Airline pilot safety publication

1. The
LEading EdgE
A Comair Central Air Safety
Winter 2010 Committee Publication
How to Assess As airline pilots, all of us have made
hundreds of landings and have an
Your Landing intuitive understanding of how
much runway it takes to stop an
Distance in airplane. On a nice day, we always
have enough pavement for comfort.
Bad Weather But what happens when it’s a snowy
night with a 5-knot tailwind and a
braking action report of poor by the
By Dean Weaver
CRJ50 First Officer previous aircraft? Suddenly, 6,000
feet of runway may not seem so long.
F
our U.S. airline crews have 2. actual landing distance is a To answer this, you must first de-
slid off runways when land- number provided by Bombardier termine where the aircraft’s main
ing during the past five years. engineers and is printed in the wheels touch the runway.
Each overrun occurred on a performance chapter of Comair’s
runway longer than 6,000 ft. Four of AeroData’s TLR report assumes the
Flight Standards Manual.
the five occurred in snowy condi- CRJ100/200, 700, and 900 series
3. dispatch landing length is a aircraft will touch down at 1,560 ft.
tions, and four of the five overruns number used by airline dispatch-
occurred at night. These accidents past the runway threshold. On a pre-
ers to determine if it is legal to cision instrument approach runway,
reveal that even experienced pilots send an aircraft to a particular
can miscalculate the distances this is on the first distance marker
airport based on the forecast past the large solid white aim point
needed to stop in adverse weather. weather conditions at the flight’s markers (see Figure 2).
Comair, the airline industry, and the estimated time of arrival.
Federal Aviation Administration have None of these landing-length num- If you fail to touch down at 1,560 ft.,
taken a hard look at why runway bers are the same, although all are it will be very difficult to stop in the
overruns occur. New guidelines have calculated by assuming the aircraft is distance depicted in the TLR.
been implemented so pilots have 50 ft. above the landing threshold at
more information on the flight deck Vref. Each number also accounts for Please see landing distance
to determine if they have enough wet or contaminated surfaces. page 2 
runway length to stop their aircraft.
This article will provide you with the
But despite these efforts, it is still
easy to get confused about landing-
tools to sift through the various
charts, tables, and manuals to InsIDe…
length numbers. Comair must cal- answer the critical question: 1 How to Assess Your Landing
culate three different landing-length
numbers on every flight.
do i have enough pave- Distance in Bad Weather
ment to stop my air-
1. aerodata’s takeoff and land- plane on this runway 4 Recent U.S. Airline
ing Report provides a landing with the current Overrun Landing Accidents
distance from threshold number. weather and
This number is printed on the bot- runway condi- 5 Factors Affecting Landing Distance
tom of the dispatch release. tions?
7 Aviation Safety Action Program Update

2. landing distance
Continued from page 1
TOUCHDOWN ZONE
Aircraft crosses the runway threshold 3000 FT.
at 50 ft. above the ground at Vref
1,000 FT. TOUCHDOWN − Touchdown for actual landing distance calculation
1,560 FT. TOUCHDOWN – Touchdown points for TLR landing distance
calculation (accounts for are at landing)
To arrive at this touchdown point aircraft how to calculate landing Standards Manual. This number is
calculation, Comair check airmen distances and what techniques pilots calculated differently than the TLR
evaluated hundreds of flights dur- should use to land in the shortest number in two significant ways.
ing line checks and watched aircraft possible distance. 1. The Actual Landing Distance number
land from control towers in CVG and The FAA is urging all air carriers is derived from Bombardier test
LGA. The average touchdown point to base the new landing-distance pilots flying new aircraft. To cer-
from those landings was 1,560 feet numbers on a realistic touchdown tify the CRJ under Part 25 Federal
for all Comair aircraft. This number point and add a 15 percent safety Aviation Regulations, Bombardier’s
was given to AeroData. It is used buffer. These landing-length num- pilots were able to touchdown firmly
as a baseline for calculating landing bers give pilots a more realistic idea at exactly 1,000 ft. from the runway
length on every TLR. AeroData then of how much runway they need to threshold and apply maximum brak-
applies a 15 percent buffer to the stop. However, the FAA still requires ing to stop in the stated distance.
total landing distance. operators to provide Actual Land- The 1,000 ft. touchdown is for dry
These numbers can be corrected for ing Distance numbers to pilots so a and wet landing numbers. Contami-
wind, no thrust reversers, and wet or suitable runway isn’t overflown in the nated runways assume a touchdown
contaminated runway surfaces. They event of a time-critical emergency. at 1,500 ft.
assume maximum use of reverse 2. The Actual Landing Distance number
Comair’s Actual Landing Distance
thrust (if available/utilized) numbers are shorter than AeroData’s does not have a 15 percent safety
and maximum braking to achieve TLR landing numbers and can still Please see landing distance
the stopping distance. Knowing this, be found in Volume I of the Flight page 3 
you can calculate your own personal
landing distance minimums based on
LEading EdgE
where you typically touch down.
The
The TLR landing numbers were
generated by Comair as a result of The Leading Edge is a quarterly publication produced by volunteer Comair pilots
SAFO 06012. The Safety Alert for who are members of ALPA’s Central Air Safety Committee. The goal of the commit-
Operators was issued by the FAA on tee is to promote and enhance safety at Comair.
August 31, 2006, after the Southwest Mail inquiries to:
Airlines overrun at MDW airport. It Comair MEC Editor: Dean Weaver
requests all air carriers re-evaluate Attn: Leading Edge E-mail: Dean.Weaver@alpa.org
the landing-distance numbers they 3490 Olympic Blvd., Suite 120
provide to pilots. Advisory Circular Erlanger, KY 41018
91–79 issued November 6, 2007, Please share any ideas, questions, or comments you have with us.
tells operators of all turbine-powered
2 ThE LEading EdgE

3. landing distance
Continued from page 2
TOUCHDOWN – 1,000 ft. from threshold
Touchdown point for calculating
Actual Landing Distance dry/wet
buffer added to total landing dis-
tance. It is the absolute minimum
stopping distance with a test pilot at
36
the controls of a new aircraft.
Comair asks pilots to apply Quick
Reference Handbook (QRH) land-
ing corrections to the Actual Land- TOUCHDOWN – 1,560 ft. from threshold
Touchdown point for calculating RUNWAY TOUCHDOWN ZONE
ing Distance number, not the TLR TLR Landing Distance Every 500 ft.
number. For example: An anti-skid
inboard and outboard failure occurs,
so the QRH applies a 75 percent
addition to landing distance. This
correction must be added to the
Actual Landing Distance in the FSM, Figure 2: On a runway with presicision instrument markings the ILS glideslope intersects
not the TLR landing distance. the runway at 1,000 feet, which is the beginning of the aim point markings. Comair’s landing
distance numbers depicted on AeroData’s TLR add 560 feet to account for the flare so the
Dispatchers use a third landing touchdown point is 1,560 feet from the threshold.
number when determining if a flight
is legal to depart to an airport. A
word of warning, the Dispatch Land- When en route, it is up to you as the In an emergency or aircraft sys-
ing Field Length number is based on pilot to determine the landing dis- tem malfunction, the QRH correc-
the longest suitable runway at the tance needed to stop your aircraft. tions must be added to the Actual
airport, which may not be the landing The TLR provides the most realistic Landing Distance numbers, giving
runway at the time of arrival. landing-distance numbers you can you a best-case landing perfor-
expect as long as you touch down mance number for landing assess-
Dispatch Landing Field Length is a ment. The corrections are added
pre-departure requirement based on to the shorter Actual Landing
Federal Aviation Regulation 121.195 Recent history has Distance number so a crew will not
and 121.197. It states that a tur- rule out a nearby runway during a
bine- powered transport category shown that the best time-critical emergency in search
aircraft must land and come to a full of a longer landing strip. If time
stop within 60 percent of the effec- way to keep your permits, you may want to consider
tive runway length. You can divide applying these QRH corrections to
the Actual Landing Distance number
aircraft out of the the TLR number to get a picture
(dry runway) in the Flight Standards dirt is to take a few of landing length required in a less
Manual for the aircraft’s weight by than best case landing.
0.6 to get the Dispatch Landing minutes to conduct Recent history has shown that the
Field Length.
a thorough landing- best way to keep your aircraft out
For example: The Actual Landing-Dis- of the dirt is to take a few minutes
tance is 3,800 ft. 3,800/0.6 = 6,333 distance assessment to conduct a thorough landing-
ft. So, a suitable runway of 6,333 ft. is distance assessment using the
required for at least one runway at the using the most recent most recent runway conditions.
destination airport.
runway conditions. The second best way to prevent
an overrun is to touch down within
An additional 15 percent is added
the first 1,560 ft., since that is the
to the dry Dispatch Landing Length
at least 1,560 ft. from the threshold touchdown point the TLR numbers
for a wet runway or low visibility and
and use maximum reverse thrust are predicated upon. 
another 15 percent for a wet runway
and low visibility. These Dispatch and braking. Make sure you use the
Landing Length numbers are depict- correct TLR numbers for the runway
ed in a table in the Flight Standards surface, i.e., wet or contaminated,
Manual, but are only pertinent when and correct for a tailwind.
dispatching an aircraft.
Winter 2010 3

4. southwest Flight 1248 Recent
dec. 8, 2005 (7:14 p.m.) The crew of Southwest Flight 1248 from Baltimore-
Washington International Airport (BWI) to Chicago Midway Airport (MDW) at- U.s. Airline
Overrun Landing
tempted to land on Runway 31C measuring 6,522 ft. in length.
The weather before landing was reported at a 1/2 statute mile with snow, freezing
Accidents
fog, and a broken ceiling of 400 ft. Wind was 090 at 11 knots (an 8-knot tailwind).
Braking action was reported good for the first half of the runway and poor the
second half. Runway 31C was the only runway available to landing aircraft due to
approach minimums and weather.
The Boeing 737 touchdown was 1,250 ft. beyond runway threshold. The captain had
difficulty unlocking the thrust reversers, and they were not fully deployed until 15 sec- Pinnacle Airlines
onds after touchdown. The aircraft rolled through a blast fence and perimeter fence,
and onto a roadway. A 6-year-old boy in one of the vehicles struck by the aircraft Flight 4712
died. The five crewmembers, along with the 98 passengers, survived; 18 were injured.
april 12, 2007 (12:43 a.m.)
Probable cause: The NTSB determined the probable cause was the pilots’ The crew of Pinnacle Airlines Flight
failure to use reverse thrust in a timely manner. A contributing factor was the delay 4712 operating as Northwest Airlink
in reverse thrust due to confusion over the autobrake system. Southwest’s failure from Minneapolis–St. Paul Inter-
to provide its crews with procedures for calculating landing distances that would national Airport (MSP) to Traverse
provide for a margin of safety was also a factor. City–Cherry Capital Airport (TVC) at-
tempted to land a CRJ 200 on Runway
28, measuring 6,501 in length.
The wind was 020 at
8 knots (an 8-knot
shuttle America crosswind). The ASOS
reported visibility of 1/4
Flight 6448 mile with heavy snow,
Feb. 18, 2007 (3:06 p.m.) The crew of vertical visibility of 200
Shuttle America Flight 6448 operating as ft., three minutes prior
Delta Connection from Atlanta Hartsfield- to the accident. Airport
Jackson International Airport (ATL) to personnel told the crew
Cleveland Hopkins International Airport they estimated a 1/2
(CLE) attempted to land on Runway 28 inch of snow on the run-
measuring 6,017 ft. in length. way prior to landing. The
Pinnacle Airlines Flight 4712 comes to rest at
the end of Runway 28 at Traverse City–Cherry aircraft touchdown occurred 2,400
The RVR for Runway 28 was reported at Capital Airport on April 12, 2007. Photo taken ft. beyond the threshold. The CRJ
6,000 ft. with a braking action of fair. Winds by the NTSB, courtesy of the Flight Safety came to rest 100 ft. beyond the end
were 310 at 12 knots (an Foundation. of the pavement after the nosewheel
11 knot crosswind). The separated from the airplane. There
glideslope was reported were no injuries to the 49 passen-
unusable. Once inside gers, three lap children, and three
the final approach fix, the crewmembers.
RVR decreased to 2,200
ft. The crew encountered Probable cause: The NTSB deter-
strong, gusty winds dur- mined the pilots failed to perform a
ing the flare and touch- landing distance assessment tak-
down and reported losing ing into account the contaminated
sight of the runway 30 runway conditions. Pilot fatigue was a
feet before touchdown. contributing factor.
The aircraft touchdown
was 2,900 ft. beyond Shuttle America Flight 6448, an Embraer 170, slides through a perimeter fence off
runway threshold. Despite the use of the end of Runway 28 at Cleveland-Hopkins International Airport on Feb. 18, 2007.
maximum reverse thrust and braking, the Photo taken by the NTSB, courtesy of the Flight Safety Foundation
Embraer 170 came to a stop 150 ft. past
the end of the runway in the snow-covered
grass. All four crewmembers and 71 pas-
sengers survived, with three minor injuries
American Airlines Flight 331
reported. dec. 22, 2009 (10:22 p.m.) The crew of American Airlines Flight 331 from
Miami International Airport (MIA) to Kingston–Norman Manley International
Probable cause: The NTSB determined Airport (KIN) attempted to land on Runway 12 measuring 8,900 ft. The pre-
that the crew should have executed a
missed approach when visual cues to the liminary investigation shows the Boeing 737 touchdown was 4,100 ft. from the
runway were not distinct and identifiable. threshold with a 14-knot tailwind. The aircraft skidded across a road and slid to a
Contributing factors were the long landing stop on the beach with the fuselage cracked and right engine ripped off. Heavy
and the decision to use ILS versus local- rain showers were reported at the airport before the accident, which is under
izer minimums, along with pilot fatigue. investigation. The six crewmembers and 148 passengers survived the accident.
Probable cause: To be determined.
4 ThE LEading EdgE

5. Factors
Affecting
Landing
Distance
By Dean Weaver
CRJ50 First Officer
Photo Credit: Bruce Leibowitz, Airliners.net
The two pilot-controlled A Comair crew lands on a wet Runway 27 at South Bend Regional Airport on August 17, 2004.
factors that contribute the
The top reasons for Combine the stopping distance and
most to landing distance float from the 5 knots of additional
are excess airspeed and an overruns are things that airspeed, and total landing distance
increases by 1,500 ft above the
extended flare. pilots control:
published number. Add snow or a
1. Failing to go-around when vis- tailwind into the equation, and land-
Bleed off 5 knots of excess airspeed ibility is lost or the approach is ing technique may double what the
in an extended flare, and the aircraft unstabilized aircraft manufacturer considers to be
can easily float to the end of the the actual landing distance on wet or
2. Landing long
3,000 ft. touchdown zone, according contaminated surfaces.
to data supplied by Federal Aviation 3. Ineffective braking, especially
Administration Advisory Circular when landing on a contaminated The amount of flare and excess
91–79. runway airspeed are the biggest factors
These findings come from the Flight when it comes to piloting technique
Making a landing assessment is criti- to achieve the published landing-
Safety Foundation, a nonprofit avia-
cal when runway surfaces conditions distance numbers, but there are other
tion organization in Alexandria, VA,
get slippery. These calculations must conditions to consider. Some other
that analyzed 1,429 commercial
include aircraft weight, airport winds, factors include:
turbojet and turboprop landing excur-
and type of runway contamination.
sions that occurred worldwide from
Wind: A 5 kt. tailwind can add 450
But this is not enough to prevent an 1995 to 2008.
ft. to the actual landing distance on
accident. Ultimately, stopping the dry pavement, according to Comair’s
The foundation discovered that excur-
aircraft within a published landing dis- Flight Standards Manual. But that 5
sion accidents are 40 times more
tance comes down to pilot technique. kt. tailwind adds 800 ft. when the run-
likely to occur than runway incursion
“I would have to say that 95 percent accidents. It defines a runway excur- way is contaminated with loose snow.
of the runway excursions we’ve stud- sion as any time an aircraft leaves the
A crosswind adds distance to a land-
ied have involved incidents where the runway on either takeoff or landing.
ing since it requires the pilot to ex-
numbers would have told the pilots tend the flare by a couple of seconds
AC 91–79 urges all turbine pilots to
that landing on the runway would to remove the crab and lower the
maintain a stabilized approach and re-
not be a problem,” said Jim Burin, wing. The advisory circular estimates
alize that landing technique plays a vi-
director of Technical Programs for the that this can add 460 ft. to landing
tal part in preventing runway overruns.
Flight Safety Foundation. “But those distance.
A pilot who adds just 5 knots to Vref
numbers don’t always help pilots
for gusty winds may add up to 250
make sense of really important things threshold crossing Height:
feet to the stopping distance on a wet
like touchdown point and aircraft Being 50 ft. high over the runway
runway, according to the advisory cir-
speed. The numbers are only accurate threshold (100 ft. AGL) will add ap-
cular. And if the pilot bleeds off those
if you use actual runway conditions at proximately 1,000 ft. to total landing
5 knots of airspeed in the flare prior to
the time of landing.”
touchdown, the landing distance swells
by an additional 1,250 ft. Please see
Factors affecting landing
distance page 6 
Winter 2010 5

6. FactORs aFFecting landing distance
Continued from page 5
distance for all turbine powered air- Taking into account the aircraft
craft, according to the Flight Safety weight, wind, and runway surface
Foundation’s Approach and Landing condition in a landing assessment is
Accident Reduction Task Force. the first step in determining if there is
enough runway to stop. Ask the tow- the Flight safety
Runway slope: Each one degree of er for recent braking action reports. Foundation issued a
runway down slope adds 10 percent Review AeroData’s Takeoff and Land- report in May 2009
to the total landing distance. Runway ing Report and estimate where you identifying runway
slope numbers can be found on the believe the aircraft will touch down incursions as one of
back of Jeppesen’s airport diagrams. based on current wind conditions and the top safety threats
glidepath angle: Trying to sneak your own landing technique. to commercial aviation
the airplane in beneath the glideslope If you believe it is unlikely the worldwide.
can actually increase landing dis- wheels will make contact with the
tance. When flying a shallower glide- They recommend the following
runway before 1,560 ft., then add strategies to prevent overruns:
path with additional power, landing a buffer to your landing distance
distance grows. The FAA states that calculations. All TLR landing-length 1. Use a runway with an ILS or
flying a two-degree glidepath instead numbers are predicated upon a precision approach path guidance
of a three-degree glidepath will add to greatly reduce the risk of an
1,560 ft. touchdown point.  overrun.
about 500 ft. to the landing distance.
2. Obtain a timely report of the run-
way surface condition and current
winds at the airport. Falling snow
can turn a good braking action
the Faa recommends the report to poor in less than 15
minutes. Be wary of landing with
following techniques to bring any tailwind.
an aircraft to a stop quickly 3. Consider all landing factors, includ-
ing temperature, pressure, wind,
runway contamination, runway
1. Stabilize the approach at 1,000 ft. above the touchdown zone slope, and aircraft landing weight
in your distance calculation.
height. Maintain a three-degree glideslope with an optimal sink
rate of 500 to 700 fpm not to exceed 1,000 fpm. 4. Good Crew Resource Manage-
ment is essential. Follow stan-
2. Cross the threshold at 50 ft. and at Vref, if possible. dard operating procedure; give a
complete approach and go-around
3. Do not delay reducing thrust after crossing the threshold. briefing early during the arrival
process. Complete all checklists
4. Land as flat as possible, being careful not to extend the flare. in a timely fashion, and keep
distractions to a minimum on the
5. Promptly bring the nosewheel to the ground after the mains flight deck.
touch down.
5. Give yourself a safety margin
6. Immediately apply maximum braking and allow the aircraft’s when considering landing distance.
anti-skid to do its job. Maximize use of reverse thrust as soon 6. Do not expedite the landing by
as all wheels are on the ground, being careful to maintain accepting a visual approach,
directional control. especially at night or at unfamiliar
airports. Always do the ILS ap-
proach if available, and make sure
the approach is stabilized 1,000 ft.
prior to touchdown. Go-around if
the approach is not stabilized.
7. In some cases, it may be prudent
to delay the landing by a few
minutes to allow airport ground
crews time to inspect or clear the
runway, or provide you with a cur-
rent runway surface report.
6 ThE LEading EdgE

7. Aviation safety Action Program
The Event Review
Committee, made up
of Comair’s Corporate
Flight Safety Office, the
FAA, and ALPA Safety
Update 3. Follow the new checklist and brief
every taxi for both departure and
landing. Make sure both pilots
agree with, and understand, the
clearance after it is given. The
route you have been cleared on
may be very different from what
Committee, has been Runway Incursions you expected when you gave your
Five runway incursions have been re- initial briefing.
tracking the following ported to ASAP since October. In two
safety trends: of these incursions, there was a loss Altimeter errors/Crossing
of separation, and pilot deviations
were filed against the crews. We have
Restrictions
Rushing seen some common trends in these WARNING: The “Altimeters” cross-
Please slow down. The majority runway incursions: check on the new Arrival Checklist
of ASAP reports have shown that may not be read until the crew is
mistakes occur when crews get in 1. The first officer is often heads- descending through 10,000 ft. The
a hurry to complete tasks. It is the down, completing checklists. cross-check has been moved to the
most common factor in reports and Prior to Approach portion of the
2. The first officer is on the number Arrival Checklist. This checklist may
therefore the biggest safety threat at
2 radio talking to the gate or ramp not be completed until only 30 miles
Comair. Pilots must take their time
while the captain is listening to the from the airport.
and be methodical, especially with
number 1 radio.
the new checklists. Crews need to be extra diligent about
We are asking all crews to recognize
Fatigue Calls that any taxi can become high-threat
cross-checking the altimeters when
descending through 18,000 ft. and
We have seen a rise in fatigue calls, when the first officer is heads-down to make sure the correct setting is
and we strongly urge pilots to call the completing checklists or using the verified by both pilots. Waiting for the
ASAP Safety Hotline within 24 hours number 2 radio. checklist item to be read may put both
of a fatigue call. Making this call
to reduce the risk of a runway pilots at risk of an altitude deviation.
gives a pilot five days to file an ASAP
computer report. incursion: Altimeters are being set to the wrong
1. NEVER accept a clearance to
number when descending through
Safety is data-driven. ASAP allows
cross a runway or hold on a run- Flight Level 180. Sometimes it is a
us to track safety threats and trends.
way unless both crewmembers wrong setting like 29.35 vs. 30.35,
We realize how fatiguing it is to have
hear the original clearance. If or it is leveling off at FL 180 and
less than eight hours behind a hotel
unsure, ask ATC to read back the pushing the Barometric Altimeter
door and then report to the gate 30
clearance. button prematurely, locking in the
minutes before departure. The Com-
29.92 setting. Both crewmembers
pany also is scheduling airport breaks
2. Brief the first officer before landing should verbalize the altimeter setting
in excess of five hours after short
to “hold all checklists until nearby to verify the number when descend-
overnights. Please file an ASAP so
runways are crossed.” There ing through FL 180. If unsure, query
we can identify why pilot rest is being
shouldn’t be any hurry to recon- Air Traffic Control before descending
compromised—it is up to each pilot
figure the aircraft after landing if through FL 180.
to assess his or her fitness to fly, and
being well-rested is part of being fit. there are nearby runways to cross.
ImPortAnt
ASAP Hotline 1-866-274-7088
ASAP (Call within 24 hours at the end of the duty day)
Info: Electronic reports are submitted to: www.comairsafety.com
Winter 2010 7