One Of The Things That Stays Emblazened In My Mind:Never Bust Minimums

One of the things that stays emblazoned in my mind is: never bust minimums. No not never! Minimums are there because the powers to be have decided that is as low as you can safely descend without ground reference.*

Oh, sorry. I am of course writing about instrument approaches. Particularly about following the prescribed approach procedures to the letter. Why am I writing about this? Because I just reviewed some recent fatal accidents on the NTSB web site. This website is recommended for any serious pilot by the way. A good place to learn from the mistakes of others.

Two recent accidents stand out. Both resulted in pilot and passenger deaths and destroyed airplanes. Both were flown by airline transport rated pilots (ATP’s). So maybe experience isn’t always the best teacher.

In the first accident, a Beech twin tried unsuccessfully to land at weather below minimums. Specifically: ¼ mile viz in light drizzle and a ceiling of 100 ft. The lowest minimums allowed on an ILS are ½ mile viz and a ceiling of 200 ft. Yes, there are lower minimums at some facilities, but these above are standard. To go below these requires special equipment and training (not generally available to the general aviation pilot).

In the second accident, again an ATP rated pilot makes a fatally bad decision in a light twin. Flying an RNAV GPS approach with a minimum descent altitude (MDA) of about 500 ft above ground the pilot continues decent to almost 250 ft above ground and crashes killing all, and destroying the plane. You have to wonder what were those guys thinking? They did not declare an emergency in either case, so conceivably could have continued to a safe alternate. Anyone filing an IFR flight plan must list an alternate airport. To list an alternate, the weather at the ETA must be at or better than 600/2 for a precision approach (ILS), or 800/2 for a non precision approach (GPS or VOR). Sometimes that means cancelling the trip if it becomes unlikely that an alternate can meet these weather conditions and/or if the amount of fuel aboard is less than required to get there.

As an example: If one were going from NYC to BOS, about a 2 hour flight in a small plane, and the weather in BOS is iffy there would have to be enough fuel in the plane available to reach an alternate airport and still have 45 minutes of fuel aboard. If everything along the pilot’s route from NYC to BOS is socked in and there is nothing better within reach of BOS then the pilot might have to go all the way back to where they started, NYC in this case. If they encounter a headwind on the way back they probably won’t have enough fuel to do it. So what to do? CANCEL and rent a car. Been there done that! Read some of my earliest blogs where I recount just such a scenario.

*The minimum descent altitude (MDA) depends on the particular airport, which runway and type procedure. The lowest standard ILS MDA is usually 200 ft. The one caveat about “busting” the MDA is this: if at the MDA and/or decision point as a marker beacon, the high intensity or other lights extending from the runway are visible, the pilot may continue the approach to the runway even though the runway is not yet in sight. That means the pilot may go lower than the published MDA under those conditions.

You Gotta Sleep Sometime

Reading about the problems that fatigue and boredom are causing in the cockpit and radar rooms, made me think back some. Sleep, we must remember is something we can’t do without. At some point it will come, regardless. The problem of course is that if you are alone at the controls, it could be a disaster unless corrected right away.

When I was flying occasional charter up in Vermont, I frequently would get a call late in the evening or even the wee hours to take a flight. It always was some type of emergency, some more vital than others. The powers to be knew that I didn’t drink much and could be counted on to be sober, hence the late calls.

One evening, about 2300 hrs or so, I got a call from the dispatcher. There was a Saab 340,a small airliner, at the Hartford Airport with a bad starter on one engine. They needed me to fly a mechanic and spare parts to fix things ASAP. Off I went down interstate 89 at METO speed and was ready to go in a little over 30 minutes. Oh how I did love to fly those birds.

The mechanic and I took off in one of the Pa-31’s and we were in Hartford (KHFD) in about 40 minutes. It was after midnight when we arrived, and I had been up since 0700 that morning, working at my “real” job as a radiologist. Yes, it was already a long day, and I was starting to yawn a bit. As the mechanic was doing his thing, I stayed in the cockpit and tried, successfully for a few z’s. An hour or so passed and in bounded the mechanic. Repair done and ready to go. I shook myself awake and cranked up the engines. Not much clearance needed, good VFR, and away we went.

I used the autopilot as was customary, fortunately. As the flight progressed, I caught myself nodding off for just a few seconds every few minutes. Somehow I was able not to get into deeper sleep. The passenger was sound asleep in the right seat. What confidence.
Staying awake while at cruise with little to do, monitor or communicate about, was the worst. Once nearing home (KBTV), things were required of me and no time for a snooze.

I feel now, even in retrospect, that if an emergency had occurred I would have been able to respond. The question is, what if something like a near miss that required me to be looking out had happened? Might not have been a good outcome. Well, there is a gamble in so much we do. Most of the time we do get away with it. This can be a dangerous way of thinking however, especially if other lives depend on us.

So, when doing your thing. Whatever it may be, flying, driving or just playing, do get your sleep, or who knows?

Hans Look Up In The Air

The last day of the year seems like a good time for reflection. I think back many years when as a boy of eight or nine, I would hop on my bicycle and head for Laguardia airport (KLGA), some two or three miles away. My intent, to stand at the end of one of the runways, and wait for a landing plane to pass closely over my head. Close enough in fact, that if I could jump up ten feet in the air I would hit one of the planes wheels. DC-3’s. DC-6s and Constellations would scream by. This continued until one day a policeman happened by and pointed to cuts in the bushes at the end of the runway. He explained in a sarcastic manner that those were due to the wheels slamming through when the plane was a bit low. After that I moved off to the side and watched from there, avoiding getting squished by a landing plane. It was only fitting that one day I would end up landing at KLGA myself. There were two of us flying down from the Boston region in an old Cessna 172 headed for Flushing airport, a small field across the bay from Laguardia. Well, when we got there it was IFR and I was only a VFR pilot at the time. Fortunately, LGA approach control was in a good mood and helped us line up on the localizer and we landed safely. Finally back at Laguardia. Was anyone watching us land?

Yes, I was hooked on aviation from the get-go. While going for a walk, regardless whom with, if I heard a plane go by, I would have to look up and see it. I still do. My wife still chides me by saying “what did your father call you when you did that?.” Hans guck inn der luft, German for Hans look up in the air. Hans being generic for any gawker I guess.

Well my love for watching planes continued. As I grew older, I would beg my mother to drive us out to the Grumman factory, farther out on Long Island, to watch the production fighter jets getting test flown. My first flight was on a Pa-18 on floats on Fourth Lake in the Adirondacks. A thrill for a little kid and one I still remember.

It wasn’t till many years later that I finally started flying myself. At the age of twenty something, in the army, I began my flying lessons in a tail wheeler, the L-19 (O-1).
From there on it was a slow progression. Getting the ratings and flying at every opportunity.

After 40+ years of flying, I decided it was time to hang up my wings. I remember my flights and continue my love affair with aviation, albeit by looking up in the air.

Why Fly An Approach Coupled To The Autopilot?

The other day I was having lunch with a pilot friend. We were discussing my recent blog “How To Execute An Actual Instrument Approach”. Apparently he got the idea that this was a coupled approach, one that uses the autopilot (AP) to follow the commands of the ILS signals. In fact, I hadn’t written that this was the case, rather describing a “hand” flown approach, without partial or complete use of the autopilot. Anyway, he questioned its use and so this blog.

As I believe that there are many advantages to making the approach, particularly the ILS, coupled to the autopilot, I will explain how to do it. Before going into the nitty-gritty however let me give my reasoning for doing it.

As you can see from my former article, or if you have done an ILS approach, you realize how busy things can get at certain times, especially in single pilot operations. The autopilot frees one up a bit to allow you to fully be aware of what and where you are in the approach. Meaning that you have some time to look at the all important approach chart without fighting a wing drop or altitude change. The latter assuming you have both heading and altitude coupling capabilities. That said, here is how it would work.
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Basically, before the approach you would have been using the “nav and alt” features of the 2-axis AP. Different models of AP have different presentations. The picture above is just one, albeit quite popular. As the controller turns you to the inbound localizer course you should have your Nav 1 tuned to the ILS frequency. Set the inbound heading on the HSI and engage the Approach button on the AP control head. The AP will guide the plane deftly onto the localizer course while you, the PIC, verify that all is well, The altitude will be held until the glide slope is intercepted, usually at the outer marker (OM). There will be audible and usually visual indication as the altitude hold grabs onto the glide slope. Again, just monitor the approach as you manage the flight taking care to slow, add flaps, check fuel selector, mixture full rich, change the props to high RPM and drop the gear. A lot to do in a short space of time.

Ok, so that’s that. Sure I practiced flying non-autopilot approaches to make sure I stayed sharp, but also used the AP as needed, respecting its limitations (just like those of its pilot).

I just ran across an excellent article discussing all of this as a further reading:
http://stoenworks.com/Tutorials/Flying%20the%20coupled.html.

How To Execute An Actual Instrument Approach

Executing an instrument approach in actual “instrument” weather (ceiling below 1000 ft and visibility less than three miles) is not a game. A simulation done at home or at an FBO (fixed base operator) doesn’t create the same level of anxiety. Why should it? Just turn it off and go about your chores.

In this article I am going to lead you through the thought processes that I deem important to get an airplane and its passengers safely on the ground in really bad weather. OK here we go.

Before arriving at MHT (see my last blog), I tuned in the weather and got the following:
Information foxtrot: Visibility less than ¼ mile in fog and light rain, ceiling indefinite. You can’t land under these conditions unless you have very special equipment and expertise to handle this essentially zero zero weather. The active runway was 35 so I got the instrument approach plate for an ILS to Rwy 35. This plate illustrated everything needed to carry out the approach and landing. It delineates the proper procedure, specifying altitudes and compass headings needed if you were to fly the procedure without being vectored by approach control. All the required radio frequencies for navigation and communication are specified. It is very important to have up to date charts as changes to the above can occur.

So, about 20 miles out from MHT I was handed off to Manchester approach by Boston center. “Navajo 711EB contact Manchester approach on 124.9, good day.” I reply:”roger
Manchester approach 123.9”. Then after changing frequencies:“ Manchester approach Navajo 711EB 6000 with foxtrot”. This lets the controller know my altitude and that I have the latest weather. Approach tells me to descend to 3000 ft. He also advises me to expect a hold until the weather improves. On hearing that, I look at the approach plate and study the hold procedure which is like a racetrack carried out on specific headings with 1 minute legs. The hold area is 8 miles NW of the field, with the starting point, an intersection called Scoop.

I have decided since I have over 4 hours of fuel remaining to try a landing and “Miss” if I have to. Miss is short for a missed approach. A very important thing to clearly have defined in your head before starting any approach, but especially in conditions like this. The controller assigns me a heading of 150 degrees which will place me east of the inbound localizer course for RWY 35. Also I am told to descend to 2000, which is 1766 feet above the runway landing zone (as noted on the chart). Now it’s time to set up my nav receivers for the localizer. After dialing in the proper frequency, I listen for the identifying Morse code signal to make sure I am on the right station. This ILS signal is what can bring us down through the murk. Without it, get the parachute out, or pull the handle if you are in a Cirrus and low on fuel.

About 5 miles beyond the airport I am waiting for the turn in to intercept the localizer. The controller tells me to turn right to a heading of 240 degrees, which will bring me to intercept the localizer. Proceeding further, the course deviation indicator (CDI) is starting to move and I am “cleared for the approach”. Now I have to go through a bit of a check list: Fuel on mains, approach flaps, advance the prop controls to high RPM, mixture controls to full rich, ready for gear down at the Outer Marker (OM). The engines now are set to go to full power in case of the go around. The OM named (DERRY), is normally the start of the approach, and is announced on the instrument panel by a blinking blue light and a specific audio tone heard in my headset. I now descend to 1800 ft and prepare to intercept the all important glide slope, which if followed in concert with the CDI needle (both centered) will place me 200 ft above the runway threshold and on centerline.

Well the OM starts blinking and the audio beeps at me so I watch for the glideslope needle to move. As it comes down, my hand is on the throttles and I prepare to drop the gear, go to full flaps and reduce power to the engines. So now it’s watch, wait and hope for a break in the fog. If at the minimum altitude of 434 ft, I “don’t have the runway” in sight, I will have to execute the missed approach. The point of minimum descent is defined not only by altitude, but also by a DME (distance measuring equipment). As the DME is at the point of minimum descent, if one stays on the glideslope, it is the point of leveling off at 434 ft. There also is a chart of time to the decision point, depending on the ground speed. This is shown on the DME instrument. In our case, at about 100 knots, the time to decide to land or not is 2:31 (Min/Sec). Although I couldn't land on my first approach, after one Miss I manged to get safely on the runway. The details of how I finally landed after a 727 landed ahead of me, were discussed in my former blog.

I hope this has given you insight as to the main things a pilot does and thinks about when landing in bad weather

The main things to glean from this article: plan ahead, follow approved procedures, be current in your flight experience, fly a well maintained airplane and practice, practice and more practice.

Instrument Flying Part II-It was early one Saturday morning.....

It was early Saturday morning in Burlington VT (BTV). I was there to fly N711EB, a Piper Navajo to Manchester, NH (MHT), a typical freight run. The date was May 30 1989, Memorial day. Weather was basically VFR with a chance for IFR in Manchester. Recent passage of a cold front raised the possibility of some ground fog, especially in the early morning.

Before heading to the flight line to do my preflight check of the plane, I needed to call the Burlington flight service station for a last minute check of the weather and to file my IFR flight plan to Manchester and back. Nothing new with the weather. I requested 9000 feet for altitude going to MHT. Estimated flight time was 30 minutes. Fuel aboard the Pa31 was 4 hours. Plenty to get there and return to BTV if I couldn’t land in Manchester. Did a quick preflight and got up into the cockpit. I loved to fly the Navajos, big and roomy with plenty of power and full de-ice capability.

After engine start and checking the various things on the after start check list, I set up the radios for communication and navigation. First I would listen to ATIS (automated terminal info service) which told weather on the field and gave taxi and runway info. As the ATIS is updated a different letter of the alphabet is assigned to it, e.g. ATIS Info foxtrot. Anyway, I copied the ATIS foxtrot and called ground control or maybe clearance to obtain my IFR routing. “ Burlington clearance N711EB IFR Manchester for clearance”. The reply: N711EB you are cleared to Manchester as filed expect 9000 as final altitude”. After confirming what I had heard I was told to contact ground control. Ground control cleared me to taxi to and hold short of runway 15. After reaching the hold point at runway 15 I did the usual pre take-off check. There is an acronym, CIGAR, standing for controls, instruments, gas, attitude, run-up. This a short cut to a lengthier printed protocol, but is sufficient for the pilot proficient in that airplane. It wouldn’t work for much more complex airline type planes, where checklists are pages long. Anyhow after checking everything: engines, radios, trim, gas and the controls I called the tower for take-off clearance. I was cleared to take-off on runway heading to 3000 feet. I taxied into position and pushed both throttles forward to the stops. Satisfied that all was A_OK I released the brakes and began my take-off roll.

As I rapidly accelerated down the runway, keeping my eye on the ASI (air speed indicator), I started pulling back on the wheel lifting the nose off and beginning my climb out. The runway heading of 150 degrees essentially placed me on the airway (V141), which would take us (the plane and me) all the way to MHT. On route we would fly over LEB (Lebanon, NH) and CON (Concord, NH) with little heading change. Minimum altitudes out of BTV were 6000 once on the airway, to avoid the tops of the Green Mountains.

Once airborne, I was told to contact departure control by the tower operator. “Departure N711EB is out of 1500 for 3000”. “ 711EB clear on course, climb to requested altitude of 9000”. “711EB, roger”. After passing through 6000' I was handed off to Boston Center: "Boston 711EB 6000". They replied" cleared to maintain Niner thousand". In 25 minutes I was passing over LEB vortac (VOR) and then on to Concord VOR (CON). Just a little course correction to the south and we are headed for MHN. Engines are purring nicely, all gages are in the “green”. As we are only about 15 minutes out from our destination, I tune in the MHT ATIS and whoa! The weather is not good. Indefinite ceiling 100’, RVR (runway visual range) 3000’, ground fog. That is below minimums which are:200’ ceiling and visibility ½ mile (200 and a half) for the ILS to runway 17, the active at this time. OK I’ll just continue and hope conditions improve. I can elect to shoot the approach and if I make it because things are better than advertised great, if not I’ll do a missed approach and either try again or enter a hold as directed by ATC. Boston handed me off to Manchester Approach and the fun began.

Before long I was told to descend to 4000‘and intercept the RWY 17 localizer and follow it inbound. Then descend to 3000’ and “cleared for the approach to RWY 17”.
Shortly after I was cleared for the approach by ATC, I was advised that the previous flight had “missed”. After completing the pre landing checklist I decided to continue and give it a try. Down into the murk I we went. Cotton wool all around, absolutely no visual cues. The autopilot was on but I constantly cross checked the attitude indicator, airspeed and altimeter. The navigation indicator for flying the ILS was constantly monitored. It very accurately shows one left or right of course or above or below the glide slope. The latter is most critical when getting down below 500’. At the outer marker, I lowered the landing gear and flaps and began the descent to the field.

Anyway, arriving at the final decision point: altitude 429 feet (200 above the runway) and about ¼ mile short of the runway, still nothing but murk. So after continuing for about 5 seconds, I advanced the throttles and after ascertaining that we had a positive rate of climb, retracted the gear and the flaps. Then after all that done, I advised the tower that I was executing a missed approach. “ Manchester tower 711EB missed approach”. Tower told me to turn left, climb to 3000’ and proceed toward the CON VOR. After I requested another approach, I was handed back to approach control and again told to head back to the CON VOR and hold 10 south on the 172 degree radial. That was good as it essentially placed us right back at the start of the final approach on the localizer, where we had been only a few minutes earlier.

So, long story short. Divine providence intervened. As I was cleared for the second approach, I was told that a 727 aircraft was just taking off and that I should be aware of possible wake turbulence. Hmmm, I thought on that, realizing that in a zero wind situation on the ground the wake turbulence could persist for some time. I decided to press on and went through the same procedure as before. Intercepted the glide slope at the outer marker, gear and flaps, fuel ok, engines and props set, good luck. Well as luck would have it at about 500 or 600 feet of altitude and about ½ mile out the murk parted. The 727 that just left had apparently displaced enough fog so that I could see sufficiently ahead to successfully land. Shortly after I landed, the fog closed in again.

End of story. Persistence, flying by the rules and numbers, leaving one an out and a bit of good luck all blended together for a happy ending to the trip.

Flying On Instruments-Part 1

This is the first in a series telling “all” about flying on instruments. I have written about flying IFR (instrument flight rules), and decision making etc., but not led you through all the nitty gritty. This first part will deal with the basic instruments and radios used.

Regardless of the type of IFR weather, there are certain basics that will always apply. Some of these conditions also must be followed in VFR flight as well. In order to achieve flight, a certain airspeed, as shown on the air speed indicator must be attained. Things that affect necessary air speeds include: temperature, aircraft weight, and flight conditions such as: turbulence, ice etc. Failure to achieve or maintain necessary
speeds may mean inadvertent stall e.g.(recent case in Buffalo). If certain speeds are exceeded however, as in an uncontrolled dive, the plane may disintegrate in mid-air. This maximum safe speed (VNE), is indicated on the air speed indicator with a red line. Prior to that there is a caution zone outlined in yellow. The safe zone is “in the green”.

The airplane attitude (position relative to the horizontal) must be kept within certain reasonable limits. This is done with the aid of info from the artificial horizon, perhaps the most important gage of the instrument flight array. This instrument gives a pictorial image of the plane’s flight with respect to bank angle and pitch (climb or descent). Turns generally shouldn’t involve more than a 30 degree bank angle. Recently a tragic crash occurred near Charlotte with bank angles achieved greater than 60 degrees. These are ok during certain maneuvers but never during instrument flight. Severe bank angles markedly increase stall speeds that may lead to disaster. Similarly, climb and descent angles are limited to relatively small values. All is done in order to maintain positive, safe control of the airplane. Problems arise when for what ever reason, a pilot gets distracted, or is too busy to keep things within safe parameters. Accidents sometimes occur for example, when an inexperienced pilot suddenly encounters instrument conditions (loss of visual cues).

The final primary instrument I will discuss is the easiest to understand, the altimeter. It is nothing more than a barometer calibrated in feet or meters. Usually it can indicate differences of 20 feet and goes from below sea level (flying in a gorge out west) to many thousands of feet. Flying either VFR or IFR generally requires adhering to certain rules that specify what altitude may be flown. In controlled airspace, as for example round major airports definite altitudes will be assigned by controllers (ATC). Almost all IFR flights are conducted under direct ATC oversight, and will entail flying an assigned altitude. Failure to adhere to this altitude may be the set up for a collision, or at least the cause for a collision alert system to activate if present on the plane. All US airliners have these systems aboard.

Finally, a functioning VHF (very high frequency) aircraft radio, preferably two or more must be aboard, enabling the pilot to communicate with ATC. Navigation radios are necessary and are frequently part of the communication radios. Several different types are needed and will be discussed later. Also a transponder is required which allows ATC to positively identify the aircraft position and altitude (mode c). ATC assigns a specific code (four numbers) to each flight.

That’s enough to get started on. I’ll discuss the pilot’s interaction with the above in a subsequent article about a real flight.