Page 30 - Volume 16 Number 2

28 • TWIN & TURBINE FEBRUARY 2012
From the Flight Deck by Kevin R. Dingman
Using the Missed Approach Procedure the Right Way
On the Rocks
Recently I received an e-mail from a reader who wrote to me about my November article Fuzzy Math. The topic of the story was landing minimums and why I thought we, as part 91 operators, should abide by takeoff mins too – even though we’re not required to do so. His comment prompted me to respond with what he called a “tutorial”. He’s right; I tend to get long-winded. Here’s what he said:
I enjoyed your recent article in T&T and would only add one suggestion. When I depart IFR, with or without a SID, I always have the instrument approach for the departure runway (ILS, GPS, etc.) programmed in the GPS unit and I plan to fly the missed approach procedure in the event of an engine out. Thank you again for your excellent article.
My response was:
It’s always nice to get mail from readers and I’m glad you enjoyed Fuzzy Math. Thank you very much for the blueberry pie and no, I won’t marry your daughter (Ok, I made that part up; he didn’t really send me any pie). The problem with trying to fly the missed approach procedure from takeoff is that the missed approach procedure begins at the missed approach point or decision
height /altitude. I can’t think of a scenario where that point would be in front of you during take off when your engine quits after airborne. You would be joining the missed approach procedure at a point and altitude not intended; almost certainly much lower. This may, or may not allow you to clear the rocks.
Wait until the MAP
Not only is the missed approach procedure based on you being close to the approach end of the runway when you begin the procedure, but ideally at an altitude at least 200 feet or so off the ground and at approach airspeed; it’s hard to do that from takeoff position. Now before you get all uproarious, I know you can “go missed” from any point on the approach you choose. You may not however, begin any turns until reaching the MAP (missed approach point). So, if the missed approach procedure starts off with: Turn left to 270 as soon as practical—it means at or above 400 agl and no sooner than the MAP. It could also say: Climb to 1,400 feet then turn left to 270. Again, you may be six miles out on final and already above 1,400 feet when you decide to go missed; perhaps due to reports of a herd of rabbits crossing the runway. This does not mean turn left to 270 right now! You still must wait until the MAP to turn.
A starting altitude of at least a couple hundred feet and approach speed at or near the runway threshold also puts you 1,000 feet or so higher than you would be at the point over the ground if your engine quits on take off. Departure Procedures and Obstacle Departure Procedures (DP’s and ODP’s) were invented for this very reason. They assume you’re making a takeoff starting at ground level, at or near the beginning of the runway, and are proceeding straight ahead along the centerline of the runway (the clearway) or making turns IAW the published DP and ODP. These procedures, if followed (both ground track and vertical speed), assure terrain clearance.
Picture This
Picture an airport that has a 9,000 foot long runway with obstructions a mile off the end of the runway, say they’re off to the left side and they continue for three or four miles further. Say it was like the old Meigs field in Chicago (before it was destroyed in the middle of the night – don’t get me started) and the city was the obstacle except the city began past the end of the runway a couple miles. Or it could be a mountain ridgeline like Palm