Ask the Expert; “War Stories” – Part 2

Ask the Expert; “War Stories” – Part 2



Based on feedback from last month’s article in which I related some interesting personal experiences – “War Stories” – I am continuing with additional tales this month. I hope you find them enlightening and enjoyable.

Split Flaps in an A90

In the early 1980s my company, Flight Review, Inc., received a call from a fellow who had just bought a used 1967 A90 and wanted to schedule initial training for both his hired pilot and himself. At that time, I was living in Hayward, California, but spent hundreds of days a year traveling to conduct on-site training. This gentleman also lived in California and the airplane was going through a pre-buy inspection at the Beechcraft West facility in Hayward, so we arranged to complete the ground school in one of Beechcraft West’s conference rooms. Ah, I could sleep in my own bed for a change!

The five days of ground training went well and then the flight training phase began. The owner was the first to fly, while his pilot rode as an observer in the cabin. I decided to head northeast out of the San Francisco Bay Area to utilize the not-too-busy airspace and airport in Marysville, about 90 miles away. This was the owner’s very first time flying a King Air. We began with a thorough preflight inspection, both interior and exterior, started the engines, taxied to the run-up area and ran through all the system checks. We took off in lovely VFR conditions, avoided the SFO Class B airspace, and climbed up to 15,500 feet. We discussed and demonstrated setting up cruise conditions, talked about descent planning, used the autopilot a bit (the old H-14 unit didn’t have lots of modes to demonstrate!) and came down to 8,500 feet to do some air work – steep turns, slow flight and stalls. We never got past the slow flight.

I assigned a heading and altitude and asked the owner to slow to 90 KIAS, clean. Next, approach flaps and 80 knots. All was going well, and the owner was doing a good job. “Landing gear down, full flaps, slow to 70,” were the next instructions I gave. As is my habit, I had my eyes on the flap position indicator as it started to move from Approach to Down.

Oops; that ain’t right! The needle went to about 60 percent then became a blur as it danced rapidly and when it stabilized, it was in the Up position. The owner said, “This doesn’t feel right!” as he was holding a lot of right aileron and right rudder to maintain the heading. From the cabin, the pilot yelled, “The flaps just broke!” Somewhere in that confusion I heard a snap. The flap motor circuit breaker on the aft end of the pedestal had just popped. I directed the owner to start a gradual descent. He was having no problem controlling the plane. We examined the flaps visually and confirmed that the two left segments were fully down as was the right outboard segment. But the right inboard was fully up. I knew this would be the case since the right inboard is the “master” flap because it contains both the position indicator’s transmitter and the limit switches. Since it was now Up, the Down limit switch was never activated. Hence the motor kept running, overloaded the circuit and tripped the circuit breaker (CB).

The three of us discussed the situation and it was suggested that we put the flap handle in the Up position and reset the CB. I agreed to try this good plan but also stated that it likely would not work. Why? Because the “Up” limit switch, activated by the broken segment that was now up and “telling” the motor not to run in the Up direction since it believed the flaps were already there. Handle Up, CB in – it stayed in fine – but no response.

We were now right over the airport at 5,000 feet. We were holding about 120 KIAS in our descent. We set up for a left downwind to Runway 32. There was no one else in the pattern. The owner had trimmed out the roll forces easily and was doing fine so I suggested he make the landing. He declined because he had never landed a King Air previously and asked me to take over. I did so and was pleasantly surprised that the airplane flew perfectly in this “three-down, one-up” situation. No more than half-travel of the aileron trim wheel was necessary to fly the airplane hands off. Unlike the 200- and 300-series with their longer wings, the 90- and 100-series have no split flap protection system since the planes were flight tested to demonstrate that any one flap section stuck up or down could easily be handled. My personal experience can now confirm this.

I carried an extra 10-15 knots into the flare since we had over 6,000 feet of runway. The landing was a nonevent and we taxied to the ramp and shut down. I asked the pilot to see if he could find any tools from anyone – it was a Saturday, so I was not very optimistic – and he left the plane to start his search.

The owner and I rolled back the aisle carpet in the cabin to start the process of gaining access to the flap gearbox, or transmission, mounted on the forward side of the rear spar beneath the floorboards. If we could disconnect the drive cables from the gearbox, we could then manually turn them to retract the other three segments and fly back to Beechcraft West for repairs, making a no-flap landing there. It had not yet dawned on me that what we had experienced was not what I was thinking. The most common reason for split flaps is that the jackscrew actuator is not operating, probably because the drive cable came loose at one of its ends. If this happens, the flap is locked in its last position.

“Hey, come look at this,” the pilot yelled to us through the open cabin door. We exited to see what he was talking about. A fellow had been watching airplanes operate at Marysville that day – must have been bored with so little traffic – and observed this King Air land and taxi in with its weird flap condition. He strolled over to ask the pilot what had happened. As they talked, the fellow walked up to the retracted right inboard flap, took the trailing edge in his hands, and freely moved it down and up on its tracks!

Whoa! When I saw that the flap could be easily moved I realized that this was not a case of a jackscrew not being driven by its cable. Instead, it must have broken entirely and we were probably wasting time trying to access the gearbox. With the bad flap segment down, the Up limit switch would no longer be contacted so the motor might now operate … except without knowing when to stop. So here was the plan: I’d go to the cockpit, pull the CB, turn on the battery and make sure the flap handle was Up. Then I would carefully push the CB in just enough to make contact and see if the motor operated. If it did, then I would “bump” the CB in and out, in and out, until those outside yelled to tell me that the other three flap segments looked to be fully up.

All of this happened as I described. I now left the CB pulled. We rustled up some duct tape and taped the right inboard segment’s trailing edge to the fuselage to keep it from dropping down until we had enough airspeed to blow it up. We did an uneventful flaps-up flight back to Hayward – with the owner again flying – and told our tale of woe to the shop foreman who had overseen the work that was just completed during the pre-buy.

Do you think the fact that the flap system had been overhauled that week played any role in this event? Nah, me neither!

BB-11’s Strange Rudder Boost

It was a true blessing in my life to be assigned as the first Beech factory ground and flight instructor on the 200-series of King Airs. What a learning experience! What a thrill!

BB-1 and BB-2 were the factory’s test machines. BB-1 has a very interesting story that I may relate in a future article and BB-2 eventually became a testbed aircraft for Pratt and Whitney of Canada – makers of the PT6. BB-3, 4 and 5 were U.S. Army airplanes with some secret “stuff” that prevented our Beechcraft Training Center people from having anything to do with them. BB-6 was Mrs. Beech’s airplane and a factory demonstrator. BB-7 and BB-8 had a large camera window installed in the belly and they went to the government of British Columbia, Canada, to be used for ground mapping as well as executive transportation. BB-9 was the first one sold to an actual civilian customer – Tom Watson, the Chairman of the Board of IBM at that time. I was not involved with BB-10 and am not sure of its early history. But then came BB-11. Rod Rodriquez, a wonderful gentleman, excellent pilot and an exceptional Beechcraft salesman in the Beechcraft West office in Van Nuys, California, sold this airplane to the government of Bolivia, to be added to that country’s “Air Force One” fleet.

Two Bolivian Air Force pilots, a Major and a Lieutenant Colonel, showed up at the Training Center as BB-11 was nearing its delivery date. They completed our five-day ground school before starting their flight training in the actual airplane, and I was the instructor assigned. The plane would be based in the executive capital city, La Paz, at an elevation of 13,300 feet! (The Major had grown up there and hence was very accustomed to thin air. He told me that when he did his first altitude chamber ride at Randolph Air Force Base while training with the U.S. Air Force, it was decided to agree that he was experiencing no symptoms of hypoxia after two hours in the chamber at 25,000 feet!)

As we performed the run-up before our first flight in the airplane, I found that the Rudder Boost was installed backward! When we added enough power on the left engine to trigger the system’s differential pressure switch, the right rudder jumped forward, not the correct, left one. (Good foot; good engine. Remember? How did that discrepancy get through Production Flight Test?!)

We taxied back to the Delivery Center and told to get a cup of coffee while the crew there corrected the error. In less than an hour, they asked us to try again. This time all was well and the training proceeded to completion with no further glitches.

For some reason – I am not sure, but I think the Van Nuys sales office had made an agreement to use BB-11 as a demonstrator for some period of time before it departed for South America – I was assigned to do another pilot checkout in this same 200 about six months later, out of KVNY. I airlined out there and met the student with whom I would be working. As we do our initial run-up, guess what? The Rudder Boost is backward again! Back we go to the shop for another discussion.

Here’s what we discovered. The original design of the 200’s rudder boost system called for plastic tubes being used to connect the regulated bleed air source to the appropriate left or right solenoid valve and then to the actual pneumatic rudder boost servo. It was found that the plastic tubes had enough length and flexibility that the left and right ones could be reversed. Not a good thing. Why? Because during single-engine operation the pilot would not get any help on the correct rudder pedal but instead the system would be applying force to the opposite pedal! So, Beech changed the design and now it called for metal lines that could only fit one way: left to left and right to right. There were so few King Air 200s at this time that I believe no AD or Service Bulletin was ever issued. Instead, the factory simply sent personnel out to the few airplanes in existence to make the switch from plastic to metal lines.

When BB-11 had its initial problem that I discovered in Wichita, it was because the plastic lines had been reversed. However, the fix that had been made then was to reverse the contacts on the Differential Pressure switch. In effect, two mistakes that now existed were canceled out and all was well. What’s the old saying? “Two wrongs make a right?” That was certainly true in this case.

So, when the Beech team came to BB-11 at Van Nuys and installed the correct metal lines, we went back to reversed rudder boost. Damn! Are mechanics and pilots so clueless that they don’t verify the system works properly after a modification like this? In some cases – like this one – I guess not!

The $10,000 N Number

In my Flight Review, Inc. days, I went to Portland, Oregon, to conduct recurrent training for the owner-pilot of a nearly new B200. This lawyer’s first and last names began with the initials T and W and his nearly new B200 was N1TW. Cool!

When he was ordering his new B200 he wanted N1TW to be the registration number in the worst way. Yet that number was already assigned. Not to be deterred, my client found who owned that airplane through the FAA registry and contacted him. It turned out that the fellow with whom he spoke operated an air freight business using Piper Navajos and this was one of those airplanes. Why the N number? Because the previous owner of this Navajo was Tammy Wynette, the country-western singing star.

Ten thousand dollars later, our lawyer had his number!

BB-1’s Drag Chute

Before the BE200 made its appearance, about the only T-tailed airplanes were the Boeing 727 and the Learjet, both of which, in their original states, had horrid stall characteristics. Understandably, Beech was worried about how the T-tail would affect the King Air. Even though wind-tunnel tests appeared to indicate that the T-tail would not be a problem on this turboprop, straight-wing airplane, nevertheless flight testing proceeded with a prudent level of caution. Before stall testing began, the prototype airplane, BB-1, was fitted with a parachute system installed in a canister that replaced the normal tail cone beneath the rudder. This drag chute was designed to be deployed in the event that a deep-stall or spin condition developed, and its drag would lift the tail, point the nose down, reduce the wing’s angle-of-attack and correct the out-of-control condition. Then, explosive bolts would be activated to release the chute and let the airplane return to Beech Field safely.

Before the actual stall tests began, Beech wanted to ensure that the chute could both be deployed and then jettisoned properly. On the first test flight, the deployment went as planned. But the jettison? No luck! For some reason, the chute stayed attached to the fuselage. Using nearly full engine power and with careful altitude management, Bud Francis managed to land BB-1 back at Beech Field safely, although it came uncomfortably close to the telephone lines at the end of the runway!

By the way, the chute was never needed during the stall testing phase. The 200 exhibited no stall condition in which forward elevator travel would not lower the nose, reduce the angle of attack and allow normal recovery.

Garrett’s Own B100 … and its Weird Engine

As you probably know, the King Air B100 is the only model powered by the Garrett TPE331 powerplant instead of a version of the PT6. This came about following a prolonged workers’ strike at Pratt and Whitney that caused the flow of PT6s to nearly cease at the Beech factory back in the mid-1970s.

Around 1982, while performing King Air training on my own through my company, Flight Review, Inc., I received a call from the chief pilot of Garrett’s Los Angeles operation. They were operating the second B100, BE-2, primarily as a shuttle airplane transporting employees between their Phoenix and Los Angeles locations, usually making two round trips a day between KLAX and KPHX.

The department had a co-pilot they were wishing to upgrade to a captain position and wanted me both to flight train and evaluate this fellow to gauge his suitability for the change.

I showed up at their Los Angeles International office – then at the FBO owned and run by Garrett – and had a meeting with the chief pilot, the upgrade candidate, and also with one of their B100 captains who would be riding along as an observer. (Probably to make sure I didn’t do anything stupid!)

We began the flight training by heading away from the Los Angeles basin to proceed to a less-crowded area … over the desert between Thermal and Blythe. All was going well and we made a lunch stop at Bermuda Dunes (KUDD) near Palm Springs. After the break, we were ready to do some one-engine-inoperative practice.

We climbed to 9,500 feet on our way east toward Blythe. We shut down the left engine per the TPE331 procedure and looked at single-engine “Magic Numbers” as we did a simulated approach and go-around. Now came time for the airstart. All went well but the engine did not start. Hmmm … did we miss a step on the checklist? We redid the procedure but with the same results. Namely, as the unfeather pump put oil into the propeller dome and the propeller blades came out of feather, relative wind provided rotation and at 10 percent engine speed, fuel and ignition were automatically activated. We could verify this by observing the ignition annunciator illuminating and the fuel flow gauge showing flow. But no light-off. About the only logical guess was that the ignitors were both bad or the ignition exciter unit had failed. As we feathered the prop again and scratched our heads some more, the captain who had been assigned as my observer woke up from his after-lunch nap and came up to the cockpit. “Golly, Tom. I’m sorry. I should have told you that we’ve never been able to airstart this engine. Just land and it’ll start fine on the ground.”

“What?! Now you tell me?!” I said in disbelief. “Heck, you guys make these engines! But you can’t do an airstart?!” “Nope. Never have been able to on this left engine.”

So now a simulated emergency has turned into a real emergency and we are faced with a single-engine landing at Blythe. No big deal at all, but so damn unnecessary had I been properly briefed. The student flies an excellent visual pattern and we touch down at KBLH with no problem, even making our way to the ramp on one engine. We take a quick bio-break and return for the ground start attempt. As you may or may not know, the fixed-shaft TPE331 design requires that the propeller be out of feather, on the low pitch “Start Locks” before doing a ground start. No problem, we merely use the unfeather pump to drive the oil into the dome so as to flatten the blades. It doesn’t work. No blade movement takes place.

Then it dawns on me why. Those fruitless attempts in the air had pumped all of our oil out of the reservoir and into the engine via the prop, but since the engine did not continue to run the oil scavenge pumps did not have time to return that oil to the reservoir. The unfeather pump was seeking oil from an empty tank. Ah, but there is an easy fix.

We exited the cockpit, went to the feathered left prop, and started turning it by hand in the normal direction. The engine rotation caused the scavenge pumps to slowly but surely return the oil into the tank. Maybe 100 or more propeller revolutions were required before the tank finally showed a normal oil level reading. Then back to the cockpit we went to find that the unfeather pump could now do its job successfully and the ground start proceeded without further problems.

Back at KLAX, I let the chief pilot know in no uncertain terms that I was less than impressed with their weird engine and with their lack of proper briefing to me!

An interesting follow-up: A few months later I received a call from the chief pilot. “Hey, Tom, just wanted to let you know. We don’t have to worry abut the engine anymore. It blew up yesterday, destroying itself, on takeoff for the flight back to Phoenix. The co-pilot you trained was in the left seat and he handled it perfectly. Thanks for your training.”

Golly! When the engine manufacturer itself cannot find and fix a problem on their own engine, who can? Don’t get me wrong; I have come to like the TPE331 as an excellent alternative to the PT6, but what a strange event this was!

Stay tuned for more War Stories from ol’ Tom.

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