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ExpressJet gave us a flight crew and a jet for the day (how cool is that?). So we went out and flew one of the more confusing things in instrument flying: a departure procedure with a "climb via". Check out the video and see what it's like.
When you're training for your instrument rating, you spend most of your time learning how to land at an airport, shooting instrument approaches. You don't spend nearly as much time learning how to depart under IFR. But if you're flying out of a congested area, or if you're climbing high, it can be difficult for ATC to keep departing and arriving traffic separated.
That's where departure procedures come in. They're like an instrument approach in reverse, keeping you separated from traffic as you climb out of the terminal area.
You typically find departure procedures in major terminal areas, like Denver or Houston. They're only flown by aircraft on an IFR flight plan, and they're used even if the weather is clear.
While they're usually reserved for aircraft climbing into or close to the flight levels, some airports use them for nearly all IFR aircraft. Salt Lake City is a good example of this. If you're in a single engine piston and departing IFR, ATC will often assign the Salt Lake Three departure.
While every departure procedure keeps you clear of terrain, some DPs are published simply for terrain avoidance. Most are simply written instructions, but some of them are charted graphically. They're called "Obstacle Departure Procedures" or ODPs. Take Walden Jackson County, Colorado. The airport is in the middle of the mountains, and it doesn't have services, but the "WALRU ONE" Obstacle Departure Procedure helps you climb out without bumping in to anything.
But by far most of the charted departure procedures are published to manage traffic. They're called "Standard Instrument Departures", but you'll usually hear the called "SIDs." And you can group them into three types.
The first is a radar vector procedure. In a radar vector procedure, ATC gives you vectors to your course. The procedure may give you an altitude to climb to, and provides instructions to follow if you lose your radios as well.
The second is a standard pilot-navigated procedure using ground based navaids, like VORs and localizers, to help you navigate a course out of the terminal area. With these procedures, you can also fly them with a GPS or RNAV system if they're in your database. The LINDZ 8 in Aspen is a great example of that.
Finally, RNAV procedures do the same thing as ground navaid based procedures, except they can only be flown by GPS or RNAV systems. And, they use waypoints instead of radials and navaids.
There's also another type of grouping for departure procedures: pilot navigation, radar vector, and combination. In pilot navigation DPs, you're responsible for your navigation throughout the entire DP. In radar vector DPs, ATC is responsible for getting you to the enroute structure, and combination DPs are just that, a combination of the previous two types. In most cases of combination DPs, ATC will vector you to a published route on the DP, and when you're established, you resume your own navigation.
If ATC wants you to fly a departure procedure, they'll usually assign it in your initial departure clearance.
Sometimes, ATC only wants you to fly the lateral course, and will assign you a specific altitude to climb to.
Other times, they'll ask you to "climb via" the SID instead of "climb and maintain". When ATC gives you a "climb via", you need to meet every altitude restriction along the route until you reach the SID's top altitude. And that's where our RITAA Five departure comes in.
To show how a climb via works, ExpressJet gave us an ERJ and a flight crew for a day (how awesome is that?!) We flew from Houston Intercontinental Airport to Corpus Christie and back, so that we could film the procedure.
We filed the RITAA Five departure, and we got it, with the climb via. Except, we were instructed to climb and maintain 4,000', which was our initial top altitude for the SID.
As we taxied out and switched to tower, they told us to join the transition via RNAV, "RNAV to TTAPS", and cleared us for takeoff.
At 600', we flew direct to TTAPS.
On our way to TTAPS, tower told us to contact departure. When we called up departure, they re-cleared us to "climb via" the RITAA Five departure. By receive that clearance, our previous top altitude of 4,000' was deleted, and we were cleared to climb all the way to the SID's top altitude of 16,000', while still adhering to all of the intermediate altitudes.
At this point, the next altitude restriction was to cross TTAPS at or below 4,000'. How do you know that? TTAPS is under the line.
Next up, we crossed BOTLL at or below 5,000'.
Then, after we crossed BOTLL, things changed. Instead of crossing fixes "at or below", we needed to start crossing the fixes "at or above". The first fix that happened at was FLYZA, where we needed to cross at or above 7,000', with 7,000' above the line.
After that, the next fixes, WINEO and RITAA were "at or above" altitudes of 9,000' and 10,000'. So the crew bugged the top altitude of 16,000' and waited for their final cruise altitude.
When departure changed us over to center, we were cleared to our final altitude for the leg: Flight Level 220. And with that, we were on our way to Corpus Christie.
SIDs aren't all that complicated to fly. But when you have lots of restrictions with a "climb via", you need to stay ahead of the airplane so you don't miss an altitude restriction.
Our ExpressJet crew briefed the SID on the ground, and in the air as they approached each fix, making sure they were at the right altitude for each crossing restriction. The same goes for you when you're flying a SID, even if you're single pilot. Brief on the ground and in the air, and you'll have no problem handling a "climb via".
Ready to start flying departure procedures from the right seat of a jet? When you're within six months of earning your hours, apply to ExpressJet.
Aleks is a Boldmethod co-founder and technical director. He's worked in safety and operations in the airline industry, and was a flight instructor and course manager for the University of North Dakota. You can reach him at firstname.lastname@example.org.