WOW!

Mike Green

Denis wrote:
[Posted on behalf of Jean-Marie Clement
(http://topfly.free.fr/en/accueil.htm)]

Dear gliding fellows,

I have been asked to participate to this thread although I do not read
your newsgroup (by lack of time only).

I own and fly a Nimbus 4DM Night VFR certified. I believe that this is
the only Night VFR certified glider. This is a special design by Schempp
Hirth (with the help of Tilo Holigaus and Biggo Berger) and myself,
built in 1998 but the idea was born in 1995 after a series of full night
landings after wave flights.

There are several independent issues to night VFR flight that must be
addressed separately.

1) The regulations: no glider can fly by night according to EASA (ex
JAR) rules. But TMG (touring motor gliders) can. And German authorities
agreed to make a special certification for my Nimbus 4DM as a TMG. Then,
the required lights are the same as any other aircraft night VFR
certified (flashing beacon on top of fuselage, navigation lights,
instrument lights, maps reading light. No landing light required but I
added one for my safety). The existing instruments were exceeding the
minimum requirement (A/H, T/B, electronic navigation, a.s.o, even though
no VOR was installed). The only difference respect to a power plane is
that it has to be operated IN VICINITY OF AN AIRFIELD APPROVED AND
ILLUMINATED FOR NIGHT FLYING. Of course, a flight plan has to be filed
and the pilot has to be Night VFR rated AND current. This is not written
but I believe that it is self understood by the authorities. In any
case, no insurance company will pay if you do not hold the required
rating. In conclusion, the pilot has to be a power plane pilot with
Night VFR rating (now standard in the new JAR FCL but old pilots have to
fly 5 hours IMC with several night navigation flights and an examination).

2) Practicing Night VFR is an other question. It is very tricky
since the term VFR does not mean anything except that you can fly only
within certain minima of ceiling and visibility (same rules as power
planes). But remember: YOU DO NOT SEE ANYTHING! No ground, no cloud,
just nothing! It is a pure instrument flying, and you need to be trained
for that.

I seriously doubt that one can safely finish a flight for several
hundreds miles if there are some clouds or mountains around. Flying IMC
is very dangerous since you never know when you are out of the cloud and
you will quickly ice and freeze and the canopy shall quickly blind up
because of internal condensation and there is no way to get it away (no
sun, no heating!). There have been many fatalities even with highly
experienced pilots because of that.

3) Why Night VFR flying? Certainly not for what Tom intends to.
Unless he wants to suicide. The German requirement makes sense: remain
in sight of an illuminated runway. Therefore, yes, you can finish a
flight after sunset providing that you always fly under these
conditions. In North Italy, we have an illuminated runway every 30-40
miles, so it is possible to fly the last 200 miles Night VFR safely
providing that the ATC approves your FPL and that there are no clouds or
may be FEW, 1/8 or less).

The original idea in designing my ship was to fly the famous 2.000km at
home, in the Alps, flying 1.000km one day and an other 1.000km the
following day, remaining "parked" at low altitude wave during the night
(not a ridge, remember that you don't see anything!) near an illuminated
airport. I already did it twice but sleeping in my bed during the night!
I had all the necessary clearances and agreements of airports managers,
but too many engine problems made me loose years and finally I found
that flying 3.000km in Patagonia in one day was more exiting than flying
2.000km in 40 hours in the Alps! May be I shall try to fly 4.000km in
Patagonia in 40 hours, but I am now 62 with usual health and fatigue
recovering limitations. Most likely somebody else younger will do it. It
has to be done!

4) The energy is not a great issue. I designed my ship with a set of
batteries in each wing and the fin (all removable after derigging), plus
all standard ones. I have a total of nearly 50 A.H which is just enough.
Of course, I cannot use the transponder during the parking night flight,
I need to reduce the lights to an extreme minimum, few radio messages,
no A/H or gyros. Weather has to be perfect and parking pattern has to be
defined by day and repeated by night with references on the ground (city
lights, highways, runway, angle, PDA with moving map).

I am now changing my lead batteries for Poly-Li-Ion batteries and the
capacity will be far in excess of any requirement. We shall have feet
heating and hot coffee for the whole night! I just removed the
conventional RC Allen A/h (1 Amp consumption) and installed a MGL
Avionics Inertial Unit with 0,3 max. Amp. I am not presently satisfied
with the operation (improvements in progress) but also the RC Allen was
not operating satisfactorily because of too low temperature (-30°C is
common in Patagonia where FL 300 is allowed for gliders).

I believe that it will be very difficult to convert a standard motor
glider to a Night VFR certified one. Cables have to go through the wings
and the fuselage. Since these ships are registered as experimental in
the US, one can do it by himself. In Europe, just forget it. It will be
in any case rather expensive. Remember that the design has to take into
account emergency situations were a set of batteries gets short circuit
and you must continue the flight. I have 3 completely battery separated
circuits and 2 electric bus: avionics and services (lights and heating)
and battery can serve any bus. In case of absolute emergency, I still
can have the landing light on and nothing else using the last available
battery. One portable head light for each member of crew is mandatory
(by law) and will allow the pilots to read the instruments.

I hope that everything is now clear. Night VFR flying in gliders is not
permitted, in motor gliders it is permitted under certain rules. Pilot
has to be Night VFR rated and current (power plane licence and training
required). Safety is a great and important issue and only those who fly
by night may have a true idea of what this means.

With regards to the OLC, it is not illogical to discard flights that are
conducted illegally. But applying this rule would also require checking
that all the necessary ATC clearances for airspace penetration have been
given. In France, this is done for records, not for OLC or equivalent
national NetCoupe. But it would give motor gliders an advantage over
pure gliders.

But how may Night VFR certified motor gliders exist in the world? One,
yes. Two, I don't think so. And the owner of the only one refuses to put
his flights on the OLC since he does not agree with the rule that
imposes to file the flight within midnight of every Tuesday otherwise
flight is invalid. The longest flight ever made in the Alps (1.350km)
had been refused because of that rule which is simply impossible to
fulfil when you outland on Tuesday evening! FAI requires 7 days and I
see no reason for not implementing this rule.

So there is no risk to accept legal only night flights on the OLC! Also
the FAI accepts them.

Cordial regards,