Airplane Windows Add Safety–And Comfort

Plenty of window area in this Sonex

The largest possible window area is obviously a safety advantage when it comes to seeing and avoiding other traffic, or even when looking at the runway while landing. That’s why most fighters and aerobatic airplanes have transparent canopies.

But windows also add–or detract–from comfort for all occupants of an airplane. The right window design makes any cabin feel more spacious and welcoming, and can also ease the discomfort of turbulence.

The Klapmeier brothers understood this when they were laying out the original design for the Cirrus. That’s why the SR20 and SR22 have big windshields, large windows in each door, and even more importantly large rear windows. In many airplanes passengers in the second row are left sitting down in a cave with a very limited view of the outside world. But not in a Cirrus. The brothers had flown enough with family members and friends in the backseats of other airplanes to understand how important this is.

Another design that did a nice job with the windows is the Bonanza, and the many Beech models it spawned. In the Beechcrafts the windows sweep up into the overhead helping to make the cabin feel larger than it really is, even for the second row of seats.

The epitome of window perfection is the Gulfstream line of business jets. In the late 1950s when engineers at Grumman were creating the stately Gulfstream I turboprop–the first purpose built turbine business airplane–they included huge oval windows in the cabin. Passengers loved them, and every Gulfstream since has had the trademark ovals. In fact, for the super speedy and super ultra long range G650 Gulfstream increased the size of the oval windows by nearly a third.

But big windows come at a price. It’s not that the transparent material costs so much, but the structural accommodations required to design in large windows is costly and heavy. And then there is the cost of annoyance and suffering when you just don’t want all of that sunlight beating in on you.

The structural penalty for big windows is mostly in weight. No matter what material the actual transparency is made from it can’t carry structural loads. That means the load carrying elements of the airframe have to be designed around the window opening instead of following their most efficient path.

In unpressurized airplanes the weight and materials costs of larger windows isn’t nearly as great as in pressurized airplanes. Perfect examples of the window size penalty in pressurized airplanes are the P Baron or the Cessna P210. Both pressurized airplanes evolved from unpressurized versions and in each the window size was cut down markedly to reduce the amount structural and transparency strength required, and thus help control weight.

In transport airplanes windows need to be redundant so failure of one layer or pane of the transparency won’t create a decompression so you can see how the weight of a big window adds up. And in the cockpit windshields and their frames have to withstand the impact of a large bird at 250 knots. Add in the heating elements and it’s easy to see how a big windshield, no matter how much pilots love them, adds weight plus construction and maintenance costs.

Early Citations are an oddity in windshields, birds and the FARs. The Cessna business jets had two Vmo (maximum indicated airspeed) limits, one for below 8,000 feet and a higher red line for above that altitude. The reason is that the airplane met the bird impact rules at the lower Vmo but, under the rules, the birds that endanger the windshield did not fly above 8,000 feet. I always wondered if the birds had read the FARs, or had altimeters for that matter.

The primary price pilots pay for big windows comes when the sun is shining. The greenhouse effect is no myth. Sit under a transparent canopy on a sunny day for very long and you are soon wishing for shade, even if it’s cold outside. Most pilots and builders of canopy airplanes devise a shade of some sort to pull over the center of the overhead for relief. But even with a shade it can quickly become unbearable under the canopy on a hot sunny day, especially on the ground.

Big windshields also extract a toll in suffering when flying toward the sun. The pilots who suffer most are those on the transatlantic routes. Flights typically leave the U.S. in the evening but the crew quickly catches up with the rising sun in the east and are broiled for the second half of the flight and arrival. The return trips usually depart in the late morning and chase the sun across the ocean assuring the pilots will be blinded and toasted for the entire trip.

Nearly all passenger cabin windows have screens and blinds to pull so being blinded and cooked is mostly a pilot problem. Pilots have propped up just about anything in the cockpit windows to block the blinding glare. And one company, Rosen, has made a very successful business of building articulating arms that allow you to position the sun visor almost anywhere over the cockpit windows. Designers of new airplanes are including effective sun glare protection devices in the original layout of the cockpit. It’s that important.

But no matter how annoying the sun may be, I still prefer being in an airplane with well designed windows. I can usually come up with some way to shade myself when needed, but there is nothing you can do to change that little slit of a windshield that is left in too many airplanes as the instrument panel glareshield has risen to accommodate ever more avionics displays.

And if you want to know what passengers think of the importance of windows just ask a Cirrus or Gulfstream salesman. They know.

Posted in Mac Clellan's Left Seat Blog | 6 Comments

What the Heck is WAAS?

WAAS has been in the news a lot lately as airplane owners study the coming ADS-B mandate and how to deal with it. We are constantly reminded that the crucial element of ADS-B “out” is a position sensor that uses WAAS-aided GPS.

WAAS stands for wide-area augmentation system. Or if you want to be one of the avionics cognoscenti you would call it SBAS for space-based augmentation system. Neither one of those terms says much about what WAAS is and how it works.

The bottom line information is that WAAS corrects errors in the GPS navigation solution over a wide area. The “wide area” for WAAS is pretty much all of North America, plus offshore water on both coasts and most of the Caribbean. WAAS compatible systems are in place or being constructed by other nations around most of the world.

As I’m sure you know GPS uses a constellation of satellites orbiting the earth at an altitude of about 11,000 miles. The GPS navigator detects the travel time of signals from several satellites to calculate the distance to each of those satellites. The position of the satellites is known so the GPS navigator triangulates using the measured distance from the satellites to establish a 3-D position.

Unlike a radar, or DME, that use a timed round trip of an electronic signal to calculated distance GPS relies on an extremely precise clock. When a GPS receiver locks on it synchronizes its clock to the satellites. The satellites in turn are synchronized to supremely accurate clocks on the ground. With all the clocks in synch the GPS navigator knows exactly when the signal left the satellite so it can calculate how long it took the signal to reach the receiver and thus calculate the distance from the satellite.

Basic GPS has a useful accuracy of around 10 meters though rarely errors can be larger, possibly as much as 100 meters. Errors in the GPS solution come from slight variability in the clocks, small position errors for the satellites, but most importantly, from distortion as the weak signal travels through the earth’s ionosphere and atmosphere. Ten meter accuracy–about 33 feet–is plenty good for en route navigation, and even for non-precision instrument approaches. But that isn’t nearly good enough for precision approaches. And the errors in vertical calculation are particularly troublesome when you want guidance to within a couple hundred feet of the ground without being able to see it.

WAAS corrects these fundamental GPS errors so that nominal accuracy both laterally and vertically is better than 2 meters.

To work its magic WAAS employs a network of ground stations at precisely surveyed locations. These stations know exactly where they are so they compare that known position to the real time calculated position from “raw” GPS signals. The WAAS ground stations create an error correction signal that is sent up to non-GPS communication satellites that are in geostationary orbit. The WAAS correction signal then comes down to a GPS receiver along with the basic GPS signals and the errors are corrected in the airborne navigator.

Equally important to the position error correction is what navigation types call “system integrity.” Basic GPS provides a position fix at one hertz, or once per second. That sounds fast, but consider that if you are flying an instrument approach at 120 knots you will cover 200 feet each second. If a position fix is missed because of some kind of signal problem you will travel another 200 feet before the next possible fix. By the time the navigator is sure there is a problem you will have gone many hundreds of feet, way too many when flying in the clouds close to the ground.

WAAS enables a navigator to fix its position six or more times a second so there are multiple opportunities to find an error. WAAS also contains information on the integrity of the system and sends a quick warning of a problem. So with WAAS a pilot will see a warning flag very quickly if there is a navigation problem, which is exactly what you need when flying a precision instrument approach.

The creators of the ADS-B NextGen system found these WAAS capabilities to be essential if the system is going to allow reduced separation of IFR traffic. If we’re going to fly closer together while in the clouds we obviously need–both controllers and pilots–to know exactly where we all are in 3-D. We also need to get the earliest possible warning if the system is failing or unacceptable errors are creeping in. That’s why WAAS, or a navigation system that equals WAAS-aided GPS, is required as the position sensor for the ADS-B out signal.

I’m unwilling to wager that even with the surveillance and navigation precision of WAAS and ADS-B that we will reduce IFR traffic separation in a meaningful way. The technology makes it possible, but I’m not sure that emotionally pilots or the public want to fly closer than 3 miles from another airplane at the same altitude in the clouds. And even if you do fly closer, will there be enough room on the runway for the airplane ahead to land, brake and turnoff?

The precision of WAAS and ADS-B makes virtually no sense for the VFR pilot where even the worst 100 meter navigation accuracy is more than enough, and missing other traffic by at least a mile, not a few meters, is the goal. But so far the FAA is sticking with its single standard of WAAS for ADS-B position sensing for big jets and little pistons.

Posted in Mac Clellan's Left Seat Blog | 17 Comments

Back To Which Basics?

T-37 was the “basic” for more than 50 years

Getting back to basics is an eternal theme in aviation. If only every pilot could have learned to fly in a Cub and still land one in a 20 knot crosswind aviation would be better off, many say.

And I agree with them if your plans are to spend your entire career flying basic piston airplanes. But for other types of flying the basics of a Cub may not apply. In fact, the techniques that are so essential to Cub flying may be the wrong ones to use flying other classes of airplanes.

The emphasis on basics and getting back to them crossed my mind when reports emerged that the flight data recorder shows the crew of the TransAsia ATR 72 that crashed shortly after takeoff apparently shut down the good engine. It seems clear one engine failed shortly after liftoff, but the ATR is fully capable of climbing away with a safe gradient on the remaining engine. And pilots practice that in initial type rating training and every recurrent session.

What could have caused the crew to move a cockpit control at a critical time that would shut down the good engine? Could it have been getting back to the basics of twin training?

In piston twins with their relatively low power it is essential for the pilot to immediately feather the propeller of a failed engine to have any chance of climbing or even holding altitude with only the good engine. It’s drummed into pilots during piston twin training to quickly identify the failed engine and then secure it.

There is a long history of piston twin pilots getting it wrong and shutting down the good engine. That’s why in transport flying the procedures are to do absolutely nothing with the engine controls after a failure until the airplane is at a safe altitude and everything is stable. A quick way to flunk a check in a transport airplane is to start moving levers or switches quickly after there is an engine problem in the sim.

A jet or more recently built turboprops does not require the pilot to immediately do anything after an engine failure except maintain the target airspeed and attitude. The jet engine will simply windmill after failure so moving the throttle or shutting off fuel will not help performance. And in all but the light turboprops the propeller will feather itself if the engine fails so yanking on engine control levers can only introduce the possibility of an error.

Even an engine fire warning in a jet is treated deliberately before “punching the engine out” because false alarms are much more common than actual engine fires. “Let it burn” until you are at a safe altitude is the standard training advice.

The military learned decades ago that teaching the “basics” applies specifically to what kind of airplane you will fly. That’s why in the late 1950s the Air Force made the T-37 twin engine jet its “basic” trainer. Air Force pilots were going to fly jets so the “basics” pilots needed to learn came from a jet trainer. Many Air Force pilots flew their entire career and then went on to the airlines without ever flying prop airplanes. Would the “basics” of a Cub made them better pilots? I don’t see how.

I never flew in the military but I know many pilots who did and there is no agreement among them on whether having experience in light piston airplanes before entering the service helped in pilot training. Some believe that it did, others don’t. But almost all agree there was much to unlearn in military training if your sole pilot experience had been piston singles.

Even when the joint services created the specs for a turboprop basic trainer, which turned out to be the Beech T6A Texan, the requirements were for the airplane to fly like a jet, not a prop. So the T6A uses electronic controls to “schedule” the engine and propeller response of mimic the spool up of a jet engine, not a turboprop. An automatic system even steps on the rudder to cancel the normal propeller effects of P-factor and torque because those won’t be there in a jet. Don’t learn something that later needs to be unlearned, in other words.

I think our regulations and training system are doing a pretty good job preparing people to be light airplane pilots. But I also think the military, and some major international airlines, also have it right by teaching a different set of “basics” from the beginning. Some nations have even adopted a “crew only” license and training program for new pilots destined for a professional career. Why teach the techniques so essential for solo flying when they don’t apply to crew resource management and crew techniques. Any pilot who has made the transition from solo flying to a crew operation knows there is much to unlearn, and old habits can came back at the worst possible moment.

I’m all for getting back to basics but we should keep in mind what is “basic” for what airplanes and how we fly. Slipping a taildragger into a gusty crosswind is an important skill for GA flying, but is very much the wrong thing to do with a swept wing jet.

There are, however, a couple basics that I can think of that do apply to all airplanes. One, you need to have fuel to keep the engines running. And, two, if you can’t hold the target airspeed, heading and altitude bad things will happen. Those “basics” can’t be practiced too much.

Posted in Mac Clellan's Left Seat Blog | 42 Comments

We Used to Fly On Time. Not Anymore

Not long ago the clock was one of the most vital instruments in the panel. We navigated by timing. Not so much anymore.

Thirty-five years ago I was dinged by the examiner during the simulator portion of my first type rating checkride because I didn’t start the clock passing the outer marker on an ILS approach. Timing didn’t seem to me to matter much on an ILS. I was going to track the glideslope down to decision height and either see the runway or fly the miss.

But to this oldtimer–pun intended–I had committed a cardinal sin. What, he demanded, was I going to do if the glideslope failed? Without time I couldn’t continue on at the localizer only minimums because I couldn’t find the missed approach point without knowing elapsed time from the marker.

Of course, since it was a simulator the glideslope could fail, and it did. I had to go around and fly the approach all over again, this time with the clock counting seconds since I passed the marker.

I thought of that experience the other day when I heard a pilot ask controllers if the outer marker on the ILS he was flying was out of service. The controllers said it had been notamed out for at least a year and they didn’t think it would ever be back on the air.

That made me try to remember the last time I saw the flashing light and heard the beeps when passing the final approach fix. Did my marker beacon receiver still work? I think so. But I hadn’t paid attention to it in so long I’m not sure.

For decades we flew along with a decent idea of our lateral path over the ground thanks to the compass. But the only way we could know how fast we were covering the ground, or if in the clouds where we were, was to note the time it took to fly between two known points.

When DME became affordable to many airplane owners that helped us know our ground speed and where we were along the route, but many VOR stations didn’t have DME. And DME was of no help when tracking into or away from an NDB so the clock was still king.

The invention of RNAV was a big help in knowing where we were because you could project the signal from a VOR/DME out to a specific waypoint. But RNAV was not usable on most instrument approaches.

The really big navigation breakthrough, at least for en route flying, was development of reasonably priced airborne Loran C receivers. The Loran C signal was based on grid navigation, not the bearing and distance techniques we had been using, so you could be guided directly to any point. Just punch in the numbers for the desired lat-long and you knew how far, how fast, and what heading to fly. It was magic.

But Loran C wasn’t accurate and reliable enough for precision terminal and approach navigation so we were still timing and turning and tuning, at least I think that’s what the “three Ts” stood for.

Then GPS was perfected. Suddenly–at least it seems to have happened suddenly in my memory–we always knew exactly where we were, where we were going and how fast. The extra WAAS satellite signal corrects GPS errors to the point that we know our position and track within a couple meters. The WAAS-based LPV approach equals the ILS signal in vertical and lateral guidance and always shows your distance from the runway with equal precision. What am I going to do if the glideslope fails and I didn’t start the clock? Who cares?

Another irony is that many GPS navigators start the clock for you. When your groundspeed hits a preset threshold the GPS starts the flight timer with no required action from you. Want to know how long you have been flying? Look at the GPS. I still do write down takeoff time after I have the airplane cleaned up in cruise, but I do that more out of fear that I will somehow mistakenly reset the timer than out of worry that the GPS box will fail.

The ultimate irony is that GPS is actually the most precise and exquisite time measuring system ever created. The navigator locates its position by measuring miniscule differences in travel time of extremely weak signals sent from satellites orbiting about 11,000 nm above the earth. GPS timing is so incredibly precise that a second we used to note is an eternity. So we still know where we are and where we are going thanks to time keeping.

The one standard maneuver that I can think of that is still measured by time instead of distance is the holding pattern leg. But even when holding the GPS creates a racetrack on the map and shows the little airplane flying over the track.

Do I miss all that hacking the clock and tracking the time? No. I have plenty to do just flying the airplane.

Posted in Mac Clellan's Left Seat Blog | 10 Comments

A Rational Way to Deal With ECI Cylinders

The FAA is simply determined to get rid of thousands of ECI cylinders used on big-bore Continental engines.

Last August the FAA issued a proposed AD that would have required approximately 36,000 aftermarket cylinders built by ECI to be junked, most of them after only 500 hours of operation. The proposed rule also called for repetitive inspections and grouped cylinders by serial number.

The NPRM drew many, many comments, most of them against the proposed AD. But earlier in January the FAA came right back at airplane owners with a revised proposal that essentially requires the cylinders to be removed from the engine after 1,000 hours of operation.

It’s true that 1,000 hours is better than 500, but to me it still isn’t necessary to accomplish the FAA’s objective. Even the NTSB, not exactly a devil may care outfit when it comes to safety, commented that the cylinders should be allowed to fly on until recommended TBO. But the FAA has again ignored the NTSB’s advice, and the advice of everyone else who commented.

The FAA says it has determined that the affected ECI cylinders suffer head separation at a much higher rate than other cylinders. There have been a few instances where the aluminum head did crack and break free from the steel cylinder barrel. Obviously that cylinder no longer functions, and there is at least some risk of fire because fuel and probably spark is still being fed to the failed cylinder head. By there have been no fatal accidents caused by these failures.

It’s impossible for the FAA to know with certainty anything about the failure rates of any cylinder or piston engine component because the data just doesn’t exist. The FAA does get service difficulty reports if shops take the time to file them, but there is absolutely no way to know how much of the universe the reports represent. It’s just hit and miss.

But, I fear the evidence fight is over. For whatever reasons the FAA is absolutely determined that the affected ECI cylinders are “unsafe”–the FAA word. So the FAA objective should be to remove the cylinders from engines in the least disruptive and costly way.

Here is how that can be accomplished. Issue an AD that forbids any ECI cylinder in the affected group from ever being reinstalled in any engine after it has been removed for any reason.

The fundamental problem is that piston engine parts are certified without life limits and without any requirement to document time in service. A cylinder, for example, remains airworthy as long as a licensed mechanic or repair station says it is. And that cylinder can be repaired in all kinds of ways and be returned to an airworthy condition.

But absolutely nothing is known about cylinders once they are removed from an engine because there is no requirement to record anything. For example, at the last annual two cylinders on my high-time engine were simply worn out. The shop bought two overhauled cylinders to replace them. The overhauled cylinders came with the required yellow tag saying they had been repaired and inspected and are airworthy.

But nobody has any clue how many hours are on those cylinders, or even what type of engine they came from. Those cylinders could have been on a turbocharged engine with the higher heat and stress involved but are now on my naturally aspirated engine. They could have come from a 520 and are now on my 550 engine. And the cylinders that came off my engine went to that overhaul shop as a “core” and were most likely repaired and are on yet another engine.

It is this “certified forever” concept of piston engine parts that is, or should be, the issue with ECI cylinders. Without an AD the ECI cylinders the FAA is worried about could fly on being repaired and overhauled repeatedly with no records kept about time in service.

My idea of an AD that simply doesn’t allow reinstallation of one of the covered cylinders would cost owners only the “core” credit we get when a cylinder is replaced or the engine is overhauled. The core credit is typically a few hundred dollars because the overhaul shop that sells you the repaired cylinder needs your old cylinder–the core–to repair and resell. So in this case you wouldn’t have a cylinder to exchange so you would be charged the core credit.

The reality is that many, even most, cylinders will develop some sort of problem during their run between major overhauls. Leaking valves are common, but rings and cylinder barrels wear, valve guides wear and so on. That means the affected ECI cylinder replacement would be spread out. When a cylinder needed to come off for any work that would be it. The cylinder would be retired. And the cost of complying with the AD would be the cost of the core credit as each cylinder is retired.

At major overhaul time all six cylinders would be trashed. The extra cost to the airplane owner would be six core credits. That’s a lot, but still so much better than junking all of your cylinders at the arbitrary 1,000 hours the FAA is proposing.

You can read and comment on the proposed ECI cylinder AD here:!documentDetail;D=FAA-2012-0002-0600

Comments are open until February 23. It may make you feel better to comment that the AD is simply not necessary, but the way the FAA blew off all of those thoughtful and supported comments in the first round I just don’t expect the AD to go away. I think the best we can hope for is to fly the affected cylinders until they need work, and then throw them away when they come off the engine. That’s bad, but not as bad as what the FAA is proposing.

Posted in Mac Clellan's Left Seat Blog | 5 Comments

What We Will Learn From Self-Driving Cars

It’s been nearly a century since gyroscope pioneer Elmer Sperry created the first true autopilot. And autopilots have come a long way since. The most sophisticated can even land the airplane, steer it down the centerline on roll out, and brake the airplane to a stop.

What hasn’t been as successful is creating and maintaining the man-machine interface between the human pilot and iron mike. In many respects the more capable the autopilot has become, the more difficult it is for the human to correctly use and manage the machine.

Now the self-driving car–autonomous operation, if you prefer–is here. Several automakers claim they could deliver a car that drives itself right now if regulators allowed it. And there seems to be wide agreement that many cars will be driving themselves down the streets and highways of the civilized world by 2020.

What this means is that instead of thousands of pilots learning to successfully use autopilots we will soon have millions, maybe many millions, of drivers doing the same thing. The expected explosion in autonomous driving machines will allow us to discover new problems, and new solutions at a very rapid pace. Nothing teaches what works and what doesn’t better and faster than having a whole bunch of people trying to learn the same thing at once.

The lessons from airplane autopilot use is that the machines are not 100 percent reliable, but the bigger problem is that more frequently the autopilot is performing as designed but the human pilot doesn’t understand how it should be functioning.

My favorite story about autopilot mismanagement came from the old King Radio company. King had a service hangar on the airport near its headquarters in Olathe, Kansas. One day an irate Bonanza owner arrived screaming that his King autopilot was trying to kill him.

The Bonanza owner said the airplane, with autopilot engaged, pitched down unexpectedly. He grabbed the controls and pulled back as hard as he could. Luckily he had a friend in the right seat who got on the controls and helped him pull. Together they pulled as hard as they could while one finally was able to pull the autopilot circuit breaker.

But the autopilot was still fighting them. It wouldn’t disengage. They both battled the nose-down control force all the way to touchdown cursing the autopilot that wouldn’t let go.

What happened, of course, is that the pilot started pulling on the controls before disengaging the autopilot. Sensors in the autopilot interpreted the pilot’s actions as the need for nose-down trim and automatically started rolling the trim in, and kept at it. By the time the pilots got the breaker pulled and the autopilot truly dead they still had full nose-down trim fighting them. They didn’t understand their original actions, and so didn’t know to simply re-trim the airplane and go land.

That’s an example of the most basic mismanagement of autopilots. More common errors are failing to understand what a mode selection will do. Or why it may or may not capture a glideslope from above. Or why it didn’t switch from roll steering to approach mode. Or what the heck is FLCH mode? And on and on.

There is a little standardization in autopilot design and function, but there are often differences in how the same autopilot operates from one airplane type to another. And, except for newer airplanes with totally standardized cockpits, there is very little complete training on how to use autopilots at the GA level.

My question is will the car guys do better? No matter how incomplete pilot training is, driving training is essentially zero. That means the car autopilot will have to be so intuitive that drivers get it right the first and every time with about the same level of instruction on how to operate the entertainment system. Well, actually it needs to be easier to use the car autopilot than the radio or there will be cars driving off to who knows where.

Driving a car in the close confines streets and roads, along with the stop and go that is part of traffic, is daunting compared to the relatively wide open spaces we fly through. But the car guys aren’t bound by evolutionary designs as we are in aviation. The car autopilot can start from scratch, using very advanced technology, and can be integrated fully during original design of the car.

But I believe there will be one issue both airplane and car autopilots share–many people just won’t trust them. I have seen that for decades in aviation where human pilots, especially when the workload is high and when they need the autopilot most, just can’t trust it and turn it off. I bet we will see the same in cars. Most of us have been driving since we were teenagers and when that darn thing does something we don’t like, or don’t expect, we’ll be looking for the off button.

However soon it happens the self-driving car can only be good news for teaching us how to make an autopilot we humans understand, and trust, at least most of the time. Let the great experiment begin.

Posted in Mac Clellan's Left Seat Blog | 9 Comments

The Affordable Aircraft Expo

The U.S. Sport Aviation Expo at Sebring this week has rebranded itself The Affordable Aircraft Expo. And I think that is a terrific idea.

The driving force behind the show has been creation of the Light Sport Aircraft category a little more than 10 years ago. LSA arrived with great promise and dozens and dozens of companies, mostly new to airplane manufacturing, built airplanes to the new standards.

The fundamental concept of LSA, and the Sport Pilot license that goes with it, is simplification. We all wanted a quicker and easier path for companies to gain approval to manufacture light and basic airplanes. And the Sport Pilot rule streamlines the requirements to qualify to fly very light airplanes under daylight VFR.

But words like simplified, streamlined, less burdensome, less complicated and on and on are really synonyms for lower cost. No matter what you call it the LSA rule was intended to make newly manufactured airplanes available for a fraction of the cost of standard airplanes from traditional manufacturers.

And the LSA rule did work. But not exactly as those of us who supported the rule hoped. A new quality LSA is less costly than a new Cessna, or Piper, but is still a lot more than many expected. Most LSA are priced north of 100 grand, and that’s still not “cheap” by anybody’s standard.

What the Sebring show people are doing now, and what I applaud, is move their focus off of LSA and target any and all affordable airplanes. LSA are the most affordable airplane if you want brand new, but existing basic standard category airplanes can be as affordable, or even more so. And then there are also homebuilts which trade sweat equity for lower price, and a range of ultralights that can get you off the ground for the fewest bucks and least required training and regulation.

Among the shiny new LSA and kit airplanes at Sebring will be at least a few equally shiny standard airplanes. Shiny because they have brand new paint and interiors, but affordable because they were built years ago and are fully depreciated.

Sporty’s is showing what can only be called a stripped down Skyhawk. The Sporty’s training concept is that for pre-solo and the big part of the whole private pilot curriculum you don’t need anything more than the most basic instruments and avionics. Sporty’s calls the airplane the 172LITE and they believe it can be rented for $99 per hour all-up.

AOPA has its own training airplane refurb project in the Reimagined Cessna 152. Again, by sprucing up an older but still sound airplane entry cost are lower than any new airplane, including LSA, and operating cost are manageable.

You can, of course, buy one of thousands of older piston singles for well under $50,000 without doing a total overhaul and get lots of flying capability for the money.

What Sebring is doing is trying to highlight the options available. For example, a new LSA will cost more to buy than nearly all older basic standard category singles, but the LSA will probably cost less to fly because of lower maintenance costs and fuel burns. There are also differing maintenance standards to consider which will impact costs.

You can fly an LSA to Sport Pilot standards using a driver’s license to certify medical qualification. That’s a plus for many pilots. But you can also fly some of the most basic standard two-seaters such as Cubs and Champs as a Sport Pilot. Those airplanes remain in their original certification category with all the requirements that go with that, but the pilot can be a Sport Pilot, or any other level of pilot who chooses not to have a current medical.

Bottom line is that Sebring is about recreational airplanes. These are not machines meant to travel on a schedule, or fly in any but benign weather. Because they offer little utility in a traditional sense pilots judge them by their recreational return on investment. And that gets us back to affordable.

Sebring is about getting off the ground on nice days just to enjoy the ride. And there are so many ways to do that I’m really glad to see a show devoted to explaining and exploring the options. Early interest in the show seems to be up so I believe The Affordable Aircraft Expo is on the right track.

Posted in Mac Clellan's Left Seat Blog | 28 Comments

The FAA Likes My ADS-B Out Performance

The ADS-B out certification in my airplane had been done by Mayday Avionics in Grand Rapids. Mayday is a very capable avionics shop. It filed all the Form 337s for the major alterations that are required under the installation STC. When the software updates, flight manuals and other paperwork and inspections were done, Mayday tested the signal using advanced ground test equipment. The ADS-B out equipment and installation in my airplane met all of the rules and is ready for the 2020 mandate.

But the FAA has been finding that not all ADS-B installations are done correctly. Or maybe there are some undiscovered equipment problems in the airplane. Or maybe not every shop has the experience and advanced equipment of Mayday. But for whatever reason a significant number of airplanes are flying with ADS-B equipment that does not meet all of the minimum requirements for actual use in flight.

So the FAA is offering to “test” your ADS-B out and send you a report. All you need to do is send an email to the address on this FAA web page: You must tell the FAA what the specific model names of your ADS-B transmitting equipment and position source.

In my case the transmission is sent by the Garmin GTX330ES transponder with extended squitter. The 330 is a Mode S transponder so it, like all transponders, broadcasts on 1090 MHz. The position source is a Garmin GNS530W navigator. The 530W and the STC it is installed under meets all of the accuracy requirements for advanced GPS navigation, including LPV approaches. That means the 530W also qualifies as a position source for ADS-B out.

I’m not sure that you need to tell the FAA when you will be flying because if you have an approved ADS-B installed it broadcasts all of the time, including on the ground. But I knew I was flying from Muskegon to Battle Creek the next day so I included that in the email, and also that I would be flying IFR.

In a couple days I received an email from the FAA along with a status report of how my ADS-B performed, and also a guide explaining how to read the report. The FAA person sending the email also included a very helpful note saying that “everything looks ok.”

Neither Muskegon or Battle Creek have the ground equipment to track ADS-B movements. So far only the larger airline airports have ADS-B ground coverage so only the flight performance of my equipment could be checked.

The FAA report shows that ADS-B signals send such complete information so everything can be known about my airplane. For example, the report includes my assigned ICAO number that is matched to my N-number. It knows my mailing address, the make and model of my airplane, and even its serial number.

The flight to Battle Creek with an ILS approach to Runway 23R took 28 minutes and 11 seconds. During that time the ADS-B out made 8,827 reports. The rules require a report at least once each second. The FAA ground network processed 2,329 reports so you can see lots more than the minimum required data were reported by my system.

The good news is that the ADS-B ground system found zero missing elements in the reports and there were no failures of any kind in any of the reports.

The horizontal accuracy was better than 10 meters at all times, and the velocity error was better than 0.3 meters per second 100 percent of the time. The source integrity level was better than 1 in 10 million. The ground system could validate 99.2 percent of all reports from my ADS-B equipment.

Even though I have been writing about ADS-B and talking with the people who designed the equipment for at least 20 years I still find the amount of data being automatically reported and its accuracy to be amazing. Even the short range approach control radars often have errors of a mile or two, or even more, but a GA level ADS-B out system is reporting the 3-D location of an airplane within a few meters.

There is absolutely no question ADS-B will allow a far superior IFR traffic system and I’m very happy to see that in real world flying with real world equipment the system is working. If you have ADS-B out installed I certainly recommend you ask the FAA to produce a report on how it’s performing. It’s free and quick and confirms the in flight operation matches ground testing.

Of course, the vast detail of the ADS-B report doesn’t answer the question of why VFR pilots flying in regulated airspeed need to broadcast so much data of such extreme precision, but that’s a different discussion.

Also, I’m happy to report that Sean Elliott, the EAA VP who handles advocacy and government affairs, was at FAA headquarters shortly before Christmas when my blog about a complete lack of guidance on how to certify ADS-B out in experimentals appeared. The FAA told Sean they were aware of the problem and were working to establish a clear path to ADS-B out certificationi for airplanes that do not have a type certificate. Nobody knows how long that will take, but at least we know the FAA is aware of the issue and knows that it must be solved so homebuilts and other experimentals can be equipped before the 2020 deadline.

Posted in Mac Clellan's Left Seat Blog | 42 Comments

Cirrus Is Making Me A Single Engine Jet Believer

I lost count long ago of how many single engine jet projects have been announced, usually with great hullabaloo, impossibly fantastic performance and even more unbelievably low price.

Many of the personal jets were the dream of startup companies that had never built an airplane of any type. Those were easy to dismiss as the longest of long shots. But established airplane builders such as Diamond and Piper invested heavily in single engine jet programs with both reaching at least the proof of concept flying airplane stage.

Even mighty Gulfstream dabbled with a single engine jet design in the early 1980s with the Hustler, later renamed the Peregrine. That project morphed from a single engine turboprop, to a turboprop with a jet engine in the tail, and finally to a single powerful turbofan before the plug was pulled.

Just over eight years ago Cirrus entered the personal jet race, if we can call it that, by announcing what was dubbed “The Jet”. Rumors of work on a jet single were so pervasive that people in the company didn’t really need a unique name because the entire GA world was simply calling it the Cirrus jet.

When it was announced The Jet was on such a long list of projects it was hard to see why it had a better chance of success than the others. But there were a few reasons I thought Cirrus maybe could pull it off.

First, Cirrus had come from nowhere to design and manufacture piston singles, something that is incredibly rare. The road was rocky, virtually none of the original predictions in terms of schedule, performance and price came true. But, still, Cirrus had become a real airplane manufacturer from scratch and that was worth a lot of points when making the betting line.

Another reason I thought The Jet might have a chance is that the initial speed, range, payload and altitude goals were the most modest, and therefore I believed most realistic. The cruise speed goal was around 300 knots, maximum range around 1,000 nm, and a ceiling below 30,000 feet.

Finally, I am impressed with the Cirrus jet engine location. Imbedding the engine in the fuselage has been done many times, particularly in fighters, but there are significant issues in designing inlet ducts that don’t rob too much power and function at the extremes of attitude and angle of attack. And that’s not to mention how to handle ice buildup inside the duct.

Locating the engine on the vertical fin as Piper proposed gives the engine a good clean air inlet but can create pitching moments when power is added or reduced. The loads on the fin are considerable so structural weight goes up. And locating such a concentration of weight at the extreme aft end of the airplane presents considerable CG issues.

The Cirrus decision to mount the engine atop the aft fuselage and send the exhaust between the stabilizers of a V-tail is a solution with, as far as I can tell, the fewest compromises and complications. There is no need for an inlet duct. The engine exhaust is not far above the water line so pitch change is small. And the engine is clear of likely FOD sources. A small ramp on the fuselage top redirects the engine exhaust upward to closely parallel the line of flight.

The big problem with the Cirrus jet was clearly lack of initial funding when the program was publically announced in 2006. A proof of concept airplane that resembled what might be actually certified was built and flew, but progress stalled. The global economic recession that began in 2008 didn’t help at all.

But that’s all old news. Cirrus new parent company appears to be committed to the jet program. Dozens of engineers have been hired, people with experience in creating certifiable and producible airplanes. New facilities dedicated to jet development have been built. And most importantly Cirrus has built three prototypes that conform to the anticipated final design.

It’s next to impossible to fully test and develop a complex airplane with only a single prototype so all significant companies build several test airplanes to assign to various segments of flight testing and certification. Cirrus has done that with first flight of its third conforming prototype jet a few weeks ago.

Cirrus has lots of work ahead to push the SF50 through to production. The Cirrus Airframe Parachute System (CAPS) is a huge project  because the jet will probably weigh at least 2,000 pounds more than the SR22 piston single, and will fly faster. But the company has taken one big potential show stopper off the table by opting for a stall barrier system as most jets use.

Last spring when it was clear Cirrus was ramping up for real to develop the jet I asked company co-founder Dale Kalpmeier why they pressed ahead when others haven’t. His response was that Cirrus has hundreds of pilots who want to buy The Jet. And that is more important than any of the difficult structural, system and aerodynamic issues Cirrus faces. Pilots want a single engine jet, and for the first time, I really am convinced they will be able to buy one before too much longer.

Posted in Mac Clellan's Left Seat Blog | 13 Comments

What a Pilot Wants for Christmas

There has been loads of reporting on psychological and behavioral studies that show we humans gain more happiness and better memories from an experience than by acquiring a new possession. In other words the lasting effects of a wonderful vacation are greater than the happiness of buying a new car or piece of jewelry.

I can believe that. Most stories we tell when among friends and relatives begin with something like “do you remember the time . . . .” And the story doesn’t often include sitting in a car salesman’s office closing the deal on a new BMW. The story is about something really wonderful–or unbelievably stupid–that we lived through.

But this reality leaves pilots in a conundrum. We want to accumulate new flying memories, but unless you’re some kind of a 60s leftover, nobody can fly without an airplane. So to build happiness we must acquire the possession–an airplane–and then we must have the experience of flying it.

Thousands of pilots have succeeded in the first step. Airports and hangars are filled with airplanes of all sorts. But increasingly we are failing at the second step to flying happiness and memory building. We just aren’t flying the airplanes we already have very much.

There is no reliable measure of flying hours in personal airplanes, but we all know it’s down, and decreasing every year. The most precise indicator is avgas sales and it has done nothing but decline for decades.

We can all rail against the cost of airplanes, but somebody already owns them. The acquisition cost is already covered. We can blame high maintenance cost, but unless we simply allow the airplane to lapse into an unairworthy condition, we are paying those, too. And, of course, the cost of fuel shoulders most of the blame. But when adjusted for inflation avgas prices have been pretty stable, and high for a long time.

I think what’s in short supply is a reason for airplane owners to fly. And that’s where we need to change. We need to accumulate the experience that research knows will stay with us and contribute to our happiness long after the thrill of acquiring the airplane is gone.

For me the reason to fly has always been to go someplace. Traveling on my own schedule is the reason I learned to fly and it has been rewarding. And thinking back, it’s the challenging flights I remember most. The beautiful blue sky smooth air trips were pleasant, but getting their safely and sanely when the weather or traffic was at its worst was most gratifying and memorable.

Other pilots I know love to shoehorn their airplane into some wilderness spot far from civilization. And I’m sure the more desolate and challenging the strip the more powerful and lasting the memories.

It’s the same for pilots who want to fly aerobatics. The perfect maneuver is a memory, but so are all the attempts to get there.

And there is a core of dedicated teachers who are so essential to create a new generation of pilots. Of course, some pilots are just building time in the right seat, and that’s necessary too, but the true teachers are logging rewarding memories along with the hours.

Something we can all do when searching for a new aviation experience and lasting memory is add a new license or rating. I don’t know any pilot who calls a check ride fun, but I also don’ t know any who forgets them.

The longest term memory builders must be the pilots who build their own airplanes. I’m not sure which memory stands out most, the years of building or the flying, but the whole process is an investment in time that surely must last a lifetime.

So the Christmas present I hope all of us pilots will give to ourselves is to fly more, challenge ourselves more, and build a bigger library of memories to carry us on. After all, if you don’ t go flying you can’t say “did I tell you about the time. . . . ”

Merry Christmas.

Posted in Mac Clellan's Left Seat Blog | 5 Comments