Archive for the ‘Safety’ Category

Single Point Failure

Thursday, October 2nd, 2014

After the Chicago Center sabotage this week where a contract technician decided to complicate the upper Midwest ATC system, it got me to thinking about single point failure (SPF) modes—not for ATC but for pilots.

But first, how could the Chicago SNAFU happen? In my long-ago prior life in the USAF there were places where no person could be alone. Our nuclear missile launch control center had a two-officer requirement so if one of us got a little weird there was somebody right there to solve the problem. No single point failures! (Wonder if we could apply some similar thinking to other government activities—editorial comment.) We’ll let others rant about that, so let’s move on to operational topics.

Perhaps the most notorious aviation SPF over the years was the dry vacuum pump. I had a pump take an unplanned vacation with only 25 hours on it in solid IMC. The obligatory partial panel approach followed. After that experience, all the IFR aircraft I flew had a backup vacuum system. Darn if it didn’t happen again some years later in VMC, but the backup was there and it was a non-event. Both aircraft were well-maintained, but the perversity of hardware is always there.

On many older aircraft there are still people operating in IMC with this critical SPF. Not so good! If you “have a friend” who’s in this situation please encourage them to either not fly in IMC or GET A SUITABLE BACKUP! You can convince them with this Real Pilot Story.

With retractable landing gear there’s always an alternative extension mode: Most of the time it works and when it doesn’t let the insurance company fix or buy the aircraft. Avoid heroics to get the gear down that have led to catastrophe.

cat-clipartThe system that gives me the biggest pause these days, after the engine itself, is the electrical system. We’re putting more and more eggs into the electronic basket. There are a number of options—a second alternator or a really good battery—but you better catch the problem fast. If that doesn’t work, the “Cat-Duck-and-Tree Method” can be employed, but it requires a lot of space and a substantial animal food budget. If you don’t know about that particular option see the fine print below!

RATThe RAT might be a simple short term solution—not the four legged variety but a Ram Air Turbine. It’s been used on many military aircraft and airliners over the years. The Airbus 380′s is bigger than yours at more than five feet in diameter. It deploys manually or automatically into the slipstream and generates a modest amount of electricity. Haven’t seen that option for light GA, but I’m sure that somebody has come up with a solution.

Unless you’re flying one of the classic gravity-fed Cessnas, there’s probably an electric fuel pump to prime and to supplement the engine driven pump. Engine driven  pumps don’t quit often but the electric pump is a potentially critical backup if the engine driven pump fails. Do you know the protocol for using yours?

Perhaps the ultimate backup is the Cirrus parachute. Some pilots look down their nose at it. However, if used correctly, it has saved quite a number of lives in addition to be being a great marketing benefit to persuade non-pilots to go fly. It didn’t help one optimist who tried to fly up the Columbia River Gorge in Oregon at night in MVFR. He was depending upon the terrain database to keep him off the rocks, but…well, you know.

“The Cat-Duck-and-Tree Method”

First, put a large cat on the cockpit floor. Because a cat always remains upright, the pilot merely has to see which way the cat leans to determine if the wings are level. Second comes the duck, which is used for approaches and landings in soupy weather. Any sensible duck will refuse to fly under instrument conditions, thus it is only necessary to hurl your duck out of the airplane and follow her to the ground.

For the most efficient use of the “Cat-Duck-and-Tree Method” follow this checklist:

  • Get a wide-awake cat. Most cats don’t want to stand up at all. It may be necessary to carry a large dog in the cockpit to make the cat pay attention.
  • Make sure your cat is clean. Dirty cats spend all their time washing. Trying to follow a washing cat usually results in a snap roll followed by an inverted spin.
  • Use an old cat. Young cats still have many of their nine lives left, but an old cat has just as much to lose as you do and will be more dependable.
  • Avoid cowardly ducks. If the duck discovers you are using the cat to keep the wings level, it may refuse to leave without the cat. Ducks are no better in IMC than you are.
  • Make sure your duck has good eyesight. Nearsighted ducks may fail to realize they are on the gauges and go flailing off into the nearest mountain. Very nearsighted ducks may not realize they have been thrown from the aircraft and will descend to the ground in a sitting position. This is very difficult to follow in an airplane.
  • Use only land loving ducks. It is very discouraging to break out of the overcast and find yourself on final approach toward duck blinds, because duck hunters will shoot at anything that flies.
  • Since the floating compass in your airplane may sometimes go off track, you should always have a small tree hanging from the cockpit ceiling. Since moss grows only on the north side of a tree you merely have to see which side the moss is on to determine in what direction the plane is flying.

(Richard Taylor, author of Instrument Flying)

Getting Out of Dodge in IMC

Thursday, September 25th, 2014

Sweeps HuskyIf you’re a VFR pilot, this week’s blog may persuade you that doing clouds is a lot of work –sometimes. Feel free to do something more productive. But if you do clouds, then it might be worth following the twists and turns. It can be tough to make a graceful exit under instrument flight rules. It’s easy when there’s a control tower or a remote communications outlet (RCO) to speak directly with a controller who coordinates the airspace to fit you into the flow of traffic. It’s not so easy when merging into the cloudy skies involves remaining VFR before getting a clearance. Had an interesting question from a friend who needed some clarification when departing his grass strip which has no departure procedure.

“I recently departed my grass strip 12 nm south of (Big Airport) VFR and the controller refused to give me my instrument clearance unless I could visually clear obstacles up to 3500’ msl. Surface elevation around here is 950’ msl. The ceiling was 2000’, so I informed him that I could not maintain visual clearance with obstacles up to 3500’ because I will be in the clouds. He then denied my request for a clearance, even though he had given me a transponder code and had me in radar contact.”

Here is what one of our pilot-controller friends with the National Air Traffic Controllers Association (NATCA) had to say:

I will preface my response with a statement that I am not providing a legal interpretation for the FAA or NATCA.

As the rule is written, unless I know that you can’t provide your own terrain and obstruction clearance until reaching the appropriate altitude, I don’t have to ask. But for the sake of this discussion, let’s assume that I do know or that you have told me.

This is the first step a controller will take in order to issue a clearance below the minimum IFR altitude/minimum vectoring altitude (MIA/MVA):

When a VFR aircraft, operating below the minimum altitude for IFR operations, requests an IFR clearance and you are aware that the pilot is unable to climb in VFR conditions to the minimum IFR altitude:

Notice the bolded text. The next step in the process depends on the answer to the following question:

Before issuing a clearance, ask if the pilot is able to maintain terrain and obstruction clearance during a climb to the minimum IFR altitude.

Again, the bolded text is my emphasis but you will notice there is no mention of maintaining VFR. If you answer “yes,” that tells the controller that you understand that you are responsible for the terrain and obstruction even if you are unable to do this in VFR conditions (ed. note: Bruce’s emphasis underlined). The controller can issue you a clearance PROVIDED no course guidance is included. If the answer is “no,” The controller will instruct you to maintain VFR and ask for your intentions.

Is it safe and legal? It is for the controller provided he/she has complied with the rules in our handbook. As a pilot, if I were to accept the clearance knowing that I have the responsibility to provide my own terrain and obstruction clearance, I would want to be able to see those obstructions OR plot out a course that would provide the required minimum IFR altitude for my route (in a large part of the country, that would be 1,000’ above the highest point 4 nm either side of the planned route). The point being is that unless the pilot is flying a published FAA procedure or the controller is vectoring in an approved Diverse Vectoring Area, the PILOT is responsible to avoid obstructions. The controller cannot accept that responsibility.

Vectoring to avoid obstructions and terrain is not necessarily a discretionary practice…these obstructions must be mapped. Towers that are shown on a sectional aren’t necessarily mapped on a radar map.

An assigned squawk code aids the controller in radar identification, and the AIM advises pilots that just because an aircraft is in radar contact doesn’t transfer the responsibility for terrain and obstruction clearance (ed. note: Bruce’s emphasis underlined).

In your example, I will assume that Class E airspace starts at 700’ agl. A departing aircraft would enter controlled airspace (class E) at 1,650’ msl. A 2,000’ overcast ceiling would put the aircraft 1,300’ below the bases. MVA altitudes are msl, so an MVA of 3,500’ in that area means the pilot would be responsible for terrain and obstruction clearance for 550’ of that climb. Our rules don’t allow for ATC to accept that responsibility. A controller who doesn’t issue the clearance is following agency rules and not avoiding liability. The expectation in this case is that the pilot wouldn’t deviate from required visibility rules.

So, by my understanding, if there’s a DP or ODP—great—you’re guaranteed not to hit anything by following the guidance. But if there is neither for the airport in question and you can’t make it to MIA/MVA while VFR, there are two options:

1) Call for a void time clearance. If your cell phone works in those environs and you can hear in the aircraft, call from the aircraft at the end of the runway. This works when VFR isn’t an option due to low clouds.

2) Depart VFR, make radio contact, and verify with the controller that you can maintain terrain/obstacle clearance (notice we didn’t say anything about staying VFR) and make absolutely sure that there is nothing that would get in your way on the way up to safe skies.

Coordinate with ATC what your heading will be as you emerge into controlled airspace so they know where to expect you.

It might involve circling up over the airport—that happens a lot in mountainous terrain. Just be sure that there’s nothing in the way. With GPS, staying close to the departure waypoint is pretty easy.

Now, who said this was complicated?

Going With the Flow

Wednesday, September 17th, 2014

traffic flow 2One of last month’s really sad accidents involved a Piper Malibu that for reasons unknown decided to land counter to established traffic at a nontowered airport. There were five fatalities including three children.

Preliminary reports, which are just that, noted that there were several aircraft in the pattern when the pilot approached to land on Runway 33. Winds were reported to be 160 degrees at six knots. Another aircraft was departing on Runway 15. The Malibu made an evasive maneuver to avoid the departing aircraft and appears to have lost control and stalled.

According to the FARs, landing aircraft have the right of way. Now, we get into a hash over when one becomes a “landing aircraft.” Could it be a one mile final, half mile final, when below pattern altitude, other? If the winds favor the opposite runway where does one draw the line? How much wind is “drawing the line”? If a calm wind runway is designated, how does one find out and when is calm not really calm? When does exercising my prerogative to land cross the “careless and reckless line?”

Manufacturers do not provide landing distance information beyond a 10-knot tailwind. For light aircraft you may see something like “increase landing distance by 10 percent for each two knots of tailwind up to 10 knots.” The cleaner the aircraft, the worse it gets. In the PA-46 POH, Piper only gives guidance for up to five knots of tailwind—if I read it correctly. That adds more than the length of a football field: He’s at the 30, the 20, past the 10; he’s into the end zone. It’s a touchdown—but it’s not on the runway. There is nothing good to say about tailwinds on landings. (I do approve of them
en route, however!)

The attorneys will get into this in great detail, but our interest is denying them the opportunity because loss of life is usually involved. 

When approaching the runway at right angles it’s pretty easy to go either way. Ditto if coming from the “wrong” end. Merely angle out a little and then set up for a standard entry. My rule is to generally go with the established flow, and if the tailwind is even slightly significant I suggest on the CTAF that I will be waiting for the others to clear and then land the other way.

Pattern etiquette is one of those sure conversation starters, and we have some suggestions in ASI’s Nontowered Airports Safety Advisor. Playing chicken in cars is dumb—so it is with airplanes.

A core tenet of the Air Safety Institute is to help pilots improve their skills and enhance GA safety through free educational programs. AOPA membership dues don’t cover these programs—donations do, but only six percent of AOPA members actually donate to the AOPA Foundation. Whether you’re a member or a friend of GA, please consider contributing today to support the institute’s important work. Imagine if GA operated on only six percent…