The International Cessna^® 170 Association

Every once in a while, I get the chance to use my 170 in a way I would really prefer not to - hard IFR. I wrote about this a few years ago, but for the benefit of those who missed my last cloud flying adventure, here's a report on a trip I flew today to take family home (the airline was full.)

First off, I won't fly if there is any possibilty of icing or convective weather.
The freezing level was at 11.000 feet and the radar showed just level one and two rain, so I was good to go. The ceilings along the route were between 800 to 1,000 feet with a couple of miles, not ideal but acceptable.

My airplane is equipped with a panel-mounted Apollo GX-55 GPS, IFR certified en-route and terminal area. I have a KX-155 nav/com with glide slope, no auto-pilot or marker beacon. And a transponder with mode C. I do have an ICOM hand held Com with an external antenna for back up.
Pretty basic, but I'm legal for Cat I ILS to 200 and 1/2. I did add pitot heat a few years ago, but the gyros are still powered by a good ole venturi. My 1952 B has the stock panel, with instruments strung from one side of the panel to the other - the altimeter is well off to the right, which is a pain in the a--, epecially on an approach.

Actually, it was a pretty routine trip to Greeneville, NC, about 200 miles distant. The weather there was good VFR. I dropped my kids off and added 10 gallons, bringing the fuel load up to 31. (I have a Fuel Hawk dip stick, modified ala George Horn.)

From about 100 miles out from home plate - Rock Hill, SC it was solid IMC
in light rain, and I was reminded what a challenge the 170 can be under these conditions. Altitude control is pretty easy, but holding a heading can be tough - it constantly wants to wander off one way or the other. Of course, spending most of my aviation life in that flying collection of computers known as the Airbus 320 tends to dull my actual flying skills.

Guess that's why I keep this airplane around.

Listening to the Rock Hill AWOS, I'm a little concerned to hear that the weather has dropped from the forecast 800 and 6 miles to 200 and one mile -yikes! I had more enough fuel for an approach and diversion to Tri-Cities, TN about 100 miles away, which was good VFR - but I really didn't want to go there if I could help it.

It was getting dark as the Charlotte Approach controller vectored me to the ILS 2 final. Night single-engine IFR...I don't enjoy it. It is a risk I have assumed only for myself; I would never allow family and friends to take this risk with me. A fellow pilot is another matter. I shudder when I hear of people hauling their trusting families in a single-engine airplane from New Orleans to Cancun over the Gulf of Mexico for 500 miles...

Cleared for the approach... I listen to the AWOS one more time - 200 overcast, 3/4 of a mile in fog. There is no tower, I broadcast on unicom at the outer marker inbound. Entering the soup again, I kill the strobes and landing lights. Actually, over the years I've come to the conclusion that low ILS approaches are EASIER at night; the visual clues appear sooner with fewer distractions. The strobes are off because I don't like the distraction and possible vertigo inducment, and the landing lights are off to avoid washing out the sighting of approach lights; years of airline flying are finally paying off...

All the way down final, I'm talking to myself like James Stewart flying that GCA approach in a B-47 (if youv'e seen Strategic Air Command, you will know exactly what I'm talking about!) A little off localizer - hold the wings level and use the rudder to change heading; works good in a DC-3 as well. I steal a glance at that altimeter located 20 feet to the right; 200 above minimums. I resist the urge to look outside; on a low approach you stick with the gauges until decision height.

Minimums - look up...nothing! Two seconds pass - then the dim outline of the approach lights appear - John Wayne..."Now I lay me down to rest" ("The High and the Mighty", 1954) Power back, maintain the glide slope...threshold lights in sight, finally at 100 feet the runway lights appear. I pull 10 degrees of flaps and wheel land, making my usual turn-off for my hangar.

What's the point of this story? I guess for me the fact I can still fly a tight approach in my 53 year old airplane without an autopilot is as satisfying as a perfect three-point landing on a 1,500 grass strip. Yes, if I had my druthers I would be in a Cessna 310 with all the bells and whistles, but that's not in the cards, at least for now. Under the right conditions, the 170 gets the job done, and I don't consider flying it IFR with no icing or thunderstorms any more dangerous than an A36 or Piper Malibu - they are all single-engine airplanes! Russ Farris

Ha! Great story. Just when I was wondering how many guys fly hard IFR with air driven gyros, you write this. Good read, thanks.

I could go look this up but I'd like to hear what the 170 guys have to say about it... What is required for an IFR certified panel and is it enforced in any way?

Russ, as a VFR-only guy I'm not real qualified to criticize, even if I was inclined to. But...."Minimums-look up- nothing! Two seconds pass,then the dim outline of the approach lights appear...". It sounds to this innocent fool that you did descend below minimums. Two seconds at say 600 fpm down after 200' AGL equals 180' AGL-- only 20 feet, but below min's is below min's. I was under the assumption that if no joy at MDA or DH or whatever you cobbed it & went missed. Period. I've heard many horror stories about IFR approaches gone wrong by people fudging on the minimums.
You're obviously current as well as well-versed in this sort of thing, at least in the big kerosene burners, so I'm sure you felt it was a safe and acceptable thing to do. I don't imagine you'd have shared this interesting and informative story with us otherwise.
So what is the deal with "minimums"?

Eric

Russ didn't say what speed he was shooting the approach at, but if ground speed was 100 knots (kinda fast for a 170, but it could be made to work), his rate of descent on a standard 3-degree glide slope would have been about 530 feet per minute, or 8.85 feet per second, making two seconds 17.7 feet. Even at 600 fpm, you'd only descend 20 ft in 2 seconds. It would only take a small amount of up elevator just prior to hitting minimums to arrest the descent.

Russ, I'm curious as to your technique for flying an ILS in the 170. Do you trim for a certain speed prior to glideslope intercept, then reduce power at intercept, or do you roll in nose down trim and leave the power in?

Miles

Ha ha, Eric - I knew when I wrote that it would raise some eyebrows. Actually, because of the location of the altimeter on my airplane I have a hard time including it in my scan every few seconds, I glanced over at it just above minimums (about forty feet) and it was a few seconds later I picked up the approach lights. I wouldn't go below minimums, of course.
However, there is a difference between going below minimums slightly on an ILS versus a non-precision approach (no electronic glide slope.) If I ever screwed up totally with no alternative - running out of fuel, everywhere socked in, as a last ditch resort you could fly an ILS right down to the touchdown zone. At least you would crash on the runway. On the glideslope at 100 feet, you are over the threshold. I don't intend to ever get into this situation.

One of the guys I fly with lost his Dad last year in a Bonanza. He busted minimums on a GPS approach - hit a 60 feet high tree 1/2 mile from the runway. Mike said he had been busting minimums for years on this approach. I was even more shocked to learn he was a retired Delta L-1011 captain...Russ Farris

Hi Miles, yep at about 500 fpm two seconds is about 20 feet. Hard to read that close on my altimeter.

What I do on an ILS is slow to about 100 MPH on the intercept heading.
Intercepting the glide slope I reduce the power to about 1,800 RPM and
trim to maintain 100 MPH on the glide slope. I keep this speed because
I can hold about 4.0 inches on the suction gauge, ensuring the gyros are spooled up. I also fly the glide slope with the elevator - you can make more precise adjustments this way. The throttle controls the airspeed, but I don't fool with it unless the speed changes more than seven or eight MPH. On good visual contact, pull the power off, slow to 80 and grab a notch or two of flaps...that's about it. Russ Farris

Tripslip; The actual requirements for an IFR airplane are suprisingly basic.
I don't have the regs in front of me, but first off, the static system needs to be certified every 24 months. Basically, the shop guy puts a machine on the static system that checks for leaks and altimeter accuracy at increasing altitudes. (if memory serves only the altimeter is checked, not the airspeed or VSI.) The transponder and encoder also need a check every 24 months, I'm not sure what the difference is over a standard VFR check, if any. George Horn could probably tell us, if we can draw him out of his shell.

Again from memory, an attitude indicator, directional gyro, turn and slip,
sensitive altimeter, VSI (I think), and a clock, in addition to the equipment required for VFR. There is no requirement for a heated pitot (I did add one), alternate static source or second com.
The nav radios required are those appropriate for the flight. If all you plan on doing is VOR approaches, then you only need a VOR reciever.

If all you have in mind is the ability to climb through a cloud deck to on top conditions, and maybe shoot a VOR approach, that's all you need.
In reality, a GPS is a huge help. Having a glide slope does expand what you can do, but it really depends on your personal minimums of what kind of IFR you are comfortable with.

It's not well known, but you can certify your airplane for Category II operations (100 foot DH, 1200 RVR) if you jump through enough FAA hoops. The main equipment additions are a radar altimeter (big bucks!) and an autopilot with an approach coupler. Plus additional maintenance requirements and initial and recurring checkrides with the FAA I heard of a guy that got his Piper Arrow approved for CAT II. Whose going to be first with a 170 Russ Farris

FAR 91.205 (C)
I just looked it up in my old FAR-AIM. In addition to what you already need for day &/or night VFR, you need 2 way radio,nav systenm appropriate to ground facilities,gyro rate of turn & slip-skid indicators,sensitive altimeter,clock,generator,gyro pitch/bank & directional indicators.
So what happened to the old needle-ball-airspeed IFR flying? Darned new-fangled rules.......

Eric

zero.one.victor wrote: ...So what happened to the old needle-ball-airspeed IFR flying? Darned new-fangled rules.......

Eric

It's still around....for those poor unfortunate souls that loose their one and only vacuum pump in IMC . That sure does get your attention!!

Hey Russ, I had to chuckle at the similiarity to the story you wrote some years ago that started "OLE GAR's" goofy response to such notable stimuli. I do admire a pilot that can hand fly his bird IFR for that length of a trip. I respect the stability of our 170's but that has to be tiring.

Here is my FWIW, If my '52 had a little Century AP or even a wing leveler, I might be able to try but I would prefer the destination weather be near cavu. As our ages approach or pass the halfway mark toward triple digits, I expect we have less and less desire to engage in that kind of self abuse.

I'm glad your approach to "near" minimums turned out OK.

Hey Gar, yep I remember that little New Orleans scenario involving a chair, some ropes and a whip - I'd post a link to it if I knew how, for the benefit of the new guys

I guess though, for me shooting an approach to minimums isn't that big of a deal - I wouldn't classify it as self-abuse (except for the altimeter located two counties to the right.) I will admit, I have done more real IFR
in this airplane than in any other lightplane...nearly all of my general aviation experience prior to the airlines was in sunny Florida and the Bahamas. I've never flown an ILS to minimums in any single-engine airplane except this one. For that matter, I can recall only one low approach in a twin - an Aero Commander 500. But I've done hundreds in the DC-8, 727, 737, 757, 767, and Airbus 321...coupled to an auto-pilot or two or three. The one exception was the Fokker F-28 (a twin-jet similiar to the DC-9.) The auto-pilot in that baby wasn't very smooth, so the drill was to hand fly it on the ILS, most of the time. By the way, in training every year I have to do a hand-flown ILS to minimums - with an engine out (simulator, of course )

I wish there was some some of gadget that you could set the decision height into that would give altitude call-outs in your headset i.e. "200 above minimums", "100 above minimums", "minimums". Kinda like an electronic co-pilot. Guess I'll have to invent it Russ Farris

I thought that airliners had a gadget like that, they call it the FO.

Hey Eric, they do! Actually, on the Airbus the airplane itself has voice callouts. I was thinking of something for the 170, or any small airplane.
Russ Farris

I remember George talking about some kerosene-burner he flew in which that gizmo picked on him, kept calling him a retard or something like that. I don't think I'd like that.

Eric

zero.one.victor wrote:I remember George talking about some kerosene-burner he flew in which that gizmo picked on him, kept calling him a retard or something like that. I don't think I'd like that.

Eric

Well, ...Thank You...for defending me Eric! I had no idea you wouldn't like me being called a "retard".

Russ, the thread to which you were referring to Ol' Gar's remarks may be found at:
http://cessna170.org/phpBB2/viewtopic.php?p=2260#2260

...now,...lessee here...turn back aroun', duck under just so... ( and crawl back into the shell.....)