Cumulo granite

And now for something completely different

Steve mentioned that we might occasionally cover some topics that aren’t political in nature. After the past few weeks, this seems like a good time to talk about something that is not related to Donald Trump or COVID-19. (Contrary to the beliefs of some of my readers, I don’t spend every waking hour fuming about the president’s latest tweets.) So, in the words of Monty Python, now for something completely different.

Those of you who follow me on Twitter may have seen tweets detailing my progress on the 400-mile challenge on the Pine Mountain Trail in Georgia’s FDR State Park. The park is located near Warm Springs, where FDR had a home away from the White House. He actually died at his Little White House in Georgia in 1945.

The challenge is to hike, walk, and/or run 400 miles in the park within a year. I started in February and, thanks to a lot of free time due to the pandemic, I’ve currently have only 31 miles to go.

One of my favorite spots in the park is Dowdell Knob, a scenic overlook where the famed president used to go for barbecues. The remains of his grill are preserved on the site, along with a statue. Less than a half-mile away is another memorial.

The small plaque on a boulder beside the trail is referred to as Plane Crash Rock and memorializes the crash of a WWII B-25 bomber that flew into the mountain in 1953. The plaque describes how the plane was enroute from Eglin AFB in Florida to Andrews AFB just outside Washington, DC. Four crewmen died in the crash and one survived.

The description left me with a lot of questions because the highest point on Pine Mountain is about 1,400 feet MSL, above mean sea level, which means that it’s only about 1,000 feet above the surrounding terrain. For a long trip, such as one from Florida to Maryland, it’s very unusual to fly only 1,000 feet above the ground. That was true even with the piston-engined bombers of 70 years ago.

Eventually, I found an exhibit that gave more details about the crash and talked to a trail volunteer who was a driving force behind the plaque. As it turned out, the plane was on a low-altitude air-sampling mission connected with nuclear weapons testing when it entered low clouds and struck the mountain not far from its crest.

In aviation terms, this is called CFIT: controlled flight into terrain. It is best described as flying a perfectly good airplane into the ground. There are many reasons that CFIT accidents happen but one of the most common is pilots becoming disoriented in areas of high terrain. In a lot of CFIT accidents, you literally never know what hit you… or more accurately, what you hit.

This scenario is humorously illustrated by the old Far Side cartoon in which two pilots ponder, “Say, what’s a mountain goat doing way up here in a cloud bank?” Similarly, there’s a pilot joke about cumulo granite, i.e. rock clouds.

I’ve had one brush with CFIT myself. In 2002, I was at my first airline job flying British Aerospace Jetstream 4100 turboprops for Atlantic Coast Airlines, which operated as United Express. I was a brand new First Officer when we departed State College, Pennsylvania for our base at Dulles, Virginia.

We took off and leveled at our initial altitude in the clouds. We were talking to air traffic control, but the controller was also talking to several other airplanes. In most cases, ATC clears you to climb to a higher altitude relatively quickly, but that day we stayed level at low altitude for a lot longer than normal… in the clouds where we couldn’t see anything.

Suddenly, the airplane screamed at us, “TERRAIN TERRAIN CLIMB CLIMB!”

So I did. Quickly.

Normally, leaving your altitude without an ATC clearance is a big no-no, but there are two exceptions to this rule. One is when you get a terrain warning from your TAWS (terrain awareness and warning system). The second is if you get a traffic alert with a resolution advisory, an instruction to climb or descend, from your TCAS (traffic collision avoidance system). In these situations, pilots are trained to react first and inform ATC later. Every second counts when you’re hurtling towards a mountain at hundreds of miles per hour.

I clicked off the autopilot, advanced the throttles, and pointed the nose up. At the same time, the captain told the controller that we were climbing due to a terrain warning. The controller acknowledged and cleared us to a high altitude. No harm, no foul. I never found out what happened but I suspect that the controller forgot about us for a few minutes while dealing with the other aircraft. We must have flown into an area with a higher minimum vectoring altitude that put us uncomfortably close to the ground.

I don’t remember what altitude we were at, but the charts for State College show the airport elevation as 1,231 feet MSL. There are low mountains southeast of the airport in the direction we would have flown to go to Dulles. At least a couple of these peaks are above 2,300 feet, about a thousand feet above the lower terrain. Very similar to Pine Mountain. I don’t know if we would have hit anything if we hadn’t got the warning, but I do know that we didn’t hit anything after we climbed.

TAWS has probably saved many lives since it was introduced. In 2002, the GPS and other sensors in the flight management system triggered a voice warning that we were in danger, but the jet I fly today seems like something out of Star Wars in comparison.

We have large moving map displays that vividly show terrain that is near or above our altitude in yellow or red. The display can also show the position of individual obstacles such as towers. If a pilot manages to avoid all that, the airplane can still scream at you to climb, a maneuver that we practice regularly in the simulator.

I’ll take all the help I can get from new technology. I have no desire for hikers in the distant future to see my name on a plaque and wonder why I flew my perfectly good airplane into a mountain.

Photo credits:

Plane Crash Rock: David Thornton

BAe Jetstream: Konstantin von Wedelstaedt/Wikimedia Commons