Boeing 707-80 prototype
"The view from the pilots seat is excellent"Flying the Boeing 707-80
A fantastic article about flying the original Boeing 707 written in Flight Magazine, 15, June 1956
Captain Spooner is the Senior captain on B.O.A.C. Stratocruiser fleet. He was the first Englishman to fly the 707.. On this flight he flew with famous Boeing test pilot Tex Johnston.
FLYING THE 707
By CAPT. ANTHONY SPOONER
15 June 1956
ON April 11, at the invitation of Boeing, I was privileged
To visit Seattle for three days and to fly the 707 prototype.
It is no small tribute to the far-sightedness of
manufacturers that the importance of the pilot's opinion, as
Expressed through his national associations and through the
International Federation of Air Line Pilots Association, is now
sufficiently recognized for such visits to be arranged.
So smoothly did the journey go that after departure by
B.O.A.C. Monarch at 8 p.m. on Monday, April 10, I was able
to touch down some 6,000 miles away at 8.30 p.m. the following
evening. I was naturally tired, partially because I had worked
my passage across the Atlantic as a navigator, but none the less
not unduly so, for both airlines had run to schedule and both
trips had been carried out in near perfect weather. Also, my
Transatlantic Stratocruiser and United Airlines' DC-6B were
exceptionally quiet aircraft. More modern piston-driven equipment
may be faster but certainly is not quieter.
During my three-and-a-half-hour transit in New York I telegraphed
ahead to Mr. Ralph Bell, Boeing director of sales, and
he kindly arranged for a car to meet me at the Seattle-Tacoma
Airport. This was but one of the thoughtful gestures which he
and his staff made. During this visit I received as much courtesy
and attention from all of Boeing as I would had I been a
potential customer with a $100 million order burning a hole in
my pocket. This is one more example of the fact that responsible
manufacturers are fully alive to the worth of pilot opinion, and
it is in keeping with the policy recently adopted by Vickers and
Bristols at home.
Out at the huge Boeing plant early next morning, I was put
in charge of Mr. Ray Chamberlain of the sales department. He
readily understood my position and for the next three days acted
as guide, counsellor and friend. He rarely left my side and
spared no pains to ensure that I saw what I wanted and got an
answer to the many questions I asked. At no time was it necessary
for me to emphasize the point that, although the operator
is the customer of the aircraft manufacturer, the pilot is the true
consumer of his products.
From Ray Chamberlain I learned that a special flight had
been arranged for me that afternoon. It should give satisfaction
to pilots to realize that such a flight, costing more than $5,000,
had been specifically arranged and that no attempt was made to
fit it in with some existing test programme. Later in the morning
I had the pleasure of a frank talk with
Mr. W. E. Beall, the senior vice-president. Points arising from
this talk were that Boeing did not necessarily confine their structural
programme to the strict C.A.A. requirements. When in
any doubt, they did not hesitate to exceed these standards. For
example, he referred me to the additional stress-factors they
had given to the window cut-outs and to the fact that, though
American design philosophy favoured a multi-path constructional
method in preference to the British guaranteed-life test-tank
procedure, Boeing, while keeping faith with all of the requirements
of the former, were in addition planning to subject a
complete 707 fuselage to a thorough water-tank test. However,
they were not contemplating wing-flexing tests.
Another point Mr. Beall rightly made was that Boeing aircraft
had carried out virtually millions of flying hours in the
40,000-ft zones and they had done this in highly pressurized,
large fuselages, yet they had never experienced a single decompression
failure in flight. Thus, in building fuselages capable
of withstanding high differential pressures, they were, in the
707, doing a little more than they had been doing in the military
field for the past seven or eight years.
The rest of the morning was taken up in conversation with
Mr. Taylor, manager of customer relations, and with Mr. Jack
Steiner, project engineer for the 707. I was to see a lot of Jack
Steiner for the next three days and I soon learned that he was
a walking encyclopedia of technical information. His office is at
the Renton Plant some miles away. In this plant, which is soon
to be considerably enlarged, the KC-135 (Boeing jet tanker) and
the 707 production lines are being laid down. Up to now, most
of the 700-odd KC-97s (Stratocruiser tankers) had been built
here and the change-over from the one type to the new types
is in full swing. To give some indication of the size of the future
production, I quote the figure I was given that some $45 million
had been expended on the jigging alone. Clearly Boeing mean
to build this new aircraft in hundreds, if not thousands.
At present the KC-135 programme is ahead of the 707
schedule. I was able to see for myself how near to flight the
first of the production aircraft were and I saw signs that others
would soon be following. There are no visible signs of any
707 assuming definite shape, but I understand that they are
already cutting metal for the first production model due to fly
early in 1958.
Here I think it worth explaining the similarity and differences
between the two aircraft. In basic appearance, both the KC-135
and the 707 are remarkably similar and both stem from the
prototype 707 which first flew 21 months ago. Certain vital
sections are common to all three aircraft. These are the wing,
the gear, the control surfaces, and sweepback. Generally it is
true to say that the underside of the fuselage is basically the
same. Initially, both aircraft will use the same type of engines,
mounted on identical pod beams. However, the similarity is
only basic. Customer requirement and conflicting standards for
military and civil usage have, in effect, made the 707 and the
KC-135 only about 25 per cent exact in detail. For example,
the upper fuselage shape of the 707 is both taller and wider than
that of the KC-135, since this latter is an upright oval and the
707 has a double bubble joined at a crease cord. Also, the customer
and civil requirements have resulted in the 707 design of
emergency flap and gear being considerably altered so as to have
no controls other than in the cockpit.
It should be emphasized that both the KC-135 and the 707
are considerably larger aircraft than the prototype now flying.
It was quite obvious from all I saw that Boeing means to
make a serious challenge in the civil aircraft field. They certainly
cannot be accused of running off a few civil aircraft on a military
production line. Possibly this change in their thinking stems
from a practical realization that it is economically unsound to
put all one's eggs into one basket. Possibly, too, they have (by
using hindsight) been kicking themselves for failing twice in the
past to cash in upon innovations in the civil market which they
pioneered only for others to profit by. I am thinking of their
model 247, which preceded the universally used DC-2 and -3
and yet was at that time the only all-metal, monocoque, monoplane
transport. I also have in mind the Stratoliner, which preceded
other four-engined pressurized aircraft by several years.
This time they seem quite determined to profit by the lead in
experience in this size of jet aircraft, a lead which they now unquestionably
hold. At the same time, they stand to profit in
experience by having a military type of certain similarity in full
production and service prior to the first civil deliveries. The
importance of this fact is immense, since it means that before even
the first civil production model gets itself into the air a vast flying
programme will have been carried out by die military cousin. How
many of these KC-135s will have been airborne prior to the first
civil deliveries is anyone's guess, but it will be many more than
150. The plant extension and colossal jigging programme
indicates some such figure. The point should also be borne in
mind that already the prototype 707 has logged over 400 hours
on over 320 individual flights.
Before leaving this subject, it should be remembered that this
prototype is neither a 707 production model nor a KC-135. Its
relationship to the production 707s is comparable with that of the
Vickers-Armstrongs 630 to the subsequent Viscount 700 series.
An interesting period was spent with Jack Steiner and the everpresent
Ray Chamberlain examining one of the mock-ups of the
707. Several mock-ups are being produced, according to varying
customer requirements. Generally, the mock-up I saw (and I think
it was the Pan American one) revealed few surprises, since most of
the details have been published some time ago. The view from
the pilot's seat is excellent, comparable indeed with that of the
Stratocruiser except for the absence of the lower windows. On
the other hand, the pilot has been placed much closer to the large
forward-facing windows, which must be about 36in across. He
is also placed closer to the side windows. I understand that the
fields of vision are now capable of exceeding the existing American
S.A.E. requirements.
The pilot's instruments (standard size) will obviously vary somewhat
from customer to customer. The engine instruments are
of the 2in size and seem to be too small. However, later in the
day when actually aloft, it did seem possible to read them without
much difficulty. In spite of this, I consider that a better-balanced
situation would result if most of the existing five rows of small engine
instruments on the pilot's central panel were shifted to the flight
engineer's panel; the central instruments could then be of normal
size. I was informed that some such arrangement was within
the bounds of customer requirement but, doubtless, at some
additional cost. It would not, I think, clutter up the flight
engineer's panel unduly and would have as an additional advantage
the merit of leaving some space in the central panel for the introduction
at a later date of additional instruments. Experience has
shown that the state of the art is always progressive and that every
year or so a vital additional instrument is developed as a positive
requirement. For instance, engine-mounting-vibration instruments
might well become a desirable addition to jet aircraft, as they have
to conventional aircraft. Another point is that at present the
flight engineer's panel does not contain all engine instruments. It
principally concentrates upon electrics (D.C. and A.C.), fuel
system and gauges, cabin pressure control and an impressive overhead
circuit-breaker panel; the hydraulic gauges are up front by the
co-pilot with the emergency change-over controls situated between
engineer and co-pilot.
The earlier proposal to hinge the flight-engineer panel so that
it could be swivelled towards the pilot has been abandoned. The
panel is reasonably close to the pilots and I would judge that
nearly all his controls can be reached by one or the other of the
pilots making a "long arm."
In contrast to the mock-up, the prototype 707 (which is generally
known as the Dash Eighty) has only three rows of 2in engine
instruments up front; it also has the radio panel mounted in the
overhead position. Such pictures as have been released did not,
therefore, give a true representation of the production aircraft.
It has been considerably redesigned so as to allow for several types
of radar. In the production machine, since part of the radar
is in the overhead panel, the radio panel has been re-located to lie
at elbow level on either side of the throttle quadrant.
The proposed method of applying reverse thrust was foreign to
me and, consequently, seemed awkward. It is, however, basically
similar to that now in use by Constellation pilots and I was
informed that it carried their blessing. The rear of the throttle
quadrant is given over to the fuel and engine cut-off controls,
thus precluding the utilization of this section for reverse thrust.
It also means that engine starting is a pilot-control operation.
Because I have been nursed for so long by efficient flight engineers
in a Stratocruiser, I am opposed to this philosophy and I would
have preferred starting to be taken over by the flight engineer.
The afternoon was given over to a flying programme. The
flight test division of Boeing is in the charge of "Tex" Johnston,
chief of flight test, and after only a brief chat with Tex and his
chief henchman, "Dix" Loesch, I was installed in the left-hand
scat of the 707-80 with Tex alongside. Dix acted as flight engineer.
ENGINE starting is pneumatic, in keeping with the modern
American practice of dispensing with the battery and using
direct A.C. generation. There is, of course, a small D.C.
battery for certain secondary purposes. Various devices are offered
by Boeing to enable one engine to be started without the use of
specialized pneumatic ground starting equipment. The customer
can take his pick according to the weight penalty he is prepared
to stand. The internal starting systems are a combination of
electrical, pneumatic and combustion and the air supply required
is drawn from compressed-air bottles.
Engine starting appears to be a simple operation but, as I have
explained before, it must be performed largely by the pilots, since
the flight engineer has no physical control over the one set of
throttles aboard. Once one engine is running3 the others can be
started internally by using the air supply and electrical power
generated by the engine so running. It was worth noting here that
all four engines will be fitted with 30 kVA A.C. generators driven
by Sundstrand drives. Starting certainly takes no longer than
in piston-engined aircraft and from the cockpit the operation is
practically inaudible. Indeed, the sound level in the cockpit is
remarkably low at all stages of flight,
Taxying presented no problems apart from some difficulty
experienced in unlocking the parking brake. I did criticize, however,
the size of the nose steering wheel; I would have preferred
a wheel of much bigger segment. From an airport congestion
angle the inability to lock the tandem bogie mainwheels on the
inside of a turn may make the parking of the aircraft in a confined
space a difficult problem. I understand that there is on the market a
polished steel plate which ground crews can insert under the
inboard wheel. This acts as a turntable and enables the aircraft
to execute the equivalent of a wheel-locked turn. I also understand
that some airports are building in similar turntables as a
permanent feature of the apron areas.
The weight at which the Dash Eighty [as the prototype is
usually called] was being flown was at almost irreducible minimum
since it had been flying nearly all morning and refuelling would
have caused a delay on a ramp which was packed solid with
production B-52s. At take-off, we were about 122,000 lb. ("Child's
IN these pages, Capt. Spooner, D.S.O., D.F.C., continues his account of
a visit to Seattle, where he was invited by the Boeing Airplane Company
to sample the prototype 707. A senior B.O.A.C. Stratocruiser captain,
and chairman of the British Air Line Pilots' Association, Capt. Spooner
made the flight as a representative of pilots, and not as a prospective
customer. In Part 1, last week, he described preparations for 707 production
and commented on various features of die aircraft Here he
tells the story of the flight, which was made in company with "Tex"
Johnston, chief of flight test, and his henchman "Dix" Loesch, who
acted as flight engineer. A few company officials went along for the ride.
play to four derated J57s producing about 9,500 lb thrust per
engine.") Fuel on board for this flight was about 20,000 lb.
I had expected Tex to do the take-off, but no sooner had he
asked me to unlock the parking brake and steer the aircraft down
the commencement of the centre line (both parking brakes and
nose steering are controlled from the captain's seat alone) than
he called, "You've got it. It's all yours." Nosewheel steering
was gradually abandoned to rudder pedal control at about 80 kt
and at about 100 kt the nose was raised well clear of the ground.
At about 120 kt, without any real recognition of the fact, I became
aware that we were airborne. It is interesting to note that, due
to careful design and recognition of the dangers involved, this
aircraft is not unduly affected by an apparent tail-up or tail-down
configuration. It will fly off at almost any reasonable attitude
and the fore-and-aft-trimming device is compensated by the individual
M.A.C. percentage as listed in the load sheet. Gear and
flaps were raised without any noticeable change of attitude and
the aircraft commenced climbing at alarmingly steep angle at
about 4,000 ft/min with a rapidly increasing indicated air speed.
The problem with this particular prototype is that there is a
limitation speed of 180 kt with the flaps in the take-off position.
This is being improved in the production models, which are
designed to permit a take-off-flap speed of up to 220 kt. Since I
had not located the flap indicator and was not anxious to exceed
the 180 kt limit until absolutely certain that the flaps were full in,
I practically had to stand the aircraft on its tail to keep the speed
down whilst checking with Tex that the flaps had come full in.
In all, it took seven to eight minutes to reach an altitude of
31,000ft with an airspeed indicating between 250 and 300 kt. At
this height the aircraft was clearly hungry for more altitude, since,
although we were now climbing at Mach number 0.8, the rate
of climb still indicated about 4,000 ft/min. (We were, of course,
almost incredibly lightly loaded.) The control of the aircraft did
not present a fraction of the difficulty the instruments did. The
latter problem was purely a question of unfamiliarity. For example,
the airspeed pointer rotated through 360 dcg to indicate each
100 kt and it took me a little time to locate the sub-pointer that
showed whether I was going at 210 or 310 kt I.A.S. Likewise,
with an altimeter winding-off the tens of thousands of feet so
rapidly, I had to hunt about with my eyes for the little hand
showing me whether I. was at 6,000, 16,000, 26,000 or 36,000!
The Sperry Flight Integration System was also strange to me,
but once I discovered a standard-type artificial horizon I concentrated
upon this rather than upon the complicated unfamiliar
instruments. The rate-of-climb indicator was off the clock most
of the time, due to our phenomenal rate of ascent, and the tiny
r.p.m. dials in the centre panel presented a percentage of maximum
r.p.m. rather than the r.p.m. themselves. Never having flown a
jet aircraft before, the significance of the other engine instruments
was largely lost to me.
Controlwise, the aircraft was almost perfect, except that I found
myself fiddling about with the fore-and-aft-trim device rather
unnecessarily.
The flying control system is worth a chapter itself, and so much
has already been written that I hesitate to add more. However,
to pass lightly over such perfection is to do it less than justice.
Basically, the aircraft has a spring servo-tab system. The forces
acting upon these tabs move control surfaces which are aerodynamically
balanced. Both controls and tabs are also statically
balanced, so that when the aircraft is at rest there is nothing
dangling down. The aerodynamic balancing is achieved internally
by methods which Boeing have evolved from much wind-tunnel
experiment, backed up by many thousands of hours' flying
experience.
Allied to this are two extra control forces. These are an adjustable
horizontal stabilizer and two supplementary lateral control
systems. The adjustable horizontal stabilizer can be controlled
either manually or electrically; and in practice the latter is used,
since some 90 turns of the trimming wheel are required between
full tail-up and tail-down positions. Manually, this would require
considerable physical effort. The electrical system operates through
a clutch to the same trimming wheel as is used manually, and
when electrical actuation is called for this trim wheel literally
whirrs around. However, if the electric motor did happen to run
away (a most unlikely event, since elaborate precautions have been
taken to prevent this), the trim wheel can be stopped physically.
It could, however, cause a pilot to lose some skin, and it might
perhaps be preferable to use the sole of the shoe rather than the
palm of the hand. Regardless of this fact, the most satisfactory
feature of this device is that, provided a good e.g. position is
established, it does not matter very much where the horizontal
stabilizer is. Except when being flown at the extreme limits of the
e.g. range, the aircraft can be handled (and, I believe, even landed)
with the trim wheel right forward or right aft. It simply requires
greater stick forces. My error in fiddling with the trim wheel was
that I was trying to achieve a perfect hands-off trim by a cautious
turn or two of the wheel. These little movements had practically
no effect whatsoever until I grasped the idea that I really had to
spin the wheel like a rotary polishing mop for anything noticeable
to take place.
Lateral control is threefold. There are two separate sets of
ailerons and the lift spoilers (two a side, on top of each wing).
The asymmetrical use of these spoilers provides, in effect, a third
set of ailerons. They are normally used as ailerons throughout
the entire flight and except when disengaged (when they lie flat)
or when no hydraulic pressure is available (when they also lie flat),
they are automatically connected to the aileron movement of the
control column. Even when being partially used symmetrically
as speed brakes, they still act as additional ailerons. When the
spoilers are in the fully "up" maximum speed-brake position, then
and then only is partial aileron effect lost, because it is impossible
to raise the spoilers more than 100 per cent. But even in this case
there is a little aileron effect, since the hydraulic follow-up
mechanism does have the effect of slightly depressing the spoiler
which is on the outside of the turn. However, since spoilers are
only used as full dive brakes or speed brakes for an emergency
descent or some such unusual proceeding and are normally partially
used in the symmetrical configuration, the condition of being
deprived of aileron (spoiler) effect seldom applies. Of the two
normal sets of ailerons, the outboard set is only effective when the
flap is down. With the raising of the flaps after take-off the
gearing of this set of ailerons is progressively reduced to zero. On
take-off, I tried to detect a reduction in lateral control ratio as the
flaps came in, but I was unable to do so; nor did I notice any
increase in aileron effect when, ultimately, I lowered flap prior to
landing.
In normal flight, the rate of roll is considerably more effective
than on any large aircraft I had previously flown, and a good
feature is that maximum bank can be achieved without the control
wheel exceeding 90 deg of movement. Thus a pilot does not get
himself into the hands-crossed-over position so difficult to maintain
without change of grip. Since the spoiler-aileron device is
hydraulically operated, the question at once arises of what happens
if the hydraulics fail. As previously mentioned, the mechanical
effect is for the spoilers to lie flat. The aircraft is now entirely
controlled laterally by the small-area inboard ailerons and, to my
surprise, the effect on control at speed is almost negligible. I
did not have occasion to try out this situation at low speed; but
the aircraft has often been landed with the hydraulic power to the
spoilers switched off, so the effect is certainly not one liable to
cause a disaster. I did try 60 deg bank turns at Mach number 0.83
using inboard ailerons alone and I was able to swing from one
turn into the opposite turn with far less effort than required when
flying a Stratocruiser. With the spoilers operating this manoeuvre,
more can be achieved easily with one hand.
Those who saw Tex Johnston perform an upward barrel roll
in the 707, starting from only a few hundred feet up, can bear
witness to the aircraft's impressive manoeuvrability.
The rest of the flying programme was taken up with demonstrations
of stalls clean and stalls with everything dangling. In both
cases, lateral control was available down to the stall, with ample
warning provided by buffeting which commenced mildly at about
20 kt above the stall and progressed to a horrible fierceness. This
is an aircraft that needs no artificial stall warning device.
Recovery from stalls presents no difficulty. Some time was
spent in the air slamming throttles back and then, with the engines
idling, pushing the power hard against the forward stops with
the kind of rough movement normally only reserved for opening
swing-doors. The absence of engine surge or pulping was remarkable.
Equally remarkable was the almost instantaneous power
response. As one threw the throttles forward one was almost hit
in the back by the acceleration forces.
At my request, Tex demonstrated an emergency descent. At
the time we were cruising along at some 310 kt I.A.S. at a height
of about 33,000ft. First action is to close the throttles and apply
full air brake. This is always possible, since there is no speed
limitation on the spoilers. The gear can be dropped at 270 kt
I.A.S. and, in a matter of seconds after pushing the control column
hard forward, Mother Earth appears straight in front of the
windscreen. Once the gear is fully down, the speed can be
increased to 320 kt I.A.S.; and, though now only inboard ailerons
are effective, ample lateral control is available. On the descent
we lost about 183000ft in one-and-a-half minutes in spite of having
to make turns away from the mountain ridge I happened to be
diving at.
Another demonstration I was able to try was the sudden pulling
back of an outboard engine. Almost no yaw effect was felt and
one twist of the rudder trim-control wheel restored flight to
normal. The engine was then completely stopped and relit without
fuss or ado, although it was felt necessary to limit our threeengine
speed to 240 kt prior to relighting. In this case, relighting
was performed at about 25,000ft; but, I understand, relighting
can be performed at up to 40,000ft.
As we had now been up about one hour, our limited fuel supply
was running low; so, after Tex had exchanged the right-hand seat
with Dix, we proceeded back to Seattle, noting on the way how
effectively the D.M.E. was performing. This appears to give accurate
indications beyond 100 miles.
As far as I can recollect, the highest Mach number reached
during this flight was about 0.86. At no time was a noticeable
change in pitch or roll apparent and, except when actuating the
air brakes at speed, there was no buffeting. The aircraft is
guaranteed to Mach 0.88 and has been flown up to at least 0.95.
The buffeting experienced by applying the spoilers as air brakes
was of moderate character and did not prevent normal control
movements from being made.
When at about 4,000ft downwind of the airport and at about 240
kt I.A.S., Dix suggested that I might like to figure out an approach
on the landing circuit for myself. In the absence of any guidance
other than that the speed over the fence should be about 120 kt,
this was an interesting exercise. The speed was rapidly lowered
by the immediate dropping of the gear and, on a wide base leg,
I was able to get the approach flaps down at 180 kt. Power was
controlled by pushing or pulling throttles, by feel rather than by
reference to unfamiliar (and largely incomprehensible) engine
instruments. Responses were so rapid that this method proved
quite effective. On finals, full flap was called for at 140 kt at
about 300ft up, and this was accomplished with little noticeable
change of attitude. The 707 is not one of those aircraft which
dives steeply with the application of landing flap. The lowering
of initial flap, 30 deg, did cause a slight nose-down attitude, but
I did not feel any urgent need to trim this out, preferring to hold
back the nose-down tendency by slightly increasing the backward
stick force. There was a slight balloon effect on the flare-out,
but it was not of such magnitude that a sudden forward movement
of the control column was called for.
A smooth touch-down was made with the nosewheel held off the
runway and there was no tendency either to sink rapidly immediately
prior to landing on or to bounce after touch-down. We
did float half-way down the long runway but this, I think, was
due to the fact that the 120 kt speed over the fence incorporated
a generous margin for beginners and also to the fact that I had
forgotten I was supposed to be doing my own throttle movements
and had, out of force of habit, called for "power off" instead of
doing so myself. On the spur of the moment, Dix suggested that
I make the landing a touch-and-go. All that was required was a
positive grounding of the nosewheel by a push forward on the
control column and the opening-up of the throttles while Dix
retracted the flaps to the 30 deg position.
Acceleration response was almost immediate and before I had
time to get my hand away from the wide-open throttles I was
again pointing almost straight upwards in an endeavour to stop
the speed building up beyond the 180 kt limitation. I was still
having trouble in locating the flap-position indicators, possibly
due to the fact that each of the four large double-slotted flaps has
a separate indicator needle. These are mounted on two gauges
on the pilot's instrument panel and from habit I was looking for
one large gauge on the co-pilot's side of the aircraft.
The next circuit was a much tighter and neater affair and
unremarkable except that Dix showed me by how much I ought
to trim out the slight nose-down effect which appears upon initially
lowering the flap. For literally second upon second, he made
the trim wheel fly around (I personally thought that the electric
motor had run wild); but, at the end of it all, though the trim
indicator was far removed from where I had had it for my first
landing, I did not notice any appreciable difference in the handling
of the elevator control and my final landing was done with some
real measure of confidence, in spite of the fact that I had only been
in the aircraft some 90 minutes and had had no proper dual and
still had no accurate notion about the correct speed and approach
pattern drills. Incidentally, it is worth notice that, with no magnetos
to check, no propeller-pitch settings to bother about, no cowlflaps,
no intercoolers, no oil-cooler flaps, no radiator settings,
the field-approach check-list is reduced to almost nothing.
On this our final landing, Dix showed me how to unload the
wing by raising all the spoilers to their maximum immediately on
touch-down. After this manoeuvre, positive nosewheel steering
and brake application are available. Whether one can land with the
spoilers full up I did not check, but I believe that the effect upon
stalling speeds is less than 5 kt. In the landing attitude these
spoilers, when used fully, do exert some pitch-down attitude
necessary for immediate effective braking.
At this weight, now only about 107,0001b, the aircraft used very
little runway in spite of the fact that there is no reverse-thrust
mechanism fitted to the Dash Eighty. Against this fact, however,
it must be remembered that production 707-120 aircraft using
this same wing area will be cleared for landings up to 165,000 lb.
A general assessment is difficult to arrive at. I suppose that my
dominant impression is that the aircraft, as I flew it, was almost
incredibly simple to manipulate and easy to fly. Yet it is as
powerful as it is docile. I believe that Boeing estimate that the
cost of the Dash Eighty prototype has been about $16 million
(nearly £5fm) of their own money, and I think that the manner
in which they allowed a non-jet pilot to throw it about and to
handle it close to the ground is perhaps a better indication of its
qualities than words can express. Some 50 "unfamiliar" pilots
have done as much, or more. These facts speak for themselves.
The next morning was taken up discussing with Ray Chamberlain
and Mr. Downey the final engineering details of the control
system. Jack Steiner later joined in the conversation and a discussion
developed about the need for greater rudder throw and/or
aileron drag effect in the low-speed (0 to 60 kt) case as applicable
to icy runways. I was favouring the addition of a booster rudder
in order to obtain some positive ground control. In this respect,
the aircraft is somewhat similar to the Bristol Britannia. The
situation may resolve itself when engines of greater power, such
as the J75 or Conway are fitted; in these cases, the rudder boost
may become a requirement in order to meet the one-engine-out
case on take-off. I also made the point that the present method
of locking and unlocking the parking brake required an unnecessary
shifting of the feet to the very top of the foot-brake pedals
in order to supply the strong physical forces required.
After lunch (during which the table-cloth got covered with
graphs of CLmax lines and Mach numbers) I continued with Ray
Chamberlain and others the discussion of details such as fuel-dump
procedures, fuel contents gauges, ground clearance, relighting
altitudes, holding-pattern heights, gust locks, fuel heating, vertical
loads, gust criteria speeds, and so forth. I was then handed over to
Mr. Dudley Nichols, and others whose names now escape me, in
order to examine the structural details of the KC-135 now being
built on the production lines. I was able to satisfy myself about
various details of the multi-path constructional system and the
machining of the integral wing fuel tank units. It was interesting
to observe that, apart from the fore-and-aft shear web, fitted with
spar caps, there is no main wing spar. A number of spanwise
stringers take their place in carrying the primary bending loads.
These and the very thick external skin carry about 75 per cent of
the stresses.
I had queried the position which would arise relative to the bag
tanks in the central wing area in the event of a wheels-up landing.
After examining the immensely strong keel beam and after noting
how much solid protection was given by the gear itself in the up
position, I was almost convinced that, short of a catastrophic
arrival, the centre-wing tanks would never be ruptured by any
wheels-up landing. I also examined the main gear trunnion. This
is placed aft of the rear shear web and is not connected with it.
An auxiliary box unit with a form of fusible link is the only solid
connection between the rear shear web, which is part of the outer
casing of the wing tank, and the main gear attachments. Thus
there seems to be little risk of the gear ever pushing its way
through into the fuel tanks; instead, if treated badly, it will break
off and disappear aft. Incidentally, this gear folds up into a very
compact space sandwiched between the massive keel beam and
the strong box section of the lower floor level.
Boeing engineering has always been on the massive scale and
these aircraft indicate a continuation of this policy. There are
many indications of great structural strength.
Another query of mine was to express concern that, in the event
of a wheels-up landing, the pods carrying the engines would get
mixed up with the fuel tanks. This subject has received a considerable
study and Boeing have been able to profit from the experience
of their military aircraft. A workable solution has emerged
which has, I understand, proved itself in operation. Again fusible
links are employed.
One ingenious feature of the aircraft is the arrangement whereby,
when the cabin pressure falls below certain safety limits, the
oxygen system available to both passengers and crew is automatically
put into operation.
On Friday the 13th Ray Chamberlain picked me up as usual
outside my hotel at 8.30 a.m. and, after clearing a few matters,
he handed me over to Mr. W. Cook, engineer-aerodynamicist,
who showed me around Boeing's vast 54,000 h.p. wind tunnel.
This, it is claimed, is the largest privately owned wind tunnel in
existence and it operates up to transonic speeds with models of
10ft wing span. Boeing stress the importance of the facility,
which has enabled them to evaluate about 150 different wing
shapes for their big jet aircraft. I observed, from one of the wall
charts, that approximately 21,000 hours of test tunnel work had
gone into their four major jets, the B-47 and B-52 having each
required nearly 8,000 hours and the K-135 and the 707 absorbed
the remainder.
Later we visited the plant where research was in progress
designed to solve the noise-level problem. Here Boeing are pooling
their experience with Rolls-Royce, though both concerns are
carrying out independent programmes. In order to speed their
work Boeing have simulated a jet orifice which realistically produces
the required airflow, temperature, and noise-level, and I
saw the various silencing attachments which had already been
tested. With one such attachment, noise level had been reduced
by as much as 40 decibels, but only at a considerable sacrifice to
speed and manufacturing simplicity. Boeing have specified that
the silencer they will ultimately fit will result in less than 2 per
cent loss of thrust, and a compromise solution between engine
thrust and maximum silencing is inevitable. To date, a loss of
15db can be achieved without overstepping the desired criteria.
Those at work on this programme paid tribute to Mr. Greatrex
of Rolls-Royce, whose nozzle is the basis of several successful
experiments.
It is interesting to note that the Rolls-Royce Conway operates
normally at about 6db less than the J75. Since, for the same
thrust, it weighs about 1,500 pounds less per engine, the case for
the Conway is a strong one. I also understand that the Bristol
Olympus still further reduces this weight and is capable of
similar amounts of thrust without noticeable increases in fuel
consumption. Boeing are fully aware that, apart from the serious
social problem of high noise-levels, there is an equally serious
structural problem. At a considerable weight sacrifice they have
thickened-up various flap and aileron sections in places where
the metals are subjected to possibly dangerous noise-level effects.
The rest of the morning was taken up with various aerodynamic
discussions regarding the control problems of high-speed aircraft.
The placing of the spoilers so that they produce neither
severe buffeting, nor changes in pitch, nor noticeable increases
in stall speeds, is a classic example of what can be achieved by a
comprehensive wind-tunnel test programme. The reversal of
aileron effect at high speed is another such example.
Out for lunch, I took the opportunity to say goodbye to Mr.
W. E. Beall and to Jack Steiner and spent an interesting half hour
with the servicing department, who were examining the wreckage
of the Northwest Stratocruiser which had just been raised from
the sea-bed nearby. I also had an interesting discussion with
Mr. Ralph Bell, director of sales, who had, via I.F.A.L.P.A.,
sponsored my visit.
It was with real regret that I said goodbye to Ray Chamberlain,
who for three whole days had spared no pains to ensure that I
saw what I wanted and got the answers to the questions in my
mind. Apart from anything else, I would have got hopelessly
lost in this huge plant, which is almost a city in itself. I believe
that they employ about 9,000 engineers; and the goods they
produce, as we all know, are contributing much to the security
of the free world. I have no reason to doubt that the company's
new embarkation into the civil field will be attended by success.
They are making a most determined effort to stay in the civil
market and to get on top. With this determination behind them
and with their great military experience to back it up, it was
gratifying to me to note with what favour they regarded the
British jet engines. As has been announced, they are offering
their customers a free choice of British or American engines, and
they have now designated type numbers for the Rolls-Roycepowered
aircraft. Who will be the first to order these aircraft,
known as the 707-420 and 707-520, is anyone's guess, but that
orders will be obtained I have little doubt.
I had meant to take it easy on Saturday and get my notes
up-to-date in preparation for the session I had arranged with
Mr. Clarence N. Sayen, in Chicago, who, apart from being president
of A.L.P.A., is also president of I.F.A.L.P.A. However,
Bill Cook, who had previously shown me the wind tunnel and
the noise-abatement laboratory, offered to show me the rest of
Boeing's experimental test section. I gladly accepted this offer
as, apart from anything else, I wanted to have another look at the
prototype Dash Eighty. I had been so busy flying the aircraft
that I had no opportunity to examine its other features.
One point I was able to satisfy myself upon is that, although
the aircraft has a servo-tab control system, the controls can be
checked for full movement on the ground. This apparent contradiction
is due to the spring control. With no air loads to
centralize the control of the servo-tab surfaces, initial movement
of the control column moves the tab and further movement
acts upon the control surface itself. A subsequent movement
will then actuate the tab.
I also had a chance to make the proper examination of the
flight engineer's panel. Details of this are not important, since
in the production aircraft there has been considerable rearrangement
of instrumentation. However, I did note that the fuel diagram
layout is essentially simple and that the auxiliary internal
tip tanks and the centre wing area tanks operate in a manner
which will not result in the aircraft being starved of fuel due to
lack of watchfulness on the part of the flight engineer. I was
also able to note that the use of direct A.C. power, generated via
Sundstrand drives, has eliminated much of the complicated conversion
of power which normally has to be accomplished. It
is worth noting that these A.C. drives are protected against
failure by malfunction indicators, overhead indicators and throw out
clutches, and by being given their own separate oil systems. I
was also delighted to see that only the day before the Dash
Eighty had been fitted up with Atkins collision-warning lights
on both upper and lower lobes.
After leaving the aircraft, we toured acres of experimental and
test departments. In these test laboratories, almost every conceivable
aerodynamic condition can be simulated. A list of the
laboratories would be over a page long. The importance of this
is the understanding of the Boeing philosophy that a $5 million
aircraft is only as strong as its weakest link. Thus, almost every
component part which comes into the plant is subsequently
re-tested in the company's own laboratories. These tests involve
the use of cold chambers, heat chambers, salt-spray chambers
sunshine and rain chambers, and even chambers in which a
highly combustible mixture of butane and air is held under
pressure while parts are operated under working conditions at
varying temperatures.
I also learned of the static tests which are a military requirement.
One military model at some time early in the production
line is virtually pounded to total destruction by the application of
abnormal stresses. Another interesting section was one in which
the sound level of 180db could be produced. With an eye to the
future so-called heat barrier, many of the latest test sections
were capable of producing very rapid rises in temperature. In
the course of this tour of inspection, I also saw the vast water-test
tank.
For those unfamiliar with the specifications of the 707, I feel
that in justice to its advanced design I must mention, in conclusion,
some of the features which appealed to me. These are:—
Airborne radar; SEL CAL; Skydrol 500 hydraulic system (with all
electrical wiring made out of Skydrol-resistant materials); anti-skid
brakes; isolated power shields; isolated radio compartment; thermal
(second spool) engine and wing anti-icing; electrical tail unit anti-icing;
emergency air brakes; free-fall emergency gear; indication of engine
reverse to each engine; high gust-criteria speeds (Vb 230 kt, Ve 350 kt);
circuit-breaker within reach of pilots; separate hydraulic motors for
inboard and outboard flaps; total absence of gust locks; lateral control
available with one flap section asymmetrical; automatic wheel-braking
during retraction; dual gyrosyn compass systems; dual V.H.F., V.O.R.,
A.D.F., HZ-1, etc.; inspection panels to all wheels when down; static
thrust indicators; inspection panels to cargo compartments; dual cables
to all controls; hydraulic system limited to 3,000 lb/sq in; Nesa
windows; underwing refuelling; rubeless tyres; two fuel booster pumps
per engine on separate circuits; Freon fire extinguishing agent; emergency
electric flap actuation; separate indicators to each of the four main
flaps; flight engineer's panel within reach of pilots.
The only omissions of importance which occurred to me
were:—
Boosted rudder; central landing light; vibration indicators attached
to the engine mountings; firmer parking-brake lock; fuel heaters; larger
engine instruments; space for let-down chart; crews' toilet (with up to
147 passengers on board, this could be quite a problem); limited turning
circle; individual fresh air vents to crews' positions; hydraulic pumps
to all engines instead of inboard engines.
Considering the balance between these two lists, and considering
how essentially simple this aircraft is to operate and
fly, the conclusion remaining is that in the 707 Boeing have
launched a product which will, I feel, make an impact upon the
industry such as no aircraft has made since the DC-3 twenty
years ago.
