AVwebFlash - Volume 14, Number 27b

July 3, 2008

By The AVweb Editorial Staff
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Top News: Government, Aviation, and Safety back to top 

An Aviation Angle On The Election

What are the differences between Senators John McCain and Barack Obama when it comes to issues involving aviation and aerospace? A special report by Aviation Week this week examines their policies, noting that "for many aerospace and aviation interests, McCain is a known but feared quantity, while Obama is a blank slate." FAA reauthorization, fuel costs, and modernizing the national airspace system will all be on the next president's agenda. Senator Obama has said he aims to modernize air traffic control, wants better aviation security, and also wants to revitalize the nation's infrastructure, including airports, according to Aviation Week. Senator McCain has taken an active role in aviation matters as they pertain to military procurement. Editor-in-Chief Anthony L. Velocci Jr. notes in the report that ironically, Sen. Hillary Rodham Clinton and her team had provided the most detailed policy positions on many of these areas.

"She produced a position paper that framed her thoughts on subjects that McCain and Obama have either skirted or ignored during 16 months of campaigning - even though one or the other, as President, will play a pivotal role in decisions that will have far-reaching consequences," says Velocci. The rest of the online report is available only to subscribers.

Federal Officials To Investigate Eclipse Jet Safety

The Transportation Department's Office of Inspector General is investigating a complaint that the FAA certified the Eclipse E500 jet "despite safety concerns raised by the engineers and test pilots," USA Today reported on Tuesday, citing "congressional officials." A briefing on the report is expected "within weeks," according to Jim Berard, spokesman for the House Transportation Committee. Questions about the certification process were raised in October 2006, when the National Air Traffic Controllers Association filed a grievance with the FAA alleging that the type certificate was issued by FAA managers over a weekend and safety issues raised by staffers were not addressed. FAA spokeswoman Laura Brown told USA Today that the FAA stands behind its certification of the jet, and Eclipse CEO Vern Raburn said the airplane is in "complete and total conformity" with federal regulations.

He added that he believes the issue is just a dispute between workers and management at the FAA.

NTSB Probes Medevac Crash

The Association of Air Medical Services (AAMS) is calling for a "rolling safety stand down" of medevac aircraft operations after the tragic collision of two medical airlift helicopters near a hospital in Flagstaff, Ariz., on Sunday. Initial reports indicated seven people had died but six people died and one woman, a nurse, survived the crash of two Bell 207 helicopters operated by Air Methods and Classic Helicopters as they tried to land on the same helipad at the Flagstaff hospital. "AAMS is recommending an industry 'rolling' safety stand down to focus the attention of the air medical crew on safety while continuing the ability to provide life saving services to their local communities," said an AAMS news release. The accident has also caught the attention of the NTSB, whose chairman, Mark Rosenker, says he's "very concerned" that this was the tenth accident involving medical airlift aircraft this year.

"We are going to try very hard to make sure we understand exactly what happened here, determine the probable cause and make recommendations to prevent it from happening again," Rosenker told The New York Times. Rosenker said the NTSB is worried about the safety record of medevac services and will take action. "We are very concerned about that," Mr. Rosenker said.

Watch for an exclusive podcast interview with Chris Eastlee of AAMS, coming this Friday to AVweb!

Visit Aircraft Spruce at the Annual 2008 Arlington Fly-In
Come join the Aircraft Spruce team at the Arlington, Washington Fly-In in Booth #43 on July 9-12 from 9am-6pm and July 13 from 9am-3pm. Take advantage of some of your favorite products on sale, complimentary ground shipping (does not apply to hazardous or oversize products) and a helpful staff to answer all your questions. The 2008 Arlington Fly-In features 128 acres of "Family Friendly" aviation exhibits, fun and a spectacular daily air show. Call Aircraft Spruce at 1 (877) 4-SPRUCE, or visit online.
Excitement (and Misery) on the Tarmac back to top 

PiperJet Starts Taxi Tests

The proof-of-concept PiperJet has started low-speed taxi tests and the jet is performing as expected, the company said this week. "Piper test pilots reported light rudder pedal forces and excellent response as the PiperJet POC was maneuvered with confidence in the tight confines of the Vero Beach factory test ramp for the first time," according to a company update released on Tuesday. The Williams FJ-443A jet engine with FADEC is a breeze to operate, the company says. The pilot simply presses a starter button, then brings the thrust lever forward when the engine monitors show that the proper speed has been reached. The FADEC system automatically corrects for heat, humidity, and altitude. The next major milestone for the POC jet will be high-speed taxi tests, the company said.

In those tests, pilots will accelerate to just below liftoff speed, to check runway handling characteristics and elevator control authority. Next after that -- first flight. Click here for a Piper video of the first taxi tests. Click here for a recent podcast of a Russ Niles interview about the jet project, with Piper's Bob Kromer.

Related Content:
View pics of the PiperJet under construction here.

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Disgruntled Airline Pax Take Their Case To Court

Kate Hanni, an advocate for airline passengers' rights, put it this way this week: "We won't take this sitting down (or belted to a seat locked in the upright position) any longer!" A federal judge in Oakland, Calif., has agreed to hear her case against American Airlines, the airline that left her and a planeful of passengers trapped on the tarmac in Austin, Texas, for nine hours in December 2006. Hanni says the passengers were denied access to food and water, and the toilets overflowed -- which the airline denies -- and went on to form the Coalition for an Airline Passengers' Bill of Rights, to take her case to Washington and the courts. Hanni also succeeded last week in disengaging the Bill of Rights from the stalled FAA reauthorization bill, so it can proceed on its own.

The bill would require airlines to create detailed plans specifying how they will provide food, water, restroom facilities, ventilation, and medical treatment for passengers on board an aircraft that is on the ground for an extended time without terminal access. The bill also would allow the Transportation Department to assess fines against airlines that do not comply.

Sensenich: Right on the Nose ... Again!
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U.S. Aviation and the Rest of the World back to top 

U.S. And EU Aviation Industries Agree To Collaborate

Officials from U.S. and European aviation agencies and industry wrapped up a two-day meeting in Brussels on Tuesday with general agreement on business and safety issues. FAA Acting Administrator Bobby Sturgell and Antonio Tajani, head of transport for the European Union, signed an agreement to promote technical cooperation between the FAA and the European Aviation Safety Agency (EASA). The agreement addresses aircraft certification, environmental approvals, and maintenance, and aims to enhance safety while reducing regulatory costs for manufacturers, operators and aviation authorities. Pete Bunce, president and CEO of the General Aviation Manufacturers Association (GAMA), welcomed the new agreement. "We view this strategic partnership between the U.S. and the European Community as a real milestone that will advance our shared safety visions," said Bunce.

"The relationship between the U.S. and Europe has proven its resilience and continued trans-Atlantic cooperation will increase efficiency and help bring new products to the global market more expeditiously. It's good for aviation safety and business, it's good for Europe, and it's good for the United States." Bunce added that he hopes the next step will be to update validation processes and EASA certification fees and charges. Those concerns had held up the agreement for several months.

Canada Levies Back Taxes On U.S. Pilots

U.S. pilots who fly in Canada pay a fee for their use of their airspace, but recently, the Canada Revenue Agency (the equivalent of the IRS) told Nav Canada it should have been collecting taxes on top of those fees. So the agency is trying to retroactively collect those taxes, going back five years, AOPA reported this week. "We have always opposed user fees, and this latest insult shows just how flawed and inefficient the system is," said AOPA President Phil Boyer. "How much is Nav Canada now going to spend to attempt to track down the pilot of the aircraft to collect this tax? A simple fuel tax makes so much more sense." AOPA is asking Nav Canada to waive the back taxes for U.S. operators. "This burden shouldn't be placed on the backs of pilots who rightfully believed that they had completely fulfilled their financial obligations to Nav Canada," said Boyer.

"Chasing after customers who have paid for services in full is poor business practice."

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Tough Times for GA back to top 

GA Struggles To Survive In Australia

Too much regulation and too many small airports closing down or being sold off to the private sector are the main culprits causing the decline of general aviation in Australia, according to the Australian unit of the Aircraft Owners and Pilots Association. "A viable GA industry is essential for the health and expansion of aviation in Australia," the group said in a report issued this week. If the country would adopt a set of rules more like those in the U.S., as New Zealand has done, the industry could yet rebound, the group said. And the government should reconsider its policy of selling off its GA airports, the report said. Commercial operators hike their prices, driving out small flight schools and private owners. Notably, while the GA industry overall is in trouble, the recreational aircraft sector in Australia is booming. More than 4,000 recreational/sport aircraft and over 1,000 gliders are flown there.

"The less onerous regulatory requirements that are helping the recreational sector to grow need to be applied to traditional GA," AOPA says. "CASA [the Civil Aviation Safety Authority] needs to adopt a more proactive, less punitive role."

In Greece, GA Struggles To Be Born

While Australia's GA community has problems, in Greece, no GA community even exists. "Which is precisely why the International Council of Aircraft Owner and Pilot Associations (IAOPA) decided to hold their biennial World Assembly in Athens," the group said this week. "Yiouli Kalafati, president of AOPA Hellas (Greece), wanted to show Greek authorities what they could gain by promoting, rather than restricting, general aviation," said Phil Boyer, president of IAOPA and AOPA-USA. "The presence of general aviation representatives from 26 different nations around the world helped change attitudes in Athens." Kostas Hatzidakis, the Greek Minister of Transportation, attended the meeting, held June 9 to 14. "His perspective on GA was positive and forward looking," said Boyer. "This attitude can only help the cause of GA in Greece. We are pleased to see that holding our World Assembly in Greece has had a positive effect on the government's perception of GA."

About 125 delegates and observers from around the world attended the IAOPA World Assembly. Pilots from other nations counseled U.S. pilots to continue resisting user fees. Direct user charges have only harmed GA in other parts of the world, AOPA said. Also, IAOPA resolved to urge national and international regulatory authorities to permit affordable and practical alternatives to emergency locator transmitters (ELTs) for general aviation. The group also addressed security issues, and sponsored Icarus 2008, the first air show and general aviation Aero Expo in Athens.

Piper Matrix — Piper Compelling
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News Briefs back to top 

Historic B-17 Bomber Makes Trans-Atlantic Flight Back to Europe

Almost 65 years to the day after the original 390th Bomber Group departed for their trip across the Atlantic, the Liberty Belle B-17 is repeating her historic journey to England. The flight, which departed on June 30, took the historic aircraft on its original famed route, which originates from its home base in Georgia. Day one of the Liberty Belle's trip took the B-17 to Bangor, Maine, then to Goose Bay, Canada, where it stayed for the night. Day two's first stop was Narsarsuaq, Greenland, for a short fuel stop. Then it was off to the "Lost Squadron" location on the Greenland Icecap followed by another stop at Reykjavik, Iceland. After one more short stop at Prestwick, Scotland, the Liberty Belle will be back at home base at RAF Airfield in Framlingham, UK. The total round-trip distance is 7,800 miles.

While in England the Liberty Belle will be participating in many different events to commemorate the brave airmen and all other service men and women who fought in the war. A team of documentary filmmakers will also be on board to record this historic journey. While on tour visitors will be to visit with the crew, view this historic aircraft, and be able to purchase a chance to go on a flight in the famed aircraft.

On the Fly ...

The FAA needs to be a better job overseeing airlines, according to a report issued this week by the Transportation Department's Office of Inspector General. The FAA says the report is "extremely helpful"...

Cockpit traffic alerts occur up to 10 times more often around some U.S. airports than at European hubs, the Wall Street Journal reports...

FAA is offering bonuses up to $75,000 for air traffic controllers to move to Alaska, and up to $100,000 for some New York posts...

Houston's 1940 Air Terminal Museum is raffling off a 1947 Cessna 140, tickets are $50, just 2,500 will be sold, Friday July 18, is the last day to buy. Call 713-454-1940 or email info@1940airterminal.org for info.

What You Don't Know About Charts Can Hurt You — Or Worse
Instrument flying and aeronautical charts are inextricably linked. From SIDs to IAPs, this interactive course will get you up to speed on instrument charts and how to use them effectively in the system. Covering everything from departure procedures to approach plates, it's a comprehensive look at the world of IFR charts — both NACO and Jeppesen. Begin the IFR Insight Charts course today!
Reader Voices back to top 

Question of the Week: What Level of Performance Would Tempt You to Go Electric?

This Week's Question | Previous Week's Answers


Last week, we asked how much is too much for avgas.

At what price did most readers say they would stop flying? Shockingly, 29% of those who responded said they're already too high (and I've already quit)! Another 45% of respondents drew the line at various points along the $7/8/9/15-a-gallon spectrum we outlined, and the final 26% of you said I could never quit, no matter how much I have to pay for gas.

For a complete (real-time) breakdown of reader responses, click here.
(You may be asked to register and answer if you haven't already participated in this poll.)


With fuel prices constantly on the rise, we've been getting a lot of QOTW suggestions from readers about alternative power. Here's one from Bruce B., who sent us a rather specific list of characteristics and wonders if any of these might tempt AVweb readers to make the jump to a battery-powered electric airplane:

What would be the minimum acceptable speed, climb rate, cruise speed, payload and flight time endurance acceptable to make you consider owning a battery-powered electric airplane if it cost under $150,000?
(Remember that fuel and maintenance costs would be greatly reduced!)
Click the link for options.

Have an idea for a new "Question of the Week"? Send your suggestions to .

This address is only for suggested "QOTW" questions, and not for "QOTW" answers or comments.
Use this form to send "QOTW" comments to our AVmail Editor.

AVweb's Newstips Address ...

Our best stories start with you. If you've heard something 200,000 pilots might want to know about, tell us. Submit news tips via email to newstips@avweb.com. You're a part of our team ... often, the best part.

Precise/Cirrus Fixed Oxygen Is Now Available as an SR22 Retrofit
Because every SR22 deserves the best, we have acquired STCs for the G2 and G3 Models. The Precise Flight Certified Fixed Oxygen System, unique in its clean and simple integration into the aircraft, is making its way "standard" on the industry's leading airframes. Click here to find out more about the Precise Fixed Oxygen System.
New on AVweb back to top 

The Savvy Aviator #59: EGT, CHT and Leaning

Why does proper leaning procedure seem to be such a confusing subject for pilots when it's so darn easy?

Click here for the full story.

Of the many tasks that we have to perform as pilots, leaning the engine is one of the simplest. Leaning is vastly easier than shooting a circling approach in low IMC, picking the smoothest route through a cold front or deciding when to overhaul the engine. Yet no subject I know seems to trigger more discussion and debate among pilots, nor to provide more misinformation and bad advice.

Although I usually devote this column to maintenance-related topics, aircraft owners seem to ask me more questions about leaning procedures than just about any other subject. It's obvious to me that, despite the simplicity of this subject, it remains poorly understood by a lot of aviators. So I thought it might be worthwhile to revisit my approach to leaning, and then address some of the questions that pilots seem to have about it.

The best source I know for in-depth information about optimal powerplant management is the 2-1/2-day Advanced Pilot Seminars (APS) course developed by my good friends George Braly, Walter Atkinson and John Deakin. This outstanding seminar is offered both as a "live" course several times a year in Ada, Okla., and occasionally elsewhere, and is also available in a home-study, on-line version. Tuition is about $1000 for the live course and about $400 for the on-line course. I've taken both the live and on-line versions, and both are excellent.

The objective of the APS course is to offer pilots an in-depth understanding of powerplant management, both theory and practice. It offers a huge amount of information on the subject, and most APS graduates liken the experience to drinking from a firehose. But many pilots are reluctant to invest the time, money and neurons into gaining that level understanding of powerplant management. Many are just looking for a simple, cookbook-like approach to leaning that doesn't require a rocket scientist to master.

Forget the POH!

Most Pilot Operating Handbooks (POHs) provides precisely such simple, cookbook-style guidance. Most call for operating the engine in cruise at "recommended lean mixture," which is typically defined as leaning to peak EGT and then richening until EGT drops by 50°F. (Or in shorthand, "50°F ROP.") Many POHs also authorize operating at "best economy mixture" (defined as peak EGT) for power settings less than 55-to 65-percent power.

Unfortunately, this POH guidance leaves a lot to be desired. 50°F ROP is almost precisely the worst possible mixture setting from the standpoint of engine longevity. The maximum cylinder head temperature (CHT) and peak internal cylinder pressure (ICP) occurs almost precisely at 50°F ROP. So using the "recommended lean mixture" assures that your engine operates at the hottest, most stressful corner of its operating envelope.

"Best economy mixture" (peak EGT) is only slightly better, providing a bit cooler CHTs and a bit less internal stress on the engine, but not by much. Furthermore, peak EGT is certainly not the best economy mixture; minimum brake specific-fuel consumption (BSFC) occurs at a substantially leaner mixture than that, well lean of peak EGT (LOP).

Why would so many aircraft manufacturers publish such bad advice in their POHs? Well for one thing, back in the 1960s and 1970s when many of the POHs were written, the relationships between EGT, CHT and ICP were not as well understood as they are today. The conventional wisdom at that time was that richer mixtures were better for the engine, and leaner mixtures were worse. A culture of fear evolved, promulgated by the flight instructors of the day: If you leaned too aggressively, you'd blow up your engine.

With today's sophisticated instrumentation, we now know that this isn't true. The hottest, most stressful mixture is about 50°F ROP, and mixtures that are richer or leaner are better for the engine. At 75-percent cruise power, you want to stay well away from that worst-case mixture setting, either by operating at least 100°F ROP (preferably richer) or at least 20°F LOP (preferably leaner), take your pick.

Given the choice between operating ROP or LOP, LOP operation has some compelling advantages: It's cleaner, cooler, less stressful on the engine, and uses a lot less fuel. Or, as the latest APS mantra goes: "Leaner is greener."

Also, many aircraft engines in the 1960s and 1970s typically would run unacceptably rough if you tried to lean them beyond peak EGT. Today, with tuned fuel-injector nozzles and digital engine monitors, we are able to operate these engines deep in the LOP regime without roughness. Even most carbureted engines can be operated at least somewhat LOP if the pilot knows what he's doing.

That POH "recommended lean mixture" (50° ROP) does offer a reasonable compromise between best power and best economy. What 50°F ROP does not provide is good engine longevity, which is something that the manufacturers don't care much about but owners definitely do. (Premature cylinder replacement is a major expense item for an aircraft owner, but a revenue item for the manufacturer.)

CHT is the best proxy we have in the cockpit for peak internal cylinder pressure (ICP). Peak ICP and peak CHT occur at almost exactly the same mixture setting. This is the mixture that's hardest on the engine because it creates the greatest stresses. Except at low power settings -- say 60-percent power or less -- it's a good place to avoid if you care about engine longevity.

So while many pilots still follow the antediluvian POH guidance, we can do a lot better. Note that the leaning recommendations in the POH are not limitations; they are mere suggestions (and often not very good ones, in my view). A pilot is under no regulatory obligation to follow them (which, in my view, is a good thing).

How I Lean

Over the past decade, I've evolved a dead-simple approach to leaning that has worked very well for me in my Cessna T310R turbocharged twin. My engines obviously love it, since they're both now more than 900 hours beyond TBO and running great. With minor variations, my approach should work for just about any piston-powered airplane.

Perhaps the most controversial aspect of my technique is that I don't use EGT as a leaning reference for cruise flight. EGT is extremely useful for troubleshooting engine problems, but as a leaning reference it leaves quite a bit to be desired in my opinion. That's because optimum EGT varies with cruise power setting, altitude and temperature, so leaning by reference to EGT turns out to be relatively complicated.

I find it a lot easier to lean in cruise by reference to CHT and fuel flow. In this respect, I depart from what is taught in the APS course. APS teaches an EGT-based approach that's more accurate but more complicated. I use a CHT-based approach that's dead simple yet still puts me in the ballpark and obviously has made my engines live long and prosper.

Here's how I do it. First, I decide upon my objective: Do I want to go fast (i.e., achieve maximum airspeed) or do I want to go far (i.e., achieve minimum fuel consumption)?

If my objective is to go fast, then I lean so that the CHT of my hottest-running cylinder does not exceed a pre-established target value. That target depends on the aircraft and to some extent the OAT, but for most legacy aircraft (Beech, Cessna, Mooney, Piper, etc.) and most OATs, a target of about 380°F works well. (For more recently-designed aircraft like the Cirrus SR22 or Diamond DA42, with their superior engine-cooling systems, 350°F is a better number.) At unusually cold OATs, the target figure should be lowered a bit.

If the CHT of the hottest-running cylinder exceeds the target value, then I enrichen a bit more (if ROP) or lean a bit more (if LOP) to bring the CHT down to the target. Conversely, if the hottest CHT is lower than the target value, I can save a bit of fuel by leaning a bit more (if ROP) or gain a bit of speed by enrichening a bit more (if LOP).

Personally, I always cruise LOP for all the reasons cited earlier (cooler, cleaner, cheaper, greener), but your mileage may vary.

If my objective is to go far, then I lean so that my GPS-coupled fuel totalizer system shows forecast fuel remaining at my destination to be not less than my target minimum fuel reserve (which for me is one hour of fuel at cruise fuel-flow). If the totalizer forecasts that I will arrive at my destination with less fuel than this, then I lean further until the totalizer does show enough reserve fuel. If I find that I cannot lean enough to achieve the necessary fuel-reserve figure without experiencing engine roughness, then I know I'll need to make a fuel stop.

If you choose to cruise ROP, then you also have to make sure that you don't lean so far as to exceed your target CHT. If you can't find a mixture that simultaneously yields the required fuel reserve and doesn't exceed the target CHT, then you'll either have to reduce power, switch to LOP operation, or make a fuel stop.

If you don't have a GPS-coupled fuel totalizer, then you can calculate your reserves manually from fuel quantity, fuel flow and GPS-derived time-to-destination, but that's a lot more work. For anyone who flies a lot of long-distance fuel-critical missions (like I do), a GPS-coupled fuel totalizer is probably number 3 on the "Things You Just Gotta Have" list, right behind a digital engine-monitor and real-time, satellite weather in the cockpit.

Frequently-Asked Questions

When I operate LOP, my EGTs are noticeably higher than when I operate ROP. Won't those higher EGTs harm my engine?

Indeed, if you run 20° LOP instead of 100° ROP, your EGTs will be higher -- 80°F higher, to be exact. This is nothing to worry about. At cruise power, your engine is not capable of producing EGTs high enough to harm anything. When I cruise my T310R LOP (which is the only way I fly it these days), I generally see EGTs in the mid-1500°F range. Given the extraordinary longevity and reliability I've obtained from my engines, they're clearly quite content with those EGTs.

If I operate at peak EGT or LOP, don't I risk burning my exhaust valves?

This question belies a common misconception that burned exhaust valves are caused by high EGTs. This is not correct. Burned exhaust valves are caused by valve-guide wear and valve-stem wear, and the best way to keep that from happening is (1) to keep CHTs down, and (2) to run a lean mixture to minimize build-up of combustion byproducts on the valve stem. The leaner you operate (while keeping CHTs at prudent levels), the happier your exhaust valves will be.

Why do you recommend keeping CHTs at or below 380°F, while TCM sets its CHT red line at 460°F and Lycoming sets it at 500°F? Aren't you being excessively conservative?

Both TCM and Lycoming specify CHT limits (460°F and 500°F, respectively) that should be considered emergency limits, not operational limits. Allowing your CHT to get anywhere close to those values for significant periods of time will most likely result in premature exhaust-valve problems and increased incidence of cylinder-head fatigue cracking. I do not like to see CHT above about 400°F, which is the temperature at which the aluminum alloy from which your cylinder head is made loses one-half its tensile strength. (The strength decreases rapidly as the temperature rises above 400°F.) For legacy aircraft, I recommend a maximum target CHT of about 380°F just to provide a little extra cushion, and consider any CHT above 400°F to be grounds for "doing something right now" to get it down. (For modern designs like the Cirrus and Diamond, reduce those CHTs by 30°F or so.)

The higher the power setting, the further away from 50°F ROP you need to stay to keep CHT at or below the target. As power decreases, this "zone to avoid" around 50°F ROP becomes narrower and narrower. When power gets down to about 60 percent, the avoidance zone disappears and you can run the mixture pretty much anywhere you please without overtemping or overstressing anything. (The APS folks refer to this zone to avoid as "the red box.")

In my view, the best way to manage our piston engines is the same way we manage turbine engines: by limiting temperature, specifically by CHT (which is the best proxy we have for ICP). For best engine longevity, set the mixture somewhere that produces CHTs no higher than 380°F (or 350°F for modern designs). This can be very ROP, or slightly LOP, or even right at peak if the power is low enough. What's important is that you limit CHTs to a maximum target value. How you accomplish that is less important from the standpoint of longevity.

My engine monitor uses a spark-plug gasket probe on cylinder number two because the threaded boss on that cylinder is already occupied by the factory CHT probe. Is that why my number two CHT always seems to run hot?

Yes it is. A spark plug gasket probe generally results in a CHT reading that's about 40°F hotter than a normal, threaded probe on the same cylinder. To avoid this problem, you can purchase a "piggyback" probe for your engine monitor that will screw into the threaded boss on the cylinder, and that will allow the factory probe to be piggy-backed on top of it. The piggy back probe sometimes reads slightly lower than the regular probe, but it's a whole lot closer than the spark-plug gasket probe.

All this LOP stuff may be fine for you fuel-injected guys, but I fly a Cessna 182 with a carbureted O-470 engine. I've been told that LOP operation is a bad idea for carbureted engines. Do you agree?

LOP operation is fine for any engine that can run smoothly in that configuration. However, LOP operation requires fairly even mixture distribution among the cylinders. That's sometimes difficult to achieve in a carbureted engine, particularly the O-470 engine in a Cessna 182 (which is famous for its poor mixture distribution).

There are a couple of techniques you can use to improve the mixture distribution of your carbureted engine and thereby enable the engine to be leaned more aggressively before it starts to run rough. One is to use a touch of carb heat during cruise (particularly in low OATs). The other is to avoid full-throttle operation, backing off the throttle until you can just see the slightest drop in MP. The warm induction air and the slightly cocked throttle plate both improve fuel atomization and mixture distribution in your engine, and will enable you to lean more aggressively before the engine starts running rough.

You should feel quite comfortable experimenting with these techniques to see if you are able to operate LOP without creating uncomfortable engine roughness. Contrary to popular belief, you can't hurt anything by operating LOP. If you get your engine to run smoothly LOP, I suggest you try it (and you'll probably like it). If you can't, then you'll have to be content with ROP operation.

My Cessna 182 has a Texas Skyways O-520 conversion. I also have an Electronics International UBG-16 engine monitor and FP-5 fuel flow system. Texas Skyways is dead-set against LOP operations. They recommend operation ROP up to a maximum of 1825°F of CHT plus EGT combined. For my engine, this normally equates to 50°F ROP. How would you recommend I operate this engine?

The notion of using CHT+EGT as a leaning target has absolutely no scientific basis behind it. Electronics International does recommend this technique it in its UBG-16 users manual, but it's poor advice in my opinion. CHT is the most important parameter for cylinder longevity, because it correlates with ICP. I disregard EGT altogether when leaning, although EGT is enormously useful for troubleshooting. If you use EGT+CHT as a leaning reference (as Electronics International suggests), the EGT overwhelms the CHT in the sum and you lose the most important part of the information (which is CHT).

Don't get me wrong: The Electronics International UBG-16 is an excellent engine monitor, and E.I.'s technical support is top-notch. But the UBG-16 user's manual ... not so much, in my opinion.

I suggest you keep CHTs at or below 380°F (or 350°F for modern designs). There is no limit for EGT. My cylinders generally see EGTs in the high 1500s and they obviously haven't caused a longevity problem. My cylinders and valves use exactly the same metallurgy as yours.

You caution against excessive CHTs, but is it possible for CHTs to be too cold?

Yes, it's possible to run CHTs so cold that the tetraethyl lead (TEL) in the 100LL is not properly scavenged and starts creating metallic lead deposits in the combustion chamber and lead-fouling the spark plugs. However, in most engines, it takes very cool CHTs (down in the mid-200s °F or lower) for an extended period of time (hours) for this to cause a problem. We usually see this problem in airplanes used for fish spotting, pipeline patrol, search and rescue, and other "loiter-mode" operations. Unless you fly at very low power settings (e.g., 50 percent) and/or at very high altitudes and very cold OATs (e.g., FL240 and -30°C), it's not usually a problem.

I fly a Cessna 172 with no CHT or EGT or fuel flow instrumentation. How should I lean my engine?

After stabilizing in cruise and reducing power to the desired cruise RPM, slowly lean the mixture until you feel the onset of perceptible engine roughness. Then slowly richen just to the point that the roughness goes away. With your limited instrumentation, that's the best you can do ... and it's not a bad technique.

Having said that, I would strongly recommend that you consider installing a digital engine monitor in your airplane. To my way of thinking, having an engine monitor is even more important in a four-cylinder, single-engine airplane than it is in six-cylinder single or a twin. If you fly a four-cylinder single and you lose a cylinder in flight, you don't have much left.

See you next month.

Want to read more from Mike Busch? Check out the rest of his Savvy Aviator columns.
And use this link to send questions to Mike.

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Around the World in 70 Days, Weeks 6 & 7: Asia

"We've been gone over 50 days now, and had just one weather-related delay," says Thierry Pouille, organizer of Air Journey's unique round- the-world GA tour, now in Asia. "It's just chance, really!," he admits, noting that several times weather would have been a factor if they had planned to fly just a day before or after. "We've been lucky." Part of the group's luck stems from Pouille's work ethic. Back in Florida now, he is staying up nights and sleeping during the day, to manage the needs of his group of five world-spanning aircraft.

Click here for the full story.

"We've been gone over 50 days now, and had just one weather-related delay," says Thierry Pouille, organizer of Air Journey's unique round- the-world GA tour, now in Asia. "It's just chance, really!," he admits, noting that several times weather would have been a factor if they had planned to fly just a day before or after. "We've been lucky." Part of the group's luck stems from Pouille's work ethic. Back in Florida now, he is staying up nights and sleeping during the day, to manage the needs of his group of five world-spanning aircraft. And his daughter, J.P., travels to each site a day ahead, to be sure all details are looked after.

The pilots made it to Hong Kong on Wednesday. "I believe our PC-12 was the first of its kind ever to land there," Pouille said. After much fruitless effort trying to plan a GA flight across China, the decision was made to park in Hong Kong and visit via commercial flights instead. "China just doesn't understand the needs of this kind of GA aircraft," Pouille said. All five of the airplanes on the trip are pressurized, turbo-powered, and owner-flown. "With all of the extra problems there surrounding the recent earthquake, and now the Olympics, we decided to skip it for this year, and try another time."

"Another time" will be soon -- Pouille said the round-the-world trip will definitely run again next year. Changes next time will include longer layovers -- pilots and their companions found they need three nights per stop to have time to enjoy each destination. Also at least one week-long stop will be planned, allowing time to rest and take care of any maintenance or other issues that can crop up on such a long trip. And he hopes that stops in China can be managed for next year's trip.

This year, an Australian pilot joined the group for part of its Southeast Asian tour, and Pouille said he welcomes such flexibility. "We have a constantly changing group, with friends and relatives joining up and leaving, and that's good for the group dynamics," he said.

Since our last AVweb report, the group has visited Ahmedabad, in India, and the Taj Mahal; they then flew on to Thailand, where they explored both the green hills of Chiang Mai and the seaside resort of Phuket. Next stop was Cambodia, and the spectacular temples at Angkor Wat, then stops in Viet Nam, at Hanoi and Ho Chi Minh City. Finally, they flew an 850nm leg to Hong Kong, adding hundreds of extra miles to divert around Chinese airspace. Now the pilots have a week off from flying to be tourists in China, before taking off again -- next stop, Taiwan.

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AVweb Insider Blog: Why Hal Shevers of Sporty's Is Turning Away FAA Business

So your local FAA guys are amiable as can be and a pleasure to chat with, but you'd still rather not have them underfoot whenever you turn around? You're not alone — on the AVweb Insider blog, AVweb Editorial Director Paul Bertorelli explains why Sporty's front man Hal Shevers has deciced it's just more trouble to rent airplanes to the FAA than it's worth.

Read more.

Join NAA and Help Shape the Next Century of Flight
It's a great time to join the National Aeronautic Association (NAA), the nation's oldest aviation organization. At $39 a year, NAA membership is a terrific value for any aviation enthusiast! Members receive the Smithsonian's Air & Space magazine, plus access to aviation records and much more. To become an NAA member, sign up online or call (703) 416-4888 and press 4.
Your Favorite FBOs back to top 

FBO of the Week: Columbia Air Services (Southern Vermont Regional Airport, KRUT, Rutland, VT)

Nominate an FBO | Rules | Tips | Questions | Winning FBOs

Hands down, our latest "FBO of the Week" ribbon goes to Columbia Air Services at Southern Vermont Regional Airport (KRUT) in Rutland, Vermont.

The Cessna Pilots Society recently held their annual gathering in Rutland, and praise for the FBO has been pouring in to AVweb ever since the participating pilots returned. Almost everyone who took time to rate the FBO pointed out that the staff stayed very busy throughout the five-day event but never faltered when it came to top-notch service and friendliness, working their fingers to the bone to provide tie-downs, refreshments, rental cars, and local information. In particular, Kate, Al, and Brian received a lion's share of praise for going the extra mile to help out these Cessna flyers.

(And while we can't send hats to everyone, we will be sending one to AVweb reader Abbott de Rham, who was the first to sing the praises of Columbia. It's certainly gratifying to know we have so many regular readers and contributors among the CPS membership!)

Keep those nominations coming. For complete contest rules, click here.

AVweb is actively seeking out the best FBOs in the country and another one, submitted by you, will be spotlighted here next Monday!

Understanding Your Airplane's Mechanics Could Save Your Bank Account
Light Plane Maintenance is the monthly magazine for aircraft owners who aren't satisfied with just flying. Aircraft repair can be simple when explained in concise, step-by-step details. If you want to truly learn about the workings of your airplane (and save a few dollars, too), Light Plane Maintenance is for you. Order online today and receive LPM's Top 40 Maintenance Tips as a gift.
AVweb Media: Look, Listen, Laugh and Learn back to top 

Exclusive Video: Inside Diamond's D-Jet Personal Jet Aircraft

Original, Exclusive Videos from AVweb | Reader-Submitted & Viral Videos

With new personal jets popping up all the time, AVweb takes a look at what may very well be the next certified single-engine very light or personal jet to enter the market. Diamond's D-Jet is expected next year to earn its type certificate, and that's when the company hopes to make first deliveries. Diamond recently announced plans to upgrade the aircraft with Garmin's G1000 Synthetic Vision package and the Williams FJ33-19 powerplant — offering 20 percent more thrust and a 4,000-hour TBO. AVweb's Glenn Pew offers this look inside.

Don't see a video screen?
Try disabling ad blockers and refreshing this page.
If that doesn't work, click here to download the video directly.

Reader-Submitted Photos back to top 

Picture of the Week: AVweb's Flying Photography Showcase

Submit a Photo | Rules | Tips | Questions | Past Winners

Each week, we go through dozens (and sometimes hundreds) of reader-submitted photos and pick the very best to share with you on Thursday mornings.  The top photos are featured on AVweb's home page, and one photo that stands above the others is awarded an AVweb baseball cap as our "Picture of the Week."  Want to see your photo on AVweb.com?  Click here to submit it to our weekly contest.


Submissions remain high this week as we sit between the long weekends of Canada Day and U.S. Independence Day. That means we get a three-day weekend, an excuse to eat way more barbecue than anyone should, and plenty of great airplane pictures to show off on our PDA while we wander around outdoors looking for the mustard. And better still, AirVenture is only weeks away! But don't worry — you can enjoy the same great photos as us while sitting in front of your computer, even if work prevents you from taking a day off (or good sense prevents you from gorging yourself).

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copyright © Bob Rybak
Used with permission

F-15 Fly-By

Bob Rybak of Saunderstown, Rhode Island kicks off the summertime fun with an air show photo from the Rhode Island National Guard's recent affair. As this week's top photo contributor, Bob will get an official AVweb baseball cap to shade his eyes during the next weekend air show he gets out to visit.


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Used with permission of Darrell Rayfield

Needing a Tow

Here's something you don't see every day — at least not in our line of work. Darrell Rayfield of Roanoke, Virginia tells us the Virginia State Police helicopter seen here broke down on the rooftop helipad of Carilion Roanoke Memorial and had to be towed to the hangar for repair by this Black Hawk.


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Used with permission of John English

Doug Wildhagen Beats Up the Sky in His Magni Gyroplane

While we're stuffing our faces and staring up at the sky this weekend, John English of Lawrence, Kansas will likely be up there playing passenger and snapping photos, as he did recently with Doug Wildhagen.


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copyright © Owen Peterson/
Sanderson Geophysics

Used with permission


We fell in love with this image from Owen Peterson of Ottawa, Ontario (Canada) while playing around with our monitor in "POTW" headquarters today. If you happen to have one of those portrait-style monitor layouts (or if you're just messing around with turning your widescreen on its ear, as we did), this looks fantastic as a desktop wallaper.

(Or, you know, you can just enjoy it without tipping your monitor on its side.)


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Used with permission of Timothy O'Connor

Hot Air Balloon Reveille

Timothy O'Connor of Batavia, Ohio sees us off with a serene moment from his first-anniversary balloon ride. "Our squadron (gaggle?) ... land[ed] at Caesar Creek Glider Port where a Boy Scout troop was camping," writes Tim. "We woke them up with the sound of the burners and balloons."


Spend a Few More Minutes with Us Before You Wander Off ...
There are more reader-submitted photos in the "POTW" slideshow on AVweb's home page, including a couple of Independence Day-themed shots you won't want to miss!

And click here to submit your own photos to "POTW."

A quick note for submitters:  If you've got several photos that you feel are "POTW" material, your best bet is to submit them one-a-week!  That gives your photos a greater chance of seeing print on AVweb, and it makes the selection process a little easier on us, too.  ;)

A Reminder About Copyrights:
Please take a moment to consider the source of your image before submitting to our "Picture of the Week" contest. If you did not take the photo yourself, ask yourself if you are indeed authorized to release publication rights to AVweb. If you're uncertain, consult the POTW Rules or or send us an e-mail.

More AVweb for Your Inbox back to top 

AVwebBiz: AVweb's Business Aviation Newsletter

HAVE YOU SIGNED UP yet for AVweb's NO-COST weekly business aviation newsletter, AVwebBiz? Reporting on breaking news, Business AVflash focuses on the companies, the products and the industry leaders that make headlines in the business aviation industry. Business AVflash is a must read. Sign up today at http://www.avweb.com/profile/.

Names Behind the News back to top 

Meet the AVwebFlash Team

AVwebFlash is a weekly summary of the latest news, articles, products, features, and events featured on AVweb, the internet's aviation magazine and news service.

The AVwebFlash team is:

Timothy Cole

Editorial Director, Aviation Publications
Paul Bertorelli

Russ Niles

Contributing Editors
Mary Grady
Glenn Pew

Features Editor
Kevin Lane-Cummings

Click here to send a letter to the editor. (Please let us know if your letter is not intended for publication.)

Comments or questions about the news should be sent here.

Have a product or service to advertise on AVweb? A question on marketing? Send it to AVweb's sales team.

If you're having trouble reading this newsletter in its HTML-rich format (or if you'd prefer a lighter, simpler format for your PDA or handheld device), there's also a text-only version of AVwebFlash. For complete instructions on making the switch, click here.

Aviate. Navigate. Communicate.