◆ SpookStack

AIR COMME. -_ ensines were idled astern; altitude at thie tithe was 120 metera (304 feet), About 2 minutes prior to dropping the bow trail ropes all rnginen were put full astern for A period of about 1 minute fo atop the ahip: after which the forward engines were Idled abead and the after engines were idled astern. When the trail ropes bed been drop the forward engines were fiven a short burst ahead; then idled ahea Release of Ballast Starting at a peint about three-quarters of a mnfle from the landing point 300 kllo- grams (661 pounds) of water ballast was Toyped from ballast bag at frame 77. ‘Then in rapid order, from the aime frame, at about intervals of 1,000 feet, ballast was dropped twice again, the second time, $00 kilograms (661 pounds), the third, 500 kilé- rams {1,100 pounds). Th clease, of 100 kilograms (2,420 poun of water ballast took place within a period pf’ 2 to 8 minutes before the trail ropea were dropped. Valving of Gas According to witness H. W. Bauer's Bketch, gas was valred on the wheel for 15 BecOnds approximntely 10 minutes before dropping the bow trail ropes: ship proceed: ing a fw eruisin speed. About 8&8 minutes prior to dropping of ropes, gas in celis 11 to 16, first_five forward cells, wag valved for 15 seconds; ship then proceeding at 15 meters per second (approximately 3: miles per hour). Approximately 4 to 6 minutes before dropping the ropes, gas in eels 11 to 16, was again valved for 15 seconds; spect of ship 12 to 13 meters per second (approximately 27 miles per honr}, About 2 minutes prior to dropping of rapes, gas 1p eells 11 to 16 was valved for 5 seconds. Crew os Ballast According to the elevstor man who had taken over the elevator helm in tbe landing approach. the ship was etill slightly tai) heavy after dropping water and valving ZAs. consequent'y six men of the crew were sent forward to the bow in order to equalize the weights. Ile was unable to account for the tail heaviness of the ship after the ballast had been dropped. Tail Heaviness The ship was weighed off to the west of the field and was found a Iittle Heht. There followed the trimming operations that have been described In_the preceding para- eraphs. There ig evidence to show that the tail of the ship was heavy during the maneurer. Witness Albert Sammt, second in command of the ship, accounted for thiy condition by saying that it was due to the consumption of fuel: that it gave him no concern because it was very little. There waa diversity of opinion advanced regard- ing this condition of the ship. Witnesses H. W. Bauer and C. E, Rosendahl consid- ered it to be normal. The latter stated that the ship’s tail heaviness bad been fogically accounted for, under the circum. stances in which it landed in a lcht wind with little alr flow on the tail surfaces and consequently Httle aerodynamic Mft, 120 pounds midway from the tall of the ship would he felt by the elevator man and be noticed by those In the control car who were watching the inclingmeter for that very thing: that the condition did not exist from the time of the dropping of the bow trail ropes during the 4 minutes intervening be- fore the fire broke out. 7544—3T- 2 27 To other witnesses the ship appeared heavy in the stern; among them witnesses Benjamin May, in _ehaorge on top of the mooring most, and W. A. Buckley, assistant mooring officer. Witnessea Hlugo Eekencr inicated, according to bie information, that while the ship may have remained in satin- factory trim from the tippe the trall ropcs were dropped until it burned such interval Woe a@ short period of time. He did not think that a hydrogen leak would have been #o large that In such a relatively short time ‘it could have been noticed. He men- Hons the testimony of witness H. W. Bauer, relating to the trimming operations tno which a very short time before the accident six men had been ordered forward. From rthis he infers that shortly before the ship reached the Janding position it was neces- sary to trim ship by putting weight for- wird, and that the elevator man could hardly have noticed anything during this interval because the ship had no more for- ward speed. He further atated that careful calculation showed that the trimming mo- ment effected by these operations amounted to,at least TO,000 to 80,000 meter kilo- grams (506,391 to 578,033 foot-pounds) of trimming effect ; when this effect is com- ared with the trimming moment that cou'd obtained aerodynamically at full eruis- ing speed by the use of the elevator controls in the order of 150,000 to 200,000 meter kilograms (1,088,124 to 1,446,820 foot- pounds), then it became clear to him that the ship was very badly out of trim, Witness Eckener aleo testified that wit- nesses in the control car had reported that the out-of-trim condition originated approxi- mately one-half hour before the landing maneuver after Boing through the rain clouds; that the ship beeame tail heavy by running through heavy rain because’ the weight of the ruin is greater In {ts effect on the horizontal fins, which are hebind the center of avity. There is also another apparent effect of rain upon the ship, That is the tall would seem to be heavy to the elevator man while the ship was running through rain, because it automatically has a tendency to nose up since the ecnter of gerodrnatoic pressure moves aff. Thijs ef- fect, however, disappears very rapidly after passing through rain and in the present nstance must have disappenred quickly be- enuse the ship ag a whole was light.” Tha ship, 10 minutes after passing through heavy rain clouds, should have again been in good trim. In the opinion of witness Eckener, however, ft appeared so tall-heavy that It became necessary to apply a trim- ming effect of some 70,000 meter kilograms (506,391 foot-pounds}, Furthermore, he in- dicated that Hf the abip bad been as tail- heavy before 1t proceeded through the rain clouds, it would not have been operated without the release of ballast. As no tes- “mony was given that ballast had beon dropped before the ship moved into the tain clouds, witness Eckener believed that some unusual condition in the ship micht have developed prior to the ship's ianding. With regard to the amount of rain that the ship had been exposed to during the landing maneuver, there appears to be some difference of opinion, Witness Sammt stated that there was a little rain as the ship crossed the field at the beginning of the maneuver, not heavy enough to weight the ship down as much as §00 kilograms (1.100 pounds) ; that waa the only rain experienced during the last 2 houre of the flight because they had avoided the raln carried in the weather front. As the ship tock a fina! bear- ing on the fleld it made a wide turn Into quiet weather, returning to the field in this condition. According to him, the frent had BULLETIN oF peseed and the weather was favorable for landing. The sky was overcast but without