An IFR pilot may choose to fly VFR on a nice day -- but how good does ''nice'' have to be to let go of the IFR safety net? This week's Probable Cause report investigates the issue.
May 28, 2006
This article originally appeared in IFR Refresher, December 2004.
IFR accidents typically fall into a few specific categories: Someone will get it wrong on climbout or approach, weather smites an unsuspecting pilot or a plane encounters something substantially more solid than a puffy cloud.
Which makes the following accident interesting in what the pilot didn't do. It also highlights the traps into which IFR pilots can fall, especially when conditions appear benign and the idea of filing and flying IFR may seem unnecessary.
For me, this particular accident also hits a little closer to home because it took place at a former employer of mine. The incident happened a few months before I was hired there, so I never got to know the pilot. But all accounts from those who did know him indicate he was a good, safe and conscientious pilot.
If you read the NTSB accident report, the cold hard facts in this incident appear simple. The 29-year-old pilot, flying a Piper PA-32R Lance, was en route from Greenville (KPGV), in eastern North Carolina, to Concord, N.C., (KJQF) about 20 miles northeast of Charlotte. The pilot was employed by a Part 135 cargo carrier and was transporting bank checks for one of its customers. It was mid-March and sky conditions were clear at the time. Capitalizing on this, the pilot elected to conduct the flight under VFR conditions and, armed with an onboard IFR-approved GPS, set off for KJQF. At around 4:30 p.m. and about halfway to its destination, the plane struck a guy wire supporting a 1,749-foot-tall television tower.
According to the accident report, a witness saw the Piper flying lower than he had seen other planes fly over the tower on previous occasions. As it collided with the wire, the plane "jolted to the left and exploded in mid-air," the report quotes the witness as saying. The NTSB determined that the plane struck the tower at around the 1,425-foot level, or around 1,825 feet MSL. The pilot was killed and the impact toppled a section of the tower. Although the plane was destroyed by the impact, company records show it was properly maintained and the NTSB ruled out mechanical problems as contributing to the crash.
In the end, the NTSB determined that the probable causes for the accident were the pilot's inadequate visual lookout and his failure to maintain obstacle clearance.
While it would be hard to argue the report's conclusions, they raise a deeper question: Why did an experienced IFR pilot decide to go VFR at low altitude and find himself on a collision course with one of the few tall obstacles along his route?
As is sadly the case with fatal accidents, we will never know the true answer to that question. We can only surmise -- guided by experience with this type of flying -- about what went into the pilot's decision-making process that day. The goal here isn't to find fault, but to explore the potential false traps that were in place so we can learn from this unfortunate event.
There is little doubt the pilot was experienced. According to company records, he had been with the company for almost nine months and had a little more than 1,700 total hours with around 600 hours in Piper Lances. In addition to being instrument current, he had commercial and flight-instructor certificates and was a company check airman. He also held a ground instructor certificate with advanced and instrument ratings. A toxicology test taken after the accident showed no traces of drugs or alcohol.
The routing from KPGV to KJQF takes you essentially on a westerly heading. A direct-line plot shows the track passing one mile north of the tower as it was depicted on the Charlotte Sectional. If you are to file an IFR flight plan for this route, even direct, your clearance would read direct to Raleigh (RDU), then Liberty (LIB) followed by the NASCAR 1 arrival. By taking you over the top of KRDU, ATC keeps you out of the northeast/southwest arrival and departure corridors that serve the airport, while the NASCAR arrival organizes the flow of general aviation traffic into the busy Charlotte terminal area. You could request a direct routing, but during the late afternoon push -- which was when this accident happened -- it is rarely granted. The pilot most surely knew this.
Compared to the direct routing, the IFR routing takes you slightly further north. Glancing at a chart, the detour might seem significant, but in actuality it only adds six miles to the total direct distance of 163 NM.
There's an aviation axiom that states that we can never get there fast enough. This attitude is fostered especially in the freightdog community, where "fly fast" is akin to gospel. This could explain why the pilot elected to forgo the IFR flight plan and launch direct VFR instead. But why was he so low?
The NTSB report we obtained did not include any winds aloft information for that day. But writing from experience, prevailing winds in North Carolina are typically from the west, especially if you have a strong high-pressure area sitting over the South. It's not unusual on a westbound trip to have a 30-knot headwind on the nose. Perhaps that was the case that day and the pilot decided to stay low, where the winds usually aren't as strong.
How Clear Is Clear?
The weather at the time was clear, or more accurately, clear of clouds. While we often equate that with visual conditions, that is not always true. The accident report included a surface weather observation report from a nearby airport taken half an hour after the accident, showing a visibility of 10 SM. Incidentally, the winds were from 160 degrees and 6 knots, showing that the winds, at least near the ground, were light.
Unfortunately, automated weather detection equipment isn't foolproof and it can report conditions that aren't indicative of what is going on in the area. By coincidence, I was flight instructing at the time the accident occurred in an area not more than 50 miles away. I cut the lesson short because haze had severely reduced flight visibility, especially when facing into the sun. I had even told my student, who was only a few lessons into his flying career, that for all practical purposes we were IFR. The comment stuck in my mind later that evening when I heard about the accident on the local news.
The direct course from KPGV to KJQF is about 265 degrees. The NTSB estimated that at the time of the accident, the sun was 22 degrees above the horizon with a true bearing of 250 degrees. In other words, the pilot was flying with the sun right in his eyes. The Piper Lance, like most piston singles, has a Plexiglas windshield, which is prone to hazing and crazing. These effects are magnified when facing the sun head on. Add to that the natural haze that existed and forward visibility is almost non-existent. By the time the pilot saw the tower and the guy wires -- if he ever saw them -- it was probably too late.
Weighing The Options
Risk assessment is a skill we exercise every moment we fly. The only way we won't get killed in an aircraft accident is to stay on the ground and live in a cave. That's obviously impractical, so we weigh the risks we are willing to take versus the gains to be made. Sometimes the answer is very clear. Got a line of Level 5 thunderstorms heading your way? Let's wait it out. Better yet, let's drive. Sometimes, however, the answers are a little muddier.
Based on an average groundspeed of 110 knots (which is factoring in a 30-knot headwind), it would have taken one hour and 29 minutes to fly the direct route versus one hour and 32 minutes for the IFR route. In this case, a three-minute shortcut shouldn't warrant giving up the protective umbrella that an IFR flight plan provides. However, staying low where winds are lighter, giving a ground speed of 125 knots, the direct route would have taken one hour and 18 minutes, a savings of 14 minutes. With a ground speed of 135 knots, the time shortens by another six minutes.
Perhaps the pilot wanted to please his customers -- and his boss -- by getting to KJQF early. Or maybe the reasons were more self-serving. Regardless, he must have weighed the options and decided the benefits outweighed the risk, which in his mind were probably minimal. Not only was the weather clear, although the visibility was marginal, but the pilot had flown this particular leg on numerous occasions before and he was familiar with the area.
It's this familiarity that may ultimately provide the final piece of the puzzle. The plane was equipped with an IFR-approved GPS and there's no doubt he would have used it to navigate his direct course. While the GPS is a great tool, it also introduces a level of complacency into the cockpit. With its steadfast accuracy, pilots -- especially those who regularly fly IFR -- have developed a habit of keeping their eyes inside the cockpit.
It's unfair to second-guess someone's decision after the fact. In hindsight it's easy to say that the pilot should have filed IFR and conducted the flight under the watchful eyes of ATC. But faced with a 20-minute time savings, I'm sure many of us would be tempted to do what this pilot did.
So what can we do as IFR pilots to avoid such an unfortunate incident?
Begin by make a realistic assessment of the gains to be made by flying VFR versus the safety that comes with filing IFR. This gain/risk threshold will vary from pilot to pilot, and is going to be influenced by numerous factors. Some of those include the pilot's comfort level with VFR flying, the anticipated weather en route and the type of mission that is at hand.
Note that I didn't mention familiarity with the local area. This is one of the traps. In this particular case, the pilot lived 10 miles from the tower with which he collided. If he was over unfamiliar territory, he may have been more vigilant or stuck with the IFR flight plan and let ATC keep him clear of traffic and obstacles. Should you go the VFR route, make sure you're armed with all appropriate information. Low altitude IFR charts do not depict obstacles and are therefore misleading. It's always a good idea to carry a Sectional or WAC chart with you at all times, even if you regularly file IFR.
Then consider the weather and the geography. Clear in Arizona is not the same as clear in North Carolina. Inversion layers will trap humid air with the resulting haze greatly limiting forward visibility. If you're in a part of the world you're not familiar with, talk to a local pilot or get some insight from the FSS briefer when you're filing your flight plan.
Only then should you ask if the time saved is really worth it. In the case of this unfortunate young pilot, his savings were never realized.
More accident analyses are available in AVweb's Probable Cause Index. And for monthly articles about IFR flying including accident reports like this one, subscribe to AVweb's sister publication, IFR Refresher.