From Big to Little

When slumming down from a heavier airplane to a lighter one, watch the V-speeds and dont count on the automation. As Pat Veillette reported in Aviation Safety, there isnt any.

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If you’re ever lucky enough to fly a transport-category simulator, you’ll probably be overwhelmed by the first few minutes of the experience. The big airplane’s systems are complex and compared to a light aircraft, the handling can best be described as whale-like. Anticipation and patience are critical skills.

Sight Picture 1But what about the other side of this coin, the heavy jet pilot slumming down into a light GA airplane? Does it present similar pitfalls? Indeed it does, especially for pilots who haven’t stepped into anything small for many years. There are lots of examples in the accident record that show that transitioning down has smeared an otherwise clean safety record for some big metal drivers. Ironically, as I was preparing this article, a nearby NTSB field office was investigating fatal accidents in general aviation aircraft suffered by four pilots from the same major airline.

Why? There’s no pat answer other than to say that compared to heavy-aircraft airline flying, GA’s little airplanes have simpler systems with fewer automatic back-ups, rarely have icing protection, use single-person crews, have vastly different handling characteristics and, in general, the training may be less thorough. Yet all of these risk factors can be addressed in one way or another so that transitioning down needn’t be unusually risky.

War Story

Sight Picture 2A classic example of pilots caught in the trap of transitioning down happened to the U.S. Air Force. Cadets at the Air Force Academy destined to be trained as pilots undergo a flight screening program during their senior year. In my time, the program used the Cessna 172, which flew for 30 years without a single fatality.

The chief of staff then decided that an “enhanced flight screening program” was needed and the Academy acquired the British-built T-3 Firefly, which was capable of 200 mph speeds and full aerobatics. Instructors were chosen from the rated military pilots on the Academy’s staff, pilots with heavy jet experience of all kinds. In parallel to the Academy’s program, the Air Force operated a flight screening program staffed by civilian instructors in Hondo, Texas. That program also used the T-3.

With the acquisition of the T-3 and the modification of its large fuel-injected engine into such a small engine nacelle, the program was troubled from the start, with 53 unexplained engine failures, thought to be fuel-system related. How these failures were handled by the pilots is telling. When I went through the screening program in Cessna 172s, simulated forced landings were part of the curriculum and it’s a maneuver practiced many times during a civilian pilot’s training.

But on September 30, 1996, an Academy instructor pilot and cadet were practicing a simulated forced landing. The engine actually failed during the maneuver and they were unable to safely execute the forced landing, a maneuver that should have been benign. Both aircraft occupants were killed. The accident was the second of three fatal mishaps the screening program suffered. One involved an unrecoverable spin, the other a stall/spin in the pattern.

When High Time Means Squat

One pitfall CFIs face when transitioning an experienced pilot into a smaller or simpler aircraft is what I call the “skygod complex.”

It’s another way of saying, well, heck, if this guy has 20,000 hours in Boeings and MacD’s, who the heck am I to tell him how to fly a Skylane?

I fell into the trap about 10 years ago, when I was asked to check out a retiring airline captain, Tom, in our flying club’s Mooney. He was one of those perfect aviation specimens: military trained, with Vietnam combat experience, type ratings in a half dozen airliners and thousands of hours of time, including his last assignment as a Pan Am 747 Captain.

Despite his pedigree, Tom was down-to-earth and unassuming and, more important, he made it clear that I was in charge of the training and he would complete whatever task I put before him. He had the professionalism of a guy who had been through the training ringer many times and knew what was expected.

We hit it off well and and after an hour or two on the ground, reviewing systems, we headed for the airplane. In the air, we breezed through the usual stuff, including slow flight and stalls, steep turns and emergency procedures. His instrument flying under the hood was superb. We had taken off late on a winter afternoon so in the remaining daylight, I made sure Tom did a couple of simulated engine-failure approaches to a pasture, figuring to save the landings on hard pavement until after dark. That was a mistake.

For the first normal landing, I suggested an approach speed of 75 knots; a little fast for our light weight but acceptable for the first attempt. Tom nailed the speed but 50 feet above the runway, he commenced a surprisingly abrupt flare. “Oh,” I thought, “he’s just used to a larger airplane; he’ll correct that.”

He didn’t. He actually continued to increase the pitch until the airspeed sagged toward 60 knots. The airplane ballooned, with the speed decaying to near a full stall, still 40 feet above the runway. I waited too long to fix it.

With the stall buffet nibbling, I took the airplane, crammed in full throttle and lowered the nose gingerly. We were sinking like an anvil and in the glow of the landing light, the runway was rushing closer at blinding speed. At first, I wondered how I’d explain a totaled airplane to the club but as we neared the runway, I worried that we would survive at all. We hit hard but level. With full power, the resulting bounce put us back at 20 feet and we motored around the pattern. “I’ve got it,” I said weakly and belatedly.

Luckily, there was no damage to the aircraft and the next day-in broad daylight-Tom completed the checkout with no problems.

The fact that he nearly crumpled the airplane on the first try was my fault, not his. Since he was transitioning down, I assumed that landing the Mooney would be child’s play. The fact that he hadn’t flown a light aircraft in 30 years and his last frame of reference for landing flare was a 747 didn’t register with me. Further, both of us had the arrogance to attempt his first landing at night, a gross mistake.

After that incident, I was more circumspect of transitioning pilots into smaller, simpler airplanes from something larger. To assume that what works in a big airplane necessarily works in a small one can be a costly error. With our bounced landing, we got off cheap and the lesson stuck.

– Paul Bertorelli

All three of the instructor pilots had flown large transport aircraft in their previous Air Force assignments, while instructors at the sister-base in Hondo, Texas were civilians under contract with the Air Force, whose backgrounds included years flying small, piston-powered aircraft. One of the instructors at Hondo was quoted as saying, “If the engine quits, we know how to land the airplane and walk away from it. The Air Force guys just know how to bail out when that happens.” Adding insult to injury, the former chief of staff suggested that having three transport pilots in the right seat contributed to the accidents.

The T-3 screening program has since been scrapped and the Air Force’s expensive Firefly fleet sits idle in Hondo. Even if the airplane itself was flawed, the Air Force’s experience harshly illustrates the difference between big and little airplanes.

Not The Same

For starters, the difference in flight momentum is substantial. A larger aircraft has more momentum due to its mass. It will tend to retain its speed and direction more solidly than will a lighter aircraft. However, once disturbed, a heavy airplane takes longer to get back to the desired altitude and heading.

I once took a small experimental for a test flight. The aircraft was so light that a child could have picked up the tail to reposition it. On final approach, I couldn’t believe how quickly the airplane lost its momentum. Conversely, it also regained momentum faster with power application. It took far different control reaction to keep the aircraft on speed in wind shear or turbulent air that I’d expect in a heavy airplane.

Speed and speed control are widely different between light and heavy aircraft. Consider that a Cessna 172 can comfortably fly an approach at 60 knots, less than half the speed that a heavy aircraft might fly on final. In a jet-powered heavy-even a turboprop-slowing down for approach has to be anticipated well ahead of the point where on speed must be achieved.

Similarly, the decision for a go-around has to be made many seconds sooner in a heavy than it would be in a light aircraft. Power response in a piston aircraft is almost immediate; in a jet, there’s likely to be some lag.

The sight picture from the cockpit is utterly different, too. A light aircraft pilot trying to land a larger aircraft for the first time will be alarmed at how high the flare begins. On the other hand, the heavy driver may tend to flare a little airplane 50 feet too high.

If handling and speed are different between light and heavy aircraft, systems can be like night and day. In general, the larger aircraft have more redundant systems that are more reliable.

Redundancy is expected and accepted in transport aircraft; in light airplanes, it’s optional. Take the attitude indicator, for example. In a jet, if the attitude indicator on either side malfunctions, the pilot can switch the source of attitude information driving the indicator, commonly called an ADI in airline circles. In the rare circumstance that both attitude indicators fail, a battery-powered standby indicator will provide attitude information for 30 minutes after a total electrical failure.

For all practical purposes, there’s no such thing as “partial panel” in the heavy metal. That said, take your heavy metal buddy out of his jet and put him into a Bonanza and have him fly simulated partial panel. He’ll probably make a hash of it. That doesn’t make him a bad pilot, just one who hasn’t been trained in the peculiarities of little airplanes.

De-icing and anti-icing is another area where jet pilots are often caught short when they get into a GA aircraft. On one common turboprop, the engine is protected from icing by a heated inlet plus pilot-activated inertial separators which direct the heavier ice particles overboard before they reach the compressor section. When the separators are deployed, the powerplant gets less air which means that it also produces less power.

Now compare that to something larger, like the Boeing 727. The engine anti-ice diverts bleed air from the engine and re-introducing it into the inlet also decreases power output, as with the turboprop. But the power loss isn’t as noticeable as it would be on a PT-6-powered King Air.

Jets tend to slip through ice without much concern, while propeller aircraft slug it out in ice and can quickly pick up dangerous loads. I mention this because I was reading one accident narrative in which a retired airline captain who had flown jets for most of his career was flying a turboprop in icing conditions and apparently failed to understand how engine anti-ice would seriously sap the airplane’s performance.

I once tried to explain the limitations of icing equipment on lighter aircraft to a friend who flies large transport aircraft in the military. He couldn’t see a problem. To him, climbing is always the quickest way to get out of icing. That works well in aircraft which have the power to climb but piston aircraft don’t always have that luxury, especially if they’ve picked up some wing icing or are already near service ceiling.

Somehow, merely reviewing the manual doesn’t always drive this home. Book knowledge is critical but understanding how to use the systems in flight is more important, information that isn’t always contained “in the book.” Sometimes it comes only from trial and error, sometimes from luck and occasionally from good instruction. Sadly I think we rely too much on trial and error rather than sound, well-developed curriculums to help with transitions.

What to Do

And now we get to the crux of the matter: training. Although the heavy pilot may be at some disadvantage in transitioning down, he can easily be trained to adjust. And transitioning down isn’t limited to going from a jet to an Archer; the same advice applies if you’re going from a Baron to J-3.

It’s critical to understand that procedures can be quite different between aircraft. For example, you’d think that unusual attitude recoveries would be identical, regardless of aircraft. I did too until I was doing some research at a major airline. The training department was adding unusual attitude recoveries to the training programs.

We found that during a nose-high unusual attitude, adding power created such a large pitch-up moment that it increased the high angle of attack, making things worse. Clearly, the airline needed another recovery method. And aircraft manuals for smaller aircraft are often lacking in this fine-point detail so that pilots trained in one maneuver may mistakenly apply the same strategy to another aircraft, assuming it will work.

Aviation Safety Cartoon

In developing a training curriculum, remember this: similarities between aircraft may be small but differences can be quite large. If you’re an instructor transitioning a pilot downward, common sense will dictate where the risk areas are. Here’s a short list:

Tricks And Traps

Do:

  • Review the critical V-speeds.
  • Note effect of weight on stall and approach speeds.
  • Concentrate training on fuel, electric and back-up systems.

Don’t:

  • Assume the transitioning pilot will know the landing sight picture.
  • Overlook review and limitations of any aircraft automation.
  • Neglect to point out limited backup systems.

Systems: Review the aircraft systems carefully, with emphasis on the fact that light aircraft have little redundancy compared to transports. Fuel, electrical and vacuum are the important ones to review.

Speeds: Light aircraft fly comfortably at speeds far slower than larger aircraft do and, in general, the speeds don’t vary as widely with weight as in transport aircraft. Critical speeds? Vs, Vso, Vlo, Vne and Vref, what airline pilots know as weight-dependent final approach speed.

Engine/fuel management: For a jet or turboprop pilot, managing a piston engine may be a throwback to the dark ages. Emphasis should be on power management and leaning, which will markedly impact range planning.

Emergency procedures: The important items are engine failure drills and system emergencies, such as vacuum, electrical and instrument failures. These may be trivial in a large airplane, life-threatening in a small one.

Avionics and autopilots: It’s a fact of life that a pilot used to a 727 with steam gauges may encounter glass-cockpit-state-of-the-art in a Bonanza or Saratoga, especially with regard to the latest generation GPS. Briefing up this equipment-including all aspects of autopilot operation-should be on the must-do list.

A well-developed training curriculum, complete with reference material and an experienced, motivated and insightful instructor is the best way to transition into another aircraft, whether it be smaller or larger. If the transition down is done with care and guidance, it will be a pleasure for both the pilot and the CFI.

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