View Full Version : ASI failure: it can be good for you!
The other day I got airborne from a short farmstrip. During the takeoff roll the ASI needle stayed put, but I decided that I was too far along the short strip to abort safely, and continued with the take off. The ASI remained motionless throughout the three minute flight that ensued. At first I felt more than somewhat perturbed, but then I recalled how my instructor used to encourage me to fly the picture, not the dials, by putting his map over the panel on base and final. If that did not work (although usually it did), he could just beat me around the head with the map. Suffice it to say that the landing back at the strip was rather better than the previous one, for which the ASI had been working.
Flying the aircraft back to base the next day, I was entertained by the ASI deciding to work backwards. Pulling up steeply showed an acceleration to 140 knots. Landing for fuel en route, and back at base, each landing was better than the last.
It is interesting to experience these minor equipment failures as one broadens one's experience. Obviously, all of this relates only to flying visually in good weather.
AerBabe
30th May 2004, 09:08
This reminds me of the 'famous' equipment malfunction report:
Problem: "Balance ball stuck"
Engineer: "Congratulations, you have just flown a co-ordinated turn"
During my PPL training my instructor would cover up various instruments with post-it notes. I recall flying whole circuits with 'broken' instruments. I suspect this kind of practise ends up in the same category as PFLs - something we should do more often, but don't seem to get round to.
When I was flying my new toy last week, I was pretty pleased with myself when my instructor said the ASI seemed to be broken on the climb out. :ok: (Of course, had it been 'broken' and stuck at 0 kt I wouldn't have been so pleased).
Finals19
31st May 2004, 02:12
Its a scary feeling initially tho!
During my night rating my instructor decided to fail my instrument and cockpit lighting during final approach...! At first I was like "oh ok"...then as I evaluated the situation it became more like "yikes, no visual on the ASI!!"
The point he was trying to teach me was as stated above - fly the big picture and feel the aircraft. Of course not something to be tried on your own (although think about it, it could happen at night) The a/c will give you masses of warning before any impending stall (we are talking 172 here). During the whole thing he wasn't the least bit peturbed. It taught me a thing or two.
:ok:
I quite enjoyed the one session on limited panel IMC that I did pre-PPL, but I can imagine that it'd be nervewracking in real life. As for night flying, that is something which I don't do, but, if I did, I would take along a lightweight headtorch with a red filter over the bulb. The headlamps sold in climbing shops now weigh nothing and fit in a small pocket. That, or a pen light that could clip to one side of a headset.
PS: Aerbabe: does the balance ball go in the middle? I've never seen that.
chrisN
31st May 2004, 08:39
Had ASI failure in my glider last Thursday. (Self induced - I had failed to properly tighten a connection.) It happens to be a high performance glider where small changes in the picture can be associated with quite large changes in speed, and it needs pretty close to the right speed on approach to avoid being too fast and taking half the county to stop rolling - and I was flying from a small site.
I had GPS (a handheld Garmin 89, but held in a clip near the panel).
When free from the tow, I found a thermal and climbed to gain height and time. Then I did several trial runs into and down wind, practising straight stalls. I noted what the GPS said about ground speed each time. By halving the difference between up and down wind readings, I could deduce the wind speed, and the correction needed to GPS reading when flying into wind to get airspeed.
I used the GPS and the deduced correction factor as an additional cue to the picture when on final approach into wind.
Worked for me.
FlyingForFun
4th Jun 2004, 08:55
I'm a bit late on this thread, but thought it was still worth mentioning the few hours I spent in a J3 cub (getting my float-plane rating, actually, although that's not very relevant).
In this delightful aircraft (as I'm sure most of you know already), the dials are all in the front, the pilot sits in the back, and the instructor (in my case) sits in front blocking the pilots view of the dials! By leaning one way or the other, I could just about make out the altimeter and the tach, which were at either side of the non-standard instrument layout. And I completely agree with FNG and everyone else - not being able to see the guages does wonders for your flying!
(It did get interesting, though, when my instructor asked me to fly headings or speeds, and I had to point out I couldn't see the required instruments!)
FFF
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Hello FFF, maybe you can try the "look at the instruments and I'll punch you" routine with recalcitrant pre-solo studes. Where are you instructing?
Has a J3 got enough go to carry floats? I'm pretty sure that the L4 I sometimes fly would never make it off the water if someone put floats on it, but the Continental in that one is a bit, well, fatigued.
treadigraph
4th Jun 2004, 13:19
FNG,
I had a jolly in one of Jack Brown's float J-3s in Florida (was that where you were FFF?) a few years ago - I weighed considerably more than my current svelte-like just under 14st and the instructor was considerably heavier than me. No problem! Mind you, we didn't go much above 500ft, but that was all part of the fun! Not sure if it was 65hp or 95hp though...
83 3708
4th Jun 2004, 13:33
I took off with a blocked static source about ten years ago. Most interesting....nothing was reading what it should.
Luckily it was a good VFR day and I was flying a Rallye so I couldn't have had a better combination. Would not like to try it in IMC though:uhoh:
Flew the circuit using the 1000 foot cow method (you know the one, how big is a cow when viewed from 1,000 feet). Slowed down until the slats popped out then increased speed until they poped back in again and used that power, attitude and trim for the descent.
When I got back to the hangar an engineer unplugged that static pipework from the sensitive bits and blew comprssed air down it. Loud pop as an insect was shot across the airfield far faster than it was designed for and all was well again.
Regards
83
My ASI failed due to a broken seal on the instrument itself, although I had been perturbed before flight by the blade of grass sticking out of the pitot tube (the hospitable farmer had mowed the strip that morning). The pitot system was not, on this occasion, the cause of the problem, but I noted another lesson for country flying: put the pitot cover on even if you intend to fly again later.
shortstripper
4th Jun 2004, 18:10
I'm surprised Evo hasn't spoken up on this one!
Our group a/c has had a seriously under reading and often variable ASI since we got it. Despite my best efforts I still haven't managed to track the problem. I take my hat off to Evo for doing his tailwheel conversion with basically a useless ASI.
I've kind of got used to it now and I bet my landings will deteriorate if we ever get it working properly :\
SS
I've got used to it now too, and I don't really care that much that it doesn't work. I do some stalls most times I fly to see what the ASI will say today, but I tend to ignore it when landing. The aeroplane tells you before it stalls anyway, and I bet that if I flew a really out of shape approach the picture out of the window would just seem all wrong. Controls wouldn't be right either.
I do carry a few extra knots, so landings are a bit floaty and I've never got short field right, that would take a working ASI. Still, it'll probably all go to pieces once you fix it and I start flying speeds again ;)
Now, as to why the ASI doesn't work... :confused:
FlyingForFun
7th Jun 2004, 10:26
I had a jolly in one of Jack Brown's float J-3s in Florida (was that where you were FFF?)Yes - good guess, that's where I was!
The floats do add lots of drag. But the terrain in Florida is very flat, the lakes are very big, and you rarely go above 500'. So it doesn't really matter!
FFF
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Turns out the seal was OK and there was a multi-legged critter in the air lines after all: reinforces the lesson to self re sticking the pitot cover back on between flights.
Interesting. I've always wondered what approach would be like with no ASI. Maybe next checkride I should ask my instructor if they'd mind 'hiding' it for me and playing safey pilot.
Give it a try, Paulo, and you may be surprised at what a non-event it is to lose the ASI for a visual approach. You can just fly it by look, feel and sound.
Tinstaafl
10th Jun 2004, 21:24
I always gave my students ASI & other instrument failures as part of their circuit training. It was just another aspect of their course.
whatunion
11th Jun 2004, 14:22
sometimes better to cover up the instructor and watch the ASI!
Bumz_Rush
12th Jun 2004, 17:51
Feel the aircraft, feel the controls, listen to the air flow. know throttle angle/position. I used to demonstrate night no panel flight in a PA31 to all students. Flying is a state of mind, not a reading on an instrument. Have a safety pilot with you, take off by feel, and air flow. Cruise by looking out the window, approach by setting a power, check config and speed. then feel the response. listen. Confidence is the key. practice is essential. Go for it.
I was talking to a fellow aviator. He drives the 320 bus, I fly g4. we both agree that newcomers to professional avation are not pilots but computer game experts.......what do you guys think...
I was talking to a fellow aviator. He drives the 320 bus, I fly g4. we both agree that newcomers to professional avation are not pilots but computer game experts.......what do you guys think...
I was talking to a fellow aviator. He drives the 320 bus, I fly g4. we both agree that newcomers to professional avation are not pilots but computer game experts.......what do you guys think...