Saturday, December 15, 2007

Take Off Decisions in Single Engine Airplanes

Triggered by my review course, I was going to write an entry on V1, introducing it with a comparison to take-off decision making in single-engine airplanes, and multi-engine airplanes incapable of accelerating to rotation speed after an engine failure, but I quickly discovered I had enough to say about each to make this into three blog entries. So here's the first.

I'm returning to a common theme of this blog when I say that pilots spend much of our training and mental energy preparing for what might go wrong. One of the obvious things that might go wrong is for an engine to fail, and one of the worst places that could happen is just as we're taking off. We'd be at too low a speed to safely fly an aircraft, but at an unreasonably high speed to taxi, and the runway ends abruptly not far ahead. Any time spend pondering the best course of action could be very costly, so pilots work out in advance what the options are and at what point the options change, and then practice the hell out of them, so that should the worst occur, the hesitation before taking correct action would be no longer than the time to recognize the failure plus the reflex time required for mental intention to turn into muscle action.

An engine could fail at any point in the take-off sequence, from first applying take-off power to reaching a safe altitude after getting airborne. Which situation a failure places you in depends on what kind of airplane you are flying, where you were in the take-off sequence at the time of the failure, and the environmental conditions.

Clearly a single engine airplane that experiences an engine power loss on the take-off roll is in situation must stop the take-off attempt, no matter how little runway remains, or how close the airplane was to flying speed. The pilot's job is to quickly recognize the failure, retard the throttle to eliminate any remaining engine power, and apply the brakes as heavily as necessary in order to stop before departing a safe stopping surface. The checklist probably also asks the pilot to secure the engine at this time, too: shutting it down completely as well as closing the emergency fuel shut off valve and turning off the electrical master. In short: if the engine stops, then immediately stop the movement of the airplane, fuel and electricity. If the airplane is already airborne, then the checklist is almost identical, except that the first item on the list is "land straight ahead," which may involve extending flaps.

For the single engine airplane (or any airplane that loses all engine power after take-off) there comes a point in the climb out where it becomes possible to turn around and return to the airport rather than gliding to a landing straight ahead. This point is going to depend on aircraft weight, pilot skill, wind, runway configuration at the airport, and the terrain available for the straight ahead (or nearly so) landing. Some pilots memorize an altitude above ground level at which they can turn back. A good way to determine this is to actually practise it at altitude. Start in flight well above terrain and aligned with a geographical feature like a road or stream. Apply climb power and pitch to your take-off attitude. At an even thousand altitude, retard the throttle to idle. Immediately lower the nose to best glide speed and start a one-eighty degree turn. When you are re-aligned with the geographical feature and in a configuration that would allow you to land on it, check your altitude. Adding some as an allowance for any obstacles you'd have to maneuver around to actually get back to your departure airport, you now have an idea now of how much altitude you need to turn around. Obviously if you determine this with just you in the airplane at 4000' asl, the result isn't going to be sufficient with your family and baggage on board(*), or at a density altitude of 7000'.

It's not a simple problem and no one rule will work for every airport in all conditions. If straight ahead is only jagged mountains then what do you do? Some choose "don't use that airport." A controlled landing on almost any kind of terrain is safer than a stall-spin resulting from an unsuccessful turnback, and if you aren't going to be landing at the airport anyway, landing into wind gives you a slower, safer touchdown speed. Single engine pilots are also advised to pick a go/no-go point along the runway, such that if they are not flying by that point, they abort. That would allow them to recognize an underperforming engine or insufficient runway length while it was still an anecdote and not an accident.

There may be cases where a powerful single engine aircraft loses some engine power, but has enough power to, and the pilot deems it safest to continue rather than abort. I can think of two instances where people I know experienced a partial power loss immediately after take-off and chose to limp around the circuit on three cylinders. It's impossible to make all the decisions in advance. You have to follow a general rule that if there is any doubt in ability to take-off and climb over obstacles, abort the takeoff. If airborne, maintain flying speed above all else. If unable to maintain altitude and speed, land at the safest place you can reach without risking flying speed. Airspeed, as the old saying goes, is life. Altitude is life insurance.

*Yes, yes, glider pilots: I know that glide range isn't a function of weight, but stall speed is, and that's how single engine pilots die in this maneuver.

Friday, December 14, 2007

So, You Want To Be A Pilot, Eh?

Reader James Ball sent me his recently-published guide to Canadian aviation careers, So, You Want to be a Pilot, Eh? to see if I would review it for you guys. After reading it I'm happy not only to review it but to recommend it. Judging from my own experience and the e-mail I receive, there is certainly a need for such a book, and I can't think of a comparable career guide for prospective Canadian pilots. The closest might be Landing the Big Job, but back when I bought that one, So, You Want to be a Pilot, Eh? would have been a much better choice, had it existed.

James starts where the student pilot should start, with the question "do you really want to be a pilot?" He honestly explains the parts of the career that are tough, holding out no false hope to the waverer, while maintaining a sense of humour. "It's difficult to keep track of all the different licences and ratings that are available to pilots. It can be even more difficult to pay for them all." He gives an excellent jargon-free and Canada-wide overview of the industry, from dollar-a-jumper paradropping jobs up to major airline captains drawing six figure salaries. As he discusses different hiring policies and corporate histories he refers obliquely to companies as, for example, "one operator based in Norman Wells, NWT." Those made me laugh as James and everyone else who has been around the circuit a few times can recognize the operator just by the base.

I liked the good Canada-specific advice he gives regarding joining the military to learn to fly, working the ramp and working the dock. Those are areas in which Canada is quite different from the US, and their airline job-hunting or career guides don't apply. James also gives many useful website URLs. These will unfortunately change in less time than it take to read the book, but James is providing updates and errata on his blog. Perhaps he will group all the recommended URLs on one page there, to spare readers from having to type them in.

James gives good guidance, much of it straight from the Transport Canada website, without trying to take the place of more comprehensive guides on topics like passing written examinations and flight tests.

The resume guide is very worthwhile, as aviation resumes are different than those in other industries. It is vital that your hours be clearly visible and reference contact information be actually given. James says this, but I'm going to underline it here so that anyone hunting around the net for pilot resume advice finds it and buys the book.

There were a few things I didn't like, such as James' advice to student pilots out on a solo, "After you've completed the checklist, take some time to explore your local area." Flight instructors recommending this book should censor that part. Also one of the books he recommends is of such poor quality that my local aviation store has dropped it (but they do carry So, You Want to be a Pilot, Eh?).

There are items I wanted to add, such as the possibility of other more stable and lucrative careers in aviation, but that would make it a different book. There's nothing missing within the scope of the book and I was frequently surprised to see excellent but not widely-known tips. And there was even one that I had never heard of, "abstain from sexual activity for a few days" before an aviation medical. Is this folklore or based on some kind of fact? Unless it gets you pregnant, I don't know of any physical changes as the result of sex that persist long enough to drive to the doctor's office. Perhaps this is a male thing, and one of my readers will enlighten me.

I caught a few editing glitches, the military requirement for Basic Officer Training and Foreign Language Training mentioned twice in consecutive paragraphs in the same section, but there is no fluff here. James has a concise style and still fills over two hundred pages with useful information.

This would be a great purchase for the family of a prospective pilot. Amend the cover with a sticker to make the title read "So, Your Kid Wants to be a Pilot, Eh?" and give it to your mom. I would recommend this book not only for Canadians thinking about a flying career, but to student pilots, pilots looking for their first job, and instructors looking to move on. Also if you're a foreign commercial pilot interested in working in Canada, this book contains what you should know about the Canadian industry and process. It's also written simply enough for ESL students, and laid out so you can refer to one part or another, but it's readable and interesting enough to go right through, as I did.

The list price is $24.95 and there's a Buy It Now link on James' website but it seems that the publisher and distributor have changed their links, so go straight to Chapters to buy it online. It's even on sale at $16.46 which equates to about eight minutes of dual instruction time, converted to student pilot dollars.