Coastal Flooding in southern New Jersey

I want to pause and write about the northeaster that is slowly moving its way up the eastern seaboard.

This storm -- the remnants of Tropical Storm Ida -- has been affecting southern NJ, Delaware and environs for a couple of days with rain, high winds (gusts ranging from 40 mph to 59 mph), and severe coastal flooding. For those of you who are interested, the latest advisories from NOAA may be found here. In the event that the link expires, I am copying the flood advisory below.

A fishing boat, the Sea Tractor was lost in rough seas from this storm off of Cape May, NJ on Wednesday night. The Coast Guard has suspended the search. For more information, see this article.

Coastal Flood Warning


COASTAL HAZARD MESSAGE
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
239 PM EST FRI NOV 13 2009

DEZ001>003-NJZ012-013-016-020>023-027-140500-
/O.CON.KPHI.CF.W.0004.000000T0000Z-091114T1500Z/
NEW CASTLE-KENT-INLAND SUSSEX-MIDDLESEX-WESTERN MONMOUTH-SALEM-
OCEAN-CUMBERLAND-ATLANTIC-CAPE MAY-SOUTHEASTERN BURLINGTON-
239 PM EST FRI NOV 13 2009


...COASTAL FLOOD WARNING REMAINS IN EFFECT UNTIL 10 AM EST
SATURDAY...


A COASTAL FLOOD WARNING REMAINS IN EFFECT UNTIL 10 AM EST
SATURDAY.


HIGH PRESSURE TO OUR NORTH AND LOW PRESSURE TO OUR SOUTH WILL
MAINTAIN A NORTHEAST TO NORTH WIND ALONG THE COASTS OF NEW JERSEY
AND DELAWARE INTO THE WEEKEND. THE FLOW WILL KEEP WATER FROM
DRAINING AWAY FROM THE COASTLINE AND TIDAL DEPARTURES WILL REMAIN
QUITE HIGH. WATER WILL BE TRAPPED IN THE BACK BAYS OF NEW JERSEY AND
DELAWARE FOR AT LEAST ANOTHER THREE OR FOUR TIDE CYCLES.


WHILE THE HIGH TIDE EARLY THIS MORNING WAS LIKELY THE HIGHEST OF
THE STORM... MODERATE TIDAL FLOODING IS EXPECTED AGAIN DURING THE
HIGH TIDE CYCLES LATE THIS AFTERNOON INTO THIS EVENING AND EARLY
ON SATURDAY MORNING. AS A RESULT... THE COASTAL FLOOD WARNING
CONTINUES INTO SATURDAY.


FOR SANDY HOOK... NEW JERSEY ON THE BAY SIDE... THIS AFTERNOON`S
HIGH TIDE IS AT 451 PM WITH A FORECAST HEIGHT AROUND 7.5 FEET
MLLW. THE HIGH TIDE EARLY ON SATURDAY MORNING OCCURS AT 526 AM
WITH A FORECAST HEIGHT AROUND 7.5 FEET MLLW.


FOR SEASIDE HEIGHTS... NEW JERSEY ON THE OCEANFRONT... THIS
AFTERNOON`S HIGH TIDE IS AT 421 PM WITH A FORECAST HEIGHT AROUND
7 FEET MLLW. THE HIGH TIDE EARLY ON SATURDAY MORNING OCCURS AT
456 AM WITH A FORECAST HEIGHT AROUND 7 FEET MLLW.


FOR ATLANTIC CITY... NEW JERSEY ON THE OCEANFRONT... THIS
AFTERNOON`S HIGH TIDE IS AT 437 PM WITH A FORECAST HEIGHT AROUND
7 FEET MLLW. THE HIGH TIDE EARLY ON SATURDAY MORNING OCCURS AT
509 AM WITH A FORECAST HEIGHT AROUND 7 FEET MLLW.


FOR CAPE MAY... NEW JERSEY ON THE OCEANFRONT... THIS AFTERNOON`S
HIGH TIDE IS AT 511 PM WITH A FORECAST HEIGHT AROUND 8 FEET MLLW.
THE HIGH TIDE EARLY ON SATURDAY MORNING OCCURS AT 543 AM WITH A
FORECAST HEIGHT AROUND 8 FEET MLLW. WATER LEVELS IN THE BACK BAYS
WILL LIKELY RUN FROM ONE HALF TO ONE FOOT HIGHER THAN THOSE ALONG
THE OCEANFRONT.


FOR LEWES... DELAWARE ON THE BAY SIDE... THIS AFTERNOON`S HIGH
TIDE IS AT 551 PM WITH A FORECAST HEIGHT OF 7 TO 7.5 FEET MLLW.
THE HIGH TIDE EARLY ON SATURDAY MORNING OCCURS AT 621 AM WITH A
FORECAST HEIGHT OF 7 TO 7.5 FEET MLLW.


FOR REHOBOTH BEACH... DELAWARE ON THE OCEANFRONT... THIS
AFTERNOON`S HIGH TIDE IS AT 450 PM WITH A FORECAST HEIGHT OF 7 TO
7.5 FEET MLLW. THE HIGH TIDE EARLY ON SATURDAY MORNING OCCURS AT
522 AM WITH A FORECAST HEIGHT OF 7 TO 7.5 FEET MLLW.


FOR REEDY POINT... DELAWARE... HIGH TIDE OCCURS AT 822 PM THIS
EVENING WITH A FORECAST HEIGHT AROUND 8 FT MLLW. THE HIGH TIDE ON
SATURDAY MORNING OCCURS AT 850 AM WITH A FORECAST HEIGHT OF 7.5 TO
8 FEET MLLW.


CONDITIONS ARE FORECAST TO IMPROVE GRADUALLY LATE IN THE WEEKEND.


PRECAUTIONARY/PREPAREDNESS ACTIONS...


A COASTAL FLOOD WARNING MEANS THAT FLOODING IS OCCURRING. COASTAL
RESIDENTS IN THE WARNED AREA SHOULD BE ALERT FOR RISING WATER AND
TAKE APPROPRIATE ACTION TO PROTECT LIFE AND PROPERTY.


DO NOT PARK YOUR VEHICLE IN A LOCATION THAT IS PRONE TO TIDAL
FLOODING. ALSO... AVOID ROADWAYS THAT ARE PRONE TO TIDAL
FLOODING.

Importance of safe aerial operations

I had hoped to be able to begin writing today about some of the other weather conditions and visibility limitations that can ground fire fighting aircraft. This would be a nice follow-up to my recent posts about winds. My idea was to begin by writing about fog, so I have spent some time over the three days or so reading more about fog and then look at other weather conditions and visibility limitations that can ground air tankers.

As sometimes happens, I found that I need more time before I am ready to write about fog, other visibility limitations that can ground air operations. I have written about winds grounding aerial fire fighting operations, and I suspect that there are other weather related conditions that can ground air operations. Thunderstorms come to mind, and perhaps there are more.

But while I do need more time before I can write about some of these issues in more detail, I do want to emphasize the importance of safety. Tankers and helicopters will not fly when conditions are present -- high winds, turbulence, fog, thunderstorms, other visibility restrictions, etc. -- that will jeopardize safe aerial firefighting operations.

While I am learning more about fog, inversions, thunderstorms and the like, I will continue to write about other topics. For example, I have promised some friends that I will write more about some of the different types of helicopters used in firefighting. I will begin doing so on Monday.

In the meantime, I want to leave you with this thought:

Lives are not replaceable.

Air Operations on Sheep Fire (Oct. 2009)

Aerial firefighting operations can be grounded reasons other than high winds and turbulence. One example is fog. Another example is thunderstorm activity. I had hoped to write something in a little more details about fog today. Unfortunately, that post will have to wait.

In the meantime, enjoy this video. It was shot by Nick Mitchell at the Sheep Fire that burned outside of Los Angeles in early October. According to Nick's blurb on youtube, the video was shot before air operations were grounded due to 50 mph winds on nearby ridges.

Lives are not replaceable

I have been giving considerable thought to one of the last sentences in my post of November 6.. Recall that I ended with:

Strong winds and bad turbulence are dangerous to all aviation interests, include aerial firefighting operations, leading to grounding of aerial fire fighting operations. So, if you are living near a wildfire AND the winds are strong AND you don’t see tankers and helicopters making retardant or water/foam drops on the fire there is a reason. They are not flying because it is not safe to do so.

I gave careful consideration to what I can add given that I am not an aerial firefighter. Nor am I resident of the wildland/urban interface in parts of America that are especially vulnerable to wildland fires such as southern California, the southwest, the northwest, etc. Nor am I a (ground) wildland fire fighter. For that matter, I am not a structure firefighter nor am I a first responder (e.g. EMT).

But I have been writing about aerial wildland firefighting for about ten or eleven months now, and I have learned a lot of things, including (and not limited to) reasons tankers don't fly. That is:

• Lives are not replaceable.
• Pilots and crews care about what they do, and they are good at it. They want to help the wildland firefighters on the ground protect your home, AND they want to do so safely.
• Lives are not replaceable.
• Strong winds, rotors and turbulence WILL overpower an airplane. Flying in strong winds and turbulence including but not limited to downdrafts and rotors puts pilots and crews at great risk for fatal crashes.
• Lives are not replaceable.
• Pilots want to be safe, they don't have a death wish. And they want you to be safe.
• Lives are not replaceable.
• Not only does a tanker crash put the lives of the pilot and crew in jeopardy, it puts the lives of all those on the ground in jeopardy as well. This includes you, your family, and your neighbors.
• Lives are not replaceable.
• Perhaps wildland firefighters on the ground can save your house, but they won't be able to save your house if a tanker crashes into it.
• Lives are not replaceable.
• Post-crash fires might exacerbate an already bad situation, perhaps increasing the size of the wild fire.
• Lives are not replaceable.

In summary, there are certain rules with regard to sustained and gusting winds and turbulence that tanker pilots must deal with.The most important one being, If the winds are blowing strong enough that aircraft are likely to be destroyed, they won't fly. But also, if winds are blowing strong enough that retardant will be blown away before it hits the ground, they don't fly.

Lives are not replaceable.



postscript: I read in one of the Interagency Online Aviation Training Modules that what is good for an airplane is also good for a helicopter. And what is bad for an airplane is bad for a helicopter. So, I assume (for the time being) that what I wrote above applies equally to airplanes and helicopters. I hope to look into how downdrafts, rotors, and turbulence affect helicopters flying fires in the coming weeks and will write about what I find here.

Why tankers don’t fly: safety concerns and high winds

If you have been following recent LA Times articles, see for example this article , or Bill Gabbert’s blog then you know valid concerns have been raised regarding tankers and helicopters not being deployed to the Station Fire in the early morning hours of the second day of the Station Fire. These are legitimate concerns that should be addressed, however I am not addressing them here. Rather, I am concerned with high winds as a reason why tankers and helicopters don’t fly.

Knowing that many fires out west are in or near mountainous terrain, I got interested in learning more about winds and turbulence that occur in mountains and how they affect aviation interests. I went first to one of my general aviation books -- The Complete Pilot by Bob Gardner. Here I read about what is known as mechanical turbulence. If I understand mechanical turbulence correctly, mechanical turbulence occurs when a building or a mountain disturbs that the flow of the wind current, sometimes creating strong downslope winds on the lee side of the building or mountain. These winds are also known as down drafts or bad air. Strong down drafts (see the picture above) can have more down power than airplanes have climb power. A pilot caught in such a down draft may not be able to fly out of the downdraft.

The picture below illustrates something known as rotor winds, a pilot unfortunate enough to tangle with these winds is flying into winds that are likely to overpower an aircraft with often fatal consequences.

There have been fatal tanker crashes while flying fires where down drafts and/or rotor winds may have been a major factor in the crash including a fatal crash out west in the late 1990s and one or two fatal crashes in the 1970s (also out west).

Wind and turbulent conditions can be forecast by meteorologists. Strong winds and bad turbulence including but not limited to rotors and down drafts are dangerous to all aviation interests, including aerial firefighting operations, leading to grounding of aerial fire fighting operations. So, if you are living near a wildfire AND the winds are strong AND you don’t see tankers and helicopters making retardant or water/foam drops on the fire there is a reason. They are not flying because it is not safe to do so.


REFERENCES

For more information about mountain wave turbulence, please go to this web page from the Australian Transport Safety Bureau, they are the source of the images that I have included here. I like that document, not only for the wonderful graphics but for a short and succinct explanation of mountain wave turbulence. While written for the Australian audience, I certainly got a lot out of it. Sparky Imeson, who wrote a book about mountain flying writes about mountain waves and rotor winds here. Sadly, Sparky died when his plane crashed earlier this year. His family is keeping up his web page on mountain flying. He has numerous articles on many other subjects related to mountain flying and I highly recommend them.  If I am correct, I believe he gave presentations on mountain flying at training sessions for air tanker pilots. I myself have spent at least a couple of hours on his website, and find myself frequently referring to it.

Good Drop, Effective Drop

When I started working on this article on the factors that make for an effective retardant drop, I was thinking about things like drop height (altitude), drop speed (aircraft speed) and winds. Then as sometimes happens, I set the draft aside for a few days. During this period I took some time to go through some files that I have accumulated over the last several months, along with some correspondence with a couple of my tanker pilot friends. The result, thanks to my reading (listed at the end of this article) and my correspondence with a couple of my tanker pilot friends is what you see here.

As I read through my files and reviewed some of my correspondence, what was driven home to me is that a good drop is when the crew completes the drop in a safe manner and returns home.

What makes for an effective drop then? Well, I have already talked about two factors: the tank system (some examples of tank systems currently in use may be found here, here, and here) and retardants . Other factors include the right altitude (height at which the retardant is dropped), correct airspeed, and calculating the drift of the retardant due to winds.

To set the stage, it is important to say what an ideal drop is, that is what is the tanker pilot aiming to do in making the drop? I understand from my reading as well as e-mails with a couple of tanker pilot friends that the goal in making an ideal drop is that retardant has no forward speed and rains down on the vegetation.

One of my tanker pilot friends tells me that one of the reasons that you want to eliminate forward speed of the retardant  is to (hopefully) eliminate shadowing. As I understand it, shadowing means that all the retardant is plastered against the side of the tree, bush, even grass facing the drop while the backside is left untouched by retardant. Eliminate forward speed of the retardant and shadowing of the retardant is eliminated.

In addition, retardant drops at forward speeds can be very dangerous to ground crews who have not moved away from the drop zone. Fortunately, Incident Command will usually be able to clear ground crews from the drop zone to avoid these situations.

My tanker pilot friend made a couple of more pertinent points on retardant drops. First, he told me that dropping retardant at too high an airspeed (aka drop speed) can shear the retardant load apart so that it disperses too much leaving gaps in the coverage. Two, dropping to high, especially in high winds means that pilots won't be able to predict where the retardant will land.

Finally, he went on to say that if it is safe to do so in these high wind conditions, pilots might be able to make a retardant drop from a lower altitude so that some retardant line can be built. There might be gaps in the line, and the pilots may not be able to predict the coverage level, but at least there will be some retardant line that will slow the fire until the ground crews can get there.

As I was doing my background reading for this article I was impressed by the problems of making retardant drops in high winds. That is, when making drops in high winds, not only does the pilot/crew risk not knowing where the drop will end up, they are flying in very extremely dangerous conditions.

References:

I am including links to some of the USFS documents that I read while doing background research for this article. Before you read the documents below, I should caution you that some of the numbers cited are under ideal conditions in the laboratory, so to speak. Aircraft performance in actual drop conditions on the fire line will be different.

Lavalette, Greg. Safe Drop Height for Fixed-Wing Airtankers. 0057-2317-MTDC. Aviation Tech Tips (March 2000). US Forest Service, Technology and Development Program, Missoula Technology and Development Center, Missoula, MT.

Suter, Ann. Aerial Delivery Systems User Information: Wind Speed and Drop Height. ug-7. Wildland Fire Chemical Systems - MTDC. February 2005. US Forest Service.

Suter, Ann. Aerial Delivery Systems User Information: Drop Speed. ug-13. Wildland Fire Chemical Systems - MTDC. February 2005. US Forest Service

Additional Aerial Delivery Systems User Information documents, Safe Drop Height for Fixed-Wing Airtankers, and other documents relating to testing aerial delivery systems may be found on this USFS webpage.

What's next and review

I am resuming with two articles I have been working on for a couple of weeks: (1) what makes for effective retardant drops and (2) more on how winds affect and interfere with aerial firefighting operations. Look for the first of these articles later in the day on Wednesday with the second article coming sometime on Friday. Recall that I wrote here that I had to take some more time to do some background research. If you want to refresh your memory on what I was writing about you might want to go back and read these posts:

• October 19: Engine failures with happy endings
• October 21: 40-year veteran air-tanker pilot speaks
  

Memories: Hemet-Ryan AAB 1964-1971

I'd like to thank TL Stein for his permission to post this video. The video is in memory of his Dad, Chief Thomas W. Stein. Chief Stein shot the footage over the course of seven years (1964-1971) during his career with the California Department of Forestry. TL Stein shares his feelings about this video:

When aerial firefighting started out, it was an entirely new concept and science.  For 30 years, people had experimented with various ideas until what we know as the "retardant tank" was made the solution.
 
What is seen in the video, is basically the way it was in it's first 10 years of life.  The planes, the people...pioneers with an idea and a concept.  I'm proud my father was a part of this history and this is the major reason it's important to me to be sure it is documented as best I can.

Plan on spending about 12 minutes to watch the video, you will see some vintage air tankers and get a feel for what life was like at an air attack base in the late 1960s. History helps to form the present. To appreciate what air tanker and helicopter pilots did 45 years ago is to appreciate what they do today. 

Enjoy!

Another video from fire pirates

Here is another fire pirates video that I found on youtube. Enjoy

Postscript (10;30 AM): Opps. Just realized that I accidently posted the same video twice. I have just corrected this post with the second of two fire pirates videos from you tube. The first fire pirates video may be found here.

Life at Paso Robles Air Attack Base (1993)

I found this video, shot at Paso Robles Air Attack Base (CA,) on youtube several weeks ago. Not only did I enjoy seeing some now retired air tankers in action (e.g. tanker 127, PB4Y2), but I enjoyed the glimpse into life at an air attack base. You will also see tankers being loaded with retardant, including a loading error, and a couple of retardant drops.

I asked one of my air tanker pilot friends to id the aircraft in the video (in order of appearance):

Aero Union tanker #03, P2V Neptune
Cessna O-2, CalFire Air Attack #340
PB4Y-2, Hawkins and Powers tanker #127 (Silver 4 engine)
P-3, Aero Union tanker #22
DC-4, Aero Union. tanker #15 (mixmaster clip)

Enjoy!

National Fire Weather, red flag warnings in SE CA & SW AZ

With the fall Santa Anna wind season underway in southern California, and knowing that the area had been under red flag warnings in recent days, I was curious to find one national fire weather page where I could go and see fire weather watches and red flag warnings for the entire country. I found the National Fire Weather page, and have bookmarked it. In today's map (the map you see will be differ depending on that day's fire weather) there is a red flag warning for portions of southeastern California and southwestern Arizona:

FNUS55 KPSR 281153
FWFPSR

FIRE WEATHER PLANNING FORECAST FOR SOUTHWEST AND SOUTH-CENTRAL
ARIZONA AND SOUTHEAST CALIFORNIA
NATIONAL WEATHER SERVICE PHOENIX AZ
453 AM MST WED OCT 28 2009

...RED FLAG WARNING IN EFFECT FROM 11 AM MST/11 AM PDT THIS MORNING
TO 5 PM MST/5 PM PDT THIS AFTERNOON FOR SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA DUE TO STRONG WINDS...LOW RH VALUES AND A HIGH FIRE
DANGER...

.DISCUSSION...
BREEZY TO WINDY CONDITIONS WILL CONTINUE TODAY IN THE WAKE OF A VERY
STRONG LOW PRESSURE SYSTEM. RELATIVE HUMIDITY VALUES WILL DROP INTO
THE LOWER TEENS THIS AFTERNOON...WHICH COMBINED WITH THE WINDS WILL
POSE A FIRE DANGER ESPECIALLY ACROSS SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA. WINDS WILL DECREASE LATER TONIGHT AND INTO
THURSDAY THOUGH THE LOW RELATIVE HUMIDITY VALUES WILL REMAIN.
TEMPERATURES WILL BE WELL BELOW NORMAL THROUGH THURSDAY.

Loma Fire (CA) contained

I wrote about the Loma fire three days ago, here. According to CAL Fire, the fire is 100 percent contained.

aerial firefighting - views from the cockpit

Speaking of aerial wildland firefighting, enjoy this video. Some of the shots were taken from the cockpit.

Loma Fire

This is the Loma Fire, currently burning in near Santa Cruz, CA. 20% containment, 600 acres. Fire started about 3 AM this morning. See this report on Fox 35 for more information. You will see a tanker dropping retardant near the end of the video. CAL Fire has information on this fire at this site.

kudos to initial attackers

A few months ago I wrote this post that I called Reflections on S-2T's, SEAT's and Initial Attack. I was speaking to the important work that CAL Fire's S-2T's and SEAT's on National or State/local contracts do to aid ground crews in putting out fires during the first hours after the fire is reported (aka initial attack). I need to add that helicopters, both those with buckets and well as type II helicopters with fixed tanks play an important roll in fighting fires in the initial attack phase.

I have written about specific large fires including campaign fires such as the Station Fire, but have not written much about these two to ten acres fires. So, I have been on the lookout for video footage of a such a fire, one that was contained within the first two to three hours. Earlier this week, there was a 10 acre brush fire in San Marcos, CA just north of San Diego (of unknown origin) that seemed to have been "knocked out" in under two hours. Helicopters and CAL FIRE S-2T's added ground crews in these efforts. I found out about this fire here, following the supplied link to this video footage shot from a San Diego's CBS8 news helicopter.

The video is just over 16 minutes. You will see several water/foam drops from what appears to be a fixed-tank type II helicopter. I saw a shot of a CAL Fire S-2T, tanker 88 fly by but did not see the drop (although I could of missed something). There are also shots of ground crews and engines working the fire.

upcoming posts

After posting the link to Bill Waldman's video yesterday, I had intended to continue along these same lines with articles on what makes for an effective retardant drop, and how winds factor in to the retardant drop. I am still doing some background research on these articles so I won't be able to start with this series tomorrow. I do hope to have this background research finished sometime early next week. 

In the meantime, stay tuned for tomorrow's article that I am calling Kudos to initial attackers.

40 year veteran air tanker pilot speaks

Here is a great video from myfirevideos.net sponsored by wildland fire lessons learned center. The speaker on this video is Bill Waldman, a 40-year veteran air tanker pilot and recently retired from Aero Union where he was the chief pilot. During his long career he logged over 10,000 hours in flight time, making over 13,000 retardant drops. In this video, part of the lessons learned series of the wildland fire lessons learned center, he speaks about the lessons he learned during his career as a wildland firefighter whose tool is an aircraft. While speaking directly to other tanker pilots and crew, I believe that the lessons he learned are applicable to ground crews, other emergency services workers, as well as us civilians. I learned a lot from watching this video.

The most important thing that I took from watching this video, and I have watched a couple of times by now, is the importance of safety. That is, Mr. Waldman offers this advice to firefighting aircraft pilots (young and old):

What we do is a job, it is not an emergency. Don't risk your life and die over a tree. That is primary. Do a job, do it safely, and go home at night.

Plan on spending about 15 minutes to watch the video.

If the above link doesn't work, go to myfirevideos.net and look for a video called "I am a wildland firefighter - aircraft is my tool. I'd like to thank Bill Gabbert who posted about this same video here. You might want to check out Bill's article to see the comments a couple of air tanker pilots made to Bill's article.

Engine failures with happy endings

You will recall from my first post in the density altitude series that low air density -- which equals high density altitude -- affects engine performance. Engine failure in any plane can lead to disaster. In ideal conditions, engine failure in a multi-engine plane does not have to end in a crash. But in a tanker carrying a load of retardant, engine failure often means dumping retardant in order to avoid a crash. Most air bases used by tankers have a designated area where retardant can be safely dumped without harm to people, property, or the environment. But in an emergency situation, the pilot is not always able to reach the designated dump area.

Air density can affect how much time the pilot has to dump the retardant in the event of engine failure. My friend G (air tanker pilot) has this story:

I lost an engine in a P-2 on take-off out of Missoula on a fairly cool day, about 78 degrees.  It was almost a non-event.  I feathered the bad engine and continued to climb out to a spot where I could jettison the load without endangering anybody on the ground.  On a hot day, it would have been an entirely different story.

Engine failures can require quick action and a measure of luck irregardless of air density. Here are some more stories from G:

1. I saw a DC-4DC-6 lose an engine right at rotation, about six inches above the runway. The DC-4 DC-6 is not overpowered and that guy had to pitch the load in a heartbeat.  His retardant tank couldn't have been more than three inches off the runway and he just painted the Kalispel, MT airport runway all the way down.  That shut down the airport for two hours, but the crew lived to tell about it.  That crew was Canadian and I made sure he got the safety award that month for averting an airplane crash with quick thinking.

2. I lost an engine at Chico, CA in a P-2 right when I got the nose wheel off the ground and I knew we couldn't fly out of there.  I had to decide and act in about a second and a half, so I shut it down and did a panic stop, using every inch of available runway and a little more.  But, we were alive.

3. I lost an engine in the PB4Y2 out of Jeffco, CO and I had to find a spot to pitch the load pretty quickly.  Fortunately, there was a big field behind some houses right off the end of the runway and it went there.

Density altitude and helicopters (part 3 of 3)

Density altitude affects all aircraft equally, the higher the density altitude, the lower the performance of fixed and rotor-winged aircraft. In helicopters a higher density altitude will, among other things, translate to

(1) a lower hovering ceiling at a given gross weight, and

(2) the higher the density altitude the more power is needed for a vertical take-off and under certain weight and density altitude conditions, there may not be enough power for a vertical take-off. if that is the case, the helo pilot may need to do what is sometimes known as a running take-off.

For more information on the affects of density altitude on helicopters see this article

Density altitude defined, effect on airtanker performance (part 2 of 3)

Low density air means high density altitude. An air tanker pilot friend, G, explains:

High density altitude is called that because the low density air found in hot air mimics the air found at HIGH altitudes. At HIGH altitudes and HIGH temperatures, there is not only less air for an engine to "breathe", but there is less air for the wings to ride on as well.

High density altitude is also known as performance altitude. High density altitude caused by high temperatures and high humidity can occur at lower elevations but is more of a problem at airports at higher elevations such as those in California and the southwest. If you are based at an airport at 3,000 feet above sea level and the air temperature is hot (e.g. 95 degrees) your performance altitude is going to be higher. The higher the density altitude the longer runway you will need to take off at a given gross weight. This can be computed and G explains how this works:

The entire exercise of computing density altitude is used to predict aircraft performance on hot days or in high places or both. All the airplane manufactures publish charts that help you determine how much runway you'll need at a particular gross weight and a particular altitude.  You add up the weights, figure the density altitude, (which tells you the altitude your airplane will act like its flying at), go to the performance charts and you find that at 8800 ft and full gross weight, your airplane needs, say, 6500 feet of runway to get airborne.  If the airport you are parked at only has 4000 feet of runway, you're hosed.  You either get rid of some weight, or wait until evening when the air cools.

What this means for air tanker pilots is that tankers working wildfires, e.g. in California or the southwest, may be forced to carry lower loads of retardant in order to compensate for higher density altitudes.

In my final article on density altitude, posting this Sunday, I will write a short piece on how density altitude affects helicopters.