Ask any Vatsim controller for a list of most common pilot mistakes, and he or she is sure to include incorrect execution of departure instructions. Departing an airport under IFR has certain requirements; these requirements are communicated in the IFR clearance. The phraseology of that clearance must be very precise so that the controller and pilot know what should happen. This article will give different departure scenarios and attempt (and may even succeed) to cover all possibilities. Where needed, there will be sections titled “controller perspective” and “pilot perspective” to discuss items of interest. Some parts of this article are written from the perspective of what's expected of the pilot. Controllers will still find at least some of this information useful, since they need to know what is expected of the pilot too.

Definitions

Minimum enroute altitude (MEA) - The minimum altitude established for an airway or other published route.

Minimum vectoring altitude (MVA) - An altitude depicted on a controller's display which establishes the minimum altitude for IFR aircraft not operating in a DVA or on a published route.

Diverse vector area (DVA) - An area associated with a departure runway which establishes a range of headings which may be assigned to departing aircraft. Aircraft are not required to be at or above the MVA if a DVA is established so long as they are assigned an altitude which is at/above the MVA.

References

Aeronautical Information Manual (AIM) - This is a guide which describes basic flight information and air traffic control procedures. There are some parenthetical references to the AIM below which reference specific AIM paragraphs. There are several pages in the AIM dedicated to departure procedures in section 5-2. The Vatsim website training materials describe some of what is in the AIM, but all virtual pilots operating in the U.S. should at least be familiar with the AIM's contents. On the same website referenced above there is a link to download a searchable pdf version of the AIM.

FAA Order 7110.65 - The controller's main source of information. I'm sure every controller reading this is familiar with it. Pilots might find the information in it useful as well, just to learn the rules by which the controller must work. Parenthetical references below starting with 7110.65, refer to paragraphs in that document.

What should I do after takeoff?

The primary question faced by a departing pilot is how he/she will navigate to the first fix on his/her route. First of all, do not just fly runway heading (unless it is assigned by the controller or is part of a departure procedure you are assigned by the controller); this is a very common mistake, but can be hazardous to your health (well, hazardous to your virtual health) if there is high terrain or traffic in your area. Also, do not just fly direct to your first fix (unless this is assigned by the controller). Your clearance will tell you exactly what is expected of you in very precise phraseology. The inclusion (or exclusion) of one word in the clearance can make a difference in what is expected of you. Let's examine the possibilities:

Controller provides no route to first fix

In some instances, the controller will provide no course guidance to reach the first fix, either to allow the pilot flexibility to choose his/her own route, or because the controller cannot assign a route due to terrain or other considerations. In this instance the pilot is on his/her own to navigate to the first fix on his route and avoid terrain and obstacles.

Phraseology

On a flight leaving Grand Canyon (GCN) flying to Denver with a first fix of GCN VOR, if the controller chooses not to assign a route to GCN, the phraseology could be either “cleared to Denver, as filed...” or “cleared to Denver, via GCN direct TBC...” No course guidance is provided in either clearance because there are no instructions on how the pilot should reach GCN VOR; the pilot is responsible for ensuring terrain separation.

Pilot perspective

This type of clearance gives a good deal of flexibility. You may proceed by any reasonable route to GCN, then proceed via your cleared route. Do not fly runway heading expecting further guidance from the controller; the controller just expects you to begin your route at GCN, how you get there is up to you. You still have the option of flying the obstacle departure procedure (discussed below) if terrain is a consideration. The most important thing to realize is that you have responsibility to avoid terrain and obstructions.

Controller perspective

Because of the flexibility provided to the pilot, this type of clearance should only be used where separation from traffic is not a concern. For airports without an obstacle departure procedure, approved headings, or a diverse vector area, this is almost always the only option. In those cases if there is a concern for traffic separation, you may ask the pilot if a particular course will permit terrain and obstruction avoidance (see 7110.65 4-3-2-c-3 for more information). The phraseology would be something like “would an assigned heading of 250 permit terrain and obstruction avoidance?”

Controller instructs the pilot to proceed direct to the first fix

In this case, the pilot will proceed direct to the fix specified as soon as practical after departure. By assigning the direct route, the controller assumes responsibility for terrain and obstruction separation. Note that the only difference between this clearance and the “controller provides no route to first fix” section above is the inclusion of the word “direct.” Now, the pilot is expected to proceed direct to the fix specified as soon as practical after departure.

Controller perspective

This type of clearance is essentially a radar vector. If you assign direct to the first fix, the course to that first fix must be within the diverse vector area established for the runway of departure. If there is no DVA, or the SOP does not expressly permit the assignment of a direct routing, then the controller may not issue a clearance using the “direct” phraseology to a departing aircraft. An advantage of assigning direct to the first fix is that the controller will know exactly where the aircraft will go after departure.

Controller assigns a heading for radar vectors to the first fix

The pilot will fly the assigned heading until otherwise instructed by the controller. In this case, the controller is responsible for terrain and obstacle clearance...unless the pilot agrees to accept terrain separation responsibility.

Phraseology

The phraseology in the IFR clearance will be something like, “cleared to LAX via fly heading 190, vector to HEC.MITTS2 arrival...” In that case, the pilot will fly heading 190 until otherwise instructed by the controller.

Pilot perspective

The most important thing the realize is that you are expected to fly the heading given until other instructions are provided. An initial vector may be followed by additional turns to other headings; the controller expects you to fly the assigned heading until you are given instructions to proceed direct to a fix or instructed to join an airway or other route.

Controller perspective

The use of this type of clearance requires that the assigned heading be approved for that departure runway or that a DVA be established for the runway in question. If there is no DVA or the heading is not approved, you may assign a heading, but you must have the pilot verify that compliance with the clearance will permit terrain and obstruction separation (see above and 7110.65 4-3-2-c-3 for phraseology). If the pilot agrees then he/she accepts responsibility for terrain and obstruction avoidance. If you assign a heading to a departure, it's one of the few times that a purpose for the vector is not necessary (7110.65 5-8-2); however, the cleared routing must be understood by the pilot.

Controller assigns the obstacle departure procedure (ODP)

At airports with published instrument approach procedures, there will generally be an ODP published as well. In NOAA chart books, the ODPs are published in the takeoff minimums section near the front. ODPs are sometimes published without respect to which runway is used; in most cases though, each runway will have an ODP associated with it. Compliance with the ODP assures terrain and obstruction clearance. The only time a pilot is required to fly the ODP is if it is assigned by the controller.

Phraseology

If a pilot is planning to depart San Luis Obispo (SBP) with a first fix of Morro Bay (MQO) and the controller requires the pilot to use the ODP, the phraseology would be something like “cleared to LAX, via the San Luis Obispo runway 29 departure procedure, Morro Bay, then as filed...” Let's look at this procedure:


Note that the procedure varies depending on the runway used for departure. The controller assigned the procedure associated with runway 29, so after takeoff, the pilot flies runway heading and intercepts the MQO 050 radial inbound to MQO, then proceeds on his/her filed route (as long as he/she is able to comply with the restrictions in the section beginning with “all aircraft”).

Pilot perspective

If the controller assigns the ODP, you are expected to fly it immediately after takeoff without further instruction. If the ODP is not assigned you may choose to fly it, unless the controller assigns a heading, direct to a fix, or a SID (AIM 5-2-7).

Controller perspective

At uncontrolled airports, controllers generally do not choose the runway of departure. If the controller assigns the ODP and all procedures will allow for traffic separation, ask the pilot which runway he will depart and assign that runway's departure procedure, or use the less restrictive phraseology "San Luis Obispo departure procedure." If a particular runway's departure procedure is required, then the controller may assign that procedure; the pilot is expected to advise the controller if he'll be unable to comply. The only reason for the controller to assign the ODP is if there is a concern for traffic separation; otherwise, use the less restrictive phraseology given in the “controller provides no route to the first fix” section.

Controller assigns a Standard Instrument Departure (SID)

SIDs are similar to ODPs, except that SIDs are generally developed to facilitate efficient traffic flow rather than ensure terrain/obstruction clearance (this is not always true...some SIDs are designed for terrain avoidance as we'll see below). The key part of the SID chart is the text portion which describes exactly what is expected of the pilot. SIDs can be quite complex and are covered in detail below. The most important part of any SID chart for a pilot is the “departure route description” section, that will tell the pilot exactly what is expected of them (this will be beaten into your head over the next few sections). You should not accept a clearance for a SID without at least reading the departure route description section; do not rely on your FMS/GPS to guide you through a SID without at least reading the departure route description. Several SID graphics are included below; to keep the file sizes down, each chart has been reduced in size and quality. A full quality pdf version of each chart can be viewed by clicking on the chart on this page. Some of these charts have been superseded by newer procedures, but have been retained in the article since they illustrate certain concepts; always check for the latest charts before flying.

Radar vector SID

Some airports publish SIDs which include no pilot navigated route, but instead assign a heading to be flown after takeoff. An example of this type of procedure is the MEADOWS1 SID out of BFL:


The key to this departure is the text under “departure route description.” This is a pretty straight-forward SID as departures off all runways are instructed to fly runway heading. In this case, pilots must remember that you are required to fly runway heading until otherwise instructed by the controller. The phraseology used by controllers for this SID should be “clrd to SFO via the MEADOWS 1 DEPT, as filed...” or “clrd to SFO via the MEADOWS 1 DEPT, AVE, as filed.” The term “transition” should not be used since there is no published route associated with this SID. There are examples of radar vector SIDs which assign headings other than runway heading; in those cases, turn to the heading instructed in the departure route description.

Hybrid Radar vector/pilot nav SID

These types of SIDs instruct the pilot to fly a particular heading initially for vectors to a route published on the SID chart. This type of procedure can be confusing and it is quite common for pilots to execute these incorrectly. The most important thing to remember is that you fly the charted heading (or the heading assigned by ATC) until otherwise instructed. A commonly flown example of this type of SID is the LOOP4 departure out of LAX:


Again, when looking at any SID chart, the pilot should start by looking at the textual description. The LOOP4 instructs the pilot to fly a 250 heading when departing runways 24L/R, or to fly a heading of 235 when departing runways 25L/R. Initially this is exactly the same as the “controller assigns a heading...” section above; the pilot is required to fly the published heading until otherwise instructed by the controller. There is also a restriction to cross the SMO 160 radial at or below 3000. Note that the dotted lines after the 15 mile arc are for lost communication only. The use of "thence...." at the end of each runway's departure instructions can be confusing, especially on charts which have several sets of runways; when you see "thence," it just means to look for the next line that begins with a set of ellipses (the "...." symbol) to get the next portion of the route. Eventually, the controller will give instructions to join the SID. The phraseology on the LOOP4 is usually, “turn left direct LAX VOR, resume the LOOP4 departure, comply with restrictions.” So the pilot turns left to a direct course to the VOR, and after the VOR tracks the published course (or, in ATC speak, “resumes the XXX departure”). The instruction to “comply with restrictions” requires the pilot to comply with the charted altitude restrictions on the chart. Again, to emphasize, the pilot is required to fly the heading given in the departure route description until given other instructions by the controller. Do not begin a turn to follow the published transition to DAG until the controller instructs you to do so.

A second example of this type of SID is the MCCARRAN 3 SID out of Las Vegas (LAS). This chart is split across two pages so that the graphic depiction can be more detailed. However, as always, the most important part for the pilot is the departure route description:







The procedure varies substantially depending on the runway used for departure. The procedure is most complex off runways 1L and 1R. Off those runways you'll make two turns as part of the SID (at 2500' MSL turn left to 315, then at 4500' MSL, turn left to 180). The procedure is designed like this to avoid terrain. The controller will expect you to make those turns without further instruction (or to look at it another way, the IFR clearance that included the MCCRN3 DP was your instruction to make those turns). Continue to fly the heading assigned in this SID until the controller gives further instructions to join your route.

Pure pilot nav SID

These types of SIDs require the pilot to fly a specific route to reach a fix. Again, the secret to knowing what's expected of the pilot is in the text. Read the textual description and look at the graphic. Let's examine a few of these types of charts. Here's the BORDR5 SID from San Diego (SAN):


Again, to fly this SID correctly, the pilot must read the “departure route description.” Note that the departure instructions vary depending on the runway used for departure. Each runway's route ends at BROWS intersection and the route descriptions end with “then via [transition] or [assigned route].” Normally on the BORDR5 you'll be assigned either the JLI or IPL transition, so after BROWS intersection, proceed via the route described in those sections. If you're cleared via the BORDR5 departure, the controller expects you to fly the departure after takeoff without further instruction; don't wait for instructions like "join the departure."

The second “pilot nav” SID we'll examine is the Pomona 6 departure from ONT:


For the 100^th time, the place to start in examining any procedure is the departure route description. All runways instruct a 255 heading after takeoff (runways 8L/R require a right turn to that heading). Then you intercept the POM 114 radial to the POM VOR, then proceed via your cleared transition or route. Note that this SID includes crossing restrictions at POM (at/below 8000), BUCKK intersection (at/above 14000), and FROUN (at/above 14000). These are established to protect traffic on other procedures in the L.A. Area. Controllers and pilots both should note that when an assigned altitude is amended or restated, the charted altitude crossing restrictions no longer apply, unless the controller states "comply with restrictions." Also, ensure you read the notes on each procedure you fly. This procedure includes several notes about aircraft equipment, climb gradients, and crossing restrictions. If you're cleared via the POM6 departure, the controller expects you to fly the departure after takeoff without further instruction; don't wait for instructions like "join the departure."

One of the more complex pilot nav SIDs in L.A. Center's airspace is the CATHERDRAL 8 SID (NOTE: always file the code included in parenthesis in your flight plan; in this case, if you were planning the PMD transition, file CATH8.PMD like it shows next to “Palmdale Transition” in the departure route description) out of Palm Springs (PSP):


The complexity of this procedure is required due to the steeply rising terrain around Palm Springs. It would be challenging to make sense out of this procedure using just the graphic depiction. Once again, the most important part of the chart is the departure route description. The departure route varies depending on the runway used for departure. However, no matter which runway is used for departure, the procedure leads to the 104 radial outbound from the PSP VOR. You must fly outbound to EMRUD intersection prior to turning back direct to the PSP VOR. After PSP, you then proceed via the transition or route contained in your clearance. This might seem counterintuitive since each transition begins at PSP VOR; however, the procedure is designed this way to allow aircraft to reach a safe altitude prior to beginning the transition. Note that each transition has a minimum crossing altitude at PSP prior to beginning the transition on the SID, if you will be unable to meet the minimum altitude, advise the controller and expect alternate instructions (likely a turn in holding over PSP or radar vectors to continue your climb). If you're cleared via the CATH8 departure, the controller expects you to fly the departure after takeoff without further instruction; don't wait for instructions like "join the departure."

Pilot Perspective

Hopefully, it's been repeated enough that the most important thing to do is read the departure route description. It has all the information you need to fly the procedure track. If you have questions about flying a procedure, always feel free to ask the controller for clarification. If you have not read the departure route description for the procedure, do not file for it or accept a clearance for it. These procedures are easily available, using the links on the LA Center or VATSIM homepages. As was said before, just because a procedure is included in your FMS or GPS database, do not assume that it includes every detail you need to fly the procedure; always read the departure route description. Finally, as has been said numerous times before, the inclusion of a SID in your IFR clearance (and your acceptance of that clearance) means that the controller expects you to fly it, as described on the chart in the "departure route description," immediately after takeoff. Don't wait for instructions like "fly the departure;" SIDs were designed to reduce the number of required radio transmissions.

Controller Perspective

SIDs are pretty straight-forward for a controller as long as you understand what the pilot is expected to do. A controller is always required to include the SID name (and transition, if applicable) in the IFR clearance. Also, when a pilot's assigned altitude is changed or restated, it deletes all published altitude crossing restrictions; including “comply with restrictions” to a clearance requires the pilot to comply with published altitudes.

Controller provides a “short range” clearance

There are times where a controller can't issue a clearance all the way to the destination airport, but instead initially clears the aircraft to a nearby navaid or waypoint (this does happen occasionally in the real world). This type of clearance will normally be used when the controller can't issue a climb clearance to the MEA or MVA required for the route beyond the clearance limit fix. For example, let's say an aircraft would like to depart Boulder City Airport (61B) southeast of Las Vegas for St. George, UT (SGU) with a route of BLD V21 MMM. Due to traffic inbound to LAS, the controller can't assign an altitude at/above the MEA on V21 which is 7500'. To get the aircraft airborne, the controller could use a short range clearance and keep the LAS approach corridor open.

Phraseology

Using the example above, the controller would use the phraseology (7110.65 4-6-1-b) “cleared to the BLD VOR, no delay expected, maintain 5000...” Once the aircraft was airborne the controller could assign holding at BLD, issue a radar vector after the aircraft reached the MVA, or issue a clearance to the destination.

Pilot perspective

This is an unusual clearance. If you get one like it, the controller likely has a traffic conflict and will be expecting compliance with the clearance. Do not proceed beyond the clearance limit fix specified. If you arrive over the fix and further instructions are not received, enter holding at the fix and maintain the assigned altitude. Query the controller when frequency congestion permits. As with any clearance, if you are unable to comply, or do not understand it, request alternate instructions or clarification from the controller.

Controller perspective

This can be a very useful strategy to deal with unique traffic situations. However, it is uncommon and the controller should have some confidence in the pilot's ability prior to issuing it. Once the aircraft is airborne, remember that it still needs a clearance to its destination. If the pilot will reach the clearance limit fix, provide holding instructions with an EFC or delay vectors.

Summary for Pilots

When you receive your IFR clearance, it should be very clear what the controller expects of you. Probably the most common pilot mistake on departure is flying runway heading when something else is expected. The only time it is appropriate to fly runway heading awaiting further instructions is when the controller states something like "fly runway heading" or when you are assigned a SID or other procedure which instructs the pilot to fly runway heading. Otherwise, determine what is expected of you and fly it after departure without further instruction from a controller. If you are unsure what is expected of you, ask for clarification prior to departure.

Other Considerations

What route should I file?

There are some good resources for route planning on Vatsim. LA Center uses Simroutes. When you visit the site, all you need is the departure and arrival airports. You might get more than one route back; in that case read the notes to help you decide which route is most appropriate.



Cleared vs. Filed route

The route you file in your flight plan is merely a requested route. The route in your IFR clearance is the only route that matters once you start flying. If you are cleared "as filed," then your filed and cleared routes are the same. If the controller amends any part of your route, you must make sure you understand it. The controller will update your flight strip so future controllers will also expect compliance with the same cleared route. Always feel free to ask for clarificiation if you don't understand any part of your clearance.

Changes to clearances

There are times where a controller will need to amend a clearance. For example, let's say a pilot is initially assigned a SID, but due to traffic, the controller later assigns a heading. The pilot is expected to fly the heading, not the SID. Always fly the last clearance you've received and if there's confusion, clarify with the controller prior to departing or executing the new instruction.

Notes for pilots operating at airports with an operating control tower (or a radar controller working the tower)

Operations at airports with an operating tower are pretty straight-forward. An IFR release may be required from the radar controller, but it will be worked out “behind the scenes” by the controllers. You takeoff when cleared for takeoff and comply with the IFR clearance issued. Don't wait for instructions to “proceed via the departure” or “proceed on course” or anything like that. Your IFR clearance provided the initial instructions, fly them. If you were assigned a SID, immediately begin flying the SID (you did read the textual departure route description, right?), if you were assigned a heading, turn to that heading.

Notes for pilots operating at airports with no control tower or with the tower closed

Pilots in the real world normally do a fair amount of training and flying out of non-towered, or uncontrolled, airports. On Vatsim, these operations are much more rare, and errors by pilots operating out of these fields are common. The first thing to understand is that you will not be “cleared for takeoff.” That is a clearance only issued by a tower controller (remember that on Vatsim, approach and center controllers normally run at least some of the towers in their airspace...LA Center controllers normally run towers at all controlled airports). The term “uncontrolled airport” can be misunderstood. It only refers to whether or not a tower is operating at that airport, not whether IFR operations are controlled.

The actual clearance from an uncontrolled airport will be the same as one received at a controlled airport; however, there are some additional IFR related communications that are possible. As mentioned previously, at a controlled airport, the tower controller will coordinate an “IFR release.” At an uncontrolled airport, that is worked out directly between the controller and the pilot. If a controller issues a clearance, but does not want you to depart without further communication, he will issue an instruction to “hold for release.” This means that the clearance has been issued for the convenience of the pilot, but the aircraft is not authorized to depart. In this case, the pilot will need to contact the controller to request an IFR release.

When you're ready for departure, request a release from the controller. He/she will likely respond with something like, “released for departure, clearance void if not off by 0300Z, if not off by 0300Z advise L.A. Center not later than 0330Z of intentions, time 0247 and one-quarter.” This means that you must be airborne no later than 0300Z, otherwise your clearance is no longer valid; if you find that you are unable to depart by this time, you are required to advise LA Center of your intentions by 0330Z. If you are unable to depart prior to the “void time,” you may request a new time and if approved by the controller, depart at that point.

If a clearance is issued without the instruction to “hold for release” and without a “void time,” the clearance has an implied release for departure. Clearances like this are somewhat common in the real world, but normally not issued in L.A. Center airspace. The reason is that they tie up the airspace around the airport, and preclude other aircraft from arriving or departing that airport under IFR.

Notes for controllers working uncontrolled airports and class D controlled airports ~ the 1-in/1-out rule

Smaller airports which can't use radar separation generally are limited to having one aircraft cleared for an approach or one aircraft released for departure at one time; this is sometimes referred to as the "1-in/1-out" rule. In ZLA, class B and C towers are generally permitted to use some degree of radar separation, otherwise they too would be limited to 1-in/1-out. Class D and uncontrolled airports (at least in ZLA) are not permitted to use radar separation at all, so they generally must only allow one IFR aircraft to be released for departure or one IFR aircraft to be cleared for an approach to the airport. There are some notable exceptions which can improve the efficiency of the airport's operation. These are advanced ATC procedures meant to help controllers better manage traffic. Adherence to the "1-in/1-out" rule will always ensure that required separation exists. Using this rule is even acceptable to pass a center OTS; but when you're at a point in your ATC "career" where you'd like to consider advanced techniques to provide more efficient service, consider the following paragraphs.

Timed Approaches

Timed approaches are used extensively in the real world to permit a steady stream of IFR arrivals, even in poor weather. These aren't typically used on vatsim (but for an event involving a class D airport, their use should be considered). Timed approaches are covered in 7110.65 6-7; they require an operating tower, certain weather minimums, and that an instrument approach be utilized (visual approaches may not be used with timed approaches, unless other approved separation is used). 7110.65 6-7 talks at great length about using time between arrivals to ensure separation in a non-radar environment (hence the origin of the term "timed approaches"); in the real world there are places where aircraft hold outside radar coverage and thus ATC still uses timing for separating aircraft on the approach. On Vatsim, we always operate in a radar environment and therefore can disregard all mention of timing and just use the minimum distance between aircraft (5 or 6 miles) over the FAF/OM. Between similar performing aircraft, the 5 miles would be adequate; if a fast corporate jet followed a Cessna 172, that distance would need to be increased substantially (just as it would in a radar environment). Keep in mind that it's theoretically possible that both aircraft could end up flying the missed approach procedure as well. The spacing over the FAF/OM should consider that possibility at least to the point where diverging courses could be established in the radar environment.

Separating departures from arrivals outside the radar environment

If IFR departures will be conducted from class D or uncontrolled fields while aircraft are cleared for an approach, they must comply with 7110.65 6-3-1 (unless visual separation is used...see below). An approach controller may generally permit a departure if it will be airborne before the approaching aircraft reaches a fix at least 4 miles from the field. With a tower, this can be fairly easy to accomplish, since the tower controller can be responsible for ensuring the appropriate separation will exist (this must be done using non-radar procedures...e.g. having the pilot report over the FAF). At an uncontrolled airport, it is more difficult to accomplish; however, in some instances it might be possible to ensure appropriate separation exists by appropriately using void times or other more advanced procedures. Keep in mind that uncontrolled airports require a greater margin for error since the operations have a lower degree of certainty than those at controlled airports.

An exception to all this, is that, if one pilot has the other aircraft in sight and can provide visual separation, then both operations may be approved without restriction. For example, if the departing aircraft has the arrival in sight, he may be instructed to maintain visual separation and then released for departure; the same is true if the arrival reports the departure aircraft is sight (this can be more difficult since the pilot of the arriving aircraft must report an aircraft on the ground in sight...there could be many aircraft on the ground).

VFR climb

If a pilot requests a “VFR climb” he may be released without restriction with an aircraft on approach. The VFR climb removes the requirement for the controller to provide any separation in class E airspace. The pilot maintains VFR conditions, which relieves the controller of the requirement to provide traffic separation, but is on an IFR flight plan. If the pilot requests a VFR climb (a VFR climb can only be requested by a pilot, not assigned by a controller), the controller should use phraseology like “climb VFR to and maintain 15000” (in which case, IFR separation would not be required until the pilot reached 15000'), or “climb VFR through 17000, climb and maintain FL230” (in which case IFR separation would not be required until the aircraft reached 17000'). See 7110.65 7-1 for more info. Just like regular VFR and visual separation, VFR climbs may not be used at/above FL180.