Friday, August 19, 2005

Accident of the Week

One of the things that the IFR Pilot does to learn is read NTSB accident reports. The thought is that perhaps reading about the choices the led some pilots to commit fatal or near-fatal accidents might sharpen my own decision-making skills. Here's this week's offering from the NTSB archies:

NTSB Identification: NYC05LA134
14 CFR Part 91: General Aviation
Accident occurred Saturday, August 13, 2005 in Erie, PA
Aircraft: Piper PA-28-180, registration: N7534W
Injuries: 3 Fatal, 1 Serious.
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

On August 13, 2005, at 2114 eastern daylight time, a Piper PA-28-180, N7534W, was substantially damaged during a forced landing, following a total loss of engine power on approach to Erie International Airport (ERI), Erie, Pennsylvania. The certificated private pilot and two passengers were fatally injured, while one passenger was seriously injured. Night visual meteorological conditions prevailed for the flight that departed Jamestown Airport (JHW), Jamestown, New York. No flight plan was filed for the personal flight conducted under 14 CFR Part 91.

According to a Federal Aviation Administration (FAA) inspector, the flight originated from Smyrna, Delaware. The pilot flew to Randolph, New York, dropped off two of the passengers, and continued to Niagara, New York. He did not purchase fuel in Niagara, and fuel services were not available in Randolph. The pilot later returned to Randolph and picked up the two passengers. The pilot and three passengers then departed for Jamestown to purchase fuel; however, when they arrived, the fixed based operator was closed for the evening. The pilot did not utilize the after hours telephone number for fuel services at Jamestown, and elected to depart for Erie to refuel.

About 12 miles east of Erie, the pilot reported fuel exhaustion to air traffic control. He attempted to glide the airplane to runway 24, but it impacted a wooded area about 1 mile east of the runway.

Examination of the wreckage by an FAA inspector revealed that the left wing was compromised. The right wing remained intact, and contained about 16 ounces of fuel, with some water observed in the fuel sample.

Reading this accident really left me scratching my head, as it's one of those that seems totally preventable. Here's the route of flight (assuming all legs were flown direct):

The Airplane Flight Manual (AFM) for the PA-28-180 indicates a total fuel capacity of 50 gallons, of which 2 are unusable. The manual further states that the fuel consumption, when operating at 75 percent power, is approximately 8.8 gallons per hour in cruise flight, assuming the engine is leaned according to the manufacturer's specifications. We don't know how aggressive the accident pilot was in leaning the airplane. From my own experience, it's a lot easier to lean with the benefit of a multi-probe graphical engine analyzer. Sure beats "lean until it runs rough, then turn the mixture clockwise a bit to enrichen it," which is how I learned in the ol' 152.

Why didn't the accident pilot get fuel in Niagara? He had already landed at Randolph, so presumably knew that when he went back to pick up his passengers, he wouldn't be able to get fuel there. I've never been to Randolph, but it strikes me as the protypical country airport. Single turf runway, about 2500' in length. Couple of airplanes based there.

Admittedly, fuel at Niagara is expensive. At last report, it was $4.02. But it's not much cheaper at Jamestown, where he did try and get fuel. Per AirNav, $3.90 per gallon at JHW.

So, you land at JHW, knowing that you need fuel. You decide not to pay for a call-out. OK, I probably wouldn't want to pay $25 or so for an after-hours call out either.

But, why try to go all the way to ERI? Why not go to Dunkirk, due north of your position about 11 minutes away in a 172? Probably because it takes you away from your final destination of Erie. Yet, it seems much more prudent to make an 11 minute flight there than to try to make it a half-hour or so to Erie.

My point here isn't to castigate the accident pilot. Nor am I trying to express any value judgments. Perhaps the NTSB investigation will show that they needed to be in Erie at a time certain. I don't know.

I do know that reading about these scenarios is helpful for that little voice in my head that talks to me when I'm flying. "Are you sure that you want the NTSB to find out that you did xxxxxx?" -- whatever xxxxxxx might be. "Consider your alternatives." "Are you sure about the choices that you are making?" And so on.

The moral of this week's accident exemplifes the old aviation mantra, "You never have enough fuel except when you're on fire."


david said...

8.8 gallons per hour at 75% power is pretty optimistic for a 180 hp O-360 engine. For my smaller 160 hp O-320, the POH specifies 10 gph using normal leaning technique (rich of peak), or 8.5 gph flying lean of peak EGT (which most pilots aren't willing to do). Then again, a lot of pilots routinely fly at around 65% power, where the fuel consumptions are lower.

IFR Pilot said...

I agree. The O-360-A4M in our 172 burns pretty much right at 10 gph when leaned to 50 degrees rich of peak. The 8.8 at 75% power was taken direcetly from another NTSB report involving a Cherokee 180, and was based on the Airplane Flight Manual.