Cruise Clearance
A cruise clearance assigns a block altitude from a minimum IFR altitude up to a specified maximum. Once leaving and reporting leaving an altitude the aircraft may not be returned to that altitude. The cruise clearance is for a short distance under the control of one ATC specialist. Mandatory reporting points are required unless in radar contact.
The cruise clearance has to do with a maximum altitude and your reporting out of an altitude. Below that assigned altitude you can descend all the way to an airport and back up again if the clearance includes the word 'through'. You must remain above the minimum instrument altitudes of one or two thousand depending on terrain. If your clearance limit is an airport you can just fly the approach of your choice and land. Once you have told ATC you have left an altitude you cannot go back. You cannot file for a cruise clearance or a cruise through clearance, you must ask for it direct from ATC. The controller must enter your clearance by hand. You can also file two separate plans with the stop as a new departure. If the plan is in the computer the controller will have less trouble with the cruise through clearance. Cancel IFR on arrival and descend into Class G airspace. Below 1002’ AGL at night you can operate with only one mile visibility and clear of clouds in a an airport traffic pattern within one-half mile of the runway.
On a cruise clearance the pilot can climb and descend at will, so long as he does not report to ATC that an altitude has been left. Once ATC is advised of a pilot leaving an altitude, that altitude may not be again reached without ATC approval. Don’t report leaving altitudes.
The use of a cruise clearance is for getting via IFR to airports without an IFR procedure. You can fly to the airport at MIA and cancel for a VFR arrival. With a cruise clearance the MIA is the pilot’s responsibility.
IFR charts now include OROCAs or off-route obstruction clearance altitudes which allow a pilot to figure his own MIA’s by adding 1000’ above an obstruction with at least 2000’ lateral height of obstacle within four nautical miles. (FAR 91.177(a)(2) Current sectionals required. MIAs can be obtained from a radar approach facility. ATC will not voluntarily give you the MIA, you must ask.
Since a cruise clearance is an IFR flight plan the pilot must close it as soon as the MIA is about to be descended through.
A cruise clearance allows a pilot to fly from the minimum IFR published altitude up to the maximum specified in the clearance. If you can't get there from here, refuse the clearance. If you don't know minimum altitudes ask ATC.
Using En route Options
When flying IFR in partial VFR conditions consider asking for a block altitude that will allow you to fly either as you wish. A block clearance lets you climb, descend, and turn as you wish. As with all clearances you must understand what you are getting.
Another optional clearance is the Cruise Clearance. A cruise clearance allows you to descend as you wish and even to climb up to your initial altitude. It is not until you report leaving an altitude that you can never again climb back again. Don’t clear yourself out of an altitude you may need again.
IFR in VFR
IFR operations have radar separation that is not available to VFR operations. The assumption is that VFR aircraft can only be in VFR conditions. Under certain mixed flight conditions these two flights could merge with out warning. In Class B airspace the radar service must provide separation. VFR traffic on a practice IFR approach places primary and ultimate separation responsibility on the pilot. VFR traffic has a low priority for radar separation.
The VFR-On-top is requested by the pilot who is allowed to select an altitude below Class A airspace. This clearance requires you to operate in basic VFR conditions while following IFR strictures related to minimum altitudes and radio procedures. In Class B airspace this clearance shows on radar as VFR but gives IFR separation
A pilot can reject or refuse an ATC initiated visual approach. An accepted or initiated visual approach requires the pilot to proceed visually and clear of clouds to the airport. FAR 91.155 requirement for VFR minimums does not apply. The pilot may proceed visually and clear of clouds. The visual approach does not contain a missed procedure so you may need to expedite your request for an new clearance. The visual approach may be given by ATC at uncontrolled airports when VFR conditions are expected to prevail.
The Charted Visual Approach uses an IFR chart to show a route at a minimum altitude which navigates by visual markers as charted. The visual approach eliminates IFR procedures is NOT an IFR procedure. The charted altitudes are minimums and suggested only. There is no missed approach.
Additionally:
--Radar service ends when changing frequency.
--Flight plans must be closed by the pilot at uncontrolled fields.
Uncontrolled Airport Departure
IFR pilots tend to believe that ATC will keep them clear of obstacles. Except for airports with published instrument departure procedures, ATC does not provide terrain and obstruction clearance--not until you reach a published route, minimum vectoring altitude or minimum instrument altitude. In a mountainous area an aircraft may not have the required IFR departure performance. Your option is to request a "visual" (not VFR) which ATC understands to be visual climb as part of the IFR flight during which the pilot is responsible for obstacle avoidance.
The only place you will find terrain avoidance information will be on a current sectional or area chart.
Each airway has a useful IFR flight area from above the MEA, MOCAs, MIRAs and MCAs up to 17,999 feet. MEAs and MOCAs have either one or two thousand obstruction clearance depending on terrain. The difference in their altitudes relates to communications.
When an MEA changes at an intersection the airways have a T bar at the end. Every airway has a changeover point. If it is not shown it is halfway. Five letter CNFs or computer navigational fixes are being made at fixes for GPS use but are not to be used in ATC communications.
Only 7% of airports have control towers. For IFR you must know how to depart safely, how to get your clearance, and what to do if you decide to go back. Some airports have approaches but no departure procedure. Usually you will be told in your clearance to proceed to a particular fix on entering controlled airspace. Use a departure procedure to do this if it exists, otherwise, make your own safe routing. Controlled airspace is not necessarily obstacle free. The IFR departure procedure is solely for obstruction avoidance. On filing you have a choice of filing a DP or of following the ATC departure procedure.
A pilot may do an approach to a controlled airport but cancel on the approach in VFR and proceed to another nearby airport. The ETE destination point on an IFR flight is the point of intended landing. FAR 91.169 which refers you to FAR 91.153(a)(6). Pilots often file to an IFR airport with intention to cancel and diverting to actual non-IFR destination.
You must show up at the place and time ATC expects. How you get into controlled airspace and to minimum vectoring altitude (MVA) is up to you but until you reach MVA obstacle avoidance is a pilot responsibility. If you are in doubt about a heading being a vector with ATC responsibility just tell ATC that you will fly the (instrument departure procedure (IDP). In uncontrolled airspace you don't need a clearance. Up to 700 or 1200' AGL you can fly in the fog but you must be VFR above that.
There are several ways to get an uncontrolled airport IFR departure clearance. A remote communications outlet (RCO) may be within range, A nearby ATC facility (tower) may be used. You can use a phone and get a void-time clearance or even depart and get your clearance in uncontrolled airspace. Your initial clearance will be to a nearby fix not to your destination. The fix location usually assures radar contact before reaching.
A departure procedure exists if an obstacle is determined to affect plane of departure from either end of runway. Minimum is 200 feet per nautical mile unless higher minimum rate is specified. NOS uses T and Jeppesen lists it on airport page. Pilot is responsible even if radar is available. Radar assumes responsibility for obstacles only when initiating vectors.
Clearance Void Time
A clearance or clearance void time at an uncontrolled airport must be obtained through ATC/FSS once your reservation becomes available. A clearance void time (CVT) from an uncontrolled airport requires that the takeoff occur before that time. Radio contact time is not mentioned. Departure at that time is not authorized. FAR 91,173. The void-time clearance usually has a 10 minutes or less time during which you are expected depart to establish radio contact. In non-busy environments a longer time may be requested. The void-time clearance will not contain departure instructions but will tell you that on entering controlled airspace to proceed to a certain fix. ATC must be advised within 30 minutes of intentions from the ground if departure cannot be made before that time. If no ATC notification is made the aircraft is considered missing. This automatically cancels the IFR clearance but the IFR flight plan is still in effect.
A couple remarks about flying out of an uncontrolled airport on an IFR flight plan. First, file your flight plan by phone. If airport has a RCO call clearance and obtain a void time clearance. This means that you must takeoff and contact approach before entering controlled airspace before the void clearance time. If at an airport with no RCO, just call FSS file flight plan and get a clearance void time. Then takeoff and contact departure.
A VFR departure with an airborne IFR pick-up of a pop-up clearance is both practical and safe. It is much more efficient than a void-time clearance and is to be preferred by pilots. ATC likes it better, too. Void Time clearances tie up a lot of airspace for excessive lengths of time.
Sunday, flew to Rancho Murietta (non-tower) to visit Rancho FSS and take student through the procedure for void time departure sequence. Dave at Rancho used computer to take us through the procedure for filing and how the void time departure is sequenced through a radar facility. When we were about to leave he phoned approach and got our clearance and void time just as we were leaving. We had a ten-minute window.
Student ran ahead to preflight. It took me three minutes to get to the plane. It took two minutes to get the cockpit organized and ready to start. Suddenly, the aircraft began to rock violently. Dave, while not in his prime, had run the football field + distance to advise us that the clearance had been cancelled. We were to pick up a new clearance via radio. We picked up our clearance again in the run up area with a three minute window and made the void time with no problem. This has to be the most unique clearance cancellation on record.
Dave's extra effort is certainly an indication that some of the specialists are making the extra effort to make the system work. Even 'approach' made an appropriate apology. It was a good lesson.
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