Unicom

March 2006 Issue




Unicom: 03/06

What Did You Say?
I just finished reading “Mean What You Say” (December 2005). This is a very good article providing powerful information for pilots to include in the art of aviating, navigating and communicating. We do a pretty good job of aviating and navigating but we sure could use some improvements in communicating.

In his non-towered airports discussion, Frank Bowlin says you are either “departing” or “taxiing into position and hold.” I tell pilots to never, ever go to position and hold at a non-towered airport. Doing this puts your back to traffic that may be landing on that runway.

Several years ago, I was inbound at night to a non-towered airport on the ILS. We made all the appropriate calls on the CTAF to let traffic know we were inbound and where we were. There was no other traffic on the frequency. When I set the runway lights to our desired intensity, they shortly dimmed one level. Other than that, there was no indication that we were about to have a close encounter.

Just before crossing the numbers for our landing, I noticed a single white light on the runway centerline that was starting to move. We initiated a missed approach, side stepped to the right, and announced our missed approach. The other aircraft taxied in position and hold without any calls on the frequency and with only position lights illuminated.

If I had not seen the one white position light, among all the other lights associated with this instrument runway, we would have collided at about the time we touched down. The other aircraft took off after being in position and hold, climbed out and left the area without a single word on the frequency, or using anti-collision lights or landing lights. I even monitored the departure frequency to see if I could get a call sign.

This incident reinforced my policy of not “assuming the position” at a non-towered airport, day or night.

David Faile
Fairfield, Conn.


The only reason we know of to taxi into position and hold on the runway at a non-towered airport is to allow landing traffic to clear the runway before beginning a takeoff roll. Generally, we refrain from doing even this, and get nervous when we hold in position at a towered airport, since ATC makes mistakes, too.

----------

More Singles Vs. Twins
I have to take issue with Brian Barbata’s letter (Unicom, January 2006) implying that twins have no safety advantage over singles. While it is true that losing an engine on takeoff in a twin means you’re probably going down, this is still no worse than a single where losing an engine means you’re definitely going down.

As for gear-lowering problems, a dead engine in a twin may or may not cause a loss of hydraulic pressure, but a dead engine in a single absolutely will. In his example where the twin was destroyed on the runway because of gear trouble but the occupants walked away, one has to wonder if those people would have even made it to the runway at all in a single. The benefits of a twin are not simply in the powerplant itself, but also in the redundancy afforded by double electrical, vacuum, and often hydraulic systems.

As far as comparing the risk of single engine over water flight to single engine go-arounds in a twin, this is strictly apples and oranges. The bottom line is that if I lose an engine in my Aztec over the middle of Lake Michigan, I’ll hopefully just have a good story for my next hangar flying session. If Mr. Barbata loses an engine in his Bonanza, he’s definitely going to be swimming home. At best.

Michele Denber
Rochester, N.Y.

----------

Sneaking A Peek
I read with great interest “Top Five Approach Traps” (February 2006), which is relevant to all IFR pilots, and particularly for me, given my experience on a recent instrument flight.

On the flight in question, I wound up going missed on two attempts to get into York, Penn., (THV) on the GPS Runway 35 approach in fog and low ceilings that blanketed the Northeast for much of the week. This wasn’t the first—and probably not the last—approach that I’ve abandoned at DA in the soup. What was different was two factors which combined to create a powerful temptation to sneak a peek below decision altitude.

The first was a greater-than-normal incentive to complete the mission—intended to pick up an Angel Flight patient for a trip to Boston. The prospect of stranding a patient was was something I really wanted to avoid.

Secondly, as I approached DA, the ground was fleetingly visible straight down through the fog but never where it counts—out front. I was surprised at the mental effort required to break off the approach. I have never knowingly busted DA on an approach, but never have I been so tempted.

In addition to redoubling my commitment to fly every approach by-the-book, I’ve decided never again to look down on low approaches. There is nothing but trouble straight down—at best a distraction and at worst a siren song to do a potentially tragic thing. Thanks for the sound advice.

Len Sherman
Via e-mail


Happy to help. We’d be lying if we said we’ve never been tempted to “duck under” an overcast on a non-precision approach with the ground visible below but without sighting the runway environment. It’s a strong temptation, made especially so when someone is depending on us. By resisting the siren’s call, ya done good.

----------

Turnbacks
Your study on turnbacks shows that 500 feet is a very marginal altitude for trying to return to the runway. But you seem to have made no mention that 800 or 1000 feet may be much better and safer, depending on the pilot’s skill and other factors. Comments?

Robert A. Pease
Via e-mail


Author Rich Stowell responds: “Thanks for asking, Robert. Remember that the flight characteristics emulated in the turnback study allowed for the completion of a 180-degree turnaround within the parameters specified for a ‘successful outcome.’ It was possible in the simulation to execute a 180-degree turnaround without exceeding a 55-degree bank, without exceeding a 2500-fpm descent rate, and still return to a wings-level attitude for the last 100 feet of altitude. In other words, the simulated airplane could turn around in just 400 feet, with 100 feet to spare to set up for a normal landing.

The failed turnbacks typically failed as a result of the pilots botching the turns, usually culminating in a stall/spin. Additional altitude would not have made any difference. Moreover, additional altitude on a straight-out puts the airplane farther away from the departure end of the runway. And given the shallow climb angles of typical light airplanes, we likely would not be able to glide all the way back to the runway upon completing the turn.

Also recall that if by “better and safer” you’re looking for “greater likelihood of surviving,” the straight-ahead (or nearly so) remains a more appropriate maneuver.”