Saturday, February 14, 2009

Icing and Other Questions

Yes, the Dash 8 Q400 airplane and its siblings in the Bombardier line of Dash 8 turboprops are highly regarded airplanes, despite the landing gear problems that were associated with three non-fatal crashes in Scandinavia in the fall of 2007.

And clearly, wing-ice has emerged as the probable primary cause of the horrific crash that killed 50 near Buffalo Thursday night on a Continental Airlines flight operated by Pinnacle Airlines subsidiary Colgan Air.

So here are the major lines of inquiry as I see it:

1. Big turboprops apparently are more susceptible to icing -- which of course makes operational changes in a wing's shape and attack -- than jets. Let's have a close look at de-icing systems on the Q400, which have already been flagged by the FAA.

2. Maintenance: the next big story in commercial aviation. Who maintains the fleet, and where? Across the board, regional airlines, squeezed hard by the majors for whom they fly, have been slashing costs. Follow the money.

3. Following the money, who flies these airplanes, and under what conditions? You don't have to press very hard to find underpaid regional jet pilots who grab a miserable night's sleep in the terminal before hauling themselves back into the cockpit for the next shift -- which is then flown in technical adherence to the law.

Look at the working conditions of the crews of our regional airline system and tell me how confident you feel getting on a flight on a windy, icy night. (Or how confident they feel).

The pilot of the 74-seat Dash 8 that crashed near Buffalo was Marvin D. Renslow, 47, employed by Colgan since September 2005. The first officer was Rebecca Lynne Shaw, 24, who was hired by Colgan a little over a year ago.

According to data from IAG AirInsight, Colgan Q400 captains make about $58,000 a year. First officers (co-pilots) make ... are you ready? ... $27,000 a year.

Here's some interesting background in an e-mail from Michael Ciasullo, the managing director of IAG:

"Pilots will fly about 6-7 hours on days when they are scheduled to fly. This is called block time and is measured from the t, Pilots' formally scheduled flight time "is measured from the time they leave the gate until they pull into the arrival gate at their destination.

However, there is another thing called duty day and that is essentially from the time the pilot leaves the hotel in the morning until they get to their hotel at
night. This can make the work day up to 14 hours long. Your pay is based off
block time so as soon as you pull into the gate the pay clock stops but you
still have to sit and wait to fly the plane to the next destination. You
don't get paid for sitting in the terminal or waiting.

So, in summary, their 'off time' can be up to double their actual flying
time on the days they fly; pilots don't fly every day. They will do 6-7-8
hours a day for 2-3 days in a row maybe three times a month. All adding up
to about 75 hours or so. Pilot are limited to 1,000 hours per year of flying
by the FAA."

And therein, folks, lies a hell of a story.


1 comment:

Anonymous said...

While it's far too early to blame the Colgan crash on pilot fatigue, your points on the topic are valid ones. Many airline pilots, particularly at the regional airlines, have appalling work schedules (I fly for one of the worst offenders, so I have some small expertise in this matter). As you point out, duty days of 14 hours or more are common, as is what the FAA calls "reduced rest".

Reduced rest can be as little as 8 hours, but that time includes getting from the airport to the hotel, eating a meal, sleeping, morning ablutions, getting back to the airport and going through security screening (don't get me started on the futility of that exercise).

Despite the clear intent of the language in the Federal Aviation Regulations about reduced rest (i.e. that it exists as a means of recovering from unforeseen delays in an airline's schedule), many regionals use it as a routine scheduling tool.

Combine these facts with the reality of continuous duty overnights (which we euphemistically call "camping trips"), flip-flop schedules wherein crews change from day flying to night flying within the same three to four day trip, and rest periods during daylight hours, and it's no wonder that modernizing pilot flight time/duty time regulations tops the National Transportation Safety Board's top ten most wanted list of aviation safety improvements.

As for the Colgan crash, it may very well turn out to be ice related, but it's unlikely to be wing icing. The Q400 has a wing anti-ice system that's quite effective, but like many aircraft, it has no anti-ice system for the tail.

Here's one possible scenario: Load up the tail with ice and lower the airspeed for approach, both of which decrease the effectiveness of the tail. Throw in a configuration change as flaps are lowered (which usually pitches the nose down, requiring an increased angle of attack on the tail). Finally add the increased stall speed that goes along with banking for the base-to-final turn, and you have a recipe for an accelerated stall of the horizontal stabilizer resulting in an uncontrollable nose-over.