Out of control on short final – a freight dog learns a lesson

The life of an on-demand cargo pilot could be described in differing ways, except in sacred locales, depending on your penchant for poverty – or a hand-to-mouth existence. Most sensible men of stature in the community, possessed of cunning business sense, would scoff at the very idea of spending their lives collecting nothing but additional hours of experience to docket in a logbook. The pay is dismally low (when it eventually comes), the hours on duty are ridiculously long and fatiguing, and the aircraft, more times than not, are beset with proclivities toward self-mutilation. They can be as Machiavellian as ex-wives.

Beech 18 Volpar
The Beech 18 with a Volpar conversion is not your average twin.

One late spring night I was returning to my home airport in South Carolina in the company’s Beechcraft Model 18 Volpar convert. The venerable twin-Beech had more than proved its worth through the years. Born in 1937, the Model 18 had originally been designed as an adversary to Boeing’s Model 247 in the burgeoning but pyrrhonistic U.S. airline industry.

Air travel was viewed by the common man in the middle 1930s as a perilous fad soon to vanish from the scene – as did the Conestoga wagon decades earlier. However, newer aircraft being produced by Douglas and Boeing, among others, were much safer than those designed and built shortly after WWI. And Mr. Beech’s Model 18 proved to be a dependable, twin-engine workhorse.

The variant I was flying was a standard Model 18E that had been modified by the Volpar Company. Rather than sporting a tail wheel of the original design, this lengthened craft incorporated a nose wheel. So she sat with her twin tail off the ground like a strutting peahen. It was longer than the original Model 18 by nine feet. Most importantly, it displayed two 750-shaft horsepower turbine engines produced by the Garrett-Air-Research Company – which replaced the older, round-motor piston engines. It was marketed as the Beech Volpar Turboliner, and it served in many distinguishable roles through the years – such as Commuter Airliner and Executive Transport. Its saddle charge this night had a more dubious distinction: Chicken Hauler.

Returning home from El Paso, Texas after delivering hundreds of baby chicks to an egg producer near that desert city, “Bev” (as I named her) performed flawlessly. She was light, and she responded deftly to every delicate input on her controls. As we flew onward into the night we sailed swiftly past sleepy towns and villages across the Southland leaving behind, I imagined, a wistful cadence, beckoning young impressionable children to dream of faraway Castalian adventures. We were in harmony, Bev and I. She was purring, and I was singing. There was no better place in the world to be. Little did I expect that in just a short time Bev would turn on me like an insufferable soubrette.

Beware the beta

Throttle quadrant
That “Reverse” range is a really bad idea in flight.

On March 4, 1987, at 2:34 p.m., a Spanish built CASA 212-CC commuter aircraft with twenty-two persons aboard was on its final approach to the Detroit Metropolitan Wayne County Airport’s runway 21R. As the airplane descended through approximately two-hundred feet above the ground it banked to the right, causing its right wing to plunge into the ground several hundred feet to the left of the runway centerline. The machine skidded almost four-hundred feet into a grouping of parked airport vehicles where it came to rest beneath gate F10 of the terminal building. Fire erupted immediately. Of the passengers and crew on board, nine lost their lives that day.

The weather at the airport when the crash occurred was sublime: light winds out of the south, cool temperatures averaging thirty-eight degrees around the field, good visibility. What could have gone wrong?

Among the surviving passengers were two deadheading pilots. Each was commuting to Detroit from Cleveland, Ohio, to begin their respective flight duties. When questioned about the accident, they both recalled hearing the left engine making an inappropriate but familiar sound just before control of the craft was lost. They effectively described the sound as an intermittent growl similar to a car racing its motor rhythmically. To each of them the specific noise was attributable to a propeller moving into and out of the ground-fine pitch, or “Beta Mode,” as it is commonly defined.

A beneficial aspect of turboprop airplanes, even small personal types, is their ability to reverse the thrust of their propellers, which is utilized after touchdown when landing. Operating in the ‘Beta’ mode, the pilot has direct mechanical control over the angle of the spinning propeller blades by, again, simply moving the power lever(s). To transition from the Alpha range (normal flight) to the Beta range (reverse), the pilot merely moves the power lever(s) reward past the flight idle gate.

The flight idle gate is nothing more than a mechanical stop (a piece of metal), located at the bottom range of travel of the power lever (throttle). Pulling the throttle up, over, and rearward past the flight idle gate – into the Beta range – causes many new and exciting things to happen, especially if the airplane is still up in the air.

Northwest turboprop
Twin engine airplanes revel in symmetry.

The official NTSB report of the accident, published many months after the investigation was completed, stated, in part, that the pilot-in-command at the time of the crash had developed a chronic tendency of utilizing the Beta range while still on his short final approach in order to slow his aircraft and shorten the total landing distance. This egregious practice, likened to walking a tightrope suspended above a den of starving lions, should be first on the list of pitfalls to avoid for every prospective turboprop pilot. The consequences are disastrous.

Twin-engine airplanes revel in symmetry. That is to say, the two engines must produce equal amounts of power, so as to unleash the stallion to gallop gracefully through the heavens like a true winged thoroughbred. If this operating condition is not met, then the craft flies with asymmetric or unequal thrust. With that, it grovels through the air sideways like a vertiginous, rabid boar.

Almost home

It had been a long and exhausting day for me. I had been awake for more hours than I cared to remember, and at three a.m. on this placid night I was more than ready to get Bev back on the ground and into the barn. As I neared the field from over the farms to the west I purposely did not call the radar approach controller on his frequency. During the previous few months he had cogently enticed me into executing what he referred to as the “Johns One Approach” whenever the weather was clear. That meant that anytime I was returning to land after one o’clock in the morning I was not to bother him because he would be asleep. I was to silently approach to within five miles of the field and then simply call the tower for landing clearance. He never did say, but I assumed his name, whether first or last, was Johns. Either way it served its purpose….

I called the tower for clearance, and I was indolently greeted with the same achromatic monotony normally received from mothers-in-law.

“Yeah, uh, cleared to land – any runway. Wind is calm. Altimeter 30.04. After landing, taxi to the ramp. G’night.”

Evidently, we were late to the party.

Freight dog
There’s a reason freight dogs look like this.

I flew over the airport and maneuvered Bev around to land to the south on runway 18. In so doing, we could roll free-and-easy to the end, and I’d have only a short distance to taxi before reaching my company’s ramp. With sleep heavy in my eyes, an alluring vision of the recently laundered sheets that I had put on my bed two days before appeared in my mind, and I was getting closer to them by the mile. Gear down, flaps down, slow to Vref speed, we were almost home. All I had to do now was to glide the last couple of thousand feet. At just under about thirty feet above the runway I reduced power to the flight idle gate.

Suddenly, I was jolted out of my delectable dreamland by a violent roll to the right. Instant paralyzing fear, equivalent to several thousand volts of crippling electrical current, seemed to anesthetize my entire body. There was no time for panic, but that’s all I could manage to do. We rolled about fifty or sixty degrees. Lights blurred; all sound was silenced. Whether correct or not, I instinctively hauled back on the yoke and attempted to counteract the roll by applying left aileron and left rudder. Conscious thought had already bailed out, and reactive action was all that remained. The roll stopped, but Bev wasn’t correcting herself.

Somewhere, sometime, many years before, a very wise instructor had drilled into me the redeeming practice of undoing what I had just done if the airplane reacted intolerably to it. I automatically slammed both throttles forward to their maximum power stops. The engines, being the geared type, erupted with power immediately. With corrective action control inputs already set, Bev reacted with eager alacrity.

We leveled out quickly just beyond the edge of the runway – aimed at the sentinel pine trees I knew were out there in the dark. Still shaking, I aligned her again with the runway centerline, reduced power to idle on the left engine, and almost to idle on the right. With that, we plopped down ignominiously – more like the ruffled scowl of a vexed hippopotamus. “Thump!” I was simply thankful to get the thing on the ground in any manner.

As I taxied in I asked the tower controller if he had seen the spectacle. There was no answer. Perhaps he was a student of “Johns School of Aloof Observation.” I don’t know.

I logged almost fourteen hours of flight time in those two days, and I also logged a very valuable lesson: never get “behind an airplane.” Think. Always be ready for the unexpected; it could happen at any moment.

10 Comments

  • This problem is still around, unfortunately. Four years ago a Dash 8 in Madang, Papua New Guinea did the same thing on approach to Madang (not short final) and control could not be regained.
    It crashed and tragically fatalities were many. Only four people survived the crash and posr crash fire.

    • Bruce;

      Yes, I suppose it still occurs. Funny though…. I don’t ever remember an instructor specifically warning me about the practice of using reverse in flight. I mean no one ever even mentioned the dangers of it. You’d think they would hammer the point home early on in a training course for turbine airplanes. I guess it’s supposed to be implied, understood without saying…?? There were warnings in the flight manuals though.

    • Every US DHC-8 has a beta lockout feature. If there’s no weight on wheels, it will push the props back into alpha if the pilot pulls the triggers up to go into ground beta and ignores the loud beta warning horn. Papua New Guinea didn’t require that feature, so naturally it wasn’t installed.

      I don’t know why you’d ever want to go into ground beta in a Dash anyway. I call the combination of flight idle and props full forward in it “Elevator Mode”, because your angle of descent in one is about the same as an elevator going to the lobby in that configuration.

  • Same thing happened on a WINAIR flight into St Barths several years ago. As a small airport I have flown in and out of a lot (twice this year) was was surprised to read the report. The pilot put the one engine into “Beta” and crashed quickly. Sad to hear about.

  • Many years ago, I had some time on the Twin Otters DHC-300. In Nepal, while over the mountains towards very short airstrips, we sometimes had to fly over high mountain passes that were at fifteen to sixteen thousand feet. This was to avoid cloud build-up low over the passes and was for short durations only. But this procedure put us very high and nearer to the airport. To put the aircraft to correct descent profile configurations for the approach, many pilots would bring both power levers slightly to ‘BETA’ mode. This action gave a very hight rate of descent and help to make the approach. But many never realised the dangers lurking behind the use of ‘BETA’ in flight. Your speed during descent is high when props are coming to BETA. This more stress on the propellers. Besides, if one of the engines props do not come out of BETA during descent, it will have an unhappy ending. P&W and de-Havilland prohibit pilots to use BETA mode in flight for descent. But there are pilots who by-pass the advisory messages.
    Happy Landings.

    • After reading your comment I was thinking of a steep descent I just did in the C208 today- I would be too scared to even try and exceed that limitation (beta range in flight) to aid descent. I also find putting the throttle to idle in the caravan is plenty steep enough for a descent as it just falls like a rock at idle

      • On the Twin Otter, I tried tried using beta to increase descent rate. I was scared. I flew and trained many pilots on the Cessna Caravan. Beautiful airplane but again, I never tried using beta. Never had to. Setting the condition (props) lever to 100% was a perfect method.

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