equally spaced lights color-coded to provide a visual indication of an aircraft's position relative to the glide slope for the runway.

Location of aircraft on approach as visible on PAPI


PAPI lights on a runway.


Image Sources: 1st from our FCTM. 2nd and 3rd from Google images.

[IndiaSierra]

Rated a well deserved 5 star. Your thread is a boon to aviation enthusiasts like me.
I would like to ask you a question. During a visual approach, after the ATC vectors you to final before handing you to the tower ,how do you align the aircraft with the runway,as the runway looks like a tiny string from 2000 feet. If possible please elaborate on this.

[searchingheaven]

Originally Posted by IndiaSierra

Rated a well deserved 5 star. Your thread is a boon to aviation enthusiasts like me.
I would like to ask you a question. During a visual approach, after the ATC vectors you to final before handing you to the tower ,how do you align the aircraft with the runway,as the runway looks like a tiny string from 2000 feet. If possible please elaborate on this.

Sorry for the delay in answering. I was caught up with some work. I presume that you want to know how we align an aircraft with the runway. I will explain it below.

First off, there are 2 basic kinds of approaches.

1. Visual: In a visual approach, we proceed by visual reference and clear of clouds to the airport. We must have either the airport or the preceding aircraft in sight at all times.
   
   
2. Instrument: Approaches performed using special equipment installed at airports and in aircrafts.
   
   
   • Precision: A precision approach provides both horizontal and vertical guidance to the runway. In other words, it's tells you if you're deviating to the left or right and it tells you if you're too high or too low, before you ever see the runway. An ILS - Instrument Landing System - is the most common type of precision approach.
     
     
   • Non Precision: A non-precision (NP) approach gives only horizontal guidance. That is, it tells you if you are off to the left or the right, but not how far above or below the glidepath you are. A localizer approach is an example of a non precision approach.

ILS approaches are the most common approaches for big commercial jets like the one I fly. When the glide slope equipment of an airport is not functioning, we have make do with the non-precision localizer approach. ILS approaches are divided into categories depending on the equipment installed on the airport and the aircraft, as well as training provided by the operator. Their classification is on the basis of the decision height and the RVR - runway visibility range- required. In the following example, I will show how an ILS CAT IIIB approach is performed in a Boeing 777. The runway I landed on was 12L, OMDB, Dubai.

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

Figure 1
On the primary flight display, the barometric altitude is displayed. Radio altimeters are used for measurement of altitude for autoland systems and GPWS(ground proximity warning systems.). The decision height is set using radio/barometric altimeters. The aircraft is at a altitude of 2680 feet, according to the barometric altimeter, which is set to the local pressure of 29.92 inches. Notice the 'RADIO' label at the bottom right? That label indicates the landing minimums or the Decision height. It is 200 feet for this approach. This is the height at which the we must have adequate visual reference to the landing environment (i.e. approach or runway lighting) to decide whether to continue landing; or go around. For a CAT IIIB approach, DH can go down to 50 ft or less.

Also notice that the localizer is captured at about 11 NM out{DME 10.7- Distance measuring equipment - 10.7 nautical miles}. This means that the aircraft now has lateral guidance towards the runway. But localizer only tells you if you're left or right, not if you're too high or low. Vertical guidance is provided by glide-slopes. If the glide-slope equipment was not working ,we would use Instrument Approach Chart and descent tables.



Figure 2
At about 8 NM(not shown explicitly in the image), the Glide slope is captured, i.e the aircraft now has vertical guidance toward the runway. The autopilot on the 777-300ER is capable of automatic descent, landing, flare and roll-out. You can see the pink diamonds on the centre line, both laterally and vertically. This means that the aircraft is on the exact descent slope towards the runway and will land on the centre line.

Most of the airports I have flown to, have a G/S capture distance of about 7-10 NM and localizer capture distance of around 15 to 22 NM. This depends on the maintenance of the equipment installed. Also, important is your angle of interception. If you are turning to final at a high deviation angle, then the capture distance decreases. Localizer is generally captured at 13NM within 35° of runway course and 19 NM within 10° of runway course. Glideslope is captured by 10NM within 8° of RWY centreline.



Figure 3
This photo shows the Autopilot of the B777W, going into autoland mode. LAND3 is annunciated when 3 Auto Pilots, 3 Radar Altimeters, 3 ILS receivers, 2 ASA(Associated sensors) are active and working. In LAND3 Mode, the aircraft's computers can provide guidance upto rollout after landing. If you notice closely, you will see that ROLLOUT and FLARE mode are armed. This means that they will be activated as soon as some condition are met. Flare will activate when aircraft is 50 ft AGL. And Rollout mode will activate when touchdown is sensed using weight-on-wheel sensors. Note that there is a difference of 60 ft between the altimeters. This is because runway 12L is 62 ft above MSL.


PS: These images have been reproduced from my thread (Link to thread). Also, there are other approaches like RNAV as well, but I haven't included those for the sake of simplicity.

[IndiaSierra]

Thank you so much for such a detailed response,I had never expected this.
You have answered quite a few percentage of the question but still a small part of it is still unclear,maybe you had mentioned it but I failed to understand. In your explanation you explained how you align with the runway.I am specifically talking about Visual Approach and not any Instrumental like VOR,RNAV,NDB etc.My question stands that how do you align an aircraft in such a way that after touchdown the noose wheel exactly falls on the center line? Another question,in aircrafts where you do not have a camera on the nose wheel,how do you make the noose wheel stick to the taxiway centerline for optimum wingtip clearance during taxi?

[McLaren Rulez]

Great thread, searchingheaven.

Since there's been quite some discussion on the AF incident and related technical questions, I thought some of our members here might like this (rather long) article on that topic.

http://www.vanityfair.com/news/busin...ight-447-crash

[norhog]

Beautiful thread this.
Got a chance to fly ANA 787 from Tokyo to Beijing. It is quite. I was seated in 21 C over the wings. It felt like in the childhood having riden Premiere Padmini, first ride in a Marutis 800. From prrrr to suuuuuiii.
I have a couple of questions but was never able to get much on them.
1. During take off, when the plane rotates, and just lifts off the ground on most of airplanes in tropics between the engine pod and fuselage there is a fat band of white cloud or something formed flowing over the wing. What is that. Guessing the water vapour becoming fog due to low pressure, can your goodselves explain this phenomenon.
2. On 777, 787 there is a, for lack of correct word, aleoron kind of thing, between flaps and aleoron, that moves very fast up and down and acts as a spoiler on the landing roll period. What is that?
3. There is a small winglets on the external surface of engine pod on the fuselage side, can be seen from the window seat, on a 777, 787. What is its function?
4. What is the power output of a 777 engine in kw and bhp?
5. Any pollution regulations for aircraft engines considering co2 is pumped in upper atmosphere.
Thank you in advance.

[honeybee]

Great resource, McLaren Rulez. So having two side sticks not linked to each other seems to be a design choice by Airbus that relies more on pilots communicating with each other verbally, and Boeing chooses the sticks to be interlinked so that the pilots communicate through their actions.

If it were a car, I would choose Boeing.

But then again, the driving school cars have the same dual control setup, no? There's an extra set of pedals to the co-driver seat, except the steering wheel. So that is essentially Airbus philosophy.

[apachelongbow]

Originally Posted by honeybee

Great resource, McLaren Rulez. So having two side sticks not linked to each other seems to be a design choice by Airbus that relies more on pilots communicating with each other verbally, and Boeing chooses the sticks to be interlinked so that the pilots communicate through their actions.

If it were a car, I would choose Boeing.

But then again, the driving school cars have the same dual control setup, no? There's an extra set of pedals to the co-driver seat, except the steering wheel. So that is essentially Airbus philosophy.

Its not a easy comparison in layman terms. Airbus is a protected aircraft. What it means is in normal terms, the aircraft will allow the pilot to do what he/she feels to escape emergency situations (like avoid colliding into terrain or other airplanes), however it will prevent any moves which will ensure the aircraft enters a dangerous condition like loss of control, or stall or high speed incursions. Hence the sidesticks are not linked (sidesticks are like computer game joystick, its got no mechanical levers or rods, but mere electronic chips, circuitry and computers), but inputs of both sidesticks are algebraically added to each other, as long as both inputs together don't exceed one single sidestick full deflection. So if I put a sidestick input down and you put in a pull up input at the same time, we will algebraically cancel each other out, that's why there is strict rules of only one pilot flying and the other monitoring. There are enough lights and sounds to tell the pilots in case there is dual input (both sidesticks operating) and its possible to cancel the other sidestick operating by means of pushing a button.
Regarding dual controls on a Boeing, it seems useful in teaching a trainee how to fly (but large jets are not places to teach someone to flare and land, they must learn that in smaller airplanes), and even with both yokes operating that Fly Dubai jet went into ground, so sometimes there can be both pilots who lose situational awareness at the same time.

[vishy76]

Rated the thread a well deserved five stars.
Searchingheaven sir,
Can the autopilot land the aircraft in crosswinds or severe headwinds and tail winds?
Can it counteract winds with the help of the rudder like the pilots do and align the aircraft with the runway shortly after touchdown in a crosswind landing like this one?
pic source-downloadvids.net