When departing IFR from a tower-controlled airport, planning your initial route is easy. You may have a challenging departure procedure, but you depart as cleared or as directed, immediately under positive control. It sounds complicated, but its actually easier than the alternative.
The alternative, since you asked, is an IFR departure from a non-towered airport. In this case, youre entirely responsible for terrain clearance until you make it into controlled airspace and you must plan an obstacle clearance departure route on your own. Your options (and responsibilities) are different depending on whether its
VMC, marginal VFR or IMC. What do you need to consider? How do you choose?
No Rules, Just (be) Right
If you want to know what youre expected to do under a given set of circumstances, the first place to look is the regs. FAR 91.175 specifies what pilots are required to do for takeoff and landing under IFR. Although 91.175 gives us a lot of good information about landing minima and decision heights, and what needs to be visible to proceed from the missed approach point to landing, it is basically mute on the subject of instrument departures.
While the regulation gives guidance about instrument takeoffs, it points out that such information “applies to persons operating an aircraft under Part 121, 125, 129, or 135….” Part 91 pilots, regardless of the type of airplane flown, have no specific guidance (or limitations) on instrument departures.
Basically, then, there are no rules-meaning you are solely responsible for figuring a safe way to make it from the departure runway to the first altitude or fix of your instrument clearance. The absolute worst thing you can do when departing a non-towered airport is presume your clearance assures obstacle avoidance before you reach published IFR minimum altitudes and routes in controlled airspace.
Making a Plan
How can you plan your non-towered IFR departure? Start with the VFR charts. All too often, once we earn an instrument rating, we stop considering the information available on sectional charts and in the Airport Facilities Directory (A/FD). Spend a few minutes looking for obstacles and picking a route based on visual chart information and the A/FD. This is especially valuable if youll have to travel beyond the immediate airport area before establishing on a cleared altitude or route.
Another thing to do is check the instrument approach procedure (IAP) charts for the runway youll use for departure. Youre looking for a charted departure procedure (DP), a pre-planned IFR route providing obstruction clearance from the terminal area to the en route structure. There are two types of DPs: obstacle departure procedures (ODPs) and standard instrument departures (SIDs). An ODP is recommended for obstruction clearance and may be flown without ATC clearance. Conversely, ATC clearance must be received prior to flying a SID.
Look also for non-standard takeoff minimums. Although these are not required for the Part 91 operations most of us fly, they provide valuable clues to obstacles in the departure path and procedure you can use to avoid them. If there is a recommended ODP, it will appear in textual form with the takeoff minimums.
On the departure airports IAP chart youll also find the areas minimum safe altitude (MSA-sometimes minimum sector altitude) for each quadrant. Under U.S. rules, we all but ignore the small circular diagram on the approach chart, instead following charted procedures. But this is vital information to have during emergencies and off-routing flight such as initial climb from a non-towered airport. Remember the MSA is a 25-to-30-nm ring around a specific fix-not necessarily the airport-and provides little else in the way of detail, so there may be safe routes and procedures closer in to the airport. Dont ignore the overall message: Obstacles are out there.
A great clue to what you could expect on departing is the charted missed approach procedure. The “miss” is designed to take the airplane from a minimum altitude (DH, DA or MDA) safely back up to an altitude and location where ATC can talk to and (possibly) radar-identify it. Although you will have to get from the runway to arrival minimums on your own planning, once at DH/DA/MDA and if still within the confines of the airport, you have a charted route to get there. Take off and fly the published missed.
When considering the miss and how to get away from the runway, use the obstacle clues represented by circling minima. Climb as rapidly as possible to Category B minimums. Then plan to be at Category C minimums before youre 1.7 nm out, at no less than Cat D by 2.3 miles off the end of the runway and at least Cat E circling minimums within 4.5 miles of liftoff.
Finally, check the IAPs for the other available runways at the departure airport, if any. If winds, runway slope and aircraft performance permit, you may have a safer route available taking off in another direction, even if its opposite your eventual direction of flight.
All of which presumes your departure airport has at least one published approach. If not, or the facility only has approaches that use navigational equipment you cant receive or identify in your airplane, youre entirely on your own. Look again at the sectional and A/FD for any information about obstacles and terrain. Adhere to right-hand traffic patterns and other peculiarities of the particular runway youre departing-sometimes nonstandard patterns are obstacle-driven. Dont forget to check Notams for all those unlit towers. Consider simply climbing in the airport traffic pattern-which, if flown “tight,” is clear of obstructions-until you reach a safe altitude.
If a local pilot is hanging around the FBO, ask him or her how best to depart under IFR. Consider the performance of the airplane discussed-your twin may be able to climb faster than the other pilots single, for instance, but youll also have a greater turning radius so more-distant obstacles may be more of a factor for you.
Offer to pay the local CFI for 15 minutes of time to review your departure planning and clue you in to local obstructions. Even if he or she doesnt teach instrument flight, chances are few others have as intimate knowledge of the immediate airport environment than a local CFI.
Look at whats gone wrong in the past. If youre an AOPA member-and if not, why?-go to www.aopa.org/members/airports and find your departure airport. On its information page, scroll down and click “ASF Accident Reports.” This is an AOPA Air Safety Foundation collection of NTSB accident reports of events that took place near the selected airport. Any obstacle-related accidents here will help solidify for you the danger areas for your own instrument departure. A very nice resource.
Finally, arrive with departure in mind. Think about how youll depart before you ever fly into the airport. If you arrive in visual conditions, eye the area with an IFR-departure plan in mind…when landing, look for obstacles you might not be able to see when time comes to leave.
When it comes to safely planning an instrument departure, weather conditions play a big part in what you need to do. Observe and make a clear distinction between different weather conditions.
If its solid IMC, you cant see obstacles and youve got to plan your way out. Talk to locals who fly IFR, look at the sectionals for indications of towers, wires and terrain, and study the instrument arrival procedures for clues to ways to climb out IMC. Write down your specific plan, in terms of headings, distances and minimum altitudes that will take you from the surface to published IFR routes and altitudes in controlled airspace. Launching from a non-towered airport directly into IMC without this level of forethought is suicide.
If the airport and surrounding area are under good visual meteorological conditions (VMC), seeing and avoiding obstacles on departure will be easier. You can get a clearance on the ground or, if the local airspace isnt too complicated or too busy, you may be better off to launch VFR and pick up your clearance airborne. This gives you the maximum flexibility for picking a safe departure route that takes you in the direction of your planned route. Make sure, however, that youll be able to remain VFR until you pick up your clearance.
You also need to avoid airspace requiring two-way communications or a clearance for entry unless you make that additional contact prior to receiving your IFR. Any number of situations may delay contact with ATC, or prevent controllers from issuing your clearance immediately when you make radio contact.
Marginal VFR-more correctly, marginal VMC-may be the riskiest weather for attempting to pick up your IFR clearance once in the air. Other IFR traffic in the area may prevent ATC from issuing your clearance right away. Lower-than-expected clouds or nearby Class B, C or D airspace may sandwich you between clouds and surface obstacles.
More and more IFR initial and recurring training occurs in larger schools and formal training organizations. Most of these facilities at located at tower-controlled airports, and conduct a large percentage of their flight training locally or to other tower-controlled airports. Consequently, departing IFR from a non-towered airport is something taught less and less-even though general aviations greatest utility comes from utilizing the entire airspace system, including these airports.
Centralized training leaves a non-towered-airport procedures gap in many instrument pilots education, whether theyll fly professionally or for personal transportation. Fill that gap in your personal safety by devising scenario-specific plans for departing IFR from non-towered airports.
Tom Turner is a CFII-MEI who frequently writes and lectures on aviation safety.