Odds and ends

Sorry for the recent drought in entries, but as you may have heard we've had a bit of rain recently in Southern California . . . and my roof leaks. Like a sieve, lately. So the nice weather we've had for the last couple of days, which has for once coincided with my weekend, has seen me outside on the roof. Thus, this missive is mostly a composite of recent news items that I found interesting, with no particular connection to each other or anything else I normally comment on:

It's been a month for weird collisions. First, a couple of communications satellites collide in orbit. That news was followed by the announcement that a couple of submarines had collided beneath the surface of the planet's second-largest ocean. Then today, I heard about a train that hit a couple of girls who were sleeping on the tracks! Here are links to each of the stories:

Russian and US satellites collide

Nuclear subs collide in Atlantic

2 Teen Girls, Injured by Train, Cope with Change


Ever-so-slightly related to the first two stories, respectively, are two more. One about a joint effort to send a space probe to Jupiter's moon Europa, and the other about a recent discovery of a French battleship sunk in World War One:

Jupiter in space agencies' sights

Danton wreck found in deep water


I don't have anything special to say about the crash of the Colgan (flying as Continental Connection) Dash-8 last week. All the information I have came from public media sources, so no inside information stuff here. From the sound of it, the airplane had accumulated a load of ice, perhaps more than realized by the crew. When they extended the flaps on approach to Buffalo, the altered air flow over the wings and particularly the tail may have caused them to experience a loss of control. This could have been exacerbated by the reportedly gusty crosswinds in the area. The flight data recorder indicated that they attempted to retract the landing gear and flaps in their efforts to regain control, but ran out of altitude. While I have no Dash-8 piloting experience, I will say that the accepted practice in small general aviation aircraft is to leave the flaps up if the pilot suspects he may have accumulated ice. This quote comes from an FAA Advisory Circular to pilots about the effects of icing:

A tailplane stall occurs when, as with the wing, the critical angle of attack is exceeded. Since the horizontal stabilizer counters the natural nose down tendency caused by the center of lift of the main wing, the airplane will react by pitching down, sometimes uncontrollably, when the tailplane is stalled. Application of flaps can aggravate or initiate the stall. The pilot should use caution when applying flaps during an approach if there is the possibility of icing on the tailplane.


Links:

BBC: Plane crash in NY state kills 50

FAA Advisory Circular 91-51A

Capt. Dave's blog, part 1

Capt. Dave's blog, part 2