Mind Your Fuel Status, Part 2

Princess Juliana Airport
Princess Juliana Airport
Credit: Westend61 GmbH / Alamy Stock Photo

In Part 1, we discussed how fuel planning affected flights a few decades ago.

The DC-9 arrived at Princess Juliana Airport and shot an NDB (yes, those were still being done in jets in the 1970s). Reaching minimums, the captain saw the runway but was too far off heading to complete the approach. He missed and started a VFR approach at low altitude and dirty. The second approach resulted in a miss due to poor visibility from a rain shower on the base leg, again making it impossible to properly align with the runway in time.

The captain, feeling an even slower speed would facilitate the contact with the runway through the rain, lowered full flaps and started, for the third time, at 130 kt. On the third attempt, they were properly lined up when they sighted the runway, but they were too high to make the approach. You can almost feel the adrenalin as the story continues from this point.

They cleaned up the aircraft and headed for the filed alternate. ATC, not knowing their fuel state, held them low for an extended time due to a traffic conflict.

Then, the fuel low-level lights came on.

I’m sure the crew was hyper-aware that things might not be going “according to plan.” They could not believe the fuel lights illuminated. In their minds, they had done almost exactly what they had planned, gone to St. Maarten, shot the approach and diverted to St. Thomas. The lights had to be wrong.

They changed the destination to St. Croix as it was closer.

Finally cleared to 12,000 ft., the captain began a climb, slower and at a lower power setting than normal, thinking that would conserve fuel.

Then, as the truth of the fuel lights sank into his awareness, the captain felt certain they would have to ditch. He requested to descend again as they were at about 7,000 ft. They came down to 5,000 ft. initially and later descended farther to get the ocean in site. Cabin warnings were issued that the flight might have to ditch, but they were not taken seriously by some of the passengers. Even though the flight attendants were breaking out the life rafts and some passengers had assumed a crash position with pillows folded in their arms, it didn’t sink into all of the passengers’ consciousness. As the flight was down to 100 ft., some felt that the closeness of the water was due to the fact they were about to land at St. Croix. Some of the passengers were standing when the airplane jolted into the water. A flight attendant who was warning people to sit was killed because she was not secure.

Twenty-two passengers were lost in the ditching.

That’s a reach back, I’ll admit, but that’s the way fuel planning was often accomplished 50 years ago. If anything different than the plan happened, you ventured deeper and deeper into unknown territory with each missed change of plan or missed approach.

Fast forward almost a half century to a modern saga. I searched and searched the internet but could not find an official government report on this next one, so I will be intentionally vague. Besides, the objective here is not to find fault, but to generate thought and discussion.

A modern jetliner with 153 passengers on board took off for a 2-hr. domestic flight.

En route to the destination, the flight proceeded normally enough for the first 45 min. Cabin service was accomplished, and the general mood was relaxed. About halfway to the destination, for a period estimated to be 15-20 min., they encountered so much turbulence that some of the passengers were visibly praying and some crying. It was terrifying. Anyone who’s flown into something like that knows it can also be nerve-wracking, to say the least, for the folks in the front chairs.

On schedule, the flight made its approach to destination. Some unofficial accounts have passengers saying that on final approach, they could look down and see the ground. About the time they were starting to relax, the power came up and the crew elected to head for the alternate.

Panic began to set in with the passengers, most fearing, with the announcement they were heading for an alternate, that they’d have to go through the “dark clouds” and turbulence again.

Now, the difference between this flight and the ONA flight was that there was equipment on board to tell this pilot not only how much fuel he had, but how much he would have when he landed at his alternate. You might say, he was able to start worrying earlier. Then the alternate arrival fuel began to go “below plan.”

On the way to the alternate, the pilot informed the passengers that the flight was getting low on fuel. Already unnerved, this did absolutely nothing to calm the tension in the cabin. After descent to the alternate, the crew again discontinued the approach as the weather there had gone below minimums. The trip headed for a second alternate. Passengerswere distraught.

En route to the second alternate, weather broke at the first alternate just behind the flight. They turned back. When they finally landed, passengers thought, initially, they were at the second alternate. The pilots were so busy trying to come up with a plan, and then execute that plan, that they didn’t take the time to inform the passengers where they were going. It’s estimated they landed with less than 10 min. of fuel.

Two situations, 50 years apart: one where the low fuel-light illumination caught the pilots off guard, the second where the pilots knew at each second what fuel they would have when they changed destinations.

As I read these stories, I’m not going to sit here and say, “If only they’d stuck with the original diversion or shot a coupled approach, or circled the destination, they’d have probably got the airplane on the ground safely in one case or with a lot less consternation in the second.

In both cases, I’m glad I wasn’t in the situation. If the first flight had landed in San Juan, what would have been the reaction when the airplane in front of them and the airplane in back of them had landed at Princess Juliana Airport? In the second case, was the crew second-guessing why they didn’t couple an approach and just ride it until they saw the lights at the lower approach minimums that would have authorized them to use it? Was such an approach even available?

There has always been a “cooperative tension” between those who design airplanes and those who are operating them. I once had a friend who had a T-shirt that read “Aero Engineers, Annoying Fighter Pilots for 100 Years.” The simple truth is those engineers and designers have made airplanes unbelievably more reliable, safe, comfortable and durable over the years. We could not progress without those changes.

But no matter how sophisticated the system, in this case the fuel planning part of that system, there comes a time when the person in the front has to just grab the airplane, make a decision, and carry through with that decision. They may do it by grabbing the yoke/sidestick and throttles or they may do it by simply pushing buttons on a fully functioning autopilot. But if that moment comes, it will come after all the planning has been done and when circumstances have rendered that planning moot.

Pilots take that responsibility on their shoulders when they push back and that is a fact that no amount of automation and progress can change.

Ross Detwiler

Ross Detwiler was a U.S. Air Force fighter pilot and corporate chief pilot—flying a Dassault Falcon 7X before retiring. He also was as member of the…