c5load From United States of America, joined Sep 2008, 917 posts, RR: 0 Posted (5 years 1 month 2 weeks 3 hours ago) and read 4583 times:
I was spotting over at BWI about a week ago and saw a DC-9-30 from DTW come in. It looked cool in the old NWA colors, but that's beside the point. Unless I was crazy and saw things, it didn't have normal flashing wingtip strobes. Instead, they seem to rotate back and forth similar to the acl. Was this how the early strobes were?
"But this airplane has 4 engines, it's an entirely different kind of flying! Altogether"
KELPkid From United States of America, joined Nov 2005, 6658 posts, RR: 3
Reply 2, posted (5 years 1 month 1 week 6 days 21 hours ago) and read 4481 times:
Quoting LAXintl (Reply 1): Navigation beacon and strobes in the past were simply high intensity bulbs.
Strobes are not bulbs. Strobes are (were? ) tubes filled with Xenon gas that had two electrodes (one at either end of the tube). To make a strobe go "blink", you apply a high electrical voltage, which causes the Xenon gas therein to emit a bright light as the outer electrons in the gas go to a higher energy state and then release the light when they return to their previous state... Nowadays, though, new "strobes" are just really bright LED's. However, many genuine strobe installations remain in service, not only on older planes, but also on ambulances, fire engines, even fire alarms in buildings.
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
LAXintl From United States of America, joined May 2000, 27435 posts, RR: 50
Reply 3, posted (5 years 1 month 1 week 6 days 19 hours ago) and read 4436 times:
No early strobes like lighting was very much bulbs.
On older aircraft, like props, 707, and even maybe early 747s as I recall, they were simply most often paired white bulbs that would cycle on off. No fancy xenon as stroboscopic lighting systems did not come into being till the early 1960s.
It was not until 1971 when FAA/CAA and later ICAO came up with standard that required stroboscopic lighting to flash about 60-times per minute at some minimum candela value and gave manufacturers till 1976 to be in compliance. As I recall the L-1011 was the first US aircraft certified that met that standard.
From the desert to the sea, to all of Southern California
stratosphere From United States of America, joined Sep 2007, 1680 posts, RR: 5
Reply 5, posted (5 years 1 month 1 week 6 days 14 hours ago) and read 4367 times:
Quoting c5load (Thread starter): I was spotting over at BWI about a week ago and saw a DC-9-30 from DTW come in. It looked cool in the old NWA colors, but that's beside the point. Unless I was crazy and saw things, it didn't have normal flashing wingtip strobes. Instead, they seem to rotate back and forth similar to the acl. Was this how the early strobes were?
Yes early DC-9's and even early 727's have an oscillating light instead of a strobe. At NW it was only some of the -30 models that had them the 40-and 50's had strobes.
Thinking more about it, this same DC-8 also had its green forward starboard wingtip light lit by an oscillating light, like some of the DL Shuttle 727s I watched at DCA back in college. I was slightly bummed that the DC-8's red forward port wingtip light was stationary and that the red ACLs were both strobes. After all, those select DL Shuttle 727s had both the oscillating red/green wingtip lights and rotating ACLs...very cool to watch for it made the aircraft almost seem "alive". Then again, we all know it's perfectly natural for old aircraft to be a patchwork of different types of lights after going through "millions" of MRO cycles.
Anyway - question: why did some of those early aircraft have oscillating red/green forward wingtip lights while the norm has long been to have them stationary?
AA737-823 From United States of America, joined Mar 2000, 6137 posts, RR: 10
Reply 10, posted (5 years 1 month 4 hours ago) and read 3853 times:
Quoting LAXintl (Reply 3): On older aircraft, like props, 707, and even maybe early 747s as I recall,
The old girls I've worked on all had a single, stationary bulb, and a rotating chrome reflector. Kind of a pain, because the motor to the rotating reflector went out almost as often as the bulb did. And on the upper deck of the 747, you must go through the cabin ceiling panels to replace it. Which always happens in January, which means that you're going to let snow and deice fluid into the cabin, or at least into your eye.