by David Palmer
Cracked throttle briefly about halfway down to clear spark plugs of potential fouling after long minutes' idling (Adam says two-strokes touchy that way); then again about 30 feet above opening itself to provide moment's crisper response to controls: Necessary for final steeply banked turn, dive-and-duck squeeze through shaft's narrow bottom.
Plunge from early midday sunlight into relative gloom beneath foliage precipitated only momentary pupil accommodation crisis, but blindness persisted long enough to supply genuinely ugly thrill before vision returned.
Looked around quickly; simultaneously raised flaperons to 50 percent, reducing aerodynamic braking effect without substantially affecting lift. Also brought power back up to maximum available. Amounted to maybe 25 percent, but not complaining; appreciated every little bit: Even partial throttle improved glide characteristics; and every second remained airborne boosted odds on spotting safe landing site.
But not encouraging picture: Beyond small glade in which found self, dimly green-lit cavern beneath foliage extended out of sight in all directions; roof supported by massive columns, fairly regularly spaced; most closer together than would prefer under circumstances; by and large offering just about enough room for ultralight's passage. Alert, skilled pilot might stave off disaster for several whole minutes before inevitable caught up. Dyed-in-wool ultralight freak probably wax ecstatic over challenge.
And welcome to it! Own interests much simpler, more basic: Just wanted to get down in one piece—and immediate outlook less than reassuring: Lesser trees obscured forest floor between sequoias, plus intermittent underbrush furnished dense ground cover.
Became, therefore, engrossed in feverish search for any approximately level, unobstructed surface on which stood remote chance of setting down relatively intact before unwinding altimeter closed off debate.
Search not instantly productive. Nothing visible beyond what already described. Nothing anywhere but vast, unyielding sequoia trunks above; smaller trees, bushes below, all capable of snatching fragile plane from air, smashing to ground out of control.
Finally looked straight down and—behold!—Heaven-sent solution . . . !
If pilot enough to bring off.
(Heaven apparently not big on sweeping, all-encompassing fixes. Maybe concerned that doing too much for supplicant erodes self-respect, destroys incentive, is somehow demeaning. Perhaps. But at that moment trading self-respect for tangible assistance would have seemed bargain.)
Hole through which descended, plus clearing, both created when enormous sequoia toppled sometime in recent past. Carcass sprawled along ground for hundred yards, splintering smaller trees, crushing other vegetation beneath incredible bulk. Resultant clearing possibly 100 feet wide at crown end, 50 at root.
Trunk diameter uniformly at least 35 feet from base halfway to top; first 150 feet unobstructed by branches. If could line up approach, would be ample room to land flying flea on fallen giant's curved upper surface . . .
If could line up approach:
Room to circle available in widest portion of clearing only: over crown, lowest, most massive branches of which projected upward, blocking glide path to trunk from that direction. Impossible to descend steeply enough after clearing branches without building up prohibitive velocity before touchdown. Never get stopped before colliding with gnarled roots.
However, to land other way along huge log required approach from out amidst trees: First entering forest, completing 180-degree turn amongst Brobdingnagian sequoia trunks, reentering glade on final—all without becoming oversize bugspot on tree trunk . . . .
Hoped Adam would take good care of Terry.
Well, no point dwelling on possible unpleasant side effects; obviously only solution at hand.
Eyeball reconnaissance, strategy review, subsequent conclusion, occupied only couple plane lengths after clearing opening; greenery still almost in reach overhead as juggled what probably would be last relatively unhurried decision before reaching ground: Selection of left- or right-hand approach pattern—euphemistic description of brief-but-agonized nail-biting over where trees more closely spaced.
Bore off toward monster tree's root end. Intended to set up basic 180-degree approach. Hard to beat for simplicity, plus should minimize exposure time in forest. Would parallel log; penetrate forest just far enough to execute 180-degree turn; emerge from trees on final, right over root end, ready for flare-out, touchdown, routine quick stop.
Debated briefly, unhappily, before settling on airspeed of 35 knots, 13 over normal stall. Would have proceeded even more deliberately if had druthers; but cushion essential safeguard against accelerated stall should circumstances require sudden high-gee vertical bank or the like. As well might.
But ought to be all right. Only about twice flat-out running pace, after all; slow enough to permit noting trees as approached, evaluate separation, make deliberate go/no-go decision, take evasive action as necessary. Sure. Probably. (If alternate route accessible.)
Besides, 35 knots efficient airspeed: Optimum glide angle; maximum flying time available before ground intersected glide path. Maybe several whole minutes.
Had time for single deep breath as exited clearing; then learned whole new meaning for word "busy":
Glided between first two massive columns with room to spare. Bore slightly right to clear still another monolith; then initiated gentle left bank to circle it—when bark-covered wall unexpectedly materialized in path, appearing suddenly from behind one already using as pylon.
Huge trunks separated by 12-15 feet. Barely.
Slammed stick against left stop, then yanked back hard. Craft jerked upright on wingtip, warped violently into turn, structure trembling under gee loading. Skimmed inner tree so closely, wondered briefly why rudder tip didn't drag. Shot through slot like watermelon seed; then leveled, angling toward wider gap visible ahead.
Considerably lower now, of course. Elementary aerodynamics: Only so much lift produced at given airspeed. Turn increases induced drag, causing speed loss. Lower nose to get speed back, sink-rate increases. Turn steeper, sink faster. Straightforward energy exchange.
High-gee maneuvers grossly wasteful. Couple more episodes like that, find self on ground ahead of schedule.
Plus noted compass now useless: Violent maneuvers had it spinning merrily.
Glided straight ahead between two other trunks, watching compass with peripheral vision to see if might stabilize in time. Apparently not; dead-reckoning time for Kamikaze Kid—assuming own orientation not equally scrambled by now, as well could be.
Grazed safely past, between several conveniently placed trees, trying to get headed back toward where thought clearing lay. But before completed turn, had to duck around still another bole.
Suddenly mere passenger: Combat computer spotted impossibly closely-spaced cluster of gargantuan trunks immediately ahead; engaged. Sat helpless; watched as plane
. . . stood vertically on left wingtip, tore through left-hander between first two trees, thence instantly—without reversing bank—into subsequent right-hander, pulling negative gees; reversed control inputs coordinating what amounted to inverted turn. Then
. . . airframe bucked, buffeted, shuddered on verge of accelerated stall, as sliced left again between two columns so close together that actually felt bump as main gear grazed bark beneath fanny. And
. . . emerged on final in clearing, wings level, lined up with log, heading straight for massive roots bulging from lower end—now too low to clear. But
. . . throttle already jammed forward, stick back; engine howling deafeningly at full power. Plane ballooned upward several yards, clearing roots by fraction; staggered for timeless instant on brink of stall as engine sputtered again; then stick forward . . .
And suddenly back in control, easing stick back, yanking flaperons down to full drag/lift position, closing useless throttle, flaring out, feeling pounding as wheels bounced on rough, corrugated bark paving log's upper surface. Braked to stop in matter of feet. Killed
engine.
Silence echoed through forest.
Sat unmoving for indeterminate span, blinking fast, breathing hard, disbelieving.
Reviewed past 30 seconds' events; speculated odds on anyone surviving. Concluded never find room to write all those zeros.
And suddenly in grip of giggles: Terry would have loved wild ride. Could almost feel manic twin clutching shoulder as careened amongst sequoia trunks, inches from disaster. Would be crouched, wings half-spread, bobbing head, yelling, "Wheeee-e-e . . . !"
Giggles intensified; shortly indistinguishable from hysteria. Shakes set in soon after. Quite some time before able to unlock quick-release buckle, shrug off harness. First attempt at standing garnered predictable results: Jell-O knees not useful when planning serious legwork.
Decided better deal with physical, emotional condition first:
Removed helmet. Extracted canteen from emergency knapsack mounted behind seat. Poured water on head, shook excess from hair, mopped face with sleeve. Leaned back against seat, closed eyes, took deep breath, held, released slowly. Triggered relaxation sequence; felt body gradually unwind as emotions subsided.
Sat for long moments with eyes shut, breathing regularly. Then opened, looked around.
And fought off momentary resurgence of hysteria. Time-Life photos failed to communicate how big sequoias are. Scale of surroundings distorted reality: They looked normal; I felt small. No one could stand in clearing without reevaluating own importance in Scheme of Things. Example: Can walk better than ten feet laterally from centerline on top of log before encountering important grade—log, for Heaven's sake. . . !
And looking up . . . Opening through foliage almost vanishes in distance, against background. Nobody, viewing this scene, would believe airplane gotten in here via own wings! Even miniature airplane. (Almost don't believe it myself—combat computer one hot pilot . . . !)
Okay, enough awe, philosophy; places to go, things to do, people to meet. Stranded by sick engine nearly 100 miles from anywhere, with lightweight minimum of supplies, tools—and no mechanical background. (How's that for promising scenario . . . ?)
Looked around, evaluating surroundings with eye toward eventual departure. Quickly apparent that, while probably no more fun than arrival, flying out possible, assuming can get engine running: Ultralight designed for passenger weighing 250 pounds maximum; own weight a third that. Resultant angle-, rate-of-climb far better than manufacturer's specifications. No problem anticipated climbing back to, through opening in greenery overhead, ascending chimney beyond to open sky.
Takeoff, however, potentially every bit as hairy as landing; reasons identical: Have to launch into forest, return; then circle wide end of glade, spiral up to, through opening.
Only "into forest" part gives pause. Done that already, thank you.
Return trip bound to be less thrilling, though. Ample time to scout route first; won't be improvising second by second.
But no point worrying now. Becomes consideration only after manage to fix engine. . . .
And background or no background, logic (and time spent looking over Adam's shoulder [lectures almost as compulsively as Daddy]) dictates infernal combustion engine operation dependent on three primary requirements: gasoline, oxygen, spark. As side issue, need correct gas-air mixture. Spark timing critical also.
No, too basic; engine runs fine—but loses oomph after few seconds' brisk operation. Now what easy-to-find, easy-to-repair-without-tools-or-specialized-knowledge failure could cause that?
(Sure better be something like that; only class of problem falling within expertise. Otherwise might as well be total.)
Pushed plane along trunk with some difficulty due to rough bark. Arrived at first tier of branches; turned ship about, nose toward roots. Employed light nylon line included in emergency kit to effect tiedown, using branches as anchor.
Yanked pull-cord. Came out by roots. Said bad word. Then prop-started engine gingerly—first time ever handled propeller with ignition on. Uncomfortable sensation: like violating parents' warning about sticking fingers in electric fan.
Ran up, timed failure. First try produced full-throttle run of almost 20 seconds; then held consistently at five through five more tests.
Good; at least failure mode consistent. Nothing worse than trying to diagnose intermittent problem.
Now all had to do was figure out why . . . .
Shut down engine again. Then realized had forgotten acoustical earplugs; Adam not kidding when remarked unprotected flight left him half-deaf. Exhaust note even louder, standing next to craft, than when flying; helmet offers degree of protection, plus some noise carried away by slipstream. Curious sensation: Yelled experimentally; felt voice in throat, but almost inaudible via ears.
Not particularly worried. Deafness following loud noises usually temporary; results when ears' defenses cut in: Short-term paralysis of ossicles insulates inner ear from overload. Hearing probably return to normal soon if not further abused. (Of course, repeated exposure results in permanent loss, as rock concert aficionados often learned in past. Resolved to use earplugs faithfully hence.) Besides, even if permanent, deafness not treatable here, now. So ignored it; had other problems. Stared at engine, thought.
Problem with troubleshooting two-strokes is are so simple. Too simple: two pistons, two connecting rods, one crankshaft. Five moving parts. What can go wrong . . . ? (Also had solid-state ignition, but if problem lay there—never mind . . . .)
Ran through obvious rituals first: Replaced spark plugs (new this morning; unlikely to blame); checked for loose spark lead, condenser wire; clogged fuel pump, carburetor screens, etc.
Inserted earplugs, restarted engine, ran up, confirmed problem still present. Shut down, glared impotently.
Think: What demand increases with power setting? Gasoline, of course. Well, how about partially blocked fuel line? Perhaps allowing sufficient flow for lower output but starving engine above certain point? Sounded promising; theoretical failure matched real-life symptoms.
But how to test without wasting fuel? Certainly shouldn't dribble on log. Nearly half gone when problem arose; none to spare.
Thought for moment; weighed priorities. Surroundings' appearance suggested no dearth of water in area. Okay. Uncapped canteen, inverted, propped up; turned attention to fuel line.
Required strong fingers: Secured by stiff spring clips. Once clips removed, engine end came off without too much difficulty. Canteen empty by then so held line over opening, let flow.
Almost abandoned investigation before fairly begun; flow strong, steady, clearly adequate. But already invested water in experiment; might as well follow through. Continued, watching closely.
Bingo . . . ! At ten-second mark flow suddenly dropped to trickle.
Smug thrill of triumph, self-satisfaction coursed through soul: So there, Adam—experience not everything; logic works, too . . . !
Okay, now problem isolating cause of blockage. Probably something floating around inside tank. Anything big enough to block outlet surely visible to naked eye.
Momentarily plugged line with fingertip. Unscrewed fuel cap with other hand . . .
Tank hissed as cap loosened, like vacuum-packed jar. Detected immediate fuel-pressure increase against fingertip.
No—couldn't be that simple! Or could it . . . ?
Reinstalled fuel line on carburetor inlet. Poured fuel trapped in canteen back into tank (all but last drop, lest any water remain).
Removed cap all the way, peered down inside tank. Inlet four inches across; tank nicely crafted, bright light-alloy cylinder: Entire bottom visible if moved head around. And, as suspected, absolutely clean; nothing but gas/oil two-stroke mixture.
Then turned attention to cap. Was indeed vented, but cleverly so: intricate compound-leverage float-and-counterweight valve designed to plug breather during brief negative gees. Observed valve closely as inverted cap, then turned upright.
And there it was, big as life! Valve remained in closed
position, sealing vent tightly. Textbook physics demonstration: Fuel not replaced by air as used; resultant vacuum resists further delivery, engine loses power.
Noted, without surprise, country of manufacture: German designers notorious for overengineering, obsession with excess gimmickry. Dieter Heinz, resident madcap mechanic/social critic at small VW dealership back home, possessed in ample measure practical field-worker's contempt for Ivory-Tower theoreticians; opined most warranty recalls result of factory engineers' insistence on devising ingenious solutions to nonexistent problems. Referred to resultant debacles as "chooting zemzelves een ze voot."
Dieter speculated was real explanation of how Nazis lost war. Took particular delight in satirizing defect bulletins, highlighting technical overkill. Remember one in particular:
TO: All Noncommissioned Officers and below.
FROM: Blitzkrieg High Command Quality Control Center.
SUBJECT: Hand-Grenade Repair Bulletin Follow-up.
MESSAGE: In a previous bulletin, ZVP-111000WUB-827–D, it was reported that certain hand grenades manufactured by subcontractor Sturm & Drang between 3 June 1943 and 8 October 1943, bearing Serial Numbers 87A000-112498BZQ148 through 87A000-112498BZS157 in one-millimeter-high characters on the inside of the release lever, have detonated in 4.91465 seconds instead of the specified 4.97771 seconds. This variation exceeded manufacturing tolerances.
Bulletin ZVP-111000WUB-827–D described how to correct this defect. However, it has been learned that this bulletin contains a typographical error. If Step 3 is followed as written, hand grenades so modified will detonate in .07331 seconds and could pose a hazard to the user.
All copies of bulletin ZVP-111000WUB-827–D must be corrected as follows: In Step 3, the word "left" in the third line should be deleted and the word "right" inserted. If the corrected instructions are followed properly, the hand grenades will perform satisfactorily.