Take off sequence....?

[Techy111]

I am after a bit of advice please guys.....?

OK there i am sitting in my A/C on the runway ready to go.....

Take off roll i understand....V-ref...V-1...V-2 Rotate.....all ok so far....Positive rate...gear up....still with it...

No i start to bog down a bit.....I am learning how to use an FMC and am confused to the point where i haven't the foggiest...?

I hear on my DVD's the pilots refer to V-Nav and L-Nav which confuses the hell out of me...so i was wondering if one of you kind souls can put it in layman terms for me please...?

I understand it refers to the A/P but thats where my knowledge stops.....I understand QFE , QNH and millibars and flight levels and all things ATC as i was an ATSA2 but i want to do things in the cockpit correctly.....Thanks in advance...

And does anyone know of a good tutorial for "intercepting the glideslope" please.....?

Tony

[DanKH]

Even though some of the tutorial over at DM's site are a bit old, you can still fly them by the letter.

Along with the Tridents Peter also wrote a splendid tutorial on flying the full autoland.

Some very useful stuff can be withdrawn from there.

reg. Vnav etc. Some of our resident pilots will surely get into depth on this subject. I will humbly back out again....

[Chris Trott]

No i start to bog down a bit.....I am learning how to use an FMC and am confused to the point where i haven't the foggiest...?

I hear on my DVD's the pilots refer to V-Nav and L-Nav which confuses the hell out of me...so i was wondering if one of you kind souls can put it in layman terms for me please...?

I understand it refers to the A/P but thats where my knowledge stops.....I understand QFE , QNH and millibars and flight levels and all things ATC as i was an ATSA2 but i want to do things in the cockpit correctly.....Thanks in advance...

And does anyone know of a good tutorial for "intercepting the glideslope" please.....?

Tony

Let's see how little I can help and Leif can fill in the blanks...

LNAV stands for Lateral Navigation. This is a mode where the INS, IRS, GPS, FMC, FMS, etc. (aka Remote Navigation or RNAV equipment), drives the heading functions of the autopilot. In this mode, the RNAV equipment can fly the airplane from one waypoint to another along a pre-loaded flightplan or to intercept and follow an imaginary localizer in an RNAV approach.

VNAV stands for Vertical Navigation. This is a mode where the RNAV equipment drives the altitude-related functions of the autopilot. This includes being able to command profile climbs and descents along with driving the autothrottle modes to fly a pre-loaded profile in the system. This allows for automatic descents or climbs and speed changes to follow a published arrival or departure procedure for example or to intercept and follow an imaginary glideslope in an RNAV approach.

With both functions engaged, you can basically have the airplane fly itself from the time you engage the autopilot until you disengage it for touchdown. FSNav recreates the LNAV and VNAV functions as part of it's inbuilt autopilot (the whole "Fly Flightplan" button, modes, and options thing).

As for intercepting an ILS, generally you want to setup about 15 miles from touchdown and 2000 feet above the field elevation on a heading that is 30 degrees off the localizer course (i.e. for a localizer on a heading of 090 you want to intercept at a heading of either 060 if coming from the south or 120 if coming from the north) and about 50 knots over your final approach speed. The moment that the localizer bar begins moving, immediately turn into a standard rate turn onto thel localizer course. If you do it properly, you should roll out on the localizer. Follow the localizer at your altitude until such time as the glideslope needle or bar begins to move. When it does, begin slowing to your final approach speed plus 10 knots. When the needle/bar is 1 dot above the center of the scale, lower your landing gear and final notch of flaps. Then follow the glideslope and localizer to the runway. When at 100 feet AGL, slow to your final approach speed and try to take the throttle to idle somewhere around 20-50 feet above the runway.

If you have the ILS charts for a given runway, it makes life much easier as it will typically have all the altitudes and intercept points laid out for you so you can fly the procedure published and it will ensure that you're at the right altitude to intercept the glideslope with plenty of time to get stabilized.

I know some people here will complain about me using 30 degrees instead of 45. The reason I use 30 is because unless you're using the autopilot, you will fly through the localizer. I've tried it dozens of times in sim and real life, and it's always been the same with anything over a light single. You are simply moving too fast to be able to intercept the localizer without going through it using only a standard-rate turn (which legally is the most you can do when on an ILS because the presumption is that you're doing it because you're not looking out the window and you have to be predictable for ATC). I've talked to many other pilots, and they agree. Unless the autopilot is flying the approach, you will always blow through the localizer. If you blow the LOC in the real world, you'll get taken around again 99% of the time and occasionally you'll be given a number to call on the ground because you blew separation minimums for the aircraft on a parallel approach causing both of you to have to try again and really making ATC mad.

[Techy111]

Thank you very much Chris....That gives me loads to be going on with.....So i have to find the Correct sids and Stars for the airfield i am departing from and arriving into ....to get the correct climbout and approach courses to program into the FMC to make this as real as i can....?

Tony

[DispatchDragon]

Not much I can add to that primer there Chris

Techy - having grown up with FMCs/FMSs I'm in awe how they work so well - But I'm also concerned as I see new generations
of Commercial airman coming along who CAN'T function without them - as to Chris's 30 degree entry - its an old saw - the published entry is normally 45 degrees to intercept the localiser but as Chris points out you have to be one the ball not to fly
through the localiser so many pilots whittle it down to make a more "comfortable" interception - works fine until your shooting
an honest to pete ILS to minimums at unfamilar airport like say Gunniston where thet 45 degree entry is there for a purpose
to stop that horrible noise the aircraft makes when it flies into the side of the Rockies - so its horse for courses.

Just get airborne - soon as you have the aircraft cleaned up hit the autopilot and engage Lnav and Vnav and go to sleep
there is no skill nor much fun in it - having spent just a couple of hours in the jumpseat of some nice (A320) and not so
nice MD80 glass cockpits most flight deck crews would be well served to take up macrame.

Sorry I was brought up when the flight systems on the 1-11-300 were state of the art.

Leif

[bobdawkins]

Could you chaps repeat that

[Techy111]

Tis easy now Bob.....Twist a knob......flick a switch....then have a cuppa......

I think.....

Tony

[Chris Trott]

Tony, you definitely don't have to have SIDs and STARs, LNAV and VNAV just allow the airplane to fly the profiles automatically without pilot intervention (i.e. changing the altitude or heading selected in the AP windows). If you don't have a SID or STAR and you're not flying in a condition where you need to use them (like on VATSIM), then don't worry about it. LNAV and VNAV will take you successfully to your first waypoint and up to your cruise altitude in the fastest and most efficient way possible.

Leif - Yes, you are correct there are published approaches where a 45* intercept is a must, but they are published as such and have various additional navigational aids written on the chart to tell you when to start your turn to avoid passing through the localizer. As it is, in many aircraft (the Lears come to mind immediately), attempting a 45* intercept can only be compared to trying to take the first turn at Indy with the throttle wide open. The result won't be pretty, and will probably end up with something bent or pranged.

[cstorey]

There are differences between Europe and the USA here. In practice at major European Terminal areas virtually all arrivals are radar vectored to the ILS and you will never, except in the sim or for practice, do a procedural ILS. Secondly, if you look at the plates you will find that many have a maximum IAS stipulated ( often 185 kts) to obviate the turn in difficulties referred to. Furthermore, many procedures (particularly those with a teardrop pattern rather than a procedural turn) have different patterns for different speeds with the same end in view.

I never flew glass cockpit/fmc aircraft and thus cannot help you on v nav etc, but if you want to get an idea of when to start turning in for an ils ( at whatever degrees cut you choose) tune the adf to the relevant ndb , usually co-located with the outer marker , and make sure that the rmi shows it on one of the two needles. When that shows a bearing within about 5 degrees of the inbound course the time has come to start your turn in ( in still air - I shall not complicate matters by dealing with crosswinds here). You will usually find that soon after, the localiser needle starts to twitch as well

You will find that if you start with a slow aircraft for practice, which gives you time to think, you will rapidly find yourself able to cope with faster ones

[Chris Trott]

Actually Chris, 95% of all ILS approaches in the US are vectored as well, even into non-Approach Controlled airports. It does not mean that they don't still have published procedures that are also followed by ATC to effect terrain avoidance (Gunnison being a prime example as Lief pointed out). It's a rare event to fly a published approach procedure in full unless you either A) are training, or B) requested it from the controller (whether it be approach or center providing the service).

Also, all speed restrictions on approaches can be and are waived for aircraft safety. While it may say 185 for the approach, aircraft like the Lear (and a lot of other BizJets in fact) CANNOT do 185 knots and maintain the other performance specifications required for operation in controlled airspace. As such, those aircraft will be allowed to perform the same maneuvers at higher speeds, usually around 200-210 knots. Once the flaps drop on these aircraft (which is required to maintain 185 knots), the roll is severely limited (15 degrees in the Lear) so they are unable to make standard-rate turns and they are unable to make positive vertical changes at greater than 500FPM (which means they can't easily climb out and maintain 185 knots to avoid traffic).

It all goes back to safety and that's why most US ATC and US pilots prefer the 30-degree intercept over the 45-degree. It gives more time to react and it prevents problems with overshoot by aircraft incapable of slowing down to sub-200 knot speeds until established on final approach. Also, in the US, the minimum speed that ATC or procedures can normally restrict an aircraft to is 210 knots. Anything below that requires pilot permission (i.e. the controller can ask, but cannot command).