Based on my experience, I'll make one general statement: When something goes wrong in an airplane, do not act impulsively. Stop and think! However, one exception does exist -- an emergency procedure that requires immediate-action steps. These steps, listed in the airplane's pilot's operating handbook (POH), must be committed to memory, performed expeditiously, and practiced periodically in order to maintain proficiency.
That thought reminds me of a friend who was flying a fuel-injected single-engine airplane. While passing time on the ground awaiting a passenger's arrival, she decided to read the POH's emergency section. While reviewing the engine failure procedure, she realized that she had forgotten a critical immediate-action item.
Guess what? During the subsequent takeoff, the engine quit at 500 feet agl. Having just read the action steps in the POH, she knew to immediately turn on the electric fuel pump, which restored engine power. The mechanical fuel pump had failed. From that day forward, she periodically reviewed the airplane's emergency procedures while sitting in the cockpit and touching the appropriate switch or control.
Don't make assumptions
Making assumptions is a deadly pilot error that you must learn to avoid. I hate to repeat myself, but I've made this statement frequently: You may be an optimist on the ground, but you must be a pessimist in the air.
For example, you can't assume that the fueler, weather forecaster, mechanic, air traffic controller, and the aircraft's published fuel capacity and consumption rate are correct. You can't assume that the engine won't fail on takeoff, a radio won't fail en route, a missed approach won't be required at your destination (if you're instrument-rated), or that your destination airport will remain open.
I am not being critical of the people I mentioned, because like most pilots they are well-intentioned. I am just recognizing that they too can fall prey to the realities of the human race. According to the FAA, controllers made 1,212 errors nationwide in 2003. That's about 100 a month. Pilots made three times as many errors that year.
Activate and verify
Activate and verify is the second pilot thought process that's critical. If you activate a switch or control, you must verify that the desired action occurred. If you turn on a fuel boost pump for engine start, you must watch the fuel pressure gauge and verify that fuel pressure increases; when you turn the pump off, watch the gauge and verify that the engine-driven fuel pump is working.
To fly in IFR conditions, your VOR receivers must be checked for accuracy every 30 days. I still don't trust them. So on the first departure of the day, I'll set one receiver for the instrument approach that's in use at the departure airport -- in case I must return because of an emergency or irregularity -- and set the second receiver for the first course intercept. After I establish climb power and complete the after-takeoff checklist, I set the first receiver to what I had set on the second receiver. I am activating and verifying, because I expect both receivers to give the same indication during the initial course intercept. During 46 years of flying, I've found three VOR receivers that passed the ground test but failed this airborne dual-comparison test. If just one such failure went unnoticed, it could have been the end of my flying career. (No, the receiver's OFF flag did not appear.)
Many new airplanes are equipped with dual GPS receivers. Is that just for protection in case one fails? Of course not. The dual receivers give you the ability to verify proper operation. Often today you can verify correct GPS receiver operation during an instrument approach by comparing it to conventional radio navigation aids, but that situation is rapidly changing as we get more and more GPS-only approaches.
Evaluate and validate
Evaluate and validate is a third pilot thought process that's critical. For example, you see the oil pressure warning light during flight. Did you lose oil pressure? You must evaluate the warning indication by validating the oil pressure and oil temperature gauges in order to determine whether or not a problem exists. (If oil pressure drops and oil temperature remains normal, you've likely experienced an oil-pressure sensor or gauge failure. But if oil temperature is going up, you have a serious problem.)
If you have an unsafe landing-gear indication in a retractable-gear airplane and you are unable to resolve it using the POH procedure, you must evaluate and validate the system, which requires a full understanding of that system. For most retractable-gear airplanes, the landing-gear warning horn and the gear-down lights are independent but it is difficult to make this determination by referring to the POH. Have a mechanic make that determination by referring to the electrical system schematic in the airplane's service manual.
If they do work independently, you must validate the warning horn while the gear is extending. Climb to a safe altitude, reduce power so that the warning horn is activated, and extend the landing gear. If the horn quits, the gear is down and locked.
The principle of evaluate and validate also lets instrument pilots resolve conflicting information. This is called the triangle of knowledge, which means that you evaluate three independent sources of information. If one of the three disagrees with the other two, you have validated the two correct instruments.
Pitch information is an example. Evaluation shows that the attitude indicator (AI) indicates a climb, but the vertical speed indicator (VSI) indicates a descent. Do you use the airspeed indicator or the altimeter to validate this conflict? Neither, because like the VSI they are both working off the static air system -- which may be the problem. You must select the alternate static air system and use the altimeter to validate the correct indications.
Bank information presents a more critical example, because an assumption here can easily lead to a graveyard spiral and in-flight structural failure. Evaluation shows the AI in a left bank, and the turn coordinator (TC) in a right turn. How do you validate this conflict? You cannot use the heading indicator, because just like the AI it works off the vacuum system. You must use a completely independent bank instrument: the magnetic compass, which is powered by the Earth's magnetic field. If it shows a right turn -- the numbers are increasing -- the AI is in error and the TC is correct. If the magnetic compass shows a left turn -- the numbers are decreasing -- the TC is in error and the AI is correct.
In turbulence, you could heck the suction gauge -- it's often hidden in a remote corner of the instrument panel -- and if it shows that the vacuum system is operating, use the HI to validate the conflict between the AI and the TC. Another independent source of turn information would be a GPS navigator, if the aircraft is so equipped. Now, and only now, can you apply flight control inputs, because you are doing so based on valid information and you will not enter the deadly graveyard spiral.
Did you say, "Ha ha, I'm flying one of the new glass-cockpit airplanes so all of that headwork will not apply to me"? Sorry, that headwork will apply for as long as you fly instruments.
Your primary flight display (PFD) will indicate attitude and heading information that's generated from the magnetic-field sensors that automatically align when the system is turned on. Altitude, vertical speed, and airspeed are generated from an air data computer that receives pitot and static air pressure and outside air temperature; there are various means for displaying turn rate and rudder coordination. You will also have a magnetic compass and a conventional electrically powered standby attitude indicator, as well as a conventional airspeed indicator and altimeter.
The new system will have a flight director with a bright, attention-grabbing, computer- generated, V-shaped command bar. Caution: Never rely totally on this device, because it's a supporting indication, not a primary indication. Teach yourself to always look beyond the command bar and evaluate the PFD's basic indications while you follow the command bar's guidance.
Scanning is much more difficult with a glass cockpit, because you must read numbers on vertical displays and interpret colors. Hand-flying the airplane in instrument conditions is permissible as long as you can concentrate on just the PFD and the moving-map display. If you are a single pilot flying in IFR conditions, this is impossible, so you must have and be extremely proficient at using a high-quality autopilot -- a mandatory glass-cockpit tool.
The instrument rating practical test standards state that you must demonstrate flying the airplane when all of this gee-whiz equipment has failed and proper use of the autopilot during at least one instrument approach.
So, our technological advancements have not changed the mental requirements for instrument flight. You must learn to use proper thinking during initial pilot training so that you can fly safely into the future.
Ralph Butcher, a retired United Airlines captain, is the chief flight instructor at a California flight school. He has been flying since 1959 and has 25,000 hours in fixed- and rotary-wing aircraft. Visit his Web site.
Want to know more? Links to additional resources about the topics discussed in this article are available at AOPA Flight Training Online.
Related Articles
