Although summer is just around
the corner, one winter-type woe often hangs around long after winter is
officially past. Unforecast or unexpected IMC can turn an otherwise pleasant
flight into a stressful one.
- The flight
was conducted in VMC. Turn to final approach course was a sharp descending
turn from VMC into IMC. I immediately got disoriented and started hyperventilating.
After a short period of time that felt like forever, I decided to abandon
the approach and advised Tower Controller. I calmed myself down [subsequently]...and
successfully completed an ILS approach and landing. Though I am legally
current and have a significant amount of "real" instrument
time given my level of experience, I plan to grab an instructor and
go get some more, particularly with the VMC-to-IMC transition.
Our reporter has the right
idea. A springtime "tune-up" is a good plan for pilots, and
for aircraft, too.
Air carrier aircraft are not immune from the perils of unforecast IMC.
The next report illustrates how little prob lems can grow into big ones,
even for large aircraft.
- After takeoff,
both magnetic compass systems began to precess. We quickly determined
that we could navigate safely using our VORs and by updating our magnetic
compasses with reference to the standby compass. We were safe and legal
to continue, provided we remained in visual conditions. As we approached
[our destination], the weather deteriorated and we requested a vector
to our alternate. Due to our reduced reserve fuel from circumnavigating
en route weather, we declared an emergency to receive priority handling.
Some pilots may associate icing
only with winter flying. As the following reports illustrate, and as Murphy's
law would have it, carburetor and fuel system icing can occur anytime.
- Two tailwheel-qualified
CFIs were on board for a training flight. Carb heat was applied and
the throttle closed in preparation for a power-off stall. As the aircraft
approached a stall attitude, the prop stopped abruptly. The air temperature
and dew point were 53 and 44 degrees Fahrenheit, respectively. These
parameters plot in the region of maximum carb ice probability. Although
full carb heat was applied prior to closing the throttle, the heat may
have been insufficient.
The next reporter, a pilot
of a corporate twin, had expected better performance from his turbocharged
engines. He is now looking into ways of preventing a repeat of this incident:
- After departure...to
avoid an inadvertent cloud encounter and potential ice, I proceeded
to 17,500 feet. About one minute later, the right engine began to miss
and the EGT gauge dropped all the way down. The cylinder head temperature
on the left engine dropped abruptly, as did the [temperature] on the
right engine. Both engines were running rough. There was no change in
manifold air pressure, RPM or other engine instruments. [We made a long,
slow descent to a nearby airport]. At 6,000 feet, both cylinder head
temperatures came up and the engines smoothed out.
After some investigation back
on solid ground, our reporter found small amounts of water in the sump
A holdover from springtime
is hay fever, allergies, and sinus problems. Some pilots are affected
all year long, their afflictions causing conflictions, as this First Officer
- We were
descending in holding to FL220. The Captain (not flying) was clearing
a sinus block. I was cleared lower, I thought to FL190. The Captain
did not hear the clearance, but saw me set FL190 in the altitude reminder
and he read back the clearance to FL190. ATC responded that we were
only cleared to FL200 and turned us behind [conflicting] traffic without
A contributing factor was the
ear block, [which] made it difficult for the Captain to hear and repeatedly
distracted him as he tried to clear it.
A passenger's allergies can also make life exciting for the pilot.
- During descent,
my wife began having an allergy attack and requested her medicine from
the rear seat. As I turned to reach for the medicine, I inadvertently
disconnected the autopilot. I reactivated it, [but] in my haste to help
my wife, I neglected to reactivate the descent altitude warning system.
I was subconsciously relying on the altitude warning system to advise
me of my assigned lower altitude. The Center Controller then said he
showed me 700 feet below my assigned altitude. I immediately corrected
altitude and was then handed off to Approach.
Lesson learned: Even when flying in the company of a distraught and
medically needy wife, the pilot must always first fly the airplane.
as an anonymous ASRS staffer noted, "better to receive the nagging
of a spouse than the snagging of an aircraft by Mother Earth."
"If you want it done right,
do it yourself," common wisdom goes. Actually, doing it yourself
usually is not necessary if the flight crew and ground crew coordinate
their efforts and follow company policies regarding MELs (Minimum Equipment
Lists). In this ASRS report from a Part 135 commuter First Officer, a
breakdown in communication opened the door--or rather the cowling--to
a mishap that could have had much more serious consequences.
- Our crew
arrived late... The PIC was briefed on three open maintenance items,
and departed to speak with dispatch. I completed an exterior safety
inspection at the same time maintenance personnel began work on the
outstanding items. [We] were briefed that the first two items were completed
and signed off, and the third item was to be deferred as per the MEL.
At no time was the crew informed that a cowling had been opened in order
to look at the third maintenance item, and then been closed.
Climbing through 2000 feet...a passenger noticed the #2 nacelle cowling
had blown open.
Perhaps the greatest contributing factor was the failure in communication
between maintenance and the crew. [Usually] a second quality assurance
checker inspects and then signs off the work. This does not appear to
have happened in this instance. Perhaps, too, the crew's eagerness to
complete their trip was a contributing factor. Presently, company policy
is being reviewed to prevent this from occurring again.
It's possible, too, that the
maintenance personnel also felt the schedule pressure, and in their effort
to speed matters along, overlooked their own quality assurance procedures.
Day, Same Story
Pilots sometimes see the same
logbook write-up time after time. At some point, the write-up may be unconsciously
viewed as a "non-event," and hence given a low priority in the
course of normal pre-flight actions.
had two CDL items (Configuration Deviation List--similar to an MEL except
related to airframe items), both for covers for landing gear hinges.
This CDL is common, and the only usual flight crew action is to apply
a slight weight penalty to the max takeoff weight. [Later], a careful
reading of the CDL revealed that while two hinge covers could be missing,
they had to be on the same side. These were on opposite sides.
The pressures of on-time departures
may lead some pilots to abide by the letter of an MEL, but forget the
spirit of "safety first." More from this ASRS report:
- I was scheduled
to deadhead on this particular flight. Twenty minutes before scheduled
departure time, I was paged and told to call crew scheduling. I was
asked to then fly as Captain on that particular flight since the regularly
scheduled Captain's wife had become ill and [he] needed to return home.
"No problem," I said.
By the time I changed into uniform, obtained the necessary paperwork
and seated myself in the cockpit, it was 5 minutes prior to push. It
was then that I found out that since this particular aircraft had just
come from a rework facility, that no catering supplies were on board--no
beverages (including coffee) or snacks--and nothing could be found prior
to taking a 1-hour delay. Additionally, one of the local home town carriers
canceled a flight and sent all their passengers over with no advance
notice. The flight was now oversold.
Next, the Flight Attendant informs me that the cabin PA volume is very
weak and hard to hear. It's now scheduled departure time with every
seat occupied and everyone aware that no beverages or snack would be
served. Do I then inform the passengers that we will take a maintenance
delay to look over the PA system? No, let's make them happy and arrive
on time. After pushback and engine start, the Flight Attendant informs
me that the PA volume is so low that it cannot be heard. The MEL says
we can dispatch without it, so we proceed with alternative means. After
takeoff, I find out that one of the megaphones, which preflight checked
OK, was also not working properly...
Problems don't fix themselves. They only get worse and compound...My
late arrival to the cockpit certainly didn't help matters. Had I been
there sooner, I would not have hesitated calling maintenance. I let
being "on time" cloud my judgment of safety first. Fix the
problems early before they get worse and unfixable.
MELs are not the only source
of melancholy for pilots. Company-required paperwork can sometimes distract
pilots from their flying duties, as was the situation in this deviation
report from an air carrier Captain:
- Over the
VOR, the First Officer (F/O) requested, "Direct ABC." The
Controller responded with the altimeter and what I thought was, "When
able, direct ABC." In reality, he said, "Unable direct ABC."
The F/O responded with the flight number. I should have been more aware
that the F/O did not read back, "Direct ABC." His attention
was distracted by company paperwork. The solution is obvious: Read back
Although the Captain's suggestion
is good as a short-term fix, the "big picture" solution is for
both pilots to be fully tuned in during ATC communications.
ASRS Recently Issued Alerts
- An uncharted flight restriction
area in the Southwest
- A non-standard rotating
beacon at a Minnesota airport
- Concerns over a new FAA
flow control program (MAPS)
- Multiple incidents of Airbus
320 false engine fire warnings
- Frequency "blind spots"
at an ATC transmitter/receiver site
March 1995 Report Intake
- Air Carrier Pilots--2123
- General Aviation Pilots--848