So back flying aircraft, albeit in a simulation, I thought I’d show the differing types of panels a pilot is likely to come across in general aviation aircraft. Let’s start with the modern Cessna 172SP…

This panel has a layout of instruments common to most modern aircraft often referred to as the ‘Standard T’ because the key instruments are mounted together in a T configuration. If you look at the dials above the control column to the left of centre you will see in the top row (left to right) the Air Speed Indicator, Artificial Horizon and Altimeter. These critical gauges tell you how fast, how level and how high. Immediately below the Artificial Horizon (AH) is the Direction Indicator (DI) – that tells the direction you are flying in and forms the base of the T. That’s not to say that the instruments either side are not important, just less so. On the left is the Turn and Slip indicator – it’s a guide to how well you are flying but also a key back-up to the Artificial Horizon when there is a vacuum failure – it’s electrically powered. To the right of the DI is the Vertical Speed Indicator (VSI) which is air pressure driven – again, it’s a guide but is also a key back-up for the AH when the vacuum fails. Finally, below the VSI is the rev-counter for the engine. Although important, this instrument isn’t normally part of your basic scan even when flying in cloud because once set it shouldn’t change unless you forgot to adjust the throttle friction;-) To the extreme left are the engines and systems gauges – fuel, oil, vacuum, etc. To the right of the T are the navigation instruments associated with the avionics – something for another post. Oh – and that thing sticking up above the dash is the Compass – also an important instrument!

There’s an irony not lost on most UK pilots that the RAF devised the Standard T shown above after a lot of research on the best layout of instruments. That was in the 1930’s and yet a lot of General Aviation aircraft were still being built with non-standard layouts up until the 1970’s Here is a 1966 model Piper PA28-140 panel…

Let me say from personal experience that this is not a one-off layout built on a Friday afternoon and that two aircraft from the same batch could be delivered with different layout dependent upon the avionics build requested. Our Cherokee 140 (a 1967 build) had her instruments all over the place like this but not in the same locations. Also note that I’ve hidden the control columns so you can easily see everything including the switches below. I think the best policy is to talk about each instrument in ‘T’ order so, the Air Speed Indicator is exactly where you should expect it to be. The Artificial Horizon has however been displaced to the right with the DI taking its place in the centre of the panel. In the centre of the panel where the DI would be is a clock – just about the least useful thing to put in a pilots central field of vision. The Altimeter has found itself displaced to the left and the VSI to the extreme left. The Turn and Slip is hiding down on the bottom left. As for the engine rev-counter – that’s over on the right and at a difficult angle to read correctly. The engine and fuel gauges are grouped quite well on the right but the vacuum gauge is again so far over that it’s difficult to read easily. And the compass? That’s actually in the panel on the extreme left at the top. This is a VFR build but many VFR builds were adapted for Instrument flying at a basic level. In our aircraft the compass was relocated to the central window pillar and the top left slot held a radio navigation instrument known as an ADF – perhaps more on that in another post. I seem to recall that the clock was replaced by the turn & Slip in our aircraft and another radio navigation instrument (VOR) took the place of the T&S occupied on this dash. And I’m sure that the Artificial Horizon and the DI were swapped in our Cherokee. By the way, that red blob in the centre of the dash is the Stall Warning Light. There was an audible warning too. Unless very close to the ground, a stall in a Cherokee 140 is a non-event unlike some other types 🙂 So now I’m off to do some General Handling of the Cherokee to remind me of her foibles compared with the Cessna 172SP. I suspect that a bit more skill will be needed to fly smoothly and execute a good approach and landing even in a computer sim!

PA28-140 Cherokee over Clacton

Looking at the excellent shots of a glider on Sylvia’s blog drew me into talking about my one and only experience of flying a glider. But it then, having mentioned the flying qualities of a Piper Cherokee, prompted me that I really should tell another of my flying stories.

Our aircraft was a Cherokee 140 built in 1966 (she is still flying with another owner). Equipped with 4 seats, you needed to adjust the amount of fuel you intended to carry based on the weight of your passengers in order not to overload the aircraft. As I joked in my comment, the flying characteristics of the old Cherokee with the Hershey Bar wing were that of a house brick once the power was turned off. Not exactly a glider!

However, these characteristics could be very useful at times. For example…

I was flying in to Norwich Airport on one occasion and on contacting the approach asked for Radar Vectors for the active runway. The controller asked if I could accept an short approach as there would be an Air UK F-27 airliner on finals at the same time. I agreed to this and was positioned to intercept the glideslope at around 5 miles with the instruction to keep the speed up on the approach. Nothing simpler in our old girl. Gently ease back on the throttle once on the glideslope to maintain our normal cruise of around 95mph in the descent (normally it would be 85 slowing to 75 over the threshold). And I kept that going to the point where we were passing over the last set of lights – much to the consternation of my colleague who had never experienced this type of approach – before closing the throttle and hanging out all the flaps! To say we stopped dead in mid air would be a close approximation though it was a simple matter to ease the Cherokee down for a nose high landing on the runway. Then a careful but hardish yank on the brake handle (she didn’t have brake pedals) slowed the speed sufficiently to allow us to exit at the first taxiway. Cue an appreciative comment from the tower! The F-27 arrived around 10 mins later – I guess the controller was used to ppl’s pottering about 😉

The need to be aware of faster aircraft in the circuit was something I learnt at my original airfield of Leavesden – there were always business jets and fast twins to look out for but my colleague had learnt and flown only at quiet rural airfields. My experience was the guiding factor here. Of course, we can all get caught out no matter what our experience…

I held an Instrument Meteorological Conditions (IMC) rating and we were required to renew it regularly. On one of those renewals I was taken to Southend by the Assistant Chief Flying Instructor. Everybody hated going there because it was a Non-Directional Beacon (NDB) approach and quite complex because of a church on the runway centre line if approaching from the southwest – which was the case on that day. Anyway, for an NDB approach in an IMC Renewal test you have to fly the procedure accurately whilst not in sight of the ground (this involves putting up screens in the aircraft to prevent the pilot seeing out whilst allowing the instructor to do so). It basically involves flying a racetrack pattern based on the beacon and descending as cleared by the tower – very much the same as the holding patterns you may well have seen in various TV programmes about air traffic control. That went ok – first time around was slightly off but successfully corrected on the second.

Then I was cleared off the beacon for a procedural join for runway 06. This involves flying a specific heading outbound from the beacon whilst descending to a specific altitude before making a rate 1 (15 degree banked) turn back onto the runway heading. I made a mess of the outbound leg before beginning the turn – I suspect that as I descended I met a different wind to the one I had been flying in (very likely near the Thames estuary). The key requirement of these approaches is that you don’t bust you height – don’t descend below the height for each sector – so realising that something wasn’t quite as I would like I held off on the descent. Reaching the correct timing point to begin my turn I initiated it, still maintaining that extra height (remember that I can’t see the airfield at all – I’m reliant upon my understanding of the instruments). Having turned onto finals, the ACFI asked me where the runway was… “It’s off the right of the nose and I’m high” The screens came down and the ACFI asked “Can you get in from here?” My answer? “In this aircraft yes! In a Cessna, no chance.” Clearance sought and given by the tower I took full advantage of the house brick qualites of the Cherokee 140 (chop the power and hang out the flaps) to waffle her down to a normal approach height and a smooth landing 🙂 I passed – but if I had continued my descent when off the approved track I would have failed!

The old girl and I had many pleasant adventures before we parted company and these are examples of the mutual trust between us – It’s good to know that she is still out there providing enjoyment for another generation of pilots 🙂

Andrewsfield from the air - My home airfield for several years
Andrewsfield from the air – My home airfield for several years