Saturday, February 16, 2019

It Shouldn't Have Flown






By Steven W. Freimuth, former Captain, USAF

PROLOGUE


The following is my recollection of the events that occurred during a takeoff and flight on a September day in 1973 while flying out of U-Tapao Royal Thai Navy Airfield (UT) in Thailand.  This was after the war was over.  But we were still flying missions to maintain the peace.  While these events happened over forty-five years ago, most of them were so etched in my mind, that I can still recall them as if it were yesterday.

I am finally following up on my years of “intentions” and reducing this to paper as a result attending two Arc Light / Young Tiger reunions. It was there I met Tommy Towery and acquired the many “We Were Crew Dogs” books which he edited.  He wondered why a KC-135 pilot would be interested in reading these short stories mostly about B-52 crew experiences.  Well, I learned a lot more of the bigger picture in SEA (Southeast Asia) and stateside.  Often we were so busy  in our own activities, and in accordance with SAC’s (Strategic Air Command) “need to know” policies, that we (I) didn’t know much about the details of the roles of my fellow airmen.  And our shared suffering.  But more of that in another article.

I have chosen to use “full width” paragraphs to write the sequence of events as they occurred and what my thoughts were at that moment.  I have included “indented sections” to further explain various aircraft and performance details.  This is to assist the reader who isn’t as familiar with them to gain a better understanding of both what was going through my mind and happening to the aircraft.  Thus, read just the expanded text to get a blow by blow description.


The Aircraft:  I was going to write about the KC-135A aircraft so the reader would have a better understanding of some of its quirks and limitations.  However, I came across the following written by Robert Graves who flew them in the 1980’s.  His description included everything I wanted to say and written better.  He wrote:

The First All Jet Tanker

The KC-135 Stratotanker, produced between the years of 1956 and 1965, was a derivative of Boeing's test bed aircraft, the 367-80. From this early test aircraft, both the KC-135 and 707 were derived which is why the KC-135 has a strong resemblance to the 707, though the tanker was smaller and lighter. Still, the tanker could carry 135,000 lbs of fuel and weighed in at just under 300,000 lbs fully loaded.

Part of the impetus for the Air Force to acquire this aircraft was the cold war. The nuclear arms race was in full swing in the late '50s and the Air Force wanted to have a tanker which could refuel its new intercontinental bomber, the B-52, to allow it to reach Russia. The old KC-97, a derivative of the WWII era B-29, just wasn't up to the task.

In fact, because the angst of quickly fielding a nuclear deterrent was so high during that time, several compromises and shortcuts were made in the design of the KC-135 to get it operational faster. These were compromises which I came to despise acutely nearly thirty years later.

The first compromise was the engines. Engine manufacturer Pratt and Whitney was working on a new engine design at the time known as the bypass fan engine. This new engine was to become the basis for all modern engines and was eventually used on the 707, but it just wasn't going to be ready in time for the tanker. So the KC-135 was outfitted with older engines which incorporated a technology known as water injection to produce enough thrust. Yes, you heard that right...they pumped water into the engine.

Without getting too detailed, high pressure pumps injected water into the engines during takeoff which increased thrust by means of an increased mass flow rate. Still, the airplane was grossly underpowered. While the airplane did usually get airborne, it would take most of the runway to do so when heavy. I have seen the departure end of the runway coming under the nose during rotation more times than I care to remember.
To give you an idea of how puny the engines were, the CFM-56 engines fitted on a 737 today produce about 34,000 lbs of thrust while the tanker's original P&W J-57s produced a mere 12,000 lbs. Due to its underpowered nature, the aircraft gathered unflattering monikers such as "The Silver Sow" or "The Steam Jet". My personal favorite was "Strato-Bladder" for the bladder type fuel cells in the body tanks. 

The KC-135A was eventually re-engined in the 1980s with those same CFM engines and was redesignated the KC-135R. The new "R" models are quite sporty now and even hold some time to climb records for transport category aircraft.

This first compromise of using water injected engines led to the compromise which I came to hate the most. To feed the water injection system, a water tank was needed. Since most of the body of the aircraft where cargo bins are on a normal plane were taken up with fuel tanks, a decision was made to remove one of the two air conditioning units, or packs. This meant that the airplane was hot, and I don't mean hot as in cool, but rather hot as in fetid.

I was stationed in Okinawa, remember, which is in a subtropical climate zone. This means warm and damp winters followed by hot and damp summers. The lack of A/C on the aircraft was most pronounced when flying hour after hour of "transition" training, or touch and go practice. It wasn't uncommon to get off the airplane soaking wet. Boeing didn't even have the courtesy to install an air vent to blow on the pilots' faces. The air outlets were under the seat where what little cool air that did emanate did no one any good at all.

Old Technology

As I flew the airplane in the early 80s, it had undergone a number of technology updates to its original systems but many vestiges of older technology were still on board. We still had a navigator assigned to the crew, but he had at his disposal an inertial navigation system, or INS which made his job more or less obsolete. Airliners were crossing oceans then with similar systems which had their accuracy measured in yards while GPS was still on the design table.

The aircraft also had, however, a sextant and an overhead port with which to view the stars. Celestial navigation dates back to the time of Magellan and was the reason the navigators were still on board. Remember, this aircraft was designed to fight a nuclear war and at the time it was thought that a nuclear detonation might render all electronics useless. Therefore, the navigator was trained to use the ancient technology of celestial navigation with a sextant to determine our course while flying to nuclear armageddon. My one regret is never having had our nav teach me how to shoot the stars with the sextant.

Over-water communications were also rather dated. While we had a high frequency or HF radio which could bounce signals long distances, ours was an old tube-type radio requiring a warmup and without a squelch control. This meant maintaining a "listening watch" on air traffic control frequencies which were always full of static, whistles and pops. Of course this was a copilot duty. When the air traffic frequencies became too unusable, I might have inadvertently tuned the radio to an awesome rock station beamed out of Saipan.

The standard for overseas communications is through the use of satellites today.

Flying the Beast

As I mentioned above, the airplane was underpowered. This meant that it had to be flown very smoothly and deliberately when it was heavy, which was most of the time. There were restrictions on the angle of bank that one could use after takeoff for instance, and multiple warnings concerning what to do or not do should an engine fail on takeoff.
There were so many red warnings on the engine failure pages that I think most of us flying the beast were convinced that an engine failure was pretty much game over. Thankfully I never got the opportunity to test out that proposition. …”

 Another former crew member has described the takeoff in the following manner: “I realize that this was a long time ago but when I was stationed at Robins AFB back in the mid-1960s our KC-135A s would use between 11000 and 12000 on T/O.  It was closer to the latter on hot days.  Sometimes they would return after their missions and still have some pine needles in the intakes from the tops of trees at the end of the runway. Of course these were fully loaded airplanes.  If anyone here ever witnessed a fully loaded “water wagon” they were truly something to behold.”

 And, as an additional piece of information for the B-52 crew members reading this, I have gleaned, your maximum takeoff weight was about 488,000 lbs.  From what I have read in “We Were Crew Dogs” the maximum weight at UT was about 454,000 lbs. (with twice the engines and water).  Half of that weight would be 227,000 lbs.  My takeoff weight in the follow story was about 262,000 lbs. The base weight of a 135 was between 105,000 and 107,000.

 As a final comment before I start my tale, there was a saying in SAC: “If someone could construct a runway that would actually encircle the entire earth, SAC would could come up with a mission plan that would use every inch of it”.

AND MY STORY BEGINS


This was to be our second flight of the day.  We were assigned to fly a KC-135A, tail number 59-1475, using a water takeoff with a max fuel load of 156,000 pounds on runway 18.

THE RUNWAY:  Runway 18 is a 11,500-foot runway that ends with the overrun (or approach portion (when landing to the north on 36) followed by a sandy beach and the Gulf of Thailand.  Normal departure after takeoff is to the north.

WATER TAKEOFF AND JET ENGINES:  The KC-135A aircraft had four J-57 jet engines.  These engines were not turbofan jets In order to provide more thrust for takeoff, a 670 gallon tank of water was installed in the belly of the plane.  Electrically driven pumps furnished approximately 80 gallons per minute to each engine.  Accordingly, we normally had about two minutes of water before run out.  This increased the mass flow through the engines providing substantially more thrust.  Each engine (dry) should be able to provide a maximum of about 12,845 lbs. of thrust within a temperature range of -65 to 5 degrees.  The dry thrust would diminish substantially as the temperature rose above 5 degrees.  Water (wet takeoff) should be able to provide a maximum of about 12,925 lbs. within the 20 to 100 degree range.  

GENERATOR LOADS:  Three of the engines had generators to provide electricity while no. 4 had a cartridge start system in its place.  All the normal aircraft electrical loads could be met from the output of only one generator.  According to the charts, it would use about 94% of the rated capacity of a one generator during the highest usage period of a mission - except a wet takeoff.  The water injection pumps, that were needed for the critical two minute period, consumed about 100% of the capacity of a generator.  Thus, during a wet takeoff, about 175% of the available output of one generator was consumed with three available.  Safety and redundancy had been built in.

MAX FUEL LOAD:  According to the charts, the maximum fuel load (capacity) is 202,800 lbs. for aircraft with an upper deck aft fuel tank installed.  However, I recall that at UT, the max load was 156,000.  This lower load was the maximum that we could get airborne given the runway length and warm temperatures.

The Form 781 maintenance log indicated that this was the first flight for this aircraft after going through “corrosion control”.  I didn’t know what that was and believe the crew chief said something about “taking the aircraft apart, looking for corrosion, and then putting it back together”.  I thought about a FSAGA (first sortie after ground alert).

I also need to insert at some point that at a safety briefing, probably within the prior week or so, there was a 135 out of Grand Forks or Minot that kept popping circuit breakers during a flight.  The crew continued resetting them several times and they continued to trip.  The crew found an electrical fire.
The preflight proceeded normally until we got to the Control and Trim Check.  With the control wheel rotated to the left, Ground reported “Left ailerons up, tabs down, left spoilers 40 degrees, right spoilers down, right ailerons down, tabs up”.  (A correct call and indications.)  When I then rotated the yoke to the right I got something like “Left ailerons down, tabs up, left spoilers up, right spoilers 40 degrees, right ailerons up, tabs down”.  Something in the all so familiar call given in a standard cadence seemed wrong.  “Aah Ground, would you repeat that call.”  It was repeated the same and Ground, this time, seemed to realize that something was wrong.  After a short conversation, I believe Ground said something like “Sir, we must have a stuck actuator, let me get a ladder and a hammer to fix it.”

As we waited on maintenance, I believe at some point we may have decided to continue to complete a few of the items left in the Interior Inspection checklist that we could do without Ground i.e. altimeters check, etc.  And we waited on the ramp in the afternoon sun (usually between 84 and 88 degrees).  Think of sitting in an auto in this position with two windows open while wearing a Nomex (a non-breathing plastic bag that provided fire protection) flight suit.  Because of this, we delayed putting on the SAC required inflatable life jackets that were to be worn on all overwater takeoffs.

Maintenance must have had problems finding the appropriate SAC specified hammer as start engine time (30 minutes before scheduled takeoff time?) came and went.  I believe it was between ten and fifteen minutes before takeoff time that maintenance finished “fixing” the problem.
At this point I should point out to those unfamiliar with this fact that takeoff times are important in SAC, almost sacred.  My recollection is that the scheduled time plus up to five minutes was okay.   I never knew if it went all the way up to those under CINCSAC but at least I had been told that everyone at UT got a black mark after their name when there was a late takeoff.  And, as was the custom, one “awe sh*t” wipes out 10,000 at-a-boys.

As a SAC trained professional - and a person whose Mother taught him to “do the right thing”- my crew and I finished the Interior Inspection checklist, and began the Starting Engines and Before Taxiing checklist, and Before Takeoff checklist in record time.  While switches were being thrown and settings made, clearance was requested for taxiing.

I started to taxi as soon as clearance was given.  My co-pilot started the Before Takeoff checklist while we were taxiing.  We continued to run the checklists, throw switches, verify systems, and adjust settings.  Now there is a saying in SAC that there is only one thing worse than having a taxiing accident, that is living through it.  While well aware of that, I must admit that I made a “high speed” taxi.  In fact, a very high-speed taxi.  I think it was about four times faster than I had ever taxied before or since for scheduled flights.  Probably twice as fast as an alert taxi exercise.  I thought we might skid around the corners as we headed to the runway.  But I was going to make an on-time take off if at all possible.

As we approached the hammer head we called and received takeoff clearance.  No stopping before taking the active.  As we turned to the runway heading of 18, I brought the throttles back and my Co started the water injection.  I believe my Nav called that we crossed the threshold between four and five minutes after our scheduled takeoff time.  My crew had saved the day!

As I advance the throttles, water kicked in and we were off.  Air speed slowly increased as we rumbled down the runway.  S1 was called as our takeoff continued.

S1 is a calculated speed (V1 to the rest of the world) where if you encounter a major problem prior to reaching, you can abort and stop within the remaining runway length.

Then, just at the start of rotation, the aircraft became very quiet.  At least very quiet for a KC-135A making a water takeoff.

Water takeoff’s noise was about 126 decibels.  

“The KC-135R is a dramatically quiet aircraft in comparison to the KC-135A, which is one of the worst noise offenders in the USAF inventory. … The noise footprint has been reduced from the "A" model by 95%”

Within a fraction of second later, the boom was out of his seat and standing between the pilot’s and co-pilot’s seats with his hands on each of our head rests.  “Generators!”  I looked up and saw all three had tripped off line.  Later, I found the Nav had attempted to make a similar call but he had crushed his mic switch attached to his flight suit with an alligator clip.

It is a crew duty for the Nav and Boom to monitor the generators on takeoff as the panel is overhead between the pilots.

At this moment in my life, everything slowed and every sense was at its keenest.

My first thought was that there was no way this aircraft would fly.  I thought the loss of water was about the same as losing one and a half engines while making a heavy weight takeoff.  Next, did we have a fire on board that caused the loss of electrical?  At that moment, I caught a glimpse of my Mae West life jacket on the floor next to the center control column out of the corner of my eye.  In the rush to complete the checklists following the maintenance delay, I hadn’t put mine on for the very first time.  I will accept that glimpse as Divine intervention.  Here I was about to crash a 263,000 pound aircraft into the Gulf of Thailand and I didn’t have my life jacket on.  We’re going to fly!!
How to do that? Throttles, I reached over and firewalled them.

Normal takeoff procedures required the pilot to keep his left hand on the nose gear steering wheel (until about 90 KIAS), advance the throttles with his right hand to about takeoff EPR (engine pressure ratio) and then return his right hand to the yoke.  The co-pilot would follow the advance of the throttles with his left hand and fine tune them to about 2.85 EPR.  Takeoff thrust was determined by the EPR setting.  This was normally reached with a 94-98% RPM.  According to the Dash 1, the overspeed limit of 102% RPM should not be exceeded at any time.  If an engine overspeeds between 102-104% consideration should be given to operating on reduced power and shutting down the engine as soon as safety of crew and airplane permits.  If an overspeed exceeding 104% occurs, the danger of complete engine failure is more imminent.   The normal runway distance from the start of rotation to unstick is about 1,000 feet.

I then tapped my Co’s hand that was on the throttles. No electrical, no intercom!  He knew to check the RPM and pull them back if we were over 102%.  We were mushing through the air, over the overrun, sandy beach and then the water.  To this day, I believe it was the ground effect that kept us in the air.

Next, gear!  Normally the flying pilot calls over the intercom for the other pilot to raise the gear.  No intercom.  I immediately reached for the gear handle.  It wouldn’t come up!  We must have a hanging truck.  If I raise the gear using emergency override procedures, the gear will come up.  I will most likely lose all hydraulics as the gear will rip out all the hydraulic lines that are routed through the wheel wells for maintenance purposes.  The gear will be jammed in the wheel wells and may not come down. I can worry about landing later, I need to fly now.  I pulled the emergency override trigger.  The handle and the gear went up.  No loud crunching sounds.

The KC-135 has two main landing gear and a nose gear.  Each main gear has four tires, two forward and two aft.  These four tires are mounted in an assembly called a truck.  Each truck has actuators that level each truck after becoming airborne.  If a truck is not level, it is referred to as a hanging truck.  Raising the gear with a hanging truck using the 3,025 psi hydraulic pressure will cause the gear to be retracted.  Wheel well damage may result from emergency retraction if the main gear trucks are not level, the oleos are not sufficiently extended, or the nose gear is not centered.

According to a chart I just reviewed, the takeoff four engine maximum climb rate at sea level was 1,290 fpm and the three engine rate was 580 fpm.  The emergency procedures section of the Dash 1 states that gear drag lowers the rate of climb approximately 300 fpm at takeoff with flaps down.  An engine failure decreases the rate of climb approximately an additional 900 fpm.  The opening of the gear doors reduces the rate of climb even more while the gear is being raised.  According to this, 300 fpm plus 900 fpm equals 1,200 fpm reduction without considering the door effect.  A chart amount of 90 fpm does not provide a lot of flight cushion. Paper calculations have never provided an iota of actual lift or thrust.  And we had lost water, even worse in my mind than an engine.

The later modifications to the KC-135R designation provided a maximum climb rate of 5,000 fpm even after considering the allowable increase in aircraft and fuel weights.

While doing these procedures, I was looking out my window.  (No flight director system – no electrical power.)  I saw a Thai fishing boat.  It was a small boat with a tiny cabin leading below deck.  As we were about to fly over it, I saw the captain coming up from below deck with a white bucket full of something. He looked into my eyes and I saw the whites of his.  (Maybe you B-52 types are used to this low-level flying, this was a first for me.)  His bucket went up as he dove back down below deck.

Flaps! With the gear up we were beginning to gain airspeed. I reached over and raised the flaps.  On one of the two gauges that monitored the inboard and out board flap position (one gauge and for the inboards, a second gauge for the out boards), both needles went from about the three o’clock position to the twelve o’clock position.  On the other gauge, one needle went to twelve, the other to nine o’clock.  Asymmetrical flaps! Brace for the rolling motion!  No roll detected, bad gauge?

Asymmetrical flaps is a condition where the flaps do not retract or extend at the same rate.  This difference has the same effect as imputing a “turn” using the ailerons via the yoke.  This is extremely dangerous when at very low altitudes.  A bank angle of 30 degrees at climbout speed with flaps down could reduce climb capability by as much as 400 fpm.  As speed decreases, the effect becomes more severe, particularly in the clean configuration.

Assess your flight condition.  Gear up, flaps up, somewhere between 1,000 and 2,000 feet AGL and accelerating to over 200 KIAS.  Okay, now what.

Declare an emergency.  Battery switch emergency.  Listen to the UHF radio “click” as it cycles and tries to lock on the preset frequency.  Not enough power in the battery to lock on a frequency.  Go to “guard” position on the radio.  Still not enough power to lock on.  Dead battery.

The UHF radios had preset frequencies for items like ground control, tower, command post, etc.  To change from one preset to another you would rotate a dial with numbers, similar to an old-fashioned TV dial.  Guard was an emergency frequency that could be both monitored and transmitted on.

Shout at the Co to try and get some generators on line.  He successfully gets number 1 and 2 on line and mated to the bus.  Number 3 is toast.  This provides power to all the equipment. Get a TACAN DME (distance measuring equipment) lock at about 12 miles.  That is a long way to swim! (Even for a Minnesotan used to 10,000 lakes).  “This is _____ declaring an emergency in a left turn to 360 at 2,000 feet”.

So here we are rolling out on a 360 heading and describing to the Command Post the nature of our emergency.  About this point I told the Boom and Nav to go back in the plane and see if we had a fire, etc.  They reported no issues.  When we got back even with the base and are down wind, the Command Post asks me what is our current condition.  “Gear up, flaps up, two generators on line”.  “Roger”, is the response, “that is a go condition”.  I didn’t tell them my legs were shaking on the rudder pedals.  I don’t think that would have changed their opinion.  I was thinking “land, go to bar”.
We are now north of the base climbing through 8,000.  My number two engine oil pressure gauge starts to fluctuate and soon goes to zero.

Because more engines in the 135 were apparently shut down because of faulty oil gauges than actual loss of oil pressure, the fleet was in the process of being modified with a second low pressure sensor and indicator, a red warning light.  This aircraft had been modified.


And the number two oil light was illuminated.  Time to shut down number two engine.  Must have blown an engine seal after going to increase thrust.

“Command Post, this is _____, declaring an emergency.”  A short pause.  “Roger ____, didn’t you just terminate your emergency?”  “That’s a roger but now we are declaring a new one.”  And in addition to shutting down the engine, it caused us to lose a good generator.  We were down to one generator.  We are given clearance to dump fuel and return to land.

But, as I earlier mentioned, my Mother taught me to do the right thing.  Two things would have been wrong if we just hit the dump switch.  First, the JP-4 fuel we would dump, about 60,000 pounds (or about 9,230 gallons) to get down to maximum landing weight for braking limit purposes, would not evaporate prior to returning to earth.  There would be a whole lot of rice paddies covered with a film (or more) of JP-4.  Second, if we dump fuel with the boom up and in trail, fuel gets into the tail assembly and it needs to be cleaned somehow.

So I requested clearance to 21,000 feet.  After being granted, we start the slow, wallowing struggle to climb to that altitude.  It takes quite a while to get there but we finally make it.  “Boom, go back and lower the boom so we can dump”.  I soon get a call back over the intercom. “Pilot, I am having control problems with the boom.  One of the ruddervators isn’t working.  We may have to land with the boom in trail”. 

About this point in the flight, I am beginning to have doubts as to the air worthiness of this plane.  And more specifically, what’s next.  Systems just don’t seem to be functioning as designed.  But we successfully dump the fuel and the Boom is able to get it up and locked.

We now begin our decent.  We lower the gear handle and the gear comes down.  Again, I send the Nav and Boom back to check the visual down and locked stripes that can be seen from inside the cargo area.  I speculated that the gear wouldn’t come up, not because of a hanging truck, but rather to the fact that we must have lost electrical power while we still had the “weight on wheels” (WOW) safety interlock switch in the “on ground” position.  That prevents the gear handle from being raised using normal procedures.

Next, the flaps are lowered.  They extend without an issue. It was a faulty gauge.  This is followed by a successful three engine landing.

Because of the previous events, we are were met by the squadron or wing commander after taxiing in and shutting down.  He was kind enough to present our crew with a six pack of beer for doing a good job.  (Or for saving his promotion?)

We then had to endure a longer than usual maintenance debriefing.  I can’t recall if any of the above qualified for a “red X” in the 781.  But we did make a few entries. Someone brought to our attention that maintenance was aware of a circuit board defect that could cause a generator to trip offline. If this board experienced a vibration equivalent to that of slamming a fist on a table, it could trip a generator.  Because of the location of this board, they were replacing them only when an engine was required to be replaced.  I believe all further recollections of comments made would be censored.

EPILOGUE


For the next week or so, every evening after a flight we would be in our trailer and my co-pilot would go into the performance charts and say “it shouldn’t have flown!”.

This was very unsettling to my five-month pregnant wife, Melanie, who I had brought over for about six weeks.  She was staying at the Swan Lake Hotel but came to our trailer during the day time.  She found more to do on base as she waited for us to return from flights.  Since the war was over, I wanted to share with her some adventures in Thailand that I had on my prior two TDY’s.  This was NOT one of them I planned on sharing with her.  She did gain a greater appreciation for the risks any airman encounters when they “slip the surly bonds”.

My Co did buy me a nice lobster dinner at Camp Samae San (the Thai Marine Corps Base with US Army units adjacent to UT) with a deep-water port.  I believe the fuel and weapons for the UT aircraft came through this unit.  It was my first and only trip to their O Club, but what a club!  Real linen table cloths and napkins, real (non-plastic) silverware including salad and desert forks, real glass glasses, candle lamps on the tables, waiters, etc.  It was as good or better than any restaurant in Bangkok.  And twelve lobster tails.  Okay, they were one ounce each but tasted wonderful.  And all paid for by my co-pilot because -  even though I didn’t follow SAC policy for over water takeoffs; and whether through luck, skill or Divine intervention - I was at the controls and now we were able to eat the lobsters rather than them eating us.

Shortly after my return to Ellsworth, I put in my paperwork for a January separation.  The war was over, I heard rumors of a RIF (reduction in force), and recalled the two to three weeks of pulling Alert (with the possibility of only one to a max of three flights) a month that seem to happen whenever I was back stateside.  I don’t believe I was notified of the above citation that appeared in the December 1973 issue of SAC Combat Crew magazine until it was sent to me by my former squadron commander several months after my separation.







“YOU NEVER LIVED, UNTIL YOU ALMOST DIED.  FOR THOSE WHO FIGHT FOR IT, LIFE HAS A FLAVOR THE PROTECTED WILL NEVER KNOW.”  Vietnam 1959-1975