Airspeed is... WTF... alive?

Pretty late to the discussion, but a number of years ago, a squadron I was in had a rash of wasps building homes in the pitot tubes of our jets overnight. There was a quick succession of 2 aborts for no indicated airspeed being present during the takeoff roll. After that, maintenance decided to invest in (or find) some pitot covers to throw on at night. In the electric jet, that scenario actually becomes a bit sporty, regardless of the amount of air actually flowing over the wings. I'd posit that in a light single, if you weren't pretty familiar with the whole "pitch+power" mantra specific to your airplane, and also not equipped with an AoA probe, it could also be a little annoying to get back on the ground soundly. Not a barn burner of an emergency, but I'd say it is worth aborting in the low speed region if you have the where-with-all to get it into your scan.
 
Phillip said:
You know, the more I think about it the more I realize that this is a personality thing. Everyone has their own risk management strategies, rooted most likely in their personality traits and life experiences. you'll go for the trees hoping to stay safe in your cocoon while i'll probably take a chance on a go around grasping for options. Just the way we are.
Click to expand...


I think that you are correct on this assessment. It is very much a personality and experience kind of thing and I would agree that fighting for options is the way that I would go if I was too short sighted to require fighting and not mitigating. What do I mean? Well, my hobbies are fairly risky.... Rock climbing, rappelling, motorcycles, flying, scuba diving all involve a fair amount of risk. My job is as a Tank Commander on an Abrams where simply operating the vehicle can kill you. I've been in the Army since 1995 and have been in Combat for 2.5 years. I have managed gun trucks, personal security and kick in doors for snatch and grabs.

Why do I share all of this? Simple, to show that I know what risk is and to say that I wouldn't be here if it wasn't for knowing how to mitigate the risks associated with my lifestyle.

Have I charged my vehicle in to RPG gunners attempting to scare them before they could fire? Yes.

Would I pull power because my ASI isn't working? I have and I would again because there is a time to take a chance and a time to work the problem while sipping a cup of coffee and taking a drag of a camel.

A successful person knows when to charge and when to back off.
 
True stories:

Back in the 1970s, shortly after deicing of a P-Navajo, taking off from runway 3 at Wheeling, the copilot (me) calls "airspeed alive" and the captain not long after that aborts the takeoff. A second or two longer and we could have been in the history books from sliding off the end of that ice-covered runway and down the mountain. During deicing, the static system filled with fluid and caused a disparity in our respective instruments. We were darn lucky.

In the 1980s or 1990s a friend of mine was departing an airport in St. Louis in a pristine C-182 at night, noticed no IAS right after "rotation" and aborted. The plane came to rest, totaled, beyond the end of the runway. He walked away with minor injuries. He was darn lucky too. He is in the history books, though.

I'm not saying never abort, I'm saying there are real risks, as the airlines have been served notice courtesy of Boeing, and the industry is now training to continue the takeoff when near decision speed as the statistically best course of action. The trick with respect to IAS is to abort before there is any risk to it.

dtuuri
 
red4golf said:
Would I pull power because my ASI isn't working? I have and I would again because there is a time to take a chance and a time to work the problem while sipping a cup of coffee and taking a drag of a camel.
Click to expand...

It's a shame that you squander your otherwise-excellent risk-management with something as pointlessly self-destructive as smoking cigarettes.
 
Kritchlow said:
Well I have no doubt people don't actually say the word "rotate" if they're single pilot.. Lol!!!! Point is they do still rotate (in a trike).
Click to expand...

You rotate in a conventional gear aircraft if you have the tail up as well.

The point is that in a single pilot operation the call-out is mindless. Even if you dream of moving up to a multipilot operation, you're not going to have BOTH pilots calling airspeeds. They will work out in their CRM typically who is making the airspeed callouts and who is manipulating the controls and otherwise monitoring the flight attitude. In today's modern glass panels, even this is somewhat spurious. The target airspeeds come right up in the field of view of the pilot flying.
 
acrophile said:
It's a shame that you squander your otherwise-excellent risk-management with something as pointlessly self-destructive as smoking cigarettes.
Click to expand...
I used that as an example of something that I'd rather do then leave the ground in an airplane that is in a degraded mode. I had my last smoke while standing in line for the shuttle bus that was taking us to the airplane that would fly us home from Iraq in 2009.

Funny but when I was prepping to go to Iraq the first time in 2003, the medic conducting my medical review asked me if I wanted to stop smoking before going over because it was bad for me. She couldn't believe that I was more worried about things like lead poisoning..... it's all about perspective.

Sent from my SM-N920P using Tapatalk
 
acrophile said:
It's a shame that you squander your otherwise-excellent risk-management with something as pointlessly self-destructive as smoking cigarettes.
Click to expand...

As he said, he's mitigating risks. If, as a serviceman for the country who has been in combat, he needs the occasional cigarette to keep his stress down, I'm the last person to cast judgement. I'm sure he is well aware of the risks.

Thank you for service, red.

Edit to add... I see you quit smoking in 2009. Congrats. Not easy to do.
 
Last edited:
flyingron said:
. Even if you dream of moving up to a multipilot operation, you're not going to have BOTH pilots calling airspeeds. They will work out in their CRM typically who is making the airspeed callouts and who is manipulating the controls and otherwise monitoring the flight attitude. In today's modern glass panels, even this is somewhat spurious. The target airspeeds come right up in the field of view of the pilot flying.
Click to expand...

If one wants to verify AND make a verbal call-out during single-pilot there's nothing wrong with that.

As far as multipilot operation, the PNF (pilot not flying) made a "80 knots" callout and the PF (pilot flying) stated "verified" at the airline I flew at.
 
Phillip said:
You know, the more I think about it the more I realize that this is a personality thing. Everyone has their own risk management strategies, rooted most likely in their personality traits and life experiences. you'll go for the trees hoping to stay safe in your cocoon while i'll probably take a chance on a go around grasping for options. Just the way we are.
Click to expand...
Fine. You asked a question in your first post. People gave their opinion. It doesn't mean you need to agree with them, nor does it mean they need to agree with you.
 
Everskyward said:
Fine. You asked a question in your first post. People gave their opinion. It doesn't mean you need to agree with them, nor does it mean they need to agree with you.
Click to expand...

Well....there is that whole "keep your options thing" he is claiming. One would think aborting a takeoff is a perfectly valid option that he is disregarding.
 
SkyHog said:
Well....there is that whole "keep your options thing" he is claiming. One would think aborting a takeoff is a perfectly valid option that he is disregarding.
Click to expand...
Aborting a takeoff is indeed a valid option, unless you decide too late. Depending on the airplane and the situation, going flying without the airspeed indicator could be more safe or less safe than aborting. Personally I don't see any reason not to confirm that it's "alive". That doesn't mean you need to say anything out loud when flying as a single pilot.
 
Everskyward said:
Fine. You asked a question in your first post. People gave their opinion. It doesn't mean you need to agree with them, nor does it mean they need to agree with you.
Click to expand...
That particular bit came out of a hypothetical case that mscard88 and myself had pushed a bit too far. In retrospect we should have stopped at "it depends".
I do appreciate the input from people that had provided their takeoff checklists. I'll work on bringing those into my routine.
 
SkyHog said:
One would think aborting a takeoff is a perfectly valid option that he is disregarding.
Click to expand...

Not really, no. The question at hand is should the pilot validate all of the engine instruments while accelerating for takeoff. The book answer is yes. Great. Pass the checkride, go home. Then there is the reality. The Cherokees I fly have really dim panel lighting, with the engine instruments positioned at the bottom. So it takes more than a glance to validate the oil pressure or temperature. Sure there is an annunciator panel up top that has the "oil" light, so no real need to look down at the OP gauge I guess. But the FP is also down there below the yoke. So is the tachometer. Validating those takes the attention away from what's happening outside. So we are in fact balancing the risks of taking off with a malfunction of some sort vs the risks of not seeing something outside the window in time to react.
 
Phillip said:
Not really, no. The question at hand is should the pilot validate all of the engine instruments while accelerating for takeoff. The book answer is yes. Great. Pass the checkride, go home. Then there is the reality. The Cherokees I fly have really dim panel lighting, with the engine instruments positioned at the bottom. So it takes more than a glance to validate the oil pressure or temperature. Sure there is an annunciator panel up top that has the "oil" light, so no real need to look down at the OP gauge I guess. But the FP is also down there below the yoke. So is the tachometer. Validating those takes the attention away from what's happening outside. So we are in fact balancing the risks of taking off with a malfunction of some sort vs the risks of not seeing something outside the window in time to react.
Click to expand...
I have the same problem in my Cardinal.* The solution to the instrument location issue is just to be familiar enough with the layout to not need to hunt for the instruments. A quick glance is all it takes.

As long as the instrument is sufficiently illuminated. My solution to that? I bought a headlamp. Actually, that was a solution to many problems, and the best aviation-related $10 I ever spent.

*The panel isn't actually dim, except that due to an electrical glitch that no one has been able to chase down, running the panel lights at full brightness causes the clock display to fade out. So I dim the panel partway, and rely on the headlamp.
 
Timbeck2 said:
According to the POH, the ones I fly take off at 65 and 55 respectively.


If you read the "dumb things I've done" threads on various flying forums, there are many accounts of people who forgot to take off the pitot tube cover before take-off. Its just a check and it never hurts to verbalize your checks.
Click to expand...


Been there, done that, got the friendly "what happened" call from the FSDO a few days later....


Sent from my iPhone using Tapatalk
 
When I went to pick up the 'pico, it was fresh off of the pitot/static test three days prior.

My instructor (I was still a student) and I started the takeoff roll and airspeed was dead. After we aborted, I got out and checked for the presence of the pitot cover--it was stowed where it should be.

The avionics guy blew apart a diaphragm in the ASI and denied all wrongdoing.

I'll never use Affordable Avionics at CNO after the way they treated the previous owner on that whole deal.

I ALWAYS check for airspeed alive

Sent from my iPhone using Tapatalk
 
flyingron said:
You rotate in a conventional gear aircraft if you have the tail up as well.

The point is that in a single pilot operation the call-out is mindless. Even if you dream of moving up to a multipilot operation, you're not going to have BOTH pilots calling airspeeds. They will work out in their CRM typically who is making the airspeed callouts and who is manipulating the controls and otherwise monitoring the flight attitude. In today's modern glass panels, even this is somewhat spurious. The target airspeeds come right up in the field of view of the pilot flying.
Click to expand...

I don't disagree, but I'm failing to see what point you're making.
Oh yeah, speeds come up on modern glass... But that just replaces speed bugs.

I'm a fan of giving airspeed and engine parameters the once over on takeoff.
 
I don't know if this thread was a bad omen, lol, but it happened to me a couple days ago. Take off roll, things feel and sound good. Look at ASI when it feels like it should be coming alive and it isn't. Just as I'm ready to abort it comes alive with a sudden jerk. It fluctuated back and forth +/- 5 knots for a few seconds and then settled down.
 
Standard procedure when I flew King Air was for the PNF to call 80knts that the PF would quickly cross check on his to make sure the both showed the same speed.
 
For what it's worth, I don't think it's all that distracting to briefly check an airspeed indicator during the takeoff roll. I sometimes fly radial and turbine Ag Cats off of strips that are 20-30 feet wide and it usually doesn't take too long to register where the needle is. Granted, I'm more looking at the angle of the needle, as opposed to reading the numbers next to it, but it's close enough. I'm not necessarily looking at it to tell me when to take off, either. The airplane does a good job of telling me when she's ready. I'm glancing at engine gauges anyway, because I like taking care of my engines. If I was worried about it going off the side, well, normally you can feel them turning.

I could be doing it all wrong, but that's just my way.
 
I remember having an ASI fluctuation on takeoff, then apparently normal operation. Over the middle of Lake Erie my ASI gradually decreased to 0. Since I wasn't falling out of the sky, I attributed it to pitot tube blockage, which was shown to be the ultimate cause. I was IFR, but not IMC.
 
35 AoA said:
Pretty late to the discussion, but a number of years ago, a squadron I was in had a rash of wasps building homes in the pitot tubes of our jets overnight.
Click to expand...
I can see it being a big deal in a jet. I had that experience in Carlson, but in my case the mud bee plugged the static port, so I did not realize that anything was amiss until I gained a little bit of altitude. Then I snapped a picture and landed:
http://zaitcev.mee.nu/flying_all_those_instruments
 
The two seconds to look at the airspeed indicator makes me safer than the two seconds looking at the shortening runway in front of me. It's more critical than the door being closed but less critical than say the engine running.

About two years ago I had a mud dauber nest in the pitot tube and was getting no airspeed at all. That indicates an INOP piece of equipment which is deemed by the FAA to be a critical component for the flight and your failure to check it could be considered careless and reckless.

Or putting it another way, if you have an inop ASI on the ground, go flying anyway and have an accident, what kind of comments are you going to get when your friends read the accident report and see the phrase "contributing to the accident was an inoperative air speed indicator, which was blocked by insect debris in the pitot tube that should have been easily detectable prior to takeoff"?
 
bflynn said:
The two seconds to look at the airspeed indicator makes me safer than the two seconds looking at the shortening runway in front of me. It's more critical than the door being closed but less critical than say the engine running.

About two years ago I had a mud dauber nest in the pitot tube and was getting no airspeed at all. That indicates an INOP piece of equipment which is deemed by the FAA to be a critical component for the flight and your failure to check it could be considered careless and reckless.

Or putting it another way, if you have an inop ASI on the ground, go flying anyway and have an accident, what kind of comments are you going to get when your friends read the accident report and see the phrase "contributing to the accident was an inoperative air speed indicator, which was blocked by insect debris in the pitot tube that should have been easily detectable prior to takeoff"?
Click to expand...

I wonder what the reporter would base that dubious judgmental factoid on. I have had several such cases over the years (always when the pitot cover had been blown off or not on for other reasons). In no case was it obvious from the outside -- the nest was very deep inside the tube, with no debris whatsoever around the opening.
After the first such case, I learned to assume a blockage when the plane has been sitting in place for more than a few hours without the pitot cover. What I do is to create a makeshift "pitot clearing tool" out of folded-over safety wire, and use it to clear out the potential nest. Only then do I (sometimes) see debris showing up on the tip of "cleaning tool", i.e. no way at all to see it externally on a normal preflight.
 
If I remember correctly, they tried that on an Ag Cat some years back. Obviously, it wasn't too awesome. Lol
 
Herve Marchadier said:
Granted, I'm more looking at the angle of the needle, as opposed to reading the numbers next to it, but it's close enough.
Click to expand...

You've perfectly described why I hate having to get really slow for a short field in an airplane with a speed tape. You don't even really need to consciously look hard at a round ASI to know if that angle is "about right" and "trending up" or "trending downward" or "holding steady".

The tape will give you the trend really well (it's moving) but it requires a harder look to read the dang number than is necessary with a round ASI.

I most distinctly remember this when thermalling in the Schwietzer many years ago. Both sound and feel plus seeing that angle over there out of the peripheral vision was plenty to hold airspeed while watching the other glider in the same thermal so as not to play bumper gliders on the way up.

Also was somewhat helpful in my few hours in the Husky trying to keep the back end from swapping places with the front end.

Tapes are fine. It's just a little more effort and focus to see what speed you're really at. Trends, a tape is as good or better than a round ASI.
 
I use the ASI as a cross check to the airplane feel. If it feels just ready to fly, but we are at 70, something is really wrong. Therefore I'll check it when I'm rolling, again before I rotate and later on climbout.
 
denverpilot said:
The tape will give you the trend really well (it's moving) but it requires a harder look to read the dang number than is necessary with a round ASI.
Click to expand...
Put a bug on your Vref ahead of time. That allows you to see the trend easily without reading the number, if your glass allows user-settable bug (it should). In addition, there's a trend bar, although a bug is better.
 
denverpilot said:
You've perfectly described why I hate having to get really slow for a short field in an airplane with a speed tape. You don't even really need to consciously look hard at a round ASI to know if that angle is "about right" and "trending up" or "trending downward" or "holding steady".

The tape will give you the trend really well (it's moving) but it requires a harder look to read the dang number than is necessary with a round ASI.

I most distinctly remember this when thermalling in the Schwietzer many years ago. Both sound and feel plus seeing that angle over there out of the peripheral vision was plenty to hold airspeed while watching the other glider in the same thermal so as not to play bumper gliders on the way up.

Also was somewhat helpful in my few hours in the Husky trying to keep the back end from swapping places with the front end.

Tapes are fine. It's just a little more effort and focus to see what speed you're really at. Trends, a tape is as good or better than a round ASI.
Click to expand...


I agree with what you're saying here. Even though they are falling out of favor these days, needle gauges have always been easier to interpret quickly, at least in my mind. In a quick glance I can tell if all of the needles are where they should be, while I can't do that with a number that I have to read.

It seems like some folks take exception to the fact that a pilot would verbalize the "airspeed alive" as opposed to simply noting it. Really, I think it just becomes a memory aid. For example, I always verbalize my C-GUMPS check, even when flying alone, just because it helps me make sure I don't miss anything. Maybe I just like talking to myself? Regardless, flying can obviously be a dangerous activity, and I'm all about people doing whatever they can to make it just a little bit safer.
 
zaitcev said:
Put a bug on your Vref ahead of time. That allows you to see the trend easily without reading the number, if your glass allows user-settable bug (it should). In addition, there's a trend bar, although a bug is better.
Click to expand...

Depending on the glass, Vx and Vy are already marked on the tape. Just keep Vx on a certain spot and you're good. You can also judge your speed quickly by looking at the amount of white is under the marker.
 
You must log in or register to reply here.
Back
Top