Once up and flying, the jet is not all that different from propeller airplanes except that it requires more precision from the pilot. Because of the higher airspeeds and the wing design, very small changes in attitude will produce high vertical velocities. So, to capture and hold the assigned altitude with the necessary precision requires very accurate attitude control. The task is really compounded during turns in which — except at landing approach speed — it is necessary to bank steeply to produce a usable rate of turn. Thirty degrees is the maximum bank angle in a jet for all but unusual or emergency maneuvers, but at that angle it takes very precise nose-up pitch control, as well as bank angle control, to hold altitude.
I remember when I got my first Learjet type rating nearly 30 years ago. I had to complete all training tasks and the check ride in the airplane even though I had spent two weeks in FlightSafety's simulator and ground school course and had passed the ride in the sim. It was then the "Learjet way." But all during the training, and then for the check ride, I never was asked to wear a view-limiting hood as is normal in propeller airplane IFR training and checking. The examiner told me I was free to look out the windshield all I wanted, but he was going to be watching the instruments and there was nothing out the window that would help me stay on assigned altitude, airspeed and heading with the accuracy required. He was right. The view out the window might tell you up from down, but it sure won't help you stay right on the assigned altitude. Jet flying is 100 percent instrument flying.
Another flying-quality difference in many jets is lightly damped Dutch roll, particularly if the wing is swept. Dutch roll, of course, is caused by yaw when the advancing wing produces more lift than the retreating side and thus causes the airplane to roll toward the retreating wing. With a swept wing, this characteristic is amplified. Dutch roll can become a control issue when it is excited by turbulence, particularly at very high altitudes where the thinner air provides less natural damping. In the early days of jets, a number of pilots lost control because of undamped Dutch roll.
Many jets require the automatic yaw damper to be engaged all of the time, or at least above specified altitudes, to control Dutch roll. However, more recent aerodynamic features such as the inverted-V ventral fins found on many jets aerodynamically damp Dutch roll, making the electronic yaw damper more of a passenger comfort aid than an airplane control necessity.
Flying at very high altitudes — 41,000 feet always seems to be the level mentioned — is often cited as the reason jet pilots need to be more experienced, but why? The reason is that the air is extremely thin, and low air density can disrupt the behavior of the wing and engines. At very high altitudes, the wing is experiencing the effects of Mach, which can cause shock waves to build on the wing or tail. These waves can disrupt lift production and cause unexpected pitching if the proper airspeed is not maintained or the wing is too highly loaded by an altitude too high for the airplane's weight, by steep turns or by turbulence.
More recently designed jets have wings that are very forgiving at high altitude and high speed compared with those of jets from one or two generations ago. That means the modern jet can tolerate sloppier flying without biting the pilot, but still there are limits, and at very high altitude in any jet the pilot needs to be smooth and remain well within the operating limitations.
Fuel burn at 10,000 feet, for example, can be as much as four times higher than at 41,000 feet. The most dramatic drops in fuel flow occur above 30,000 feet, even above 35,000 feet, so in crowded airspace where you can't climb quickly, or even at all, total block fuel will be very different from when flying in uncrowded airspace.
The most critical fuel situation can often happen at the end of a flight, when controllers send you down many miles from the destination. In busy areas, controllers have to separate overlapping arriving and departing traffic. The most logical way to do that is to climb the departures as quickly as possible to get them up and over the arriving jets. That means the arrivals get stuck down low a long way out so the departures can go over them.
There is nothing a jet pilot can do about this except to load on extra reserve fuel — probably at least double the normal — when flying into crowded airspace such as the New York, south Florida or southern California areas. If you haven't been there before and don't know what to expect from ATC on arrival, be even more cautious with your fuel plan.
Jet engines also feel the effects of the thin air at altitude, and the compressors can stall if maneuvers are too abrupt or if turbulence is encountered. Again, the margins in newer engines are much better than they were years ago. Any reasonably good control of the airplane will work, but high altitude simply increases the emphasis on the need for good flying skills. Of course, the autopilot will do the flying at high altitude, and it is typically required to be engaged when flying level above FL 290 in reduced vertical separation minimum standard (RVSM) airspace, but the human is the backup for the autopilot and must be ready to assume control at any moment.
The new jet pilot will really need to be at the top of his game for maneuvering in the terminal area and for the approach and landing. More jet accidents happen on approach and landing than during any other phase of flight.
The big difference in flying the approach in a jet is again the slower engine-throttle response than that in a propeller airplane. This is particularly important when the jet is configured to land. Jets have higher wing loadings than propeller airplanes, a condition that cuts drag in cruise flight but also increases stalling speed and thus increases approach speed, which in turn requires longer runways. To help reduce the stall speed despite the smaller wing area, nearly all jets have larger and more effective flaps than a propeller airplane does, and we all know that flaps add drag as well as lift.
Because a jet will have more drag than most propeller airplanes when configured for landing, you must be careful not to allow airspeed to decay. It is crucial that the jet pilot monitor airspeed trends and move the throttles aggressively to keep the airplane from decelerating below target approach speed. This job is, again, made more difficult by the slower response from the engine. The pilot needs to anticipate the need for more, or less, power and stay ahead of the airspeed trends.