Flying a Real Airline Route

How do I find a real airline route to some destination?

The Route Finder web page will construct you a route using current actual waypoints, standard departure and approach procedures, etc. Just fill in the appropriate bits of information - departure airport, altitude, arrival airport, what kind of routing you want, and then, when it gives you the route, print it out for your use during your flight.It will give you information including waypoints, VOR/VORTAC with frequencies, etc.

The FMS export page takes a route produced by the Route Finder and translates it into a flight plan you can load directly into X-Plane's FMS.

How do I fly a route like they do in commercial service?

This is, of course, a leading question, since Ron L recently posted a detailed description in X-Plane-Tech of how its done. Ron's text follows...

Below is a narrative tutorial x-plane flight I wrote about some time ago. You can print it out and try it yourself. It's about a 2 hour flight. Read the whole thing first, as it teaches you the speeds you should use during various phases of flight.  If you like these kinda flights, you should have a blast doing this one.

-Ron L.

High Altitude Flight Plan:  KCVG – KLGA

Ron Lynd

Charts used:
Real weather file was used: http://www.x-plane.com/realweather.html

Routing: JODUB2.HVQ – J78 – GEFFS – J78 – LOONS – J78 – PSB.MIP3

Well, if you want to take a flight that introduces you to the high altitude jet route structure and gives your situational awareness a good workout, feel free to continue reading!  This flight takes you from Cincinnati/Northern Kentucky International airport to New York’s La Guardia airport.  The jet used in this flight was a Southwest Boeing 737-700 created by Morten Melhuus and Matt Moriarty.  They both did quite a fantastic job on this bird!  You can however use any aircraft you like. The cruise altitude was 37,000 feet, and the total flight time was about 1 hour and 34 minutes.

Before attempting this flight, there are a few things one should be aware of when flying on jet routes.  First, jet routes are similar to victor airways, but instead of starting as low as 1,200 feet AGL, the jet routes start at 18,000, and run up to 45,000 feet. Also, they are labeled with a “J” on the charts instead of a “V”.  Any altitude 18,000 feet and above is referred to as a Flight Level.  So 18,000 feet is referred to as FL 180. Another thing to keep in mind is that a jet aircraft typically uses various speeds throughout the climb on the way up to cruise altitude.  Once up at cruise, we refer to mach rather than indicated airspeed. The descent is based both rate and speed.  I suggest you read the entire narrative with the charts before flying the flight.

This narrative is written in such a way that it allows the flight to be flown without the charts, but having the charts obviously makes things easier.

If you have flown the previous two flights I’ve written about, you can see how the departure procedure is pretty straightforward.  On this flight, however, I will include details on the various speeds during different aspects of the climb.  We will not be using the FMS, and will be hand flying during the climb before reaching 10,000 feet.  This will give you an appreciation of how quickly things happen when you fly these powerful machines!

So we’re sitting on runway 18L ready for takeoff.  The current weight is set to 143,500 lbs, and the flaps are set to 15º.  A review of the JODUB Two departure procedure (DP) tells us that we are to climb on runway heading until 1.5 miles DME from the localizer source (ICIZ), then turn left to a heading of 165º.  Maintain 6,000, and then expect radar vectors to Cincinnati (CVG) VOR. This sounds rather benign, but when you try to put it into practice you’ll see just how fast things move.

When flying an airplane, it is important to stay one step ahead of the aircraft.  Doing so will reduce your workload, help maintain situational awareness, and increase your chances of spotting anything unusual before they become distracting, overwhelming, or even worse, a danger.  You always want to avoid situations where you have to react rather than anticipate. Trying to stay several steps ahead, on the other hand, can be almost as bad as falling behind, because when you look to far down the road you fail to see what is around you.  With this in mind, I set the Cincinnati (CVG) VOR, 117.3, in the NAV 1 radio and switched it to the active field.  The next VOR of interest will be York (YRK) VOR on 112.8, so I placed that in the standby.  The DP tells us we have to climb on runway heading to 1.5 DME from the localizer antenna (ICIZ), then turn to fly a heading of 165º. Since all we are interested in regarding this instruction is the 1.5 DME, I set 110.15 in the NAV 2 radio and switched it to the active.  After that was done, I made the DME readout visible on the lower right corner of the right EFIS by going to the Mode Selector Unit (contains switches for the HSI/MAP, EFIS range, Barometric pressure, etc.) located to the left of the Flight Guidance Panel (containing switches for the auto pilot controls) and toggled the NAV 2/ADF switch until I saw the green text on the EFIS display “VOR ICIZ 000.8.”  This means I was .8 nm away from the antenna.  If you just see the word “VOR” and several dashes, go back to your radios and click the NAV 2 button underneath the frequency fields and make sure you enter in the correct frequency.  Due to X-Planes current radio interface, setting up the radios is a bit clunky and not 100% realistic.  Hopefully this will soon change.  Since ATC will not be helping us on this flight, I did not set up the COMMs.

So now I have the radios set, the necessary charts are placed nearby, and based on my last statement, I cleared myself for takeoff ;¬)  Applied takeoff power, maintaining runway centerline.  Airspeeds alive, hit V1 (130 knots), Vr (134 knots), pulled back on the stick to a pitch attitude of 12º, positive rate of climb on the VSI, gear up, ensured speed better than V2 (140 knots).  Adjusted for runway heading 187º and took note of the DME on the right EFIS. The right EFIS is typically referred to as the Nav Display, and will be referred to as ND for the rest of this narrative.  I set a pitch attitude that allowed the aircraft to accelerate to 200 knots, and then adjusted the trim to relieve pressure.  Once I reached 1.5 DME, I turned left to 165º, and then reestablished my pitch for 250 knots after I passed through 2500 AGL.  AGL can be seen on the radio altimeter, which on this aircraft is located on the bottom of the attitude indicator in digital format. Once above 2,500 AGL, the display disappears.  I love technology!! I continued on a heading of 165º and leveled off at 6,000 MSL.  The textual portion of the departure procedure says to expect radar vectors to CVG VOR, and this is portrayed graphically with solid triangle arrows at the end of the 165º vector on the plan view.  Since X-Planes ATC is not capable of providing us with this type of radar vectoring, I set up to fly direct to CVG by selecting the HSI in the ND, and rotating the course selector, or OBS if you will, until I got a centered CDI with a TO indication, which was basically a course of 336º.  Your course may vary depending on when you reach this step.  By the time I completed the turn from 165º and recentered the CDI once, the direct course to the station was 010º.  I applied the proper drift correction, and then flew toward the station at 6,000, 250 knots.  From the time of the takeoff roll to the time I was at 6,000 heading towards CVG was approximately 4 minutes.  This is pretty quick considering there were two speed changes requiring trim adjustments, course selections, flap retractions, heading changes, and an altitude requirement.

Once I was 1.7 miles from CVG, I began to lead my turn to the next leg of the departure, which is it fly outbound on the 109º radial from the CVG VOR and begin a climb.  As I turned towards 109º and established my climb power setting of 92% N1 while pitching for 250 knots, I reset the course selector for 109º. According to the procedure, the climb gradient requirement is 300 feet per nautical mile to ROHMM intersection, and you should cross ROHMM at 17,000 feet or above unless otherwise instructed by ATC.  In this case I chose to abide by all of the altitudes since ATC was not “participating.” Several minutes after I was established on the 109º radial out of CVG, I passed through 10,000 feet MSL and reduced my pitch to continue the climb at 300 knots. In order to maintain the climb requirement at my present speed, I noticed that I needed at least a 1,500 fpm climb.  This information can be read from the climb gradient table on the DP.  If you want to convert feet per nm to feet per minute mathematically, you simply divide the groundspeed by 60, then multiply the answer by the desired feet per nautical mile climb gradient requirement.  I wasn’t too concerned however, since my climb rate had been holding 2,000+ fpm throughout much of the climb.  The next intersection defining the DP, which is before ROHMM intersection, was HOBNO. HOBNO intersection is defined by 37 nm DME from the York (YRK) VOR on 112.8 with the 291º radial, and will bring you on an inbound course of 111º. Just before reaching HOBNO, I passed through FL 180 and set my altimeter to 29.92.  18,000 feet MSL is the typical transition altitude where we switch to pressure altitude within the United States.  This is also known as QNE.

My next intersection of interest was ROHMM, just over 10 nm away. The interest was not necessarily because of the altitude requirement, I was already well above that.  ROHMM intersection is where I will have intercepted the 274º radial from the Henderson (HNN) VOR on 115.9 and begin tracking it on a course of 094º inbound.  It wasn’t long after being established on my inbound course of 094º where I started paying more attention to my mach indication. Mach is a relation of velocity at a given altitude to the speed of sound at sea level.  The mach indication will continue to increase with altitude, even though I am maintaining a climb speed of 300 knots indicated airspeed. As the mach reached .75, I adjusted my pitch to climb by .75 mach instead of 300 knots.  Don’t worry if you see the indicated airspeed now start to decrease while pitching for .75 mach, this is a normal occurrence. Depending on the outside air temperature on any given day, this transition will typically occur between FL 270 and FL 330. On this particular trip however, the transition to mach occurred passing through FL 266.

My stay on R-274 from HNN wasn’t too long, and I had already set 117.4 in the standby of my NAV 1 radio for the Charleston (HVQ) VOR.  As I noticed the DME nearing 47 nm from HNN, I knew I was almost at the end of the Jodub Two departure, marked by the JODUB intersection.  About 1.5 miles from JODUB, I began my turn to a course of 118º for the Charleston transition, which requires us to fly the 298º radial inbound to HVQ.  The transition is the .HVQ portion of JODUB2.HVQ mentioned in the routing at the top of this document.  By now my climb was averaging less than 1,000 fpm, and my planned cruise altitude was FL 370.

The Charleston transition leg was 58 nm long from the JODUB intersection, and once I was within 9 nm DME of HVQ, I began my turn to 051º for J78 as depicted on the high altitude enroute chart.  Keep in mind that DME gives you slant range distance, so if you are at 30,000 feet, your DME may read 9 nm, but your actual horizontal distance from the VOR may be only 2 nm.  A lead turn before the VOR helps minimize overshooting the airway. About 20 nm into my enroute phase of flight on J78, I reached FL 370.  You may find, depending on your weight and the air density, that you need to level off at FL 350 to burn off some weight before continuing to FL 370.  Once at cruise, I let the aircraft accelerate to mach .80, and adjusted the power to hold it there. This trip has a short enroute portion, which is a 233 nm leg from HVQ to the Philipsburg (PSB) VOR on J78. Since there was no depicted changeover point, I tracked the 051º radial out of HVQ, then switched over to 115.5 to track the 240º radial into PSB on a course of 060º at about 116 nm along the jet route, which was about 12 nm past the LOONS intersection.  If you notice on the chart, the outbound course from HVQ on J78 was 051º, but the inbound course into PSB was 060º, even though the course line on the chart looks absolutely straight.  The reason for this is a change in magnetic variation over distance.  When switching VORs at the midway point as we just did, all that is typically required is an adjustment of the course selector, a possible change in heading, and sometimes you need to re-intercept the CDI.

It didn’t take long to reach Philipsburg (PSB) VOR, which marks the beginning of the Philipsburg transition into the Milton Three Arrival (PSB.MIP3). About 8 nm DME on my way to PSB I began a course change to 093º, but I ended up overshooting the course. So, to re-intercept the 093º radial outbound, I continued the turn to about 113º.  A 20º intercept course works fairly well when re-intercepting a radial, but 20º only works well when traveling outbound just after station passage due to a sensitive CDI at close range.  The further you are from the station, the less sensitive the CDI is.  When the CDI becomes less sensitive with greater distances, interception angles of 30º to 45º work very well.  One thing I did before reaching the PSB VOR was an arrival briefing.  Basically, I looked over the Milton Three arrival before it became necessary to maneuver the aircraft, about 50 nm from PSB on J78.  I made note of course changes, altitude crossing restrictions, speeds, holds, and all of the fixes associated with them.  A fix, in case you didn’t know, is anything that can define a point in space, like a VOR, NDB, intersection, or a waypoint. Looking at the arrival, the first fix of interest to me once we become established on the transition was the heading change at the Milton (MIP) VOR.  The second fix of interest, which was equally, if not more important, was the MAARC intersection.  It sates that we should expect to cross MAARC at FL 180. Since there is no ATC guidance, we will pretend ATC told us to “descend via the Milton Three arrival, Philipsburg transition.” Whenever ATC tells you to “descend via” a STAR (standard terminal arrival route), they are telling you to abide by the altitudes and airspeeds listed on the arrival.  In this case you begin your descent at your discretion.  Keep in mind that jet aircraft are most efficient at high altitudes, so it’s in your best interest to stay at cruise altitude until you have to start your descent to make the crossing restriction.

So, how do we calculate the beginning of the descent?  Well, here is a general rule of thumb when using the standard 2,000 fpm descent at mach .80/300 knots, typically used by jet aircraft.  You take the flight level and divide it by 3.  So if you were going to descend 36,000 feet, you divide FL 360 by 3 and you get 120 nm.  In other words, at a descent rate of 2,000 fpm at mach .80/300 knots, you would start your descent 120 nm from the fix. In this case we are flying at FL 370, and we are descending to FL 180, which is a 19,000-foot descent.  3 divided into FL 190 results in a descent point roughly 63 nm from the fix, in this case MAARC.  Looking at MAARC intersection, it is defined as 25 nm DME past the MIP VOR. Based on the rule of thumb, we should begin our descent about 38 nm before reaching MIP VOR. Since we will still be navigating by the 093º radial from PSB at this point, we can start to descend at 23 DME from PSB.

OK, deeeep breath there. That was a lot to digest! Now you see why you want to brief the arrival before flying it?  Just keep in mind that this is assuming no winds.  If you have a tail wind, you would begin the descent sooner. OK, back to the flight… So once I got to 23 nm past PSB, I reduced the power and set the VVI autopilot for a 2,000 fpm descent.  At about 30 nm, I switched 109.2 for MIP from the standby to the active since we were at the halfway point between VORs. From here things move pretty fast, so keeping one step ahead is very important.  The first thing we do, now that MIP is in the active, is put the next VOR in the standby.  After setting 117.5 for Allentown (FJC) in the standby, I also made note of the course going in FJC VOR in case an adjustment in the course would be necessary.  In this case, the outbound from MIP was 117º, then once past the change over it would be 118º into FJC.  With the NAV radio set and the next course leg briefed, I continued to watch the indicated airspeed slowly creep upward as I descended at .80 mach. Soon after switching over to MIP, I made adjustments to the power setting to maintain 300 knots as I descended through FL 280.  Notice that the transition to indicated from mach was at a different altitude then when we were climbing.  There are two reasons for this.  One, because when we were climbing we maintained 300 knots until we reached .75 mach vs. .80 mach on the descent.  And two, because the temperature may have been different in the region we were descending in when compared to the region we had climbed in. Keep in mind that a METAR.RWX was used on this flight.

Soon I noticed I was about 10 nm from MAARC intersection. Based on experience, it looked as though I was a bit high.  Being concerned about not making the crossing restriction of FL 180, I increased the descent rate to 3,000 fpm and reduced the power accordingly.  I leveled off about 1 nm from MAARC, which was pretty tight.  As we can see, the flight level divided by 3 rule of thumb method is just an estimation.  To be safe, you can start your descent 10 nm sooner.  Anyway, my next altitude of concern was 13,000 feet at VIBES intersection, which is 7 nm DME from FJC.  Since it was only a 5,000-foot descent, I decided to guestimate the descent point.  I figured 20 nm from VIBES should do, so I chose to begin the descent 30 DME past MIP. Before descending below FL 180, however, we need to reset our altimeter from 29.92 to the local altimeter setting.  Since we can’t get it like we can a wind check via X-Plane ATC, the next choice is to choose the “Declaring an Emergency/Request Nearest Field” function from the ATC menu, which gives you the nearest airport name and direction.  Since we are not interested in actually going there, we just note the name of the airport, then choose Get ATIS in the ATC menu. If the airport is not under ATIS, then try Get AWOS. On this flight the altimeter setting was 29.65 in this region, which I set and then began the descent down to 13,000 feet.  VIBES is identified as 14 nm DME from FJC, so just after beginning my descent I switched 117.5 to the active and made any necessary course and OBS adjustments.

Once established on a course of 118º, I set the frequency of the next VOR of interest in the standby, which is Robbinsville (RBV) on 113.8.  RBV marks a portion of the arrival that can be quite tricky if you did not brief the arrival carefully.  Here we go… just after crossing FJC I turned to a course of 115º.  This was to last 14 nm to LIZZI intersection, but at about 10 nm DME past FJC I began the next descent from 13,000 feet down to 10,000 feet, which is the next crossing restriction located over BEUTY intersection.  The leg between LIZZI and BEUTY is very short, both in the air and also on the chart, which is why it is noted with the notation “A”.  Looking at the corresponding caption up top, it displays the course, distance, and MEA for this 9 nm portion.  Just upon reaching LIZZI, I began my 2,000 fpm descending right turn to 10,000 feet at 300 knots to a course of 143º while simultaneously switching RBV to the active and the course selector to 143º, then I set 115.4 in the standby for Colts Neck (COL) VOR and noted the next inbound course of 123º. Shortly there after, I noted I was just about to come up on BEUTY, which is 32 nm DME from RBV, so I began my level turn at 10,000 feet and 300 knots to a course of 123º.  WOAH!  Yes, trying to hand fly this would be foolish, not to mention against any air carriers standard operating procedures, which typically requires autopilot to be used during the arrival phase of flight!

Now that I was established inbound on the 303º radial from COL VOR, I made note of the next point of interest, which was the DREMS intersection.  Defined as 19 nm DME on R-303, DREMMS is where we are to turn onto an inbound course of 083º on the 263º radial from Kennedy (JFK) VOR. However, when I did turn to this course and switched 115.9 to the active, instead of receiving a signal from JFK, I was receiving a signal from a VOR with an identifier of OLT.  Idouble checked the frequency I set, then read the chart again, but something was screwy.  This being the case, I just held a heading of 083º, and then set up the La Guardia (LGA) VOR in the active on 113.1 and the course selector to 045º. The 083º heading will bring me on a descent intercept course for the R-225º out of LGA.  I knew I was going to have to start descending soon, so I started to slow to 250 knots before thinking of descending below 10,000 feet.  While I was slowing, I got the ATIS from La Guardia, which was reporting winds of 030º at 7 knots, visibility was 9 statue miles and the cloud ceiling was broken at 1,600 with an overcast layer at 3,400.  It was raining, ILS runway 4 in use, and the altimeter setting was 29.67. By now I had slowed to 250, so I began another 2,000 fpm descent down to 3,000 feet and reset the altimeter. During the descent, I continued keeping an eye on the CDI sensing the 225º radial from LGA as I pulled out the chart for ILS runway 4 into KLGA.  There was still some time to brief the approach, but it should have been done sooner. Unfortunately I had allowed the unexpected OLT/JFK identifier issue to distract me longer than it should have.

No worries though, I had set the ILS frequency (110.5) in the standby, set up 332 in ADF 1 for the PETHS LOM in the active and 385 for the ORCHY LOM in the ADF 1 standby in case of a missed approach, noted that the minimum sector altitude (MSA) was 2,800 feet, and the inbound approach course was 044º. In fact, the inbound course was very convenient because it was almost lined up with the 225º radial out of LGA I was to fly inbound on.

Eventually I was on my inbound course of 045º tracking the 225º radial from LGA to the station.  I had descended all the way down to 2,800 instead of 3,000 feet since I was well within the 25 nm radius of the navaid that the MSA was based on, which is PETHS (LG).  At about 20 nm from LGA VOR, I began to reduce power and slow from 250 down to 200 knots.  I added flaps as I slowed below 200. I checked my current weight, which was about 130,000 lbs. I was a bit heavy according to the landing chart, which can be seen in the “z” view of this aircraft. The chart called for a Vref speed of 139 knots at full flaps with a landing weight of 128,000 lbs.  Vref, in case you don’t know, is the velocity you cross the threshold at. A typical approach speed when established on the glideslope is Vref + 10.  So in my case it would be 149 knots, but since I was a bit “bloated” I decided I was going to use 155 knots just before getting established on glidepath.

Looking at the approach chart, one of the stipulations for ILS runway 4 is that radar is operating.  Bummer.  Since ATC will not be providing radar vectors, we must navigate ourselves onto the final approach course. If the approach has a LOM, it is fairly simple if you use the RMI or ADF. This 737 has a RMI, but in this particular situation I didn’t even need to use it to get on the final approach course.  Going back to the approach chart, I noticed that ATC would normally have us cross GREEN intersection at 2,700 feet. GREEN is defined as 11.1 nm DME from LGA, but on the localizer, not the radial. Keep in mind that when you switch the ILS frequency to the active, you will lose DME from the LGA VOR.  To prevent this, I set the LGA VOR in the active Nav 2 frequency as well, just like I did on the takeoff from KCVG when it was necessary to identify 1.5 nm DME from ICIZ.

At about 15 nm DME, I was at 160 knots, 30º of flaps and the spoilers were set to auto-deploy on touchdown (hit 5 a few times to bring the lever to its highest position).  I then switched the ILS frequency to the active, and noticed that the CDI was showing a deflection of 5º or 6º to the right. Normally ATC would vector us for a 30º interception angle to have us intercept the localizer, but since I didn’t have a full scale deflection I turned to a heading of 065º instead of 074º.  Once on the localizer I dropped 100 feet to 2,700. After I crossed GREEN, I began watching for glideslope activity.  Once active, I reduced power and trimmed for about 155 knots.  Quick taps on the trim was all that was necessary at this point, otherwise pitch control becomes difficult.  At about 1 dot below glideslope I extended the gear, then reduced the power and began to descend on glideslope intercept. The approach chart gives a convenient table to help estimate the vertical speed to stay on glidepath. With a groundspeed of 160 knots, 860 fpm is required, and 752 fpm will do fine with 140 knots. I set my attitude for the ballpark descent rate, and then fine tuned for any deviations experienced.  The decision altitude was 272 feet, but I was already below the clouds so it was not much of a factor.  I heard the beeping of the outer marker and saw the captains single barred needle chase the LOM in the RMI.  By now I was less than 4 nm from the runway with the airport in sight, but I stayed on the instruments since they have a habit of running away quickly on approach.  As I descended through 200 feet, I further reduced the power, but I still crossed the threshold a bit fast. Gliding past the 1,000 foot point on the runway, I was still able to touch down smoothly with plenty of runway remaining before taking a swim in the Long Island Sound.  The spoilers deployed and I activated the reverse thrusters (“.” then throttle up), applied brakes as needed.  I exited the active runway about 1 hour and 34 minutes after initial throttle up according to real time, however the aircrafts clock indicated about 2 hours.


Back to the Flying Page
 
Back to the main page